Chapter 5 Short-Term and Working Memory

We will now describe some early research on STM that focused on answering the following two questions:

(1) What is the duration of STM? (2) What is the capacity of STM?

Definition of memory

"Memory is a means by which we draw on our stored knowledge of the past in order to use it in the present" and predict the future (make predictions of what to do and not to do , e.g not engage with dangerous situations or engage with benefitical situations) 1950ies: Memory as a process with 3 operations (e.g process model) First is encoding (information from envirnoment is encoded, transformation of sensory data into mental representation) 2. Consolidating : Storing it (memory has to be maintained and permanent) 3. Retrieving (bringing memory back to presence, pulling memory out of storage system to bring it into presence) 1960ies: Memory as systems (e.g structrucal models)

Luck and Vogel (1997), Results Change Detection How Many Items Can Be Held in Short-Term Memory?

, indicates that performance was almost perfect when there were one to three squares in the arrays, but that performance began decreasing rapidly when there were four or more squares. They concluded from this result that participants were able to retain about a maximum of four items in their short-term memory.

What is STM?

A memory mechanism that can hold a limited amount of information for a brief period of time, usually around 30 seconds, unless there is rehearsal (such as repeating a telephone number) to maintain the information in short-term memory. Short-term memory is one of the stages in the modal model of memory.

What is the delayed-response task?

A task in which information is provided, a delay is imposed, and then memory is tested. This task has been used to study short-term memory by testing monkeys' ability to hold information about the location of a food reward during a delay.

Definition of echoic memory

Brief sensory memory for auditory stimuli that lasts for a few seconds after a stimulus is extinguished.

What is iconic memory?

Brief sensory memory for visual stimuli that lasts for a fraction of a second after a stimulus is extinguished. This corresponds to the sensory memory stage of the modal model of memory.

short-term memory, as conceived by cognitive psychologists, lasts 15 to 20 seconds or less. This was demonstrated... and how? What Is the Duration of Short-Term Memory?

Brown (1958) in England and Peterson and Peterson (1959) in the United States, who used the method of recall to determine the duration of STM. In their experiments, .

Disadvantages of change detection task compared to digit span task Change Detection How Many Items Can Be Held in Short-Term Memory?

Consequently, it is near impossible to rehearse them in your mind or to regroup them in larger meaningful units (like abbreviations, number sequences, or visual shapes/patterns). In other words, this procedure might be better suited to assess STM storage capacity independent from any control processes and/or LTM involvement.

What did Atkinson and Shiffrin propose?

Control process

Sperling (1960) famous experiment To determine the time course of this fading in partial report method, what additional experiment did Sperling advise? Sperling's Experiment: Measuring the Capacity and Duration of a Sensory Memory Store

Delayed partial report method

These ideas are nothing new. It had long been known that the capacity of working memory can be increased by chunking and that there is an interchange of information between working memory and long-term memory. But Baddeley decided it was necessary to propose an additional component of working memory to address these abilities. This new component, which he called the

Episodic buffer

Long-term memories of experiences from the past, like picnic are...

Episodic memories

What question did Shepard and Mezler (1971) answer by demonstrating the illsutration of an early visual imagery experiments

How do we decide whether two 3-d objects are similar or not?

What is control process?

In Atkinson and Shiffrin's modal model of memory, active processes that can be controlled by the person and that may differ from one task to another. Rehearsal is an example of a control process.

In a series of experiments Sperling (1960) managed to measure the capacity of sensory memory by means of

In a series of experiments Sperling (1960) managed to measure the capacity of sensory memory by means of the partial report method.

Sperling (1960) famous experiment Delayed partial report method Procedure Sperling Experiment: Measuring the Capacity and Duration of a Sensory Memory Store

In this method, letters were flashed on and off like before but the cue tone was presented after a short delay (Figure 5.5c).

What is short-term memory or working memory?

Information that stays in our memory for brief periods, about 10 to 15 seconds if we don't repeat it over and over as Christine did

What did Shepard and Metzler measure in the visual objects experiment?

Participant's reaction time to decide whether parts of the objects were same or different, they obtained an relationship shown in figure for objects that were the same.

Vogel et al (2005) Procedure

Performed an experiment in which they divided their participants in two groups based on their performance on a regular test of working memory Person in high capacity group were able to hold more items in working memory than participants in low capacity group In their experiment so called event related potentials (ERPS) wre recorded which someone's fitler efficency could be derived.

What is the definition of decay? What Is the Duration of Short-Term Memory?

Process by which information is lost from memory due to the passage of time.

Example of control process

Rehearsal e.g might repeat a telephone number in order to hold it in your mind after looking it up on the internet e.g blue arrow

Definition of auditory rehearsal process

Rehearsal process involved in working memory that keeps items in the phonological store from decaying.

Mathy and Feldman (2012) Results Chunking How Many Items Can Be Held in Short-Term Memory?

Results of several experiments showed that their participants' digit span depended strongly on how many distinct sequences were present in the series of numbers. Moreover, it appeared that after compression, most participants could only remember three to four distinct chunks. Mathy and Feldman (2012) therefore claimed that the true limit of STM capacity is more likely to be four than seven. This is in accord with outcomes of experiments using a change detection paradigm to study visual short-term memory.

What is mental rotation?

Rotating an image of an object in the mind.

Ericsson and colleagues (Ericsson, Chase, & Falloon, 1980) How did participant S.F able to do this? Chunking How Many Items Can Be Held in Short-Term Memory?

S.F. used chunking to recode the digits into larger units that formed meaningful sequences. S.F. was a runner, so some of the sequences were running times. For example, 3,492 became "3 minutes and 49 point 2 seconds, near world-record mile time." He also used other ways to create meaning, so 893 became "89 point 3, very old man." This example illustrates an interaction between STM and LTM, because S.F. created some of his chunks based on his knowledge of running times that were stored in LTM.

When is short term memory concerned and working memory with? Working memory?

STM :concerned mainly with storing information for a brief period of time (for example, remembering a phone number) Working memory: is working memory is concerned with the manipulation of information that occurs during complex cognition (for example, remembering numbers while reading a paragraph).

What is the sensory memory in modal model?

Sensory memory is an initial stage that holds all incoming information for seconds or fractions of a second. Information coming from the environment

What is the major difference between short-term memory and working memory?

Short-term is for information storage only, while working memory is for information storage and manipulation. Short-term memory is for information storage only, while working memory is for information storage and manipulation.

What is the short-term memory in modal model? (STM)

Short-term memory (STM) holds five to seven items for about 15 to 20 seconds.

Sperling Experiment: Measuring the capacity and duration of sensory memory Conclusion from experiments of delayed partial response

Sperling concluded from these results that a short-lived sensory memory registers all or most of the information that hits our visual receptors, but that this information decays within less than a second. This brief sensory memory for visual stimuli, called iconic memory (icon means "image"), corresponds to the sensory memory stage of Atkinson and Shiffrin's modal model (1968). Other research using auditory stimuli has shown that sounds also persist in the mind. This persistence of sound, called echoic memory, lasts for a few seconds after presentation of the original stimulus (Darwin, Turvey, & Crowder, 1972).

