PSYC 314 Exam 2 Cognition Chapters 3, 4, & 5
Cocktail party effect
Ability to attend to only one voice among many (ex: hearing your name in a noisy room)
Cluster of signts for selective attention
According to one proposal cluster of sites (the orienting system) A second set of sites (the alerting system). A third set of sites (the executive system)
Scene schemas
An observer's knowledge about what is contained in typical scenes
Attenuator
Analyzes incoming message in terms of its physical characteristics, its language, and its meaning; Annie Treisman's replacement of Broadbent's filter
Attenuation theory of attention
Anne Treisman's model of selective attention that proposes that language and meaning can be used to separate messages; words with more important meaning are higher priority than words with less important meaning; messages -> attenuator -> dictionary unit -> memory
How is unconscious interference proved?
Any manipulation that makes an object seem far away without changing the retinal size should make the object seem bigger. Any manipulation that makes the object seem closer without changing the retinal image size should make the object look smaller (Both were true)
Site on the occipital lobe where axons from the LGN first reach the cortex contains a full ensemble of cells that respond to every possible stimulus making certain that no matter what input or where its located some cells will respond to it
Area V1
Perceiving and the Limits on Cognitive Capacity: An Interim Summary
At the broadest level we suggested that two different mechanisms are involved in selective attention → one to inhibit the unwanted and the other that facilitates the processing of desired inputs. The latter has several parts: you are primed for some stim because you have encountered it often, know the targets identity ( thus prime relevant detectors), or know where it will apear (prime region of space) once located you can prime detectors for that object. Flexibility in when that selection happens. Early selection → so that unattended input receives little processing. Late selection- The unattended receives fuller analysis- even if that input never penetrates your awareness. Attention is an achievement not mechanism or process→ something we are able to do :/
What is the relationship between detection of attributes and the organization of attributes in your mind?
Brain areas that analyze a pattern's basic features do their work at the same time as the brain areas that analyze a pattern's large scale configures and these brain areas interact so that perception of features is guided by the configuration, and analysis of configuration is guided by the features Work together so perception makes sense on a large scale and fine grained level
Bottleneck model
Broadbent's model is nicknamed this because the filter restricts information flow; the large amount of info available to a person is restricted so that only some of this information gets through to the detector
What does the Necker cube show
Burner's phrase "perception goes beyond the information given"
Two Types of Priming
First perception is vastly facilitated by priming of relevant detectors. Second The priming Sometime stimulus driven That is produced by the stimulus you've encountered before (Recently or Frequently) In the past. This type of priming Takes effort And requires no resources. Third a different sort of priming is also possible. This priming is expectation driven and is under your control
Incompatible flankers
Flankers that are associated with a different response than the target; result in slowest response to target
Neutral flankers
Flankers that are associated with a response that is neither the same nor different from the target; result in intermediate response to target
Compatible flankers
Flankers that are associated with the same response as the target; result in the fastest response to target
Divided Attention: An interim Summary
Interference between tasks is plainly increased if the tasks are similar to each other, presumably because similar tasks overlap in their processing requirements and so make competing demands on mental resources that are specialized for that sort of task. But interference can also be demonstrated with tasks that are entirely different from each other—such as driving and talking on a cell phone. Thus, our account needs to include resources that are general enough in their use that they're drawn on by almost any task. Several general resources: an energy supply needed for mental tasks; a response selector needed whenever a task involves the launching of successive steps; executive control, needed whenever a task requires " rising above" prior habits and tendencies and probably others Key principle is tasks will interfere with each other and if their combined demand for a resources is greater than the amount available
Simon effect
Interference in response due to inconsistency between the response and the stimulus; incongruent tasks are harder and take more time to complete (ex: it is easier to press a button on the left when hearing a signal in the left ear instead of the right ear)
Saccadic eye movements
Movements of the eye from one fixation to the next
Same-object advantage
Occurs when the enhancing effect of attention spreads throughout an object, so that attention to one place on an object results in a facilitation of processing at other places on the object
Top-down
Scene schemas as associated with (bottom-up/top-down) processing
Conjunction search
Search for a target defined by the presence of two or more attributes
Overt attention
Shifting attention from one place to another by moving the eyes
Covert attention
Shifting attention from one place to another while keeping the eyes stationary
Sperlings partial report technique
Shows a 3x4 arrangement of letters and subject says what they can remember for full, for partial a tone signals which row to remember after you see the letters; tells us that there is a limited amount of information we can perceive or process (IV: partial or full report; DV: number of letter recalled)
Specificity of Resources
Similar resource requirements for similar tasks
Feature Binding
Priming one takes away from another! It would be shitty to have unlimited capacity because you couldn't handle all of the available info. When we overlaid attention → participants make errors in binding we might show them a red triangle and a blue circle but they bundle them wrong. Further evidence comes from visual search tasks!
