Cognitive Psychology, Chapter 5
How did Vogel and coworkers (2005) study how well the central executive controls attention in subjects without brain damage?
2 groups: high-capacity group - able to hold a number of items in WM low capacity group - able to hold fewer number of items in WM Subjects tested using change detection procedure - indicate whether cued stimuli in the test display had the same or different orientations than the ones in the memory display. Brain response called event-related potential was measured - indicated how much space was used in WM as they carried out the task. Vogel added blue bars as distractors - increase in response in high-capacity group, but an even larger increase in the response of the low-capacity group. High capacity group was better at ignoring distractors - their Central executive is functioning well.
Describe the interference of the visuospatial sketchpad demonstrated in the "F" task (Brooks, 1968).
A block letter appears then disappears. Mentally trace the outline of the block letter - say if each corner is "out" or "in". 3 methods of responding: Say yes or no, Tap L or R finger, Point to Y's or N's on paper. Conclusions: The verbal and motor responses were better than the visual response of pointing. This is because holding the letter in your mind and pointing are both visuospatial tasks, so the system becomes overloaded - selective interference.
How do we prevent rehearsal when studying the duration of STM?
A distractor task, such as the Brown-Peterson task: Hear 3 letters, then a number; count backwards by 3s; recall original 3 letters
What way have researchers suggested we describe memory capacity other than in terms of "number of items"?
Amount of information. When referring to visual objects, info has been defined as visual features or details of the object that are stored in memory.
What was the modal (multi-store) model of memory?
Atkinson & Shiffrin (1968): proposoed three types of memory - sensory, short-term, and long-term
Describe the components of Baddeley's working memory model.
Central executive: coordinates, processes, and controls attention - the head of working memory. Phonological loop: stores/manipulates verbal and auditory info - phonological store: limited capacity, holds info for only few seconds - articulatory rehearsal process: responsible for rehearsal that keeps items in the phonological store from decaying. Visuospatial sketch pad: stores/manipulates visual and spatial information. Episodic buffer: Integrates episodic LTMs into current manipulation of info, provides extra storage
What are control processes in the modal model of memory?
Dynamic processes associated with the structural features that can be controlled by the person and may differ from one task to another. Rehearsal is an example, as well as other strategies that might make a stimulus for memorable or strategies of attention
What did the immediate serial recall tasks with digits by Salame & Baddeley (1987,1989) tell us about sound and the phonological loop?
EXP 1: 3 groups - silence, spoken words, and nonsense syllables. Only performed well in silence group. - Sound interferes with phonological loop EXP 2: 2 groups - noise, speech. Noise group did well, speech did not. - Interference is specific to speech sounds EXP 3: 3 groups - foreign language opera, english pop music, instrumental. Instrumental group only did well. - All types of speech interfere.
Which lobe is important for central executive functioning?
Frontal lobe.
What is proactive interference?
Interference that occurs when information that was learned previously interferes with learning new information (old learning interferes with new learning).
How is rehearsal in STM a control process?
It allows for us to manipulate the duration of information being held in STM - rehearsal allows us to store it for longer period of time.
What is working memory?
Limited-capacity system for temporary storage and manipulation of information for complex tasks such as comprehension, learning, and reasoning. Integration of processes all acting dynamically, with the help of the central executive.
What is retroactive interference?
New learning interferes with remembering old learning.
What is the world length effect?
Occurs when memory for lists of words is better for short words than for long words. Occurs because it takes longer to rehearse the long words and to produce them during recall.
What are the limitations of these studies of STM?
Only explains how info is stored in STM, doesn't explain how info is manipulated in STM or why there are different performances on different tasks
Memory
Processes involved in retaining, retrieving, and using information about stimuli, images, events, ideas, and skills after the original info is no longer present.
What are the two main roles of the phonological loop?
Recoding visual stimuli into verbal info (when possible) and keeping verbal info active in working memory.
List and describe the structural features of the modal model.
Sensory memory - holds info for seconds or fraction of a second Short-term memory - holds 5-7 items for about 15-20 seconds Long-term memory - can hold large amount of info for years or even decades
Explain the concept of chunking (Miller).