What did Sperling (1960) determine in his famous experiment? How do Sperling determine the time course of this fading in whole report method? Sperling's Experiment: Measuring the Capacity and Duration of the Sensory Memory Store

Sperling devised an additional experiment using a partial report method.

Modal model defined the differences in

Storage capacity Persistence of information

Types of long term memory Procedural

The ability to ride a bicycle, or do any of the other things that involve muscle coordination, is a type of long-term memory called procedural memory.

What is persistence of vision? The Sparkler's Trail and the Projector's Shutter

The continued perception of light for a fraction of a second after the original light stimulus has been extinguished. Perceiving a trail of light from a moving sparkler is caused by the persistence of vision. See also Iconic memory

Definition of visual imagery

The creation of visual images in the mind in the absence of a physical visual stimulus It is type of mental imagery

What does the delayed response task results support?

The idea that the prefrontal cortex is important for holding information for brieg periods of time Also supported by memory behaviour of very young infants, which can be described as "out of sight, out of mind". That is when, an object that the infant can see is hidden from view, the infant behaves as if the object no longer exists. This behaviour has been atrributed to the fact that the frontal and prefrontal cortex does not become adequately developed until eight months of age

Setup for delayed response task in monkeys

The monkey sees a food reward in one of the two dishes Both of the fishes are covered and a screen is lowered, and then there is a delay before the screen is rasied again. When the screen is raised, the monkey must remeber which dish had the food and uncover the correct food dish to obtain a reward. Monkeys can be trained to accomplish the task but if there prefrontal cortex is removed their performance drops to a chance level, so they pcik the correct food dish only about half of the time.

Definition of word length effect

The notion that it is more difficult to remember a list of long words than a list of short words.

Definition of phonological loop

The part of working memory that holds and processes verbal and auditory information. See also Central executive; Visuospatial sketch pad; Working memory.

What is memory?

The processes involved in retaining, retrieving and using information about stimuli, images, events, ideas and skills after the original information is no longer present.

When Keppel and Underwood (1962) looked closely at Peterson and Peterson's results however, they discovered something interesting What Is the Duration of Short-Term Memory?

They found that participants' memory for the letters on the first trial was high, even when tested after an 18-second delay (Figure 5.7b). After a few trials however, their performance began to drop sharply, thus on later trials (but not the first one) their performance was poor after the 18-second delay. Apparently, the finding of poor memory at 18 seconds, such as reported by Peterson and Peterson (1959), was a result of poorer performance on later trials specifically.

What tasks is the central executive usual for?

When a person is attempting to simultaneously drive and use a mobile phone The executive would be controlling the phonological loop processes (talking on the phone and understanding the conversation) and the sketchpad processes (visualising landmarks and the layout of the streets, navigating the car)

Baddeley's initial working memory model (1974) consists of

a phonological loop, a visuospatial sketch pad, and a central executive. Correct. Baddeley's working memory model consists of a phonological loop, a visuospatial sketch pad, and a central executive.

One of the major misconceptions about short-term memory is that it lasts What Is the Duration of Short-Term Memory?

a relatively long time

If you had a high score on the digit span task, you can probably recall a Chunking How Many Items Can Be Held in Short-Term Memory?

a sequence of six to nine unrelated words, but by arranging the words to form a meaningful sentence your memory span will likely increase to 20 words or more (Butterworth, Shallice, & Watson, 1990)

Chunking can be best described as

an effective STM control process that makes use of long-term memory (LTM) contents. Chunking can be best described as an effective STM control process that makes use of long-term memory (LTM) contents

What did Sperling (1960) determine in his famous experiment? (Results) whole report method What Sperling reasoned that if participants couldn't report the 12-letter diplay? Sperling's Experiment: Measuring the Capacity and Duration of the Sensory Memory Store

because of fading, perhaps they would do better if they were told to just report the letters in a single four-letter row.

The process of storing the number in long-term memory is called...

called encoding.

We have already seen that damage to the frontal lobe in humans causes problems in controlling attention, which is an important function of the central executive. Early research on the frontal lobe and memory was carried out on monkeys using a task called the

delayed-response task

The persistence of vision effect has been known since the Sperling's Experiment: Measuring the Capacity and Duration of the Sensory Memory Store

early days of psychology (Boring, 1942).

This focused attention is a function of the central executive according to Cowman has a limit of

four items or chunks

Ten years after the introduction of Broadbent's flow chart model, Atkinson and Shiffrin (1968) launched the

modal model of memory

Monkeys with damage to the _____ lobe have difficulty with delayed-response tasks, in which they must briefly hold information in working memory.

prefrontal cortex

What does the phonological similarity effect refer to?

refers to the confusion of letters or words that sound similar

What is rehearsal?

rehearsal The process of repeating a stimulus over and over, usually for the purpose of remembering it, that keeps the stimulus active in short-term memory.

In the model of memory proposed by Atkinson and Shiffrin (1968), the initial stage that holds all incoming information for seconds or fractions of a second is called

sensory memory. Feedback Correct. Sensory memory is an initial stage that holds all incoming information for seconds or fractions of a second.

The event-related potential experiment by Vogel and colleagues (2005) showed that individual differences in working memory capacity are largely due to

the effective functioning of attention control processes. The event-related potential experiment by Vogel and colleagues (2005) showed that individual differences in working memory capacity are largely due to the effective functioning of attention control processes.

The fact that STM and the modal model do not consider dynamic processes that unfold over time is what led Baddeley and Hitch (1974) to propose Working Memory

the name working memory, rather than short-term memory. Current researchers often use both terms, short-term memory and working memory, when referring to the short-duration memory process, but the understanding is that the function of this process, whatever it is called, extends beyond just storag

What three components did Baddley propose?

the phonological loop, visuospatial sketch pad and central executive

The phonological loop consists of two components:

the phonological store, which has a limited capacity and holds information for only a few seconds; and the articulatory rehearsal process, which is responsible for rehearsal that can keep items in the phonological store from decaying. The phonological loop holds verbal and auditory information. Thus, when you are trying to remember a telephone number or a person's name, or to understand what your cognitive psychology lecturer is talking about, you are using your phonological loop.

How is change detection different to digit span task? Change Detection How Many Items Can Be Held in Short-Term Memory?

this procedure uses visual items that cannot be verbalized (little squares in different colours and presented at different places)

Should short-term memory capacity be measured in terms of "number of items" (Awh, Barton, & Vogel, 2007; Fukuda, Awh, & Vogel, 2010; Luck & Vogel, 1997) or "amount of detailed information" (Alvarez & Cavanagh, 2004; Bays & Husain, 2008; Brady, Konkie, & Alvarez, 2011)? There are experiments that argue for both ideas, and the discussion among researchers is continuing. There is, however, agreement that

whether considering items or information, the upper limit for short-term memory capacity is about three to four items.

Returning to Baddeley, one of the things he noticed was that under certain conditions it is possible to carry out two tasks simultaneously, as illustrated in the following demonstration. Working memory Demontration According to Baddley's modal

According to the modal model of memory, it should only be possible to perform one of these tasks, which should occupy the entire STM. But when Baddeley and colleagues did experiments involving tasks similar to those in the previous demonstration, he found that participants were able to read while simultaneously remembering numbers

How did Baddeley describe the central executive as being?