ADHD symptoms (attention deficit/ hyperactivity disorder) cognitive processes and neural networks
Problems in "alerting"system: has difficulty sustaining attention (right frontal cortex), fails to finish (right posterior parietal), avoids sustained effort (locus ceruleus) Problems in "orienting" system: is distracted by stim (bilateral parietal), does not appear to listen (superior colliculus), fails to pay close attention(thalamus). Problems in "executive" system: blurts out answers (anterior cingulate), interrupts or intrudes (left lateral frontal), cannot wait (basal ganglia)
Shadowing
Repeating a message out loud
Conjunction search
Response time increases with increased display size for (conjunction search/single feature search)?
Single feature search
Response time says the same with increased display size for (conjunction search/single feature search)?
controlled tasks
Tasks that are novel or that require flexibility in one's approach; these tasks usually require attention, so they cannot be carried out if the person is also busy with some other task.
automatic tasks
Tasks that are well practiced and that do not require flexibility; these tasks usually require little or no attention, and they can be carried out if the person is also busy with some other task. Usually contrasted with controlled tasks.
What did Gestalt psychologists believe
That the organization of the visual world must be contributed by the perceiver perceptual whole is often different from the sum of its parts
Cognitive load
The amount of a person's cognitive resources needed to carry out a particular cognitive task; there are low-load tasks and high-load tasks
response time (RT)
The amount of time (usually measured in milliseconds) needed for a person to respond to a particular event (such as a question or a cue to press a specific button).
Selective Vocal Attention Experiment
The attended channel contained a recording of someone speaking and as the participants listened to the speech they were required to repeat it back (shadowing), shadowing is initially hard but with practice gets easier. Participants can echo the attended channel but they pick up no characteristics of the unattended channel. Whether its gibberish or Czech. However people aren't oblivious to the unattended channel in selective listening experiments they easily report whether the unattended channel was human speech (male female, high low, loud or soft), musical instruments, or silence.
Figure 5.12 SELECTIVE ATTENTION ACTIVATES THE VISUAL CORTEX
The brain sites that control attention are separate from the brain sites that do the actual analysis of the input
Preattentive stage
The first stage of Treisman's feature integration theory, in which an object is analyzed into its features (color, shape, movement, etc); fast and automatic (occurs without intention or awareness)
Selective attention
The focusing of attention on one specific location, object, or message
Stimulus salience
The physical properties of the stimulus, such as color, contrast, or movement
Automization
The process by which tasks go from controlled to automatic (ex: driving)
Gray and Wedderburn (1960)
They did an experiment where "Dear Aunt Jane" was heard as a sentence even though the components were coming from different ears
correctly detecting the features present in a visual display but taking mistakes about how the features are bound together ex) shown a blue T and a red H and reporting a red H and a blue T
conjunction errors that occur when we overload someone;s attention which emphasize the role of attention in neural synchrony
Attention & Perception
figure 5.5! These results suggest that attention doesn't just change what we remember or what we're aware of. Attention can literally change what we perceive.