Small units (like words) can be combined into larger meaningful units, like phrases, or even larger units, like sentences, paragraphs, or stories. A "chunk" is a collection of elements that are strongly associated with one another but are weakly associated with elements in other chunks. Chunking in terms of meaning increases our ability to hold info in STM.
Describe how the change detection task is used to measure the capacity of STM (Luck & Vogel).
Stimuli are flashed, follow by darkness, then other stimuli are flashed. Subjects' job is to determine if the first picture was the same as the second one. The task is easy if the number of items is within the capacity of the STM, but becomes harder when the number of items becomes greater than the capacity of STM.
Which methods do researchers use to determine the physiological mechanisms that can hold info about events even after they are over?
Study patients with brain damage to the prefrontal cortex. - delayed-response task w/monkeys - removal of prefrontal cortex caused their performance to remember after a delay to drop dramatically. Look at prefrontal neurons that hold info and respond only in a particular location and continue to respond during a delay. Holding info in the visual cortex. -Neural mind reading: determine what subject is perceiving or thinking, used during the delay. - PF cortex may be most closely associated with WM, but there are other areas as well (distributed representation)
What was George Sperling's experiment measuring?
The capacity and duration of the sensory store. Capacity of STM is large but the duration is brief.
What is the persistence of vision in sensory memory?
The continued perception of a visual stimulus even after it is no longer present (ex: moving sparkler, rapidly flashed pictures in a movie); example of Iconic Memory (visually based memory)
What were Keppel & Underwood's alternative explanation to the decay hypothesis of forgetting?
The finding of poor memory at 18 seconds reported by Peterson and Peterson was a result of poorer performance on later trials; the drop off in memory was not due to decay over time, but to proactive interference
Describe one of the measures of STM's capacity - the digit span.
The number of items remembered at once without external aid. The average capacity of STM is about 5-9 items. Miller's magic #7, plus or minus 2
What is echoic memory?
The persistence of sound that lasts for a few seconds after the presentation of the original stimulus.
What is articulatory suppression?
The repetition of an irrelevant sound results in articulatory suppression, which reduces memory because speaking interferes with rehearsal. ("the the the")
Explain Alvarez & Cavanagh's change detection procedure that used more complex objects in addition to colored squares.
The result of this experiment was that subjects' ability to make the same/different judgment depended on the complexity of the stimuli being flashed in each screen. The conclusion was that the greater amount of info in an image, the fewer items that can be held in visual STM.
What are the results from the Brown-Peterson recall task?
Time is the main factor in forgetting. Memory trace vanished because of the decay that occurred during the passage of time after hearing the letters (decay hypothesis of forgetting)
Explain Sperling's delayed partial report method.
Used to determine the time course of fading. The letters were flashed on and off then the cue tone was presented after a short delay. When the cue tones were delayed for one second after the flash, subjects were able to report only slightly more than 1 letter in a row.
Describe the mental rotation tasks by Shepard & Metzler (1971)
View 3-D object pairs - quickly decide "same" or "different". A higher degree of rotation resulted in a longer reaction time. Linear increase, r = .97! Solving these problems requires rotating visual images in the mind.
What did Luck & Vogel's change detection study conclude?
We are only able to retain about four items in STM rather than 7.
What is perseveration?
When frontal lobe damage occurs, perseveration can occur: repeatedly performing the same action or thought even if it is not achieving its desired goal. Cannot switch tasks easily. Represents a breakdown in the central executive's ability to control attention.
When does an action slip occur?
When the central executive is working poorly. (ex: going to take your glasses off your face when you are wearing contacts)
Describe Sperling's whole report method and partial report method.
Whole report method: Subjects reported as many letters as possible from the entire 12-letter display, on average they reported 4.5 out of 12. Can be explained by rapid fading of the initial letters Partial report method: Subjects were told to report only the letters in a single 4-letter row (a tone told them which row to pay attention to after the letters disappeared). Subjects usually reported 3.3 out of 4
What is the phonological similarity effect?
the confusion of letters or words that sound similar. Conrad (1964) - immediate serial recall task with letters; high phonological similarity (BCPTV) were harder to recall than low phonological similarity (MJYFH). Conrad's conclusion - working memory deals with verbal info.