An attention controller It determines how attention is focused on a specific task, how it is divded betwen two tasks, and how it is switched between task.

In Cowman's embedded process model, working memory is explained as a

Cognitive process that are responsible for retaining information in a temporaily enhances accessible state

Definition of chunking Chunking How Many Items Can Be Held in Short-Term Memory?

Combining small units into larger ones, such as when individual words are combined into a meaningful sentence. Chunking can be used to increase the capacity of memory.

Definition of change detection Change Detection How Many Items Can Be Held in Short-Term Memory?

Detecting differences between pictures or displays that are presented one after another.

Definition of articulatory suppression

Interference with operation of the phonological loop that occurs when a person repeats an irrelevant word such as "the" while carrying out a task that requires the phonological loop

What is long-term memory in modal model? (LTM)

Long-term memory (LTM) can hold a large amount of information for years or even decades.

This idea that the limit of STM is somewhere between five and nine was suggested by Digit Span How Many Items Can Be Held in Short-Term Memory?

Miller (1956), who summarized the evidence for this limit in his paper "The Magical Number Seven, Plus or Minus Two

What is definition of whole report method? Sperling's Experiment: Measuring the Capacity and Duration of the Sensory Memory Store

Procedure used in Sperling's experiment on the properties of the visual icon, in which participants were instructed to report all of the stimuli they saw in a brief presentation. See also Partial report method; Sensory memory.

What is the word length effect?

Refers to the observation that out memory for lists of words is better for short words than long words

Results of Baddeley and colleagues experiment of word length effect What did they suggest from their findings? figure 5.14a

Suggested that the word length effect occurs because it takes longer to rehearse the long words in the phonological loop (i.e. repeating them in your mind) and to produce them during recall.

The central executive is where the major work of working memory occurs.

The central executive pulls information from long-term memory and coordinates the activity of the phonological loop and visuospatial sketch pad by focusing on specific parts of a task and deciding how to divide attention between different tasks. The central executive is therefore the "traffic controller" of the working memory system.

Brown (1958) in England and Peterson and Peterson (1959) in the United States, who used the method of recall to determine the duration of STM. In their experiments, participants were given a task similar to the one in the following demonstration. What Is the Duration of Short-Term Memory?

Trigrams of constants (BFT, CML, KWS...)

What is proactive interference? What Is the Duration of Short-Term Memory?

When information learned previously interferes with learning new information. See also Retroactive interference.

What do patients with frontal lobe damage have problems with?

Working memory and with controlling their attention A typical behaviour of frontal lobe patients is preservation

Which statement about the fMRI decoding procedure is most accurate?

fMRI decoding programs perform above chance (averaging 75% to 100%) in discriminating between two simple stimuli.

Extension of persistence of vision effect, what did Sperling (1960) wondered? Sperling's Experiment: Measuring the Capacity and Duration of the Sensory Memory Store

how much information people can take in from briefly presented stimuli.

We have seen from previous chapters that cognitive psychologists have a number of tools at their disposal to determine the connection between cognitive functioning and the brain. The major methods are:

1. Analysis of behaviour after brain damage, either human or animal (Method: Demonstrating a Double Dissociation; Method: Brain Lesioning) 2.Recording from single neurons in animals (Method: Recording From a Neuron) 3.Measuring activity of the human brain (Method: functional Magnetic Resonance Imaging (fMRI)) 4.Recording electrical signals from the human brain (Method: Electroencephalography (EEG); Method: Event-Related Potential (ERP))

Different forms of memory

1. Images that come into your mind - perceputal memory e.g done in morning, or had a nice picnic 2. Knowledge that Paris is the capital of France 3. Knowledge how to ride a bike e.g procedural memory (procedural memories once you starting thinking about consciously it interfers with performance e.g thinking how to ride a bike it interfers) 4. Retracting of a familiar route e.g way home (spatial memory) 5. Emotional memory - a feeling associated with an event - can be positive or negative (negative stays with the longest) 6. Autobiographical collections (what we done in past, integrations of different memories that combine image, space, feelings and different senses)

What is sensory memory?

A brief stage of memory that holds information for seconds or fractions of a second. It is the first stage in the modal model of memory. See also Iconic memory; Persistence of vision.

Definition of episodic buffer

A component added to Baddeley's original working memory model that serves as a "backup" store that communicates with both LTM and the components of working memory. It holds information longer and has greater capacity than the phonological loop or visuospatial sketch pad. he episodic buffer can store information (thereby providing extra capacity) and is connected to LTM (thereby making interchange between working memory and LTM possible). Notice that this model also shows that the visuospatial sketch pad and phonological loop are linked to long-term memory. The proposal of the episodic buffer represents another step in the evolution of Baddeley's WM model, which has been stimulating research on working memory for more than 40 years since it was first proposed. If the exact functioning of the episodic buffer seems a little vague, it is because it is a "work in progress." Even Baddeley (Baddeley et al., 2009) states that "the concept of an episodic buffer is still at a very early stage of development" (p. 57). The main "take-home message" about the episodic buffer is that it represents a way of increasing storage capacity and communicating with LTM.

What is working memory definition? Working Memory

A limited-capacity system for temporary storage and manipulation of information for complex tasks such as comprehension, learning and reasoning.

What did the delayed response task require?

A monkey to hold information in working memory during a delay period

While you are watching a movie, you may see actions moving smoothly across the screen, but what is actually projected, for traditional films at least, is quite different. First, a single film frame is positioned in front of the projector lens, and when the projector's shutter opens and closes, the image on the film frame flashes onto the screen. When the shutter is closed, the film moves on to the next frame and during that time the screen is dark. When the next frame has arrived in front of the lens, the shutter opens and closes again, flashing the next image onto the screen. This process is repeated rapidly, 24 times per second, with 24 still images flashed on the screen every second and each image followed by a brief period of darkness. The Sparkler's Trail and the Projector's Shutter

A person viewing the film doesn't see the dark intervals between the images because the persistence of vision fills in the darkness by retaining the image of the previous frame.

E.g Picking the red object What would a patient with frontal lobe damage do?

A person with frontal lobe damage might be responding correctly on each trial as along as the rule stays the same However, when the rule is switched (Picking the blue object), the person continues following the same rule, even when given feedback that his or her responding is now incorrect. This preseveration represents a breakdown in the central executive's ability to control attention.

Definition of phonological similarity effect

An effect that occurs when letters or words that sound similar are confused. For example, T and P are two similar-sounding letters that could be confused.

Types of long term memory semantic memory

Another type of long-term memory is semantic memory—memories of facts such as an address or a birthday or the names of different objects ("that's a bicycle").