the determination of what is the figure and what is the ground (what is being depicted and what is the background)
figure/ground organization
Very center of the retina where there are mostly ocnes
fovea
the blocking of your view of one object by some other object (monocular distance cue)
interposition
(the orienting system)
is needed to disengage attention from one target, shift attention to a new target, and then engage attention on the new target, Frontal eye field , superior parietal lobe, temporoparietal junction, pulvinar, superior colliculus
(the alerting system)
is responsible for achieving and maintaining an alert state in the brain Frontal area, Posterior area, Thalamus
where optical information is first sent in the thalamus where it is then transmitted to the primary projection area in the occipital lobe
lateral geniculate nucleus
a pattern in which cells when stimulated inhibit the activity of neighboring cells
lateral inhibition
pattern in which parallel lines seem to converge as the get farther from the viewer
linear perspective
depth cues that depend only on what each eye sees by itself
monocular distance cues
the pattern of how projected images of nearby objects move more than those of distant ones
motion parallax
How do the muscles around the retina adjust for focusing an image?
muscles tightens to focus on nearby objects muscles loosen to focus on far away objects
if neurons detecting a certain part of a stimulus are firing in synchrony with other neurons signaling another part of th stimulus, then the attributes are registered as belonging to the same object
neural synchrony
The size and shape of the area in the visual world to which a cell responds
receptive field
What are the gestalt principles of organization
similarity proximity good continuation closure simplicity
What did Hermann von Helmholtz stated about how visual system uses distance information for size constancy
simple inverse relationship between distance and retinal size. If object doubles in distance from the viewer, size of its image is reduced by 1/2 If object triples, size of the image is reduced to 1/3 initial size Allows brain to achieve size constancy by means of a simple calculation
procedure through which investigators can record moment by moment the pattern of electrical changes within a single neuron
single cell recording
correctly perceiving the sizes of objects in the world despite the changes in retinal-image size created by changes in viewing distance
size constancy
part of the brain registering the cups shape is separate from the part of the brain that is registering color or motion BUT all parts keep track of where the target is Allows for reassembling of pieces done with reference to position
spatial position
What are the advantages of parallel processing in the visual system?
speed (don't need to wait for one analysis to be complete before performing another) possibility of mutual influence among multiple systems (sometimes motion is important in discerning 3d structure and vice versa you are able to know both things at once)
Another proof that attention plays a role in neural synchrony
studies shown that synchronized neural firing is observed in an animal's brain when the animal is attending to a specific stimulus, but is not objected in neurons activated by an unattended stimulus
Object based
superimposed TV images people can focus on just one show and ignore the other. Selection cannot be space based (because both stim are in the same place) and so must be object based
What is a related pictorial cue to linear perspective
texture gradients
the task of reuniting the various elements of a scene, elements that are initially addressed by different systems in different parts of the brain
the binding problem
Early vs Late Selection
there are two ways that we might think about these results: These studies may reveal genuine limits on perception, so that participants literally don't see these stimuli; or these studies may reveal limits on memory, so that people do see the stimuli but immediately forget what they've just seen.
What do people with attention deficits due to PARIETAL CORTEX damage display
they are particularly impaired in judging features combining into objects
brain is calculating different in retinal size vs. distance and factoring it in to establish size constancy also applied to other constancies as well
unconscious interference
Patients with lesions in the what system show
visual agnosia inability to recognize visually presented objects but NO problem in recognizing orientation or in reaching
Occipital lobe to the cortex of the temporal lobe important role in the identification of visual objects
what system
Occipital lobe to the parietal cortex important in guiding your actions based on your perception of where an object is located
where system
Balint's syndrome
A condition caused by brain damage in which a person has difficulty focusing attention on individual objects
Automatic processing
A type of processing that occurs without intention and at a cost of only some of a person's cognitive resources
fixation target
A visual mark (such as a dot or a plus sign) at which one points one's eyes (or "fixates"). Fixation targets are used to help research participants control their eye position.
response selector
A (hypothesized) mental resource needed for the selection and initiation of a wide range of responses, including overt responses (e.g., moving in a particular way) and covert responses (e.g., initiating a memory search).
Stroop interference
A classic demonstration of automaticity in which research participants are asked to name the color of ink used to print a word, and the word itself is a different color name. For example, participants might see the word "yellow" printed in blue ink and be required to say "blue." Considerable interference is observed in this task, with participants apparently being unable to ignore the word's content even though it is irrelevant to their task.
