Sensation Attention And Perception

Question 1

Cognitive neuroscience

Answer 1

The field of study focussing on neural substrates of mental processing

Question 2

Sensation

Answer 2

Is the process of transforming physical stimuli to electrical signals

Question 3

Perception

Answer 3

Process of interpreting these signals for conscious awareness

Question 4

Sensation

Answer 4

Difined as initial stimulation of our sensory system
Each sensory input sends electrical signals to our brain
Each sense has it own area in the brain

Question 5

Vision

Answer 5

Light enters the eye through the cornea
Passes through the pupil and lens focuses it on the retina
Retina converts light into signals for the brain using rods and cones
Cones detect colour rods black and white
Bipolar cellls detect changes in rods and cones triggering action potentials in retina, gangalion cells

Question 6

Primary visual pathways

Answer 6

Information goes from the ye via optic nerve across optic chasm to the dorsal part of the lateral ge icukate nucleus along optic radiation’s to the primary visual cortex in occipital lobe
Information then travels along two large cortical pathways a ventral stream and a dorsal stream

Question 7

Auditions

Cells respond to auditory information and travel along 2 streams

Answer 7

Corti converts movement of inner hair cells into electrical brain activity to send to brain

Question 8

Ventral

Answer 8

What

Question 9

Dorsal

Answer 9

Where

Question 10

Deficits in visual and auditory perception

Answer 10

Key term- double dissociation
Demonstration of independence between 2 cognitive processes
Suggests functions are localised in different part of brain
Eg lesions in brain structure A impairs function x but not y whilst lesion to brain structure b impairs function y spares function x
Allows interference about brain function and function localisation

Question 11

Damage to ventral stream

Answer 11

Unable to recognise shape size and orientation of objects but very accurate reaching grasping

Question 12

Damage dorsal stream

Answer 12

Difficulty in positioning of hand when reaching for an object but object recognition
Deficits in locating sound but intact sound differentiation

Question 13

Ventral and dorsal stream case study

Answer 13

Goodall and Milner
Bilateral damage to her lateral occipital cortex
Profound defecit in visual object perception
Df retains ability to use information about for, of objects to control grasping
Ventral stream impaired
Dorsal stream unaffected

Question 14

Perception

Answer 14

How we perceive the world not neserilt how it actually is

Question 15

Top down processing

Answer 15

Higher level cognitive processing determine of perception eg prior knowledge experiences

Question 16

Bottom up processing

Answer 16

Lower level information about stimulus eg shapes and shading determine perception

Question 17

Bottom up approaches

Answer 17

Gibson - theory of direct perception
No influence of cognitive processes
Perception directly determined by moving through environment
Light entering retina sends signals to brain - visual perception
Perception of movement movement of objects around us compared to static aspects of visual scene eg driv8ng down a road behaviour in response to things we perceive based on avoidances we need not know as chair is for sitting on as shape affords the action of sitting

Question 18

Top down approaches

Answer 18

Constructivist accounts
A by product of sensations and thoughts about the world need to interpret information from senses
Influences by individual differences and past exoeinces

Question 19

Sensation vs perception

Answer 19

Sensation - bottom up process by whic our senses receive and relay external stimuli
Perception is the top down mechanism that our brains use to organise and interpret data which we put into context
In bottom up processing sensation and perception are the same we perceive items via sensation
In top down processing processing perception and sensation are separate first we use context and expectations to create holistic perception off the world and then we start to focus on smaller details usin sensation

Question 20

What is prosopagnosia

Answer 20

Face blindness is a neurological disorder whey cannot recognise familiar faces
Can observe facial characteristics such eye couloir and facial features

Question 21

Perception - Gasault psychology

Answer 21

The whole is more than just sum of its parts

Question 22

Attention

Answer 22

Selective attentions we focus on what most significant
Directs filters and controls how we process Mim formation
Can be implicit or explicit

Question 23

Visual attention

Answer 23

1) voluntary endogenous goal directed top-down
Involved in selection of sensory information and responses
Influenced by expectation knowledge and current goals
2) involuntary exogenous stimulus driven ( bottom -up)
Involved in detection of salient or conspicuous unattended visual stimuli
Unexpected and potentially salient stimulus redirects attention from current focus

Question 24

Auditory attention

Answer 24

Cocktail party effect focussing attention on a particular stimulus whilst filtering out all other information in envronmemt

Question 25

Failures of attention

Answer 25

Change blindness and intentional blindness failure. To perceive significant events in visual field by focussing attention elswhere

Question 26

Visual neglect

Answer 26

A sense of awareness on one side of visual space from a stroke
Most usually occurs in left visual field after damage to right parietal part of brain
Fail to shave left side of face
Vision is intact just attentional deficits