The repetition of an irrelevant sound results in a phenomenon called

Articulatory suppression that reduces the memory because the speaking interferences with rehearsal

Results

As can be seen in Figure 5.22b, the ERPs for trial type one (two red only), looked very similar for individuals with high versus low working memory capacity. However, the ERPs for trial type three (two red and two blue) were clearly different for these two groups (Figure 5.22d). Moreover, the ERP amplitude for trial type three was much bigger for the low capacity group as compared to the high capacity group. Indeed, for the high capacity group the ERP amplitudes for trial type three were very similar to those for trial type one (two red only) (compare Figures 5.22b and 5.22d). In contrast, for the low capacity group the ERP amplitudes for trial type 3 were very similar to those for trial type two (four red only) (not shown). What these results suggest is that, in contrast to the high capacity group, the low capacity group did not manage to filter out the blue distractor items which therefore used up valuable memory capacity. Based on these ERP results, Vogel et al. (2005) calculated a filtering efficiency score for each individual participant. As it turned out, working memory capacity and filter efficiency were highly correlated. Thus, the more efficient someone was at excluding items on the basis of their colour, the higher their working memory capacity. Consequently, the authors concluded that "the control processes that regulate access to working memory are crucial for keeping irrelevant information from consuming capacity" (p. 502). These (attention) control processes are part of the central executive system. These findings (and later many more followed) emphasize the pivotal role of the central executive system, moving further away from the earlier descriptions of short-term memory as a temporary storage system. Furthermore, it seems reasonable to suggest that the ability to effectively deploy attentional control could be the essential link for the earlier observed connection between working memory capacity and higher cognitive functioning (Johnson et al., 2013).

What is one of the ways central executive has been studied?

Assessing the behaviour of patients with frontal lobe damage

What kind of model can take into account both the dynamic processes involved in cognition such as understanding language and doing maths problems, and the fact that people can carry out two tasks simultaneously? Baddeley concluded that working memory must be

Baddeley concluded that working memory must be dynamic and must also consist of a number of components that can function separately.

What did Sperling (1960) determine in his famous experiment? partial report method Conclusion Sperling's Experiment: Measuring the Capacity and Duration of the Sensory Memory Store

Because this occurred no matter which row they were reporting, Sperling concluded that immediately after the 12-letter display was presented, participants had access to an average of 82 per cent of all of the letters but were not able to report all of them (when asked to do so in the whole report method) because they rapidly faded as the initial letters were being reported.

Definition of phonological store

Component of the phonological loop of working memory that holds a limited amount of verbal and auditory information for a few seconds.

What is the central executive?

Component that makes working memory "work" because it is the control centre of the working memory system Its mission is not to store information but to coordinate how information is used by the phonological loop and visuospatial sketch pad (Baddeley, 1996)

How did Conrad demonstrate the phonological similarity effect?

Conrad (1964) flashed a series of target letters on a screen and instructed his participants to write down the letters in the order they were presented. He found that when participants made errors, they were most likely to misidentify the target letter as another letter that sounded like the target. For example, "F" was most often misidentified as "S" or "X," two letters that sound similar to "F," but was not as likely to be confused with letters like "E," that looked like the target. Thus, even though the participants saw the letters, the mistakes they made were based on the letters' sounds. This result fits with our common experience with telephone numbers. Even though our contact with them is often visual, we usually remember them by repeating their sound over and over rather than by visualizing what the numbers looked like on the computer screen.

One way the articulatory rehearsal process (part of the phonological loop) has been studied by:

Determining what happens when its operation is disrupted. This occurs when a person is prevented from rehearsing the items to be remebered by repeating an irrelevant sound such as "the, the the" (Baddeley)

What is preservation?

Difficulty in switching from one behaviour to another, which can hinder a person's ability to solve problems that require flexible thinking. Perseveration is observed in cases in which the prefrontal cortex has been damaged. Repeatedly performing the same action or thought even if its not achieving the same desired goal.

What are ERPs (Event related potentials) derived from

EEG that can recorded from the scalp with small "sensors" called electrodes ERPS reflect a small signal changes in the EEG as a a result of a particular "event" like the onset of memory display, the retention of info in WM or the provsion of a response These singal changes are very small and only become visible after averaging multiple EGG trials The idea of averaging procedure is that EEG activity is related (time-locked) to the event/stimulus of interest will relarive increase amlitude against the random background activity (after many repetitions this will start to approach to 0) The resulting peaks in averaged ERP waveform are taken to represent certain information processing stages. The first peaks (P1 and N1) for believed to reflect stimulus detection, while the subsequent PI2 and N2 reflect stimulus processing. The P stands for positive and N stands for negative. The number refers to the rank order of the peak concerned, thus the P2 refers to the second positive peak.

Comparing ERPS to fMRI

ERPS provide little information about which brain areas these signals are coming from (poor spatial resolution) They are reliable for Cog Psych, however, because they provide very precise information about when certain events happen, in this order of milliseconds (good temporal resolution) Vogel et al used ERPS to examine working memory capacity

Word length affect difficulty according to the demonstration

Each list in the demonstration contains eight words, but according to the word length effect, the second list will become more difficult This was found in a experiment similar to the demonstration by Baddeley and colleagues. They found that participants remebered 77 per cent of the short words but only 60 percent of the long words.

What is another demonstration of the use of visual representation recalling visual patterns

Experiment conducted by Della Sala and colleagues in which participants presented with a task like this one Most people find that the pointing task is more difficult. The reason for this is that holding the image of the letter and pointing are both visuospatial tasks, so the visuospatial sketch pad becomes overloaded. In contrast, saying "Out" or "In" is an articulatory task that is handled by the phonological loop, so speaking doesn't interfere with visualizing the F.

Because visual STM is highly limited capacity it is essential to have a proper control mechanism which "selects" relevant information for executive access What mechanism is responsible for this and how does it work? Vogel and colleagues (2005) exmained this selective mechanism by using an adapted version of change detection task in which objects had to be memorised while others are ignored. An additional aim of their study was to find out whether individual differences in working memory capacity were related ot the efficiency of this selection mechanism PROCEDURE

Figure 5.22 shows different types of trials of change detection task. For all types of trials, a cue is presented indicating whether to direct attention to the red rectangles on the left side or the red rectangle on the right side of the display. Then a memory display was presented for one-tenth of a second (100 ms) followed by a brief blank screen (900 ms) and then a test display (2000 ms). The participants' task was to indicate whether the cued red rectangles in the test display had the same or a different orientation than the ones in the memory display. There were three conditions: (1) trials with two red rectangles on each side (Figure 5.22 - two red only), (2) trials with four red rectangles on each side (not shown - four red only), and (3) trials with two red and two blue rectangles on each side (Figure 5.22c - two red and two blue). During each trial the participants' electrical brain activity was recorded (EEG) and from this signal a so-called event-related potential (ERP) was calculated (see Method box). The amplitude of the ERP recorded during the retention interval (for an example see Figure 5.21) indicated how much space was used in working memory as they carried out the task (more precisely this amplitude refers to an ERP difference wave obtained by subtracting ipsilateral activity - same side as to where attention was directed - from contralateral activity - opposite side as to where attention was directed). A high amplitude would mean that all storage space is used, while a low amplitude would mean that there is still some space left. Given that this experiment is about a selective mechanism that determines which items get access to working memory, the ERP amplitude of most interest is that of condition three, because only in this condition does a discrimination of relevant and irrelevant items need to be made. Do you think that this ERP amplitude would be similar to that of condition one (two red only) or that of condition two (four red only)? And, would this be any different for individuals with low versus high working memory capacity?