Eye tracker
A device for measuring where people look (fixate) in a scene and how they move their eyes from one fixation point to another
limited-capacity system
A group of processes in which resources are limited so that extra resources supplied to one process must be balanced by a withdrawal of resources somewhere else, with the result that the total resources expended do not exceed some limit.
filter
A hypothetical mechanism that would block potential distractors from further processing. Evidence confirms this notion but also suggests that filtering is really specific and lacks the broad ability to separate all of the desired stimuli from undesired. The filter might only block already identified undesirable stimuli it is not as helpful when you need to develop a new skill aimed at blocking the new stimuli. That's because you not only block the processing of distractors, but you are also able to promote the processing of desired stimuli.
change blindness
A pattern in which perceivers either do not see or take a long time to see large-scale changes in a visual stimulus. This pattern reveals how little people perceive, even from stimuli in plain view, if they are not specifically attending to the target information.
inattentional blindness
A pattern in which perceivers seem literally not to see stimuli right in front of their eyes; this pattern is caused by the participants' attending to some other stimulus and not expecting the target to appear
goal neglect
A pattern of behavior in which a person fails to keep his or her goal in mind, so that, for example, the person relies on habitual responses even if those responses will not move him or her toward the goal. (ie. copy the flag → no plan or artistic details)
perseveration error
A pattern of responding in which a person produces the same response over and over, even though the person knows that the task requires a change in response. This pattern is often observed in patients with brain damage in the frontal lobe. (sorting cards by color and then shape)
unilateral neglect syndrome
A pattern of symptoms in which affected individuals ignore all inputs coming from one side of space. Individuals with this syndrome put only one of their arms into their jackets, eat food from only half of their plates, read only half of words (e.g., they might read "blouse" as "use"), and so on. This syndrome typically results from damage in the right parietal lobe and so they neglect the left side When exposed to a clock they remember that the numbers 1 to 12 are needed but cluster them to the clocks right side
Precueing
A procedure in which participants are given a cue that indicates where a stimulus is likely to appear; used to study covert attention, location-based attention, and object-based attention
late selection
A proposal that selective attention operates at a late stage of processing, so that the unattended inputs receive considerable analysis. All inputs receive relatively complete analysis, and the selection occurs after the analysis is finished. (According to the --- selection all inputs receive relatively complete analysis and this selection occurs after the analysis is finished perhaps the selection occurs just before the stimulus reaches consciousness or briefly after it reaches consciousness but then selection occurs so only the attended input is remembered)
early selection
A proposal that selective attention operates at an early stage of processing, so that the unattended inputs receive little analysis. (According to the -- selection hypothesis that attended input is privileged from the start so that the unattended input it receives little or maybe even 0 analysis and is never received)
Illusory conjunctions
A situation in which features from different objects are inappropriately combined (ex: thinking you saw a blue circle instead of a yellow circle)
automaticity
A state achieved by some tasks and some forms of processing, in which the task can be performed with little or no attention. Automatized actions can, in many cases, be combined with other activities without interference. Automatized actions are also often difficult to control, leading many psychologists to refer to them as "mental reflexes."
unattended channel
A stimulus (or group of stimuli) that a person is not trying to perceive. Ordinarily, little information is understood or remembered from the unattended channel
Flanker compatibility task
A task in which participants are told to carry out a task that requires them to focus their attention on specific stimuli and to ignore other stimuli
Dichotic listening
A task in which people wearing headphones hear different messages presented to each ear
shadowing
A task in which research participants are required to repeat back a verbal input, word for word, as they hear it.
dichotic listening
A task in which research participants hear two simultaneous verbal messages—one presented via headphones to the left ear and a second one presented to the right ear. In typical experiments, participants are asked to pay attention to one of these inputs (the attended channel) and are urged to ignore the other.
