Cognition - Attention and Perception

Question 1

What is the definition of perception? (Sekuler and Blake 2002)

Answer 1

The acquisition and processing of sensory information in order to see, hear, taste or feel objects in the world; also guides an organisms actions with respect to objects

Question 2

What is the structure of the eye?

Answer 2

SEE FUNDAMENTS OF NEUROSCIENCE

Photoreceptors/bipolar cells/retinal ganglion neurons/blindspot

Question 3

What is the structure of the primary visual cortex and other cerebral visual processing areas?

Answer 3

SEE FUNDAMENTS OF NEUROSCIENCE

Retinogeniculostriate pathway/retinotopic projections/parvo+magnocellular pathways

Dorsal/ventral streams - action vs perception

Question 4

What is the Muller-Lyer illusion and what does it suggest about vision?

Answer 4

Two lines same length with different arrow heads on the ends - making them appear shorter/longer

There is a difference between vision-for-perception and vision-for-action

For action = accurate interpretation of distance etc is necessary for daily functioning (ie dorsal stream)
For perception = highlighted by the ML illusion; though when pointing at the ML illusion (ie introducing an action component to the processing), the effect is diminished

Question 5

What are the qualities to a colour?

Answer 5

Hue = the colour itself 
Brightness = intensity of light 
Saturation = pale/vivid

Question 6

Why do you get negative afterimages if staring at a colour inverted and hypersaturated image?

Answer 6

Complementary colours = opponent processes - red/green, yellow/blue, black/white

You experience decreasing sensitivity to the dominant stimulus colour

Question 7

What is colour constancy?

Answer 7

Colour perception is relatively independent of light conditions/brightness

Question 8

What determines colour constancy?

Answer 8

Contrast - local = surfaces that share edges with the target; global = across the visual scene - both serve as cues to colour and in their absence, colour constancy drops

Experience - we expect certain objects to have certain colours, OVER ADJUSTING IN EXPERIMENTS ??

Chromatic adaptation - we adapt to light conditions and so sensitivity decreases over time

Question 9

How do monocular cues contribute to depth perception?

Answer 9

Perspective - linear ie illusions of depth in 2D (vanishing points); aerial ie blurring in the distance

Size - familiar ie knowledge based (I know how big a standard pint is); relative ie the same objects vary in size depending on how far away you are as an observer (“okay one last time - the ones in here are small, the ones out there are far away”)

Interposition - occlusion ie closer object is on top (can even be seen in imaginary 3D space in a 2D image)

Shadows - dimmer objects seem to be father away

Movement cues - motion parallax ie objects in the foreground go away from the direction of travel and objects in the background go with the direction of travel

Question 10

How do binocular cues contribute to depth perception?

Answer 10

Stereopsis - small differences in image from each eye (binocular disparity) are combined into a single image

Question 11

How do oculomotor cues contribute to depth perception?

Answer 11

(con/di) Vergence - eyes move towards each other when viewing close objects - get muscle feedback

Accommodation - changes in focal length ie thicker/thinner lens

Question 12

What is the aim of combining perceptual cues?

Answer 12

Minimising ambiguity + maximising similarity = clearer perceptions of the way things are

Question 13

What is the function of attention?

Answer 13

Mediation - between internal and external environments

Selectivity - deciding on what information should be processed and what should be discarded - because we do not possess the capacity to process everything fully, nor do we need to

Question 14

What are selective/divided attention?

Answer 14

Focused/selective - concentration on a single stimulus and ignoring others and distractions

Divided - attending to more than one stimulus/type of stimulus ie multitasking

Question 15

What is active/passive attention?

Answer 15

Active - self directed, top down

Passive -
environment directed ie unexpected noise, bottom up

Question 16

What is internal/external attention?

Answer 16

Internal - directed towards internally generated info

External - directed towards the environment

Question 17

What is orienting of attention?

Answer 17

Moving the focus - covert = without moving eyes/head; overt = with moving eyes/head

Question 18

What is the Posner cuing task?

Answer 18

Aim to detect the target - reaction times are measured

Participants presented with two boxes then a valid or invalid cue which indicates which box the stimulus is to appear in (or if invalid, the other box)

Cues can be endogenous = at the centre of the screen, above a fixation point, relying on info from the central visual field; or exogenous = relies on info outside the central visual field ie highlighting the box

Stimulus onset asynchrony - time between cue and appearance of stimulus; has an effect on attention, and also interacts with endo/exo cue type

Question 19

What has the Posner cuing task found?

Answer 19

Attentional shift (covert) to target area occurs prior to eye movement (overt)

Spatial attention is not completely reliant on conscious visual input

Process behind orienting = disengagement of current focus, movement to selected target and engagement of selected target

Parietal lobe damage, parkinsons, ADHD and age impact performance

Question 20

What types of information search are testable with visual search paradigms?

Answer 20

Feature search - looking for a specific feature ie finding the red T in a group of blue Ts

Conjunction search - looking for a set of features ie finding a black L in a group of black Ts

Question 21

What is an attentional blink?

Answer 21

Inability to respond to a second target when presented very soon after the first
(Heim, Benasich and Keil, 2013)

NEEDS CLARIFICATION

Question 22

What is object based attention?

Answer 22

Measure using two overlaid, semi transparent images of a man and a house - said that you cannot see both at a time and that you selectively attend to one image then the other

Different neural activities despite same spatial location

Question 23

What are the limits to attention?

Answer 23

Capacity - how many things can be attended to at a time

Bottleneck - for what (types, numbers) can be processed

Problem of early selection or late correction:
Early - limits at the start of attending, due to perceptual abilities; late - limits at the end of attending ie all info processed up to level of meaning then filtered if necessary

Question 24

What is Broadbent’s filter theory?

Answer 24

Information progresses from sensory register through a selective filter where irrelevant info stops being processed and only the relevant content passes into STM

Question 25

What is Treisman’s attenuation theory?

Answer 25

Information progresses from sensory register through an attenuator which (???) upregulates or downregulates the saliency of the stimuli before transfer to STM so the STM receives some information more preferentially (???)

Question 26

What is Deutsch and Deutsch’s theory?

Answer 26

All information passes through the sensory register to STM but the output of STM is what becomes salient during processing in STM ???

Question 27

What is inattentional blindness?

Answer 27

Failure to register changes in objects that are not your immediate focus of attention

Example - gorilla and basket ball study

Depends on whether the object will attract attention ie is it similar to the focal stimuli (colour, shape, category)

Question 28

What is change blindness?

Answer 28

Difficult to spot changes in your environment as they are occuring

Example - confederate asks for directions, gets swapped out for someone carrying a door

More complex than inattentional blindness

Difficult to actively find changing features even when actively trying

Easier to detect when object type changes as opposed to object incidence

Requirements: paying attention to the change location, encoding the old stimulus, encoding the new stimulus, comparing them both, consciously recognising there is a change - depends on working memory capacity

Question 29

What are the features of divided attention?

Answer 29

Potentially analogous to dual tasks in WM

Multiple resources or central resources?

Serial processing w/switching attention or parallel processing both tasks at the same time?