Demonstration of change detection task Change Detection How Many Items Can Be Held in Short-Term Memory?

Following the "Change Detection" demonstration, we described experiments in which two pictures of a scene were flashed one after the other and the participants' task was to determine what had changed between the first and second pictures. The conclusion from these experiments was that people often miss changes in a scene. Change detection has also been used with simpler stimuli to determine how much information a person can retain from a briefly flashed stimulus. An example of change detection is shown in Figure 5.9, which shows stimuli like the ones used in Luck and Vogel's experiment. The display on the left was flashed for 100 ms, followed by 900 ms of darkness and then the new display on the right. The participant's task was to indicate if the second display was the same as or different from the first. In this example, notice that the colour of one of the squares is changed in the second display, thus the correct answer here would be "different." This task is easy if the number of items is within the capacity of STM (Figure 5.9a) but becomes harder when the number of items becomes greater than the capacity of STM (Figure 5.9b).

Idea of USB stick Alvarez and Cavanagh did an experiment using the change detection procedure used by Luck and Vogel (1997), but in addition to coloured squares, they also used more complex objects like the ones in Figure 5.11a. Example How Much Information Can Be Held in Short-Term Memory?

For example, for the shaded cubes, which were the most complex stimuli, a participant would see a display containing a number of different cubes, followed by a blank interval, followed by a display that was either the same as the first one or in which one of the cubes was different. The participant's task was to indicate whether the two displays were the same or different.

Baddeley's demonstration of articulatory suppression Results

Found that repeating "the, the , the.." did not only reduce the ability to remember a list of words, it also eliminated the word length effect. According to the word length effect, a list of one-syllable words should be easier to recall than a list of longer words because the shorter words leave more space in the phonological loop for rehearsal. However, eliminating rehearsal by saying "the, the , the..." eliminates this advantage for short words, so both short and long words are lost from phonological loop

What did Sperling (1960) determine in his famous experiment? (Results) whole report method Sperling's Experiment: Measuring the Capacity and Duration of the Sensory Memory Store

Given this task, they were able to report an average of 4.5 out of the 12 letters. (subjects report 4-5 letters - span of immediate memory)

What does the visuospatial skecth pad handle

Handle visual and spatial information and is therefore involved with the process of visual imagery

Duration

How long does it last (persistence)

What does capacity mean?

How much information is stored

The idea that the prefrontal cortex is important for working memory is also supported by experiments that have looked at

How some neurons in the prefrontal cortex are able to hold information after the original stimulus is no longer present, continuing to respond during a brief delay

Cowman model focused on

How working memory is related to attention and suggests that working memory and attention are essentially the same mechanism

A highly similar task is the operation span task (Turner & Engle, 1989).'' Procedure

In this task, instead of reading sentences, participants are required to perform a series of simple arithmetic operations and indicate whether the given answer is correct. For example, ? (yes or no). Each sum is again followed by a single word (e.g., TABLE) which needs to be memorized. After a series of two to seven sums, the number of correct recalled words is determined and this is taken as a measure of working memory capacity. Engle (2002) suggested that tasks such as these do not measure short term memory capacity but something which is very important to higher-order cognition. He proposed that this "something" most likely relates to executive attention, and perhaps even fluid intelligence. Moreover, working memory capacity as measured by these tasks is often conceptualized as reflecting some kind of general limitation on attentional capacity.

Explanation of modal model

Information coming from the environment and e.g visual scene you are looking hits the eyes and produces a sensory memory If you pay attention to whats infront of you, it is likely the info is transformed into STM If you don't pay attention it decays quickly If the information in STM is rehearsed (repeat info in some way) it is likely transform into LTM, if you don't rehearse it might be displaced with new info. LTM is there forever unless it is interferred with. Three types of store is respected with storage capacity and persistence of info Memory was seen as a flow of knowledge only in one direction through enviro through diff stores to LTM

So for example, the letter series LTMVWMPFC can be remembered much more easily as a series of abbreviations: Miller (1956), -"The Magical Number Seven, Plus or Minus Two How Many Items Can Be Held in Short-Term Memory?

LTM (long-term memory), VWM (visual working memory), and PFC (prefrontal cortex). That is, while nine individual letters will likely surpass your STM capacity limit, three abbreviations will not. Thus, if the to-be-remembered information allows "chunking," and this is recognized by the learner, than the capacity of STM can be increased.

Funahashi et al (1989) conducted an experiment where they recorded from

Neurons in a monkey's prefrontal cortex while the monkey carried out the delayed-response task The monkey first looked steaidly at fixation X, while a square was flashed at one position on screen e.g In this example, square was flashed in upper left corner, ((in other trials, the square was flashed at different positions on the screen). This caused a small response in the neuron.

Contribution of Vogel's experiment

One of the first to provide hard evidence for the suggestion that individual differences in working memory capacity do not just reflect how many items can be stored but more how efficiently irrelevant information can be kept out. In other words, working memory capacity variations are not about the absolute size of storage sapce, but about only keeping relevant information there e.g When trying to memorise/recall friend's phone number. This is easier when you are not thinking about what you want to ask him/not worrying about homework. This is the most successful way to get and keep his phone number in your mind is to have nothing else that competes for executive attention

Example of active process occurs in simple maths problems "Multiply 43 times 6 in your head" Stop and be aware of what you are doing in your head: Working memory

One way to solve this problem involves the following steps: Visualize: 43 × 6. Hold 40 in memory Multiply . Hold 18 in memory. Multiply . Add the 18 to the 240. The answer is 258. It is easy to see that this calculation involves both storage (holding the 18 in memory, remembering the 40 and 6 for the next multiplication step) and active processes (multiplying 40 x 6, adding 18 and 240) at the same time. If only storage were involved, the problem could not be solved. There are other ways to carry out this calculation, but whatever method you choose involves both holding information in memory and processing or manipulating information.

Other types of control processes strategies

Other examples of control processes are strategies you might use to help make a stimulus more memorable, such as relating the digits in a phone number to a familiar date in history, and strategies of attention that help you focus on information that is particularly important or interesting.

Other researches

Other researchers have also provided evidence that supports the close relationship between attention and working memory (Awh, Vogel, & Ho, 2006; Awh & Jonides, 2001; Chun & Johnson, 2011; Gazzaley & Nobre, 2012; Ikkai & Curtis, 2011). This relationship has proved helpful, particularly in research that tries to map the processes of working memory on specific brain areas. Gazzaley and Nobre (2012) for example, have shown that prefrontal and parietal regions play a central role in both selective attention and working memory performance. But before we discuss these connections in more detail, let's start with some of the earlier brain research, which primarily focused on the role of the (pre)frontal cortex.

Summary of chapter

Our discussion of STM up to this point has focused on two properties: how long information is held in STM and how much information can be held in STM. Considering STM in this way, we could compare it to a leaky bucket that can hold a certain amount of water for a limited amount of time. But as research on STM progressed, it became apparent that the concept of STM as presented in the modal model was too narrow to explain many research findings. The problem was that STM was described mainly as a short-term storage mechanism. But as we saw in our description of Rachel ordering a pizza, memorizing a phone number involves transferring the number from STM into LTM, and remembering or recalling it involves transferring it from LTM back into STM. This idea that STM is involved with dynamic processes like transferring information led to a rethinking of the nature of STM, and to the proposal that the short-term process might be better called working memory.