Signal detection theory
A theory predicting how and when we detect the presence of a faint stimulus (signal) amid background stimulation
Alerting
A type of attentional processing; achieving a high sensitivity to incoming stimuli, like that achieved by air traffic controllers who must be continually vigilant
Orienting
A type of attentional processing; focusing attention where visual targets may appear; occurs in overt and covert attention
Executive control
A type of attentional processing; occurs for tasks that involve conflict, such as the Stroop task or flanker compatibility task; occurs in the frontal lobe
Controlled processing
A type of processing that is deliberate, reflective, and conscious
Feature integration theory
An approach to object perception that proposes a sequence of stages in which features are first analyzed and then combined to result in perception of an object; object -> preattentive stage -> focused attention stage -> perception
Spotlight
Attention is sometimes viewed as a ______ because attended information is enhanced but unattended information is not blocked
Endogenous attention
Attention that occurs when a person consciously decides to scan the environment to find a specific stimulus or monitor what is happening
Exogenous attention
Automatic attraction of attention by a sudden visual or auditory stimulus
Dictionary unit
Contains stored words, each of which has a threshold for being activated; words that are common, such as your name, have low thresholds
Bottom-up (because it depends solely on the pattern of light and dark, color and contrast in a stimulus)
Capturing attention by stimulus salience is a (bottom-up/top-down) process
What is single cell recording useful for
Change external stimuli and see what a cell fires more for and what it fires less for to see what it is most receptive to allows us to define a cell's receptive field
Serial processing
Cognitive process involving considering each input one at a time
Divided attention
Concentrating on more than one activity at the same time
Spacial neglect
Condition produced by damage to the right hemisphere resulting in an inability to recognize things in the left visual field
Inattentional Blindness continued
Did participants fail to see the input? Or did they see it but then, just a few milliseconds later, forget what they'd seen? For purposes of theory, this distinction is crucial, but for the moment let's emphasize what the two proposals have in common: By either account, our normal ability to see what's around us, and to make use of what we see, is dramatically diminished in the absence of attention.
What is the role of redundancy in the visual system?
Different distance cues become more important in different circumstances Ex) binocular disparity is powerful but only when objects are relatively close motion parallax is only useful if you're moving
Treisman & Gelade (1980)
Experiment that supports attention as a spotlight
Split-span
Experiment where 6 digits are presented in 3 pairs; participants were more accurate when recalling ear-by-ear (496,852) instead of pair-by-pair (48,95,62)
Change blindness
Failing to notice changes in the environment (ex: people rarely notice continuity errors in films on their first viewing)
Inattentional blindenesessi
Failing to see visible objects when our attention is directed elsewhere
When we tend to perceive an intact triangle, reflecting our bias toward perceiving closed figures rather than incomplete ones
Gestalt principle of closure
When we tend to see a continuous object rather than two smaller rectangles when it seems like an object is infant of it
Gestalt principle of good continuation
When we tend to perceive groups, linking dots that are close together
Gestalt principle of proximity
When we tend to group dots into columns rather than rows because were grouping dots of similar colors
Gestalt principle of similarity
When we tend to interpret a form in the simplest way possible: two intersecting rectangles instead of a single 12 sided irregular polygon
Gestalt principle of simplicity
Broadbent
He believed out attention is limited by the amount of information we can focus on at a particular time; said there is a 'bottleneck' in our processing that filters out everything except the information we are attention to
Location-based attention
How attention is directed to a specific location or place
Object-based attention
How attention is directed to a specific object
Focusing your attention involves a trade-off
If you focus your attention broadly, you can take in many inputs at once, and this is faster (because you don't have to search through the items one by one). But, since you're taking in multiple inputs simultaneously, you may not know which feature belongs with which (Panel A). In contrast, if you focus your attention narrowly, you'll be slower in your search (because now you do have to search item by item), but with information coming from just one input, you'll know how the features are combined (Panel B).
Do not
In a high-load task, incompatible flankers (do/do not) result in a slower response
Do
In a low-load task, incompatible flankers (do/do not) result in a slower response
ADHD
In many cases people with ADD also have ADHD hyperactivity and impulsivity - they hop from one activity to another. They reach out and play with anything in sight → reminds us just how important the ability to control our focus and resist distraction is
attended channel
In selective attention experiments, research participants are exposed to simultaneous inputs and are instructed to ignore all of these except one. The attended channel is the input to which participants are instructed to pay attention.
