Lecture Quiz 6 Flashcards
1
Q
What are the purposes of visual imagery?
A
- Memory (making the visual properties of objects available when needed)
- Problem-solving (allowing us to try out changes in the positions of objects or our bodies)
- These imply that visual mental images are like pictorial representations of the world
2
Q
Mental images can be three-dimensional
Shepard & Metzler (1971)
A
Subjects were presented with an object and asked whether another object is a rotation of the first
The larger the required mental rotation (the greater the rotation from original image shown), the longer it takes to answer
3
Q
What is Spatial Knowledge?
A
- Knowledge about where things are in the world and how they are spatially related to each other.
Can be “allocentric”, representing objects in relation to each other (like a map) - Static (does not change as you move)
- A comprehensive view of space
Can be “egocentric”, representing objects in relation to the observer (viewpoint dependent) - Dynamic (updated as you move)
- Limited view of space
4
Q
Mental images have a size
A
- In a study subjects were asked to think of a particular animal (e.g., bear) at a size corresponding to one of these squares (tiny, small, medium, large).
- After a few seconds, participants were presented with a possible property of the visualized animal (e.g., floppy ears?) and asked to indicate “True” or “False” as quickly as possible
- Largest square/corresponding animal had the shortest recall time
- The smallest square/corresponding animal had the longest recall time
- The bigger the size and corresponding animal makes it easier to recall if the visual property given was T or F - easier to place a mental image if it is larger
5
Q
Allocentric Spatial Knowledge
A
- representing objects in relation to each other (like a map)
- Static (does not change as you move)
- Comprehensive view of space
6
Q
Egocentric Spatial Knowledge
A
- representing objects in relation to the observer (viewpoint dependent)
- dynamic - viewpoint changes as you move
7
Q
How can we determine which type of spatial knowledge is being used?
A
In a rectangular room, if you need to know the location of corner A relative to where you are standing right now, you could mentally form an:
- Allocentric representation of the shape of the room - representing objects in relation to each other
- Egocentric representation of “left short wall–right long wall” view - representing objects in relation to the observer
8
Q
How can we determine which type of spatial knowledge is being used?
Rat platform study
A
Study Training phase: Rats learned to swim to a hidden platform in a rectangular-shaped tub of water
- Hidden platform sometimes in corner A and sometimes in corner C
Study Test phase: Rats now had to swim to a hidden platform in a kite-shaped tub of water
- Group Consistent: Hidden platform in corner E
- Group Inconsistent: Hidden platform in corner G
- Group Consistent swam to the correct corner on a higher percentage of trials than Group Inconsistent. Why?
- Using allocentric spatial knowledge? - like a map to make sense of space - using info to know how the platform relates to the space
9
Q
Mental representations in Pavlovian conditioning
A
Test data suggest that CS elicits a mental representation of a food US that includes flavor
ex: hear a bell and think of cheese
10
Q
Visual Imagery and Mental Representations Take-Home Messages
A
- Visual imagery experiments suggest that our mental representations can have three-dimensions and size (big and small)
- Spatial knowledge is another kind of mental representation and can be either viewpoint-dependent (ego-centric) or more like a map (allocentric)
- In Pavlovian conditioning, the CS can elicit a mental representation of the US (eg, the flavor of the US)
11
Q
What happened to Phineas Gage?
A
- Metal pole through head causing damage predominantly of the left lower forebrain and its connections throughout the left and into the right frontal cortices
- The orbitofrontal cortex was a main area of damage in Phineas Gage
- behavior changes, no speech or motor impediments, and memory was intact
12
Q
What is included in Executive Function?
A
- Executive function refers to higher-level cognitive skills used to control and coordinate other cognitive abilities and behaviors
1. Working memory - Short-term maintenance and manipulation of information
2. Inhibitory control - Self-control: controlling your attention, behavior, emotions to override a strong internal or external cue
3. Cognitive flexibility - Adjusting to new demands, rules, or priorities
13
Q
Executive Functions–Working Memory
What is the N-back task?