What did Sperling (1960) determine in his famous experiment? partial report method Procedure Sperling's Experiment: Measuring the Capacity and Duration of the Sensory Memory Store

Participants saw the 12-letter display for 50 ms, as before, but immediately after it was flashed, they heard a tone that told them which row of the matrix to report. A high-pitched tone indicated the top row; a medium-pitch indicated the middle row; and a low-pitch indicated the bottom row (Figure 5.5b). Importantly, because the tones were presented immediately after the letters were turned off, the participants' attention was directed not to the actual letters, since they were no longer present. Instead, their attention could only be directed to whatever trace remained in the participant's mind after the letters were turned off.

Baddley's three component model has been shown to explain this thing that working memory model can hold more than would be expected based on the phonological loop or visuospatial sketch pad e.g

People can remeber long sentences consisting of as many as 15-20 words, this relates to chunking when meaningful units are grouped together and related to LTM which involved in knowing the meanings of words in the sentence in relating parts of the sentence to each other based on rules of grammar

What did Baddeley and colleagues found in another study of memory for verbal material?

People on average are able to remeber the number of items that they can pronouce in about 1.5-2.0 seconds e.g Try counting out loud the words from the demonstration as fast as you can for 2 seconds. According to Baddeley, the number of words you can say within these two seconds should be close to your digit span.

Example of proactive and retroactive interference: What Is the Duration of Short-Term Memory?

Proactive interference: This makes it more difficult to learn a list of Spanish vocabulary words a little later, because the French words you have just learned interfere with the Spanish words. Thus, proactive interference occurs when old learning interferes with new learning Retroactive interference: Another kind of interference, retroactive interference, occurs when new learning interferes with remembering old learning (so in the opposite direction) (see Figure 5.8). For example, retroactive interference occurs when learning Spanish and makes it more difficult to remember the French words you had learned earlier. Most times retroactive interference and proactive interference occur simultaneously.

Example of working memory involved with manipulation of information Working memory

Rachel: "I'd like to order a large pizza with broccoli and mushrooms." Reply: "I'm sorry, but we're out of mushrooms. Would you like to substitute spinach instead? Rachel was able to understand the pizzeria's question by holding the first sentence, "I'm sorry, but we're out of mushrooms," in her memory while listening to the second sentence of their reply, and then making the connection between the two. If she had remembered only "Would you like to substitute spinach instead?" she wouldn't know whether it was being substituted for the broccoli or for the mushrooms, or why it was suggested at all. In this example, Rachel's short-term memory is being used not only for storing information, but also for active processes like understanding conversations.

Contribution of Funahashi experiment

The key result of this experiment was that there were neurons that responded only when the square was flashed in a particular location and that these neurons continued responding during the delay. For example, some neurons responded only when the square was flashed in the upper right corner and then during the delay; other neurons responded only when the square was presented at other positions on the screen and then during the delay. The firing of these neurons indicates that an object was presented at a particular place, and this information about where the object was remains available for as long as these neurons continue firing (also see Funahashi, 2006).

It is dark out on New Year's Eve, and you put a match to the tip of a sparkler. As sparks begin radiating from the tip, you sweep the sparkler through the air, creating a trail of light (Figure 5.4). Although it appears that this trail is created by light left by the sparkler as you wave it through the air, there is, in fact, no light along this trail. The Sparkler's Trail and the Projector's Shutter

The lighted trail is a creation of your mind, which retains a perception of the sparkler's light for a fraction of a second. This retention of the perception of light in your mind is called the persistence of vision.

What is modal model of memory?

The model proposed by Atkinson and Shiffrin that describes memory as a mechanism that involves processing information through a series of stages, including short-term memory and long-term memory. It is called the modal model because it contains features of many models that were being proposed in the 1960s.

After the square went off there was a delay of a few seconds:

The nerve firing records in Figure 5.26b show that the neuron was firing during this delay. This firing is the neural record of the monkey's working memory for the position of the square. After the delay, the fixation X went off. This was a signal for the monkey to move its eyes to where the square had been flashed (Figure 5.26c). The monkey's ability to do this provides behavioural evidence that it had, in fact, remembered the location of the square.

One measure of the capacity of STM is provided by the digit span Definition of digit span Digit Span How Many Items Can Be Held in Short-Term Memory?

The number of digits a person can remember. Digit span is used as a measure of the capacity of short-term memory.

We can understand the reasoning behind the idea that the amount of information is important by considering storing pictures on a USB stick. How Much Information Can Be Held in Short-Term Memory?

The number of pictures that can be stored depends on the size of the stick and on the size and resolution of the pictures. Fewer large or high-resolution pictures can be stored than small or low-resolution pictures, because they take up more space in memory.

Sperling (1960) famous experiment Delayed partial report method Results Sperling Experiment: Measuring the Capacity and Duration of a sensory memory store

The result of the delayed partial report experiments was that when the cue tones were delayed for one second after the flash, participants were able to report only slightly more than one letter in a row. Figure 5.6 plots this result, showing the percentage of letters available to the participants from the entire display as a function of time following presentation of the display. This graph indicates that immediately after a stimulus is presented, all or most of the letters presented are available for perception (82 per cent). This is sensory memory. Then, over the next second, sensory memory fades quickly. That is, after 0.1 seconds only about 60 per cent of the letters displayed were available for recall and after 0.3 seconds this had dropped to 50 per cent.

Brown (1958) in England and Peterson and Peterson (1959) found in similar results varied the time between when they said the number and when the participant began recalling the letters. What Is the Duration of Short-Term Memory?

They found that their participants remembered about 80 per cent of the three-letter groups if they could begin their recall after counting for just three seconds, but remembered only about 12 per cent of the three-letter groups after counting for 18 seconds (Figure 5.7a)

Example of ERPS

This negative waveform occurs when someone tries to keep something in working memory. The size or amplitude of this waveform indictaed how much working memory space is used by the participant

What did Sperling (1960) determine in his famous experiment? (Procedure) part of the experiment used what method? "in which he flashed an array of letters, like the one in Figure 5.5a, on the screen for 50 milliseconds (50/1000 second) and asked his participants to report as many of the letters as possible." Sperling's Experiment: Measuring the Capacity and Duration of the Sensory Memory Store

This part of the experiment used the whole report method; that is, participants were asked to report as many letters as possible from the entire 12-letter display. G

Brown (1958) in England and Peterson and Peterson (1959) interpretation of results What Is the Duration of Short-Term Memory?

This result was interpreted as demonstrating that participants forgot the letters because their memory had decayed during the 18-second passage of time after they heard the letters. That is, their memory trace vanished because of decay that occurred during the passage of time after hearing the letters.