Cells in the optic nerve that provide the input for the LGNs magnocellular cells
M cells
Cells in the LGN specialized for the detection of motion and the perception of depth
Magnocellular cells
Varied mapping condition
Mapping condition where both targets and distractors from same category targets could become subsequent distractors
Consistent mapping condition
Mapping condition where targets changed trial to trial, but target remained numbers and distractors remained letters
Early selection model
Model of attention that explains selective attention by early filtering out of the unattended message; messages -> sensory memory -> filter -> detector -> memory
Late selection models
Models of attention which proposed that most of the incoming information is processed to the level of meaning before the message to be processed is selected
An example of a reversible figure where people can routinely perceive it in one way or the other
Necker cube
Cells in the optic never that provide the main input for the LGNs parvocellular cells
P cells
Two types of cells in the optic nerve
P cells M cells
Selective Visual Attention Experiment
Participants watched a TV screen with two teams of basketball players white and black passing a ball. They were asked to follow white teams ball and signal each time it was passed. People were so intently watching the white team they failed to see a person in a gorilla suit!
Cells that appear to be specialized for spatial analysis and details analysis of form
Parvocellular cells
Path that light travels after it hits the front surface of the eyeball
Passes through cornea and the lens and then hits the retina
Some Unattended Inputs are Detected
People hear their own name and words with some personal importance when its said in the unattended stream → The Cocktail Party Effect
ADD attention deficit disorder
People who suffer from. These individuals are often overwhelmed by the flood of information available to them, and they're unable to focus on just their chosen target. They can be pulled off track by their own thoughts sights and sounds
Fixations
Places where the eye pauses to take in information about specific parts of the scene
Posner Spatial Attention
Posner study shows us that expectations change the way we process stim.They added a spacial dimension by telling participants. The next letter will be a T or it will be on the left. So they could be better prepared for stim. Task is press button as soon as you see the letter. For some trails an arrow was warning sign left right other neutral sign (+). Again accurate or misleading arrows. Familiar pattern as other posner study. High validity priming has high benefits and high costs. Misled → RTs were slower than neutral condition → evidence of limited capacity system
Dual-task
Stayer & Johnson did an experiment on this; the target task is performed alone and in the presence of a secondary task; if the target task requires little or no attention, performance should not deteriorate when the secondary task is added
Path of excitement from rods and cones
Stimulate bipolar cells which excite ganglion cells that converge to optic nerve that carries information to various sites of the brain
Attention as a Spotlight
Studies of spatial attention suggest visual attention can be compared to a spotlight bean that you can shine anywhere in visual field. Beam is movements of attention, not movement of your eyes- Beam can be wide or narrow - can be moved. Eye movement helps we look at something if we wanna learn about it but the eye movements are slow so when looking at point we can still observe the benefits of attention prior to any eye movements. Evidence suggests that the control of attention actually depends on a network of brain sites in the frontal cortex and parietal cortex. Thus there is no spotlight beam-- instead neural mechanism are in place that enable you to adjust your sensitivity to certain inputs -- a large part of "paying attention" involves priming
The Generality of Resources
Task similarity matters for divided attention we would expect that as tasks are farther and farther apart that they wouldn't interfere that ain't the case (Driving while on the phone)
Identify General Resources
Tasks as different as driving and talking on the phone compete for some mental resource describe resources that serve (roughly) as an energy supply, drawn on by all tasks. Other authors describe resources as "mental tools" rather than energy . One of these tools is the mechanism that is required for selection and initiating responses including physical responses and mental ones
Cognitive resources
The idea that a person has a certain cognitive capacity, or resources, that can be used for carrying out various tasks
Attention
The means by which we actively process a limited amount of information from the enormous amount of information available from our senses
spatial attention
The mechanism through which a person allocates processing resources to particular positions in space, so that he or she more efficiently processes any inputs from that region in space.
executive control
The mental resources and processes that are used to set goals, choose task priorities, and avoid conflict among competing habits or responses. is v important as day to day is guided by habit and prior associations-- we rely on things that we have done in the past to guide us
Anxiety, arousal, task difficulty, skills
What are four factors that influence attention?