A
- The N-back task requires participants to decide whether each stimulus in a sequence matches the one that appeared n items ago
- Task where one indicates whether each stimulus matches the one N-back (e.g., 2 trials before in the 2-back task). More and more errors as N gets larger
- the further back the trial is when asked if the stimulus matches the current trial the more errors occur
14
Q
What are the subfunctions of working memory?
A
Working memory sub-functions
- Stimulus maintenance - storing, monitoring and matching stimulus
- Stimulus removal
15
Q
Executive Functions – Inhibitory Control
What is the Stroop Task?
A
- Name font color when it is incongruent with (different from) the word, resolving conflict from a more dominant word reading response. Slower to name font colors when incongruent with color words.
- The Stroop phenomenon demonstrates that it is difficult to name the ink color of a color word if there is a mismatch between ink color and word. For example, the word GREEN is printed in red ink is difficult to name.
16
Q
Executive Functions – Cognitive Flexibility - What is the Wisconsin Card Sort Test?
A
- Sort cards into piles under reference cards based on “set”, either color, number, or shape, discovering rules based on feedback. - After a bunch of correct sorts, the rule changes.
- Example of a sorting rule: based on color, not number or shape
- What other cognitive processes might be required for this task?
- Interference control
- Memory of task set
17
Q
The sub-regions of the brain are defined by differences in what?
A
- Cell composition
- Connectivity with other brain regions
although the boundaries can be somewhat fuzzy!
18
Q
Executive Functions–Lateral Prefrontal Cortex
Evidence from lesion/damage studies suggests that sub-regions of the prefrontal cortex might have different functions, what are they?
A
- Dorsolateral prefrontal cortex for N-back task (“working memory”)
- Lateral prefrontal cortex for Stroop task (“inhibitory control”)
- Ventrolateral prefrontal cortex for Wisconsin card sort task (“cognitive flexibility”)
- On the other hand, evidence from at least some neuroimaging studies suggests activation of multiple prefrontal cortex regions across multiple types of executive function tasks
19
Q
Decision-Making & Orbitofrontal Cortex
A
- Patients with orbitofrontal cortex damage struggle with real-life decision-making and appear to be unable to learn from their mistakes
- They can be otherwise fine and perform normally on standard lab tests of working memory, inhibitory control, and cognitive flexibility.
- Orbitofrontal cortex was a main area of damage in Phineas Gage
- The Iowa Gambling Task is a laboratory measure of decision-making, which shows that orbitofrontal damage is associated with an inability to act on the delayed (future) consequences of actions
20
Q
What is the Iowa Gambling Task?
A
- Participant needs to choose one out of four card decks (named A,B,C, and D). The participant can win or loose money with each card
- At first, Deck A and Deck B seem better because of their larger worth ($100 vs $50)
- But with continued play, choosing Deck C and Deck D leads to overall gain (+$250 for every 10 cards); Decks A and B lead to overall loss (-$250 for every 10 cards)
- Players cannot predict when a penalty will occur, precisely calculate the net gain or loss from each deck, or know when the game will end
- Patients with orbitofrontal damage had difficulty learning that Deck C and Deck D lead to more money in the long term
21
Q
Prefrontal Cortex and Executive Function Take-Home Messages
A
- Executive functions are typically divided into working memory, inhibitory control, and cognitive flexibility. Laboratory tasks have been developed to measure each of these (N-back task; Stroop task; Wisconsin card sorting task)
- The prefrontal cortex is a critical brain region for supporting executive functions. Subregions of the lateral prefrontal cortex may support each of the 3 basic executive functions (but this is not so simple).
- The orbitofrontal cortex supports making decisions based on long-term consequences. An important lab task for studying this is the Iowa Gambling Task, which involves deciding between alternatives with different short-term and long-term payoffs.
22
Q
What is Attention?
A
- Attention is a set of limited-capacity cognitive processes devoted to monitoring stimuli
23
Q
What are the 3 types of attention?
A
- Altering - preparing for stimulus
- Ex: as soon as you see 0 on-screen you press a button and on to the next one - Orienting - selecting a stimulus
- Ex: fixation cross followed by an arrow point in direction (pay attention to side of the screen pointing to) - selecting a region in space (the arrow is sometimes misleading) - Executive - focus on stimulus
- focusing on stimulus - left button when A is in center and right button when B is in the center
24
Q
What is an Attentional Blink - a gap in attention?