Cowan vs. Baddeley

Thus, although this model looks very different from that of Baddeley, they agree on the most important characteristics of working memory, namely a strict capacity limit and the need for focused attention or rehearsal to prevent decay of information. In the words of Baddeley, the biggest difference between these respective models is in how they were derived: "his [Cowan's] from an initial focus on attention, my own [Baddeley] influenced by studies of short-term verbal memory" (Baddeley, 2010, p. R140)

Summary of chapter 5.2

Thus, sensory memory can register huge amounts of information (perhaps all of the information that reaches the receptors), but it retains this information for only a fraction of a second. However, like in the old-fashioned movies and the sparkler trail, this is long enough for us to experience continuous perception. Sperling's experiment is important not only because it revealed the capacity of sensory memory (large) and its duration (less than a second), but also because it provides yet another demonstration of how clever experimentation can reveal extremely rapid cognitive processes that we are usually unaware of.

Understanding working memory model

To understand this "traffic controller" function, imagine you are driving in a strange city, a friend in the passenger seat is reading you directions to a restaurant, and the car radio is broadcasting the news. Your phonological loop is taking in the verbal directions; your sketch pad is helping you visualize a map of the streets leading to the restaurant, and your central executive is coordinating and combining these two kinds of information (Figure 5.13). In addition, the central executive might be helping you ignore the messages from the radio so you can focus your attention on the directions (note here an overlap with selective attention).

What are structural features?

Types of memory indicated by boxes in models of memory. In the modal model, the types are sensory memory, short-term memory and long-term memory.

Results from Shepard and Metzler's mental rotation visual experiment

We can see that when one shape was rotated 40 degrees compard to the other shape 5.15a. It took 2 seconds to decide that a pair was the same shape However, for a greater difference caused by a rotation of 140 degrees in 5.15b. It took 4 seconds. Based on this finding that reaction times were longer for greater difference in orientation it was inferred that participants were solving the problem by rotating an image of one of the objects in their mind, a phenomnon called mental rotation. This mental rotation is an example of the operation of the visuospatial sketch pad.

To illustrate how the structural features and control processes operate together Rachel looks up the number for Mario's Pizza Place on the internet

When she first looks at the screen, all of the information that enters her eyes is registered in sensory memory (Figure 5.3a). Rachel uses the control process of selective attention to focus on the number for Mario's Pizza Place, so the number enters her short-term memory (Figure 5.3b), and she uses the control process of rehearsal to keep it there (Figure 5.3c). Rachel knows she will want to use the number again later, so she decides that in addition to storing the number in her mobile phone, she is going to memorize the number so it will also be stored in her mind. The process she uses to memorize the number, which involves control processes we will discuss in Chapter 6, transfers the number into long-term memory, where it is stored more permanently (Figure 5.3d). The process of storing the number in long-term memory is called encoding. A few days later, when Rachel's urge for pizza returns, she remembers the number. This process of remembering information that is stored in long-term memory is called retrieval (Figure 5.3e).

sensory memory.

When something is presented briefly, such as a face illuminated by a flash, your perception continues for a fraction of a second in the dark. This brief persistence of the image, which is one of the things that makes it possible to perceive movies

What did Sperling (1960) determine in his famous experiment? partial report method Results Sperling's Experiment: Measuring the Capacity and Duration of the Sensory Memory Store

When the participants focused their attention on one of the rows in their mind, they correctly reported an average of about 3.3 of the four letters (82 per cent) in that row.

The visuospatial sketch pad holds visual and spatial information Example

When you form a picture in your mind or do tasks like solving a puzzle or finding your way around campus, you are using your visuospatial sketch pad. As you can see from the diagram, the phonological loop and the visuospatial sketch pad are both attached to the central executive.

What did Sperling (1960) determine in his famous experiment? (Results) whole report method What could Sperling could have concluded? Sperling's Experiment: Measuring the Capacity and Duration of the Sensory Memory Store

because the exposure was brief, participants saw only four or five of the 12 letters. However, some of the participants in his experiment reported that they had seen all of the letters, but that their perception had faded rapidly as and when they were reporting the letters. That is, by the time they had reported four or five letters, they could no longer see or remember the other letters. Perhaps you recognize this feeling as when you are briefly aware of your last night's dream but seem to forget it at the moment you try to write it down or tell someone else about it.

Soon after the introduction of the working memory model, and in correspondence with the digit span task, several tests have been developed to assess working memory capacity. Typically these tests involve someone

being asked to remember a word or a digit while also performing another attention demanding task. For example, the reading span task. In this task, participants read aloud two to seven sentences, each of which is followed by an unrelated word. After the last sentence, participants are asked to recall the unrelated words. The number of correct words recalled is taken as someone's working memory capacity.

On the other hand, it is clear that by doing so you have not really increased your STM capacity, you have just applied a Chunking How Many Items Can Be Held in Short-Term Memory?

clever learning strategy.

Mathy and Feldman (2012) systematically manipulated the Chunking How Many Items Can Be Held in Short-Term Memory?

compressibility of number sequences by introducing certain patterns in a series of numbers that had to be memorized by their participants in a digit span task. This was done in a similar way as in our example, with sequence patterns consisting of increasing (3-4-5) and decreasing (9-8-7-6) numbers of different length.

Dynamic processes associated with the memory components that can be modified by a person and that may differ from one task to another are referred to as _____ processes.

control Correct. Dynamic processes associated with the memory components that can be modified by a person and that may differ from one task to another are referred to as control processes.

It is a beautiful spring day and your mind is wandering as you look out the window during your cognitive psychology lecture. Suddenly, a friend nudges you and glances meaningfully towards the lecturer. Before the question can be repeated, you "hear" it in your mind and answer correctly. You've been saved by _____

echoic Correct. The persistence of sound, called echoic memory, lasts for a few seconds after presentation of the original stimulus.

Other research using auditory stimuli has shown that sounds also persist in the mind. This persistence of sound, called

echoic memory lasts for a few seconds after presentation of the original stimulus (Darwin, Turvey, & Crowder, 1972).

The outcome of this constant interference is that the What Is the Duration of Short-Term Memory?

effective duration of STM, when rehearsal is prevented, is about 15 to 20 seconds or less (Zhang & Luck, 2009).

According to measurements of digit span, the average capacity of STM is about Digit Span How Many Items Can Be Held in Short-Term Memory?

five to nine items—about the length of a phone number

From the above studies it is evident that the prefrontal cortex plays a crucial role in working memory. It does not become clear however, what exactly this role is and whether other areas are important for working memory as well? Measuring the activity of the whole brain in

healthy individuals by means of fMRI may help in answering these questions. Indeed, these studies have been designed to examine how the distinct processes that make up working memory may work together. The underlying hypothesis in this research is that sustained activity in prefrontal areas is necessary to maintain abstract and coarse representations in working memory (perhaps along with some kind of rehearsal process) but that the actual detailed content of working memory is stored somewhere else, most likely in those brain areas that have been associated with their initial perception in the first place (Eriksson, Vogel, Lansner, Bergström, & Nyberg, 2015).

Ericsson and colleagues (Ericsson, Chase, & Falloon, 1980) demonstrated an effect of chunking by showing Chunking How Many Items Can Be Held in Short-Term Memory?

how a college student with average memory ability was able to achieve amazing feats of memory. Their participant, S.F., was asked to repeat strings of random digits that were read to him. Although S.F. had a typical memory span of seven digits, after extensive training (230 one-hour sessions), he was able to repeat sequences of up to 79 digits without error

When was working memory introduced? Working memory?

in a paper by Baddeley and Hitch (1974), defined as "a limited-capacity system for temporary storage and manipulation of information for complex tasks such as comprehension, learning and reasoning." The italicized portion of this definition is what makes working memory different from the old modal model conception of short-term memory.