Selective Priming
The proposal, then, is that you can literally prepare yourself for perceiving by priming the relevant detectors. In other words, you somehow "reach into" the network and deliberately activate just those detectors that, you believe, will soon be needed. Then, once primed in this fashion, those detectors will be on "high alert" and ready to fire. Let's also suppose that this priming isn't "free." Instead, you need to spend some effort or allocate some resources in order to do the priming. Why dont participants notice the shape change in the inattentional blindness studies? The answer lies in the fact they don't expect the stim to appear so they have no reason to prepare for the stim → as a result stim when presented falls onto unprepared (unprimed unresponsive) detectors → participants don't perceive the stimulus. How do you explain the "leaks" your name in another conversation at the party. Well your name on the unattended channel is a stimuli that's already primed - this isn't because your are expecting to hear your name, its because you have encountered often in the past. Thus this fires without your attention
Focused attention stage
The second stage of Treisman's feature integration theory; features are combined into perception of an object; slow and requires effort
Attentional bias
The tendency of our perception to be affected by our recurring thoughts
Stroop effect
The tendency to read the words instead of saying the color of ink; this effect occurs because the names of the words cause a competing response
Early selection theories
Theories like Broadbent's and Treisman's; propose a filter that operates at an early stage in the flow of information, in many cases eliminating information based only on physical characteristics of the stimulus
Johnsrude et al (2013)
This experiment illustrates the cocktail party phenomenon
Neisser (1964)
This experiment is an example of a conjunction search, and showed that when performing a conjunction search, it takes longer for people to find a target item in an array if it is placed later in that array
Allport Study for Specificity of Resources
Three conditions participants listened to a list of words through headphones (hear words+ hear words) similar tasks; (hear words+ see words) middle; (hear words+ see pictures) less similar - most interference in the first and least in the third. Shadow one list of words and Memory was tested for the second list later on.
Single feature search
What's faster?
Space Based or Object Based Attention
You pay attention to whatever is in a region of space and alternative is that you pay attention to objects. Both capture part of the truth. One line of evidence comes from people with unilateral neglect. If an object falls in the spatially defined region it matters not the objects boundaries BOTHER → HER respond only to right half. Further development happened with barbel study when they had two fields right and left. Patients were much more sensitive to targets on the left but as patients watched they flipped the barbell so what was on the right was now on the left. But they still saw what was in the first circle. These patents had a powerful bias to attend the right side and once locked in it is the object and not the position in space that defines their focus of attention. In conclusion they have spatially defined bias as they neglect half of space but once attention is directed towards a target it's the target itself that defines the focus of attention they follow the target
Cones enable you to discern fine detail, an ability that is referred to as.
acuity
an example of a monocular distance cue
adjustment that the eye must make to see the world clearly (amount of adjustment depends on how far away the object is)
inability to perceive motion even though other parts of vision remain normal
akinetopsia
your two eyes look out on the world from slightly different positions, resulting in each eye having a slightly different view. This difference between the two eyes
binocular disparity
correctly perceive the brightness of objects whether they're illuminated by dim light or strong dun
brightness constancy
how is binocular disparity helpful?
can induce the perception of depth even when no other distance cues are present
Posner and Snyder study
computer screen and participant had to decide same letter or different letters AA v AB. Before each pair, people saw a warning sign. in the neutral condition it was a plus sign +. tells you that the test is about to happen. in a different condition the warning sign was a letter that actually match the stimuli to come. G → GG In this case the warning signal serve to Prime the participants with stimuli. the third condition the warning signal was misleading. the warning sign was a letter it was a letter of a different stimuli H → GG. Neutral Primed, misled. By comparing the primed a neutral conditions we can ask what the benefit is from a prime. by comparing the misled and neutral conditions we can ask if there's a cost of being misled. they also added another variable: one which the warning sign was an excellent predictor of the stimuli which they called a high validity Prime. in different versions the warning signal was a poor predictor of the upcoming→ low validity condition. They found in the low validity condition misled trials occurred four times as often as Prime trials. therefore participants had no reason to trust their primes and correspondingly no reason to generate an expectation based on Primes. in the high validity condition things were reversed now primed trials occurred 4 X as often as misled trials. high validity Prime's will therefore produce a warm up effect and also an expectation affect. high validity primes help participants more than low validity primes