A
- Brief period of time after the detection of a stimulus during which another stimulus cannot be detected
- Subjects heard a rapid presentation of letters, one at a time, and saw a rapid presentation of other letters, one at a time
study: - Auditory - when number is heard - press a button
- Experimental group - target = auditory number - probe = visual x
- While paying attention to the number (target) you miss the X (probe) - when X is distant participant is able to detect it - attention blink occurs when looking for number (target) and cannot immediately pick up on the X probe
25
What is Inattentional Blindness–another gap in attention?
- We sometimes don’t see highly visible objects we are looking at when our attention is elsewhere
- Staring directly at object of interest but still can not pick up on changes - a gap in attention/disconnect between where we are looking and where our attention is
- Participants were instructed to point their eyes at a dot in the center of a screen and to make judgments about a cross shown just off to the side. Stimuli were presented very briefly and then participants made a judgment.
- If horizontal bar of the + was longer than the vertical, press left button
- If vertical bar of the + was longer than the horizontal, press right button
- On trial 4, the dot was a triangle instead of a circle.
- Afterwards, participants asked if anything had changed.
- Most participants reported no change (and could not correctly identify the new shape as a triangle, rectangle, or cross).
26
What does Visual search describe?
- In a visual search task, participants search for a discrepant target within a varying number of stimuli, ex: a blue T among brown Ts and green Xs
- For highly discriminable stimuli, multiple features (e.g., color and shape) can be processed simultaneously
- Otherwise, features (e.g., color and shape) must be processed separately (e.g., “Is it an X? “Is it brown ?”) and joined together
- Set size - how many letters displayed
- The more distractors the longer it takes to find target
27
What is Feature Integration Theory – attention is for identifying objects?
Preattentive stage vs. Attention stage?
- Attending to stimuli “assembles them”, brings them into attentional focus, and makes sense of them
- Preattentive stage: A visual scene is pre-attentively encoded on feature dimensions, which are detected automatically and in parallel across the visual field
Specifies where things are (e.g., a blue stimulus; a ‘T’ shape)
- Attention stage: Feature information is “glued together” by a limited capacity attentional mechanism
- Only features in the same location and attentional focus encoded as belonging to the same object, specifying what the object is (e.g., a brown ‘X’)
28
Types of Attention Take-Home Messages
- We can think of attention as having 3 types: preparing (“alerting”), selecting (“orienting”), and focusing (“executive”)
- The “attentional blink” and “inattentional blindness” are two examples of how we can easily miss stimuli even when looking right at them
- Visual search tasks can reveal automatic (feature search) vs. controlled (conjunction search) attentional processes
- Feature-Integration Theory describes the attentional processes that combine together different parts of a stimulus (e.g., color, shape) into a whole object (e.g., a blue car)
29
Visual attention to a region of space
What is the Spatial Cueing Task?
- Spatial Cueing Task reveals attention to a region of space
- Keep eyes on the + in the middle of the screen
- Arrow appears, disappears and a target appears on the left or right side of the screen (arrow cues what side + will be on - could be giving correct information but could be misleading)
- Press button as soon as you detect the target
- Valid trials: Arrow points to one side of screen and target then appears on that side (40% of all trials) - took least amount of time to react
- Invalid trials: Arrow points to one side of screen but target then appears on the other side (10% of all trials)
- Neutral trials with a “double-headed” arrow (50% of all trials)
30
How can Visual attention be to objects?
- Subjects were required to compare successive faces or houses and to say whether they were the same or different while undergoing functional neuroimaging
- Faces and houses were presented in the same spatial location, and one was moving slightly
Switching attention from faces to houses - object attention due to being in the same space?
- Switching to attending to houses - another brain area is used
- Different brain areas are used for diff
31
What is Neglect Syndrome?
- Patients fail to pay attention to space/objects opposite their brain lesion
- Failure to perceive or respond to a stimulus contralateral to the lesion when presented simultaneously with a stimulus ipsilateral to the lesion.
- Typically associated with damage to the right side of the brain, producing neglect of objects in the left side of space by standard neurological tests.