What did Sperling (1960) determine in his famous experiment? (Procedure) Sperling's Experiment: Measuring the Capacity and Duration of the Sensory Memory Store

in which he flashed an array of letters, like the one in Figure 5.5a, on the screen for 50 milliseconds (50/1000 second) and asked his participants to report as many of the letters as possible.

All these methods have also been used to study the relationship between working memory and the brain. An important characteristic of working memory tasks is tha

involves a delay or waiting, during which information needs to be kept accessible. Researchers, therefore, have looked for physiological mechanisms that can hold information about events after they are over.

According to the embedded process model, some activation may occur for info that is stored in LTM unless this

is given a continued or focused attention This information will fade quickyl

What does chunking enable? Chunking How Many Items Can Be Held in Short-Term Memory?

limited-capacity STM system to deal with the large amount of information involved in many of the tasks we perform every day, such as chunking letters into words as you read this, remembering the first three numbers of familiar telephone exchanges as a unit, or transforming long conversations into smaller units of meaning.

Recent measures of STM capacity have set the limit at about three to four items (Cowan, 2001). This conclusion is based on the results of experiments like one by Luck and Vogel (1997), which Change Detection How Many Items Can Be Held in Short-Term Memory?

measured the capacity of STM by using a procedure called change detection.

Individual differences in storage capacity were also observed in this and other experiments using similar tasks. Interestingly, these individual differences were found to correlate with Change Detection How Many Items Can Be Held in Short-Term Memory?

measures of higher cognitive functioning. That is, individuals with a larger storage capacity, as determined with this relatively simple change detection task, also performed better on complex cognitive tasks that measured, among other things, verbal and visual learning, reasoning/problem solving, and social cognition (Johnson et al., 2013). The high correlation between change detection performance and, for example, problem solving ability suggests that visual short-term memory capacity somehow plays a central role in higher cognitive functioning. What this role might be is discussed further in this chapter after we have introduced you to the concept of working memory. Indeed, it is probably more fitting to state that both storage and some kind of selective processing and attention control is involved in this relationship with intellectual aptitudes (Engle, 2002; Unsworth, Fukuda, Awh, & Vogel, 2014). First, however, we will discuss another way of conceptualizing STM capacity.

Not only is information lost rapidly from STM, there is also a limit as to how How Many Items Can Be Held in Short-Term Memory?

much information can be held there. As we will see, estimates for how many items can be held in STM range from four to nine.

While research in the 60s to 90s focused on the _____ that could be stored in STM, more recent research has focused on the _____ that can be stored in STM.

number of items; amount of information Correct. While research in the 60s to 90s focused on the number of items that could be stored in STM, more recent research has focused on the amount of information that can be stored in STM.

Definition of operation span task

operation spanRefers to the score obtained in an operation span task in which participants are required to perform a series of simple arithmetic operations and indicate whether the given answer is correct. Each sum is followed by a single word which needs to be memorized. After a series of two to seven sums, the number of correct recalled words is determined and this is taken as a measure of working memory capacity.

You briefly write your name in the air using a lit sparkler. Although the sparkler leaves no trace of the letters while you are writing, you are still able to perform this task due to

persistence of vision Correct. Persistence of vision is the continued perception of a visual stimulus even after it is no longer present.

Ruth very much enjoys learning new languages. She learned French in high school and is now taking Spanish. However, she finds that she often substitutes French words for the similar Spanish words she is supposed to be using. Ruth is experiencing _____ interference.

proactive Correct. Proactive interference occurs when information that was learned previously interferes with learning new information.

Keppel and Underwood proposed that, in line with the idea of proactive interference, What Is the Duration of Short-Term Memory?

recalling the letters on the first few trials created interference that made it more difficult to remember the letters presented on the later trials.

Moreover, when we introduced the modal model of memory, we distinguished between structural features and control processes (see Figure 5.2). Like Chunking How Many Items Can Be Held in Short-Term Memory?

rehearsal, chunking (or whatever memorizing strategy is employed) is considered a control process, while strictly speaking STM refers to a structural feature It is therefore possible that some people are able to store more items in their STM, not because their STM capacity is larger (i.e., more storage space) but because they use very effective control processes, often in combination with long-term memory (LTM) contents.

fMRI experiments in humans have found that the prefrontal brain areas are

responsible for maintaining abstract and coarse representations in working memory. Correct. fMRI experiments in humans have found that the prefrontal brain areas are responsible for maintaining abstract and coarse representations in working memory.

A few days later, when Rachel's urge for pizza returns, she remembers the number. This process of remembering information that is stored in long-term memory is called

retrieval

Memory is active any time

some past experience has an effect on the way you think or behave now or in the future (Joordens, 2011).

Apart from individual differences in the use of chunking strategies, it should also be recognized Chunking How Many Items Can Be Held in Short-Term Memory?

some series of numbers are easier to chunk than others (3-4-5, 9-8-7-6, 5-6 vs 5, 2, 7, 3, 1, 6, 4, 9, 2), which suggests that the capacity limit of STM also depends on the complexity or "compressibility" of the to-be-remembered materials

Long-term memory is responsible for

storing information for long periods of time—which can extend from minutes to a lifetime.

The types of memory proposed in a model, such as sensory memory or long-term memory, are called the _____ features of the model.

structural Correct. The types of memory in a model are called the structural features of the model.

What three types of memory listed in the modal model indicated in box are called?

structural features of the model

Why would memory become worse after a few trials? Keppel and Underwood (1962) suggested What Is the Duration of Short-Term Memory?

that the drop-off in memory was due not to passive decay of the memory trace over time, but to proactive interference—interference that occurs when information that was learned previously interferes with learning new information.

The rapid forgetting that Peterson and Peterson (1959) had observed was due, therefore, not to What Is the Duration of Short-Term Memory?

waiting 18 seconds but to interference caused by all of the information the participants had learned earlie

Alvarez and Cavanagh procedure used by Luck and Vogel (1997), but in addition to coloured squares, they also used more complex objects like the ones in Figure 5.11a. Results

was that participants' ability to make the same/different judgment depended on the complexity of the stimuli. Memory capacity for the coloured squares was 4.4, but capacity for the cubes was only 1.6. Based on this result, Alvarez and Cavanagh concluded that the greater the amount of information in an image, the fewer items that can be held in visual short-term memory.

. But some researchers have suggested that rather than describing memory capacity in terms of "number of items," it should be described in terms of How Much Information Can Be Held in Short-Term Memory?

"amount of information." When referring to visual objects, the amount of information has been defined as the visual features or details of the object that are stored in memory (Alvarez & Cavanagh, 2004).

The term "item" in this context reflects a Miller (1956), "The Magical Number Seven, Plus or Minus Two How Many Items Can Be Held in Short-Term Memory?

"meaningful unit" or "chunk," which itself can consist of several items.