5 - Attention Flashcards Preview

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Flashcards in 5 - Attention Deck (16):
1

What is attention

the mechanism for selecting which information to process, since the brain has a limited capacity

2

control of attention (2)

Endogenous
- attention controlled by your interests and chosen intentions

Exogenous
- automatic control of attention by the characteristics of the stimulus

3

Exogenous cuing test

- stare at the cross in the middle of the screen
- a 'cue' comes up (small image) briefly on one side
- followed by the test stimulus (a letter) on either the sam or opposite side

- reaction times and correctness will be better if cued on the same side as the test

4

Endogenous cuing test

- stare at the cross in the middle of the screen
- the endogenous cue is an arrow pointing to one side
- correct endogenous cues improve results
- must be about 70% truth in the cue otherwise participants will begin to ignore it

5

Vigilance (Pardo, Fox & Raichle, 1991)

Sustained attention task
- measured blood flow in the brain using PET

- participants either in a tactile or visual condition
Tactile:
- detect pauses in light touches on the big toe (right or left)
Visual:
- detect brightness changes to a central fixation point

Results:
- left big toe
> right parietal regions activated
- right big toe
> right and left parietal regions activated
- visual
> right parietal regions activated

Shows that there is some attention mechanism in the right side cortex

6

What does attention select for?

- features
- locations
- whole objects

7

Spatial selection

similar areas of the brain control spatial processing and attention

8

Vision

- transduction in the eyes
- travels through the optic nerve
- passes through the optic chiasm
- then to the LGN (lateral geniculate nucleus)
- then most goes to the Primary Visual Cortex
- from the Primary Visual Cortex, either:
> Ventral Stream (secondary visual cortex)
+ 'what it is', facial processing
> Dorsal stream (secondary visual cortex) [mainly parietal cortex]
+ 'where it is'

9

Bottom-up approach

Sensory information is received, computed and given meaning

10

Top-down approach

Application of preexisting knowledge to 'fill in the gaps' of sensory information
- requires context

11

Object-based selection

when paying attention to one feature of an object, you pay attention to the whole object

12

Inattentional blindness

even if you can see an object, if you are not paying attention to it, you are effectively blind to it

13

Change blindness

Inattentional blindness caused by flickering image (between images), which distracts from the change between the two images

14

Congruency effect

in image tasks where asked to focus on a central image and note whether it changes, there are also background images that may change
- if both change or both remain the same, this is Congruent
- if the focus changes and the background does not (or vice versa) this is Incongruent

The Congruency effect:
- if the background information is being taken into account, the reaction time will be quicker in the congruent conditions
(this has been found to be true)

Turns out the higher cognitive load of the attention task, the less background information is realised

15

Visuo-Spatial Neglect

condition resulting from Right Parietal damage
- causing decreased ability to pay attention and be aware of things

16

Object-Based Neglect

due to Right Parietal Damage
- unable to pay attention to the left side of objects (contralesional)