Ex:
- Patients only draw right side of clock
- Patients only name object on the right side of a room
- Cancellation test - only focusing on the right side
- Typically neglecting the left side
32
What is Space - or object-based attention deficit?
- Patients with neglect syndrome were asked to respond as quickly as possible to a target that appeared within either a left (blue) circle or a right (red) circle
- Patients neglect slower to detect targets in the left (blue) circle.
- Now, while patients watched, the barbell-shaped frame was slowly spun so that the red circle was now on the left and the blue circle was on the right
- Patients with neglect are now slower to detect targets in the right (blue) circle.
33
Selection theory – what happens to unattended stimuli?
- Early selection theory proposes that attention acts as a filter between sensory memory and short-term memory so that there is no semantic processing of unattended stimuli
- Only simple ‘physical’ properties (e.g. pitch of a voice) processed prior to hitting the filter
- Late selection theory proposes that all incoming stimuli automatically receive at least some semantic processing
- Unattended information undergoes more than just physical processing (e.g., you recognize your name in a crowded room)
34
Early vs. Late Selection Theory Study
- Study phase: All subjects heard and verbally repeated a series of word pairs; out of those word pairs:
- Two target words ( dog, cow) of the same category (animals), paired with mild shock
- Two target words (arm, leg) of another category (body parts)
- Test phase: Shadowing task (attend to one ear and repeat words), with a series of different words presented to each ear, while measuring “palm sweat” (a fear CR)
- Group 1: Target words presented in the attended ear
- Group 2: Target words presented in the unattended ear
35
Early vs. Late Selection Theory
- More recent studies suggest that:
- In high attention-demanding situations, you tend to process only the physical characteristics of unattended information.
- In lower attention-demanding situations, you tend to process not just the physical characteristics but also the meaning of unattended information.
36
Selective Attention Take-Home Messages
- “Selective attention” is choosing to attend to something rather than something else.
- Visual selective attention can be directed to a region of space, or to objects.
- Neglect Syndrome is a neurological disorder that seems to cause patients to not be able to attend to one half of space.
- Early Selection Theory and Late Selection Theory are two different accounts of the extent to which unattended stimuli are processed.
37
What is Multitasking–dividing attention between two tasks?
- Questionnaire of multi-tasking activity (e.g., cell phone use while driving) and perceived ability to multitask
- Performed a divided attention task to measure actual ability to multitask
- Series of letters intermixed with math problems, each with equation and possible solution
- Answer TRUE or FALSE for math problem and then recall letters
- Performance on the divided attention task was negatively related to measures of multi-tasking activity and perceived multi-tasking ability
38
Cell phone conversation impairs driving study
Why?
- Group 1 drove in a driving simulator (single task) and while talking with a passenger (dual task)
- Group 2 drove in a driving simulator (single task) and while talking on a hands-free cell phone (dual task)
39
Why is cell phone conversation more impairing than passenger conversation?
- Detailed video analysis of conversations
- Passenger conservations, but not cell-phone conversations:
- Passengers actively engaged in supporting drivers (e.g., pointing out hazards, helping to navigate, reminding the driver to exit at rest stops).
- Conversation stopped during a difficult section of driving
- Passenger made references to traffic conditions
40
Why does a conversation impair driving?
- Participants performed the driving task with or without also talking on a hands-free cell phone; eye fixation (i.e., where they were looking) monitored
- Later, participants were asked to identify objects that they had been looking at while driving
- Significantly lower percentages of objects were recognized when subjects were driving and talking. Inattentional blindness?
41
What is Bottleneck Theory–task switching?
- The bottleneck theory suggests that individuals have a limited amount of attentional resources that they can use at one time.
- Bottleneck at the level of “meaningful processing”
- For example, waiting to process what a road sign says while you process what a person said
- Bottleneck at the level of “response decision”
- For example, wait on a decision where to turn while deciding on a response to what a person said
42
Divided Attention Take-Home Messages
- Multitasking may involve task-switching
- We do not seem very aware of how good or bad we are at multitasking
- Poorer driving while talking on a cell phone may be due to “inattentional blindness”. Talking with a passenger may lessen this
- “Bottleneck Theory” explains divided attention as switching between two tasks