What photoreceptors have higher acuity
cones
less sensitive, so they need MORE incoming light. Are able to distinguish between colors. There are three types that respond to different wavelengths, so differential firing helps us see color
cones
where when the center square is surrounded by dark squares, the contrast makes the central square look brighter (due to lateral inhibition)
contrast effect
(the executive system)
controls voluntary actions. prefrontal area, anterior cingulate gyrus
Descrbe the case of L.M, who had akinetopsia
could detect that an object now is in a position different from its position a moment ago but reported seeing nothing in between. Could see change in position but not how it got there caused problems with crossing the street, following conversation, anxious in social settings with people moving around the room
patients with lesions in the where system show
difficulty in reaching NO problem in object identification
features of the stimulus that indicate an object's perception
distance cues
Cells fire at their maximum rate when light is presented in a small roughly circular area
dot detectors center surround cells
cells that fire at their maximum only when a stimulus containing an edge of just the right orientation appear within their receptive fields can fire more for horizontal edges vs vertical edges depending on their preference
edge detectors
how lateral inhibition highlights a surfaces edge since the edge is not being laterally inhibited as much important in highlighting an object's shape which is important in figuring out what the object actually is
edge enhancement
Pros and Cons of Practice
once a task is well practiced you can lose the option of controlling your own mental operations - practice enables many mental prcesses to go untouched by contol. If resources are not needed for a task then they can go on elsewhere.
Stimuli Based Priming
one type of --- merely by presenting the primary stimulus with no role of expectations. --- appears to be free and so we can prime 1 detector without taking anything away from the other.
plays a large role in coordination of movements pattern of how as you approach an object its image gets larger and as you move away from it it gets smaller resulting in a pattern of change in retinal stimulation
optic flow
how can spatial position be used to solve the binding problem
overlay the map of which forms are where on top of the map of which colors are where to get there right colors with the right forms also can be don with which motion patterns are where map
Characteristic of the visual system where many different steps are going on simultaneously
parallel processing
Change-Blindness Demonstration
participants are shown one picture then a second then the must spot the difference between the two pictures for most people it takes a surprisingly long amount of time and effort to locate the difference i.e. Color Changing Card Trick video!
Experiment showing inattentional blindness
participants were told they would see a + and shapes on a computer screen for 200 ms followed by a pattern mask. If the horizontal line in the + was longer than the vertical then they had to press a button → participants weren't allowed to look directly at the plus instead they looked at a fixation target. In one trial the fixation target shape was changed. Immediately after they were asked was anything different about this trial. 89% said no!
we perceive the constant properties of objects in the worlds even though the sensor information we receive about these attributes change when our viewing circumstances change
perceptual constancy
Areas where rods predominate
periphery
specialized neural cells that respond directly to the incoming lights
photoreceptors
monocular cues used by artists to create an impression of depth on a flat surface
pictorial cues
Space based
posner focus on region in preparation for stim. In this situation the stim isn't there yet there is no object to focus on → attention is spatially defined. Supported by neuroscience various studies have shown pattern in brain activation when participants are attending to position in space (top of head) and when they are paying attention to a particular object
The light sensitive tissue that lines the back of the eyeball
retina
photoreceptors sensitive to very low levels of light and play an essential role whenever you're moving around in semidarkness or viewing a dim stimulus do not detect color but can detect different intensities of light
rods
two kinds of photoreceptors
rods and cones
When steps are carried out one at a time
serial processing
correctly perceive the shape of objects despite changes in the retinal image created by shifts in your viewing angel
shape constancy
divided attention
the effort to divide your focus between multiple tasks or inputs simultaneously. Sometimes it's easy you can knit while you have a conv or listening. IT's harder to listen to a lecture and do homework. Perceiving requires resources that are in short supply. You can perform concurrent tasks only if you have the resources needed for both .If two tasks combined require more resources then you have divided attention will fail
Expectation Based Priming
the other type is --- based and is only when participants believe the prime allows a prediction of what to come --- does have a cost: with high validity primes responses in the misled condition were slower than responses in the neutral condition. misleading participants actually hurt performance. priming one wrong detector take something away from the other detectives and so participants are worse off when they were misled then when there is no prime. --- shows the same pattern if the Q detector is primed this takes away from the other detectors
