M2 Lecture 13: Feb 26

Question 1

what is Stimulus onset asynchrony (SOA):

Answer 1

The time between the onset of one stimulus and the onset of another

Question 2

do endogenous cues take more time than exogenous cues to attract attention

Answer 2

yes

Question 3

Amongst endogenous cues, what works best

Answer 3

gaze and arrows work best (bottom – up?).

Question 4

what is the Spotlight” model of attention:

Answer 4

Attention is restricted in space and moves from one point to the next. Areas within the spotlight receive extra processing.

Question 5

what is Visual search:

Answer 5

Looking for a target in a display containing distracting elements.
e.g., Finding the remote control!

Question 6

what are the elements in Visual search

Answer 6

Target:
Distractor:
Set size:

Question 7

what is target

Answer 7

The goal of a visual search

Question 8

what is Distractor

Answer 8

In visual search, any stimulus other than the target.

Question 9

what is Set size

Answer 9

The number of items in a visual search display.

Question 10

what are the types of Visual search

Answer 10

Feature search
Conjunction search
Parallel
Serial self-terminating search
Guided search:

Question 11

what is Feature search:

Answer 11

Search for a target defined by a single attribute, such as a salient color or orientation.

Question 12

what is Conjunction search:

Answer 12

Search for a target defined by the presence of two or more attributes.

Question 13

The efficiency of visual search is what

Answer 13

the average increase in RT for each item added to the display.

Measured in terms of search slope, or ms/item. The larger the search slope (more ms/item), the less efficient the search.

Question 14

what is Parallel:

Answer 14

In visual attention, referring to the processing of multiple stimuli at the same time.

Question 15

what is Serial self-terminating search:

Answer 15

A search from item to item, ending when a target is found.

Question 16

In real-world searches, what guide visual search

Answer 16

basic features

Question 17

what is Guided search:

Answer 17

Attention is restricted to a subset of possible items based on information about the item’s basic features (e.g., color or shape).

Ex.: where are the tomatoes?

Question 18

what is Scene-based guidance:

Answer 18

Information in our understanding of scenes that helps us find specific objects in scenes.

Ex.: where is the faucet? (you know to look near the sink)

Question 19

what is Feature integration theory

Answer 19

Treisman’s theory of visual attention, which holds that a limited set of basic features can be processed in parallel preattentively, but that other properties, including the correct binding of features to objects, require attention.

Question 20

what is Preattentive stage:

Answer 20

The processing of a stimulus that occurs before selective attention is deployed to that stimulus

Question 21

what is Rapid serial visual presentation (RSVP):

Answer 21

An experimental procedure in which stimuli appear in a stream at one location (typically the point of fixation) at a rapid rate (typically about eight per second).

Question 22

RSVP is used to study what

Answer 22

the temporal dynamics of visual attention

Question 23

what is Attentional blink:

Answer 23

The difficulty in perceiving and responding to the second of two target stimuli amid a RSVP stream of distracting stimuli.

Question 24

The second target is often missed if it appears when

Answer 24

within 200 to 500 ms of the first target

Question 25

what is Nonselective pathway:

Answer 25

Contributes information about the distribution of features across a scene as well as information about the “gist” of the scene. This pathway does not pass through the bottleneck of attention.

Question 26

what is Selective pathway:

Answer 26

Permits the recognition of one or a very few objects at a time. This pathway passes through the bottleneck of selective attention.

Question 27

The nonselective pathway computes what

Answer 27

ensemble statistics.

Question 28

what are Ensemble statistics:

Answer 28

The average and distribution of properties, such as orientation or color, over a set of objects or a region in a scene.

Question 29

The nonselective pathway computes what

Answer 29

scene gist and layout very quickly

Question 30

what is Spatial layout:

Answer 30

The description of the structure of a scene (e.g., enclosed, open, rough, smooth) without reference to the identity of specific objects in the scene

Question 31

is Memory for objects and scenes good

Answer 31

amazingly good and bad

can tell what something is/whereit is but if you remove one small/large aspect it often occurs inching blindness

Question 32

what is Change blindness:

Answer 32

The failure to notice a change between two scenes.

Question 33

when can changes pass unnoticed

Answer 33

If the change does not alter the gist, or meaning, of the scene, quite large changes can pass unnoticed

Demonstrates that we don’t encode and remember as much of the world as we might think we do

Question 34

what are some Disorders of attention

Answer 34

Visual-field defect: Neglect:

Extinction

Question 35

what is Visual-field defect:

Answer 35

A portion of the visual field with no vision or with abnormal vision, typically resulting from damage to the visual nervous system (occipital lobe).

Question 36

what is Neglect:

Answer 36

Damage to the parietal lobe can cause a visual field defect such that one side of the world is not attended to.
-> Typically, neglect of the left visual field after damage to the right parietal lobe
Evidence from neglect patients indicates that they sometimes neglect one side of an object rather than one side of the visual field.

Question 37

what is Extinction:

Answer 37

In visual attention, the inability to perceive a stimulus to one side of the point of fixation (e.g., to the right) in the presence of another stimulus, typically in a comparable position in the other visual field (e.g., on the left side).

Question 38

Monkeys are trained to attend to either the red or blue bar while keeping their eyes on the fixation point.

Experimenter is recording from a neuron in V4 that preferentially responds to the red bar (the response properties of the neuron were established before the experiment).

The responses of that neuron are higher when what

Answer 38

the monkey is paying attention to the red bar vs. the blue bar

Question 39

Attention facilitates what

Answer 39

the neural processing of attended stimuli

Question 40

Participants are asked to pay attention to streams of letters displayed in the left or right visual field, while maintaining their eyes on a central fixation point.

When the letter «L» or «R» appears, participants have to re-direct their attention to the left or to the right.

Activity where is enhanced

Answer 40

in the controlateral visual cortex is enhanced by attention.

Question 41

The posterior parietal cortex (PCC) controls shifts inwhat

Answer 41

spatial attention

Question 42

explain the experiment done with monkeys that explains The posterior parietal cortex (PCC) controls shifts in spatial attention

Answer 42

1. Monkeys have their eyes on a central fixation point.
2. An object appears in the neuron’s receptive field.
3. Depending on the condition, mokeys either have to ignore the object, or pay attention to it (saccade, hand reach, no overt movement).
4. The PCC neurons fires when attention is redirected towards the neuron receptive field.