What are the 2 crucial aspects of attention in James' definition?

- selection

- capacity limitation

Attention vs. Arousal:  Define 'attention'.

- Attention is a selective mechanism that allocates limited resources to important stimuli while removing them from unimportant stimuli

Attention vs. Arousal:  define 'arousal'.

Attention vs. Arousal:  define 'arousal'.

- Arousal is a global state (eg, alert vs. asleep) which is not selective.

What is the difference between Covert and Overt attention?

- Covert = visual field location where eyes are looking is different from where one is paying attention

- Overt = attention is where the eyes are looking

What is the difference between selective vs. divided attention?

- Selective = attending to one of many streams of input

- Divided = attending to multiple streams of input

What is the characteristic situation in a "Feature search" ?

- Target is found easily among distracters because it is defined by a single distinct feature

What is the characteristic situation in a "Conjunction search" ?

What is the characteristic situation in a "Conjunction search" ?

- Target is harder to find because it is defined by a combination of features that require attention to be bound.

In the feature vs. conjunction search tasks, what is meant by "Attention is capacity-limited" ?

- It means that the time it takes to find the conjunction target increases with the # of items in the display

(aka the 'set size').

Describe how the graph of RT (y-axis) vs. set size (x-axis) looks when graphing the feature search on the same graph as the conjunction search.

As set size increases, RT for feature search doesn't change (flat line) while RT for conjunction search increases linearly.

For Reflexive vs. Voluntary Attention, what example is given of reflexive attention and what example is given of voluntary?

- reflexive:  attn. drawn to yellow flower (out of field of all red flowers)

- voluntary:  focus on unopened flower

In reflexing orienting of attention, what happens to attention?

- it is captured by a salient stimulus

What typical finding regarding reflexive attention is found initially?

- a target in the cued location is detected faster than a target at another location

With regard to reflexive attention, what is

"inhibition of return" or "IOR" ?

With regard to reflexive attention, what is

"inhibition of return" or "IOR" ?

- after 300 ms, a target in the cued location is detected slower than a target at another location

Why is IOR (inhibition of return) useful?

- Because it prevents attention from 'getting stuck', for example, at the location of a flashing stimulus

What is often used to study the voluntary orienting of attention?

- Cueing paradigms

For voluntary orienting of attention, what is the typical benefit and typical cost?

- benefit = Faster to detect an object in the attended location

- cost = Slower to detect an object in the unattended location

In the Posner spatial cueing paradigm, rank the 3 types of trials from shortest reaction time to longest:

invalid, valid, neutral

In the Posner spatial cueing paradigm, rank the 3 types of trials from shortest reaction time to longest:

invalid, valid, neutral

- Valid  <  Neutral  <  Invalid

[Short RT]   <                  <     [Long RT]

In Posner's spatial cueing paradigm, what 'equations' are given for the benefits / costs of attending to the correct / incorrect location?

Benefits =   Valid - Neutral

Costs  =    Invalid - Neutral

What is early selection (in regard to attention) ?

- Select inputs prior to a full analysis

Explain late selection (with regard to attention).

 - both attended and ignored information gains equal access but at a meaningful (semantic) level.

In the dichotic listening task (studying voluntary orienting of auditory attn.), what is the goal of the task?    What was the ERP result?

- attend to 1 ear and ignore the other (wearing headphones)

- ERP:  the N1 component (at 90 ms) is larger for stimuli in the attended ear than for stimuli in the unattended ear.

On the dichotic listening task (studying voluntary orienting of auditory attn.), what was the MEG+fMRI result?  What conclusion was drawn based on this (as well as the ERP/N1 result) ?

-  Localized earlier attention effect (M20-M50) to primary auditory cortex

- conclusion: attention affects sensory processing before auditory analysis is complete

The spatial attention task studies voluntary orienting of visual attention. With which concept are its results consistent with?

- early selection

The spatial attention task studies voluntary orienting of visual attention.  Briefly summarize the method used in the experiment. What was the main result discovered?

-  Recording in right visual cortex while covertly attending either left or right VF

- Larger P1 effect 70-100 ms after stimulus onset for attended vs. unattended stimuli

(consistent with early selection)

Reflexive Visual Attention

 ___ delay,     ___  RT,    P1 ___

 ___ delay,     ___  RT,    P1 ___

which is (or is like) IOR?

Reflexive Visual Attention

 Short delay,     fast RT,        P1 larger

 Long  delay,     slower RT,    P1 inhibited (IOR)

which is (or is like) IOR?

      - long delay is the IOR one of the two

Explain how reflexive visual attention is just like inhibition of return.

- facilitated initially (ie, cued is more positive) and then inhibited (ie, cued is less positive)

Explain the effect of the irrelevant probe in the visual search task.

- irrelevant probe (probe that is not the target) displayed before the stimulus.

- if probe is presented at targets eventual location, then get larger P1

(than if target is shown somewhere other than where the probe was)

What do ERP studies show about early selection?

that it can occur in some situations

Activity in what 2 areas is modulated by spatial attention?  According to what type of study?

- contralateral LGN

&

- contralateral visual cortex

- ( based on fMRI )

What 3 'sensory attributes' are given as examples where increased activation is seen in brain regions that process that attribute?

1)  color

2)  form

3)  motion

Increased activation is seen in brain regions that process attended sensory attributes.  Which brain region goes with each?

Color :

Form :

Motion :

Increased activation is seen in brain regions that process attended sensory attributes.  Which brain region goes with each?

Color :     V4

Form :     Ventral visual processing stream

Motion :     V5 / MT

With regard to attention to features, how do ERPs depend on feature-based vs. spatial modulation?

- feature-based attentional modulation occurs

later ( > 120 ms) than spatial attentional

modulation (70 - 90 ms)