Sensation and Perception

Question 1

bottom up processing

Answer 1

environment or sensory information processing

Question 2

top down processing

Answer 2

information from own knowledge processing

Question 3

serial processing

Answer 3

processes one thing at a time

Question 4

parallel processing

Answer 4

processes many different things at the same time

Question 5

sensation

Answer 5

registering stimulation of the senses

Question 6

perception

Answer 6

processing and interpreting sensory information

Question 7

cognition

Answer 7

using perceived information to learn, classify and comprehend

Question 8

bottom up perception

Answer 8

perception starts with the physical characteristics of stimuli and basic sensory processes

Gibson - ‘direct perception’

Question 9

top down perception

Answer 9

we perceive concepts of our understanding of external stimuli based on past experience and knowledge

Gregory

Question 10

Gibson direct perception

Answer 10

info coming from sensory receptors is enough for perception to be rich and detailed

complex mechanisms not necessary

environment contains sufficient cues to provide context to aid perception
e.g. texture - depth

Question 11

Perception starts with one of the following ‘changes’

Answer 11

• electromagnetic energy (light/vision)
• chemical composition (taste)
• chemical composition (smell)
• air pressure waves (sound)
• tissue distortion (touch)
• gravity and acceleration

Question 12

perception of changes is detected by different types of receptors

Answer 12

vision - photoreceptors
taste - chemoreceptors
smell - chemoreceptors
sound - mechanoreceptors
touch - mechanoreceptors and thermoreceptors
gravity and acceleration - mechanoreceptors

Question 13

the info detected by receptors then passed on via different pathways

Answer 13

vision - photoreceptors - primary visual cortex
taste - chemoreceptors - gustatory cortex
smell - chemoreceptors - olfactory cortex
sound - mechanoreceptors - auditory cortex
touch - mechanoreceptors and thermoreceptors - somatosensory cortex
gravity and acceleration - mechanoreceptors - temporal cortex

Question 14

sensation to brain pathway

Answer 14

environmental stimulus >
receptors >
intermediate neurons >
thalamus*: neuron mass in middle of brain >
receiving area in cortex >
secondary (associative) cortex >
higher cortex

Question 15

Transduction

Answer 15

conversion of environmental energy into nerve signals

Question 16

Feedback

Answer 16

• feedback projections from different parts of the brain towards the more sensory parts of the brain
• help modulate our experience
• keep some of our experiences more stable

Question 17

Gregory

Answer 17

perception is not simply determined by stimulus patterns

it is a dynamic searching for the best interpretation of the available data

Question 18

Ways to investigate perception and sensation

Answer 18

• staining
• