Mechanisms Of Perception, Conscious Awareness & Attention

Question 1

V1 Physiology

Answer 1

Hugely and Wiesel Noble
Prize winners
Three types neurons:
Simple cells,complex cells and hyper complex cells
V1 transforms info
Orientation selective and direction selective

Question 2

Hierarchical organisation

Answer 2

Specificity and complexity increases with each level
Sensation detecting stimulus
Perception higher order process integrating,recognising,interpreting stimulus
Damage:primary visual cortex

Question 3

Damage:primary visual cortex

Answer 3

Damage to an area of PVC
Area of total blindness
Tested - fixed head , red dots flash on and off around different areas of visual field maps the scotoma
Similar to completion of blind spot Brian fills in gaps

Question 4

Functional Segregation

Answer 4

Each of the 3 levels of cortex contains functionally distinct areas
Mangnocelluar pathway colour insensitive in LGN , orientation selectivity in V1 , processing visual motion MT
Parvocelluar pathway , parvocelluar LGN layers show colour opponeny, V1 processing visual object shape

Question 5

Sensory areas of the cortex

Answer 5

Secondary - input from primary
Association - input from more than one sensory system usually from secondary
Macaque monkeys - 30 different PV areas , 24 secondary areas 7 association areas all processing visual information

Question 6

Double Dissociation

Answer 6

Damage to central stream - no conscious perception , but can interact with objects

Dorsal stream damage - can consciously see objects but can not interact

Question 7

Association

Answer 7

Responsible for complex sensory processing
Interaction between and output
Known as cognition

Question 8

Prosopagnosia

Answer 8

Unable to recognise particular faces
Unable to recognise other specifics
Inability to recognise specific objects belonging to a complex class of objects

Question 9

Capgras delusion

Answer 9

Result of damage to ventral what / conscious perception stream
Unconscious recognition can be hypothesised
Evidence of parallel processing

Question 10

Double dissociation: Capgras delusion

Answer 10

-sufferer believes that close family members are impostors

Although facial recognition is intact , parallel unconscious system for emotional recognition of face damaged

Question 11

Brain pathology

Answer 11

Fusiform face area - activity increase during face recognition
Other classes of Visual stimuli
Also found in monkeys
-early deprivation of visual input to right hemisphere impaired development of expert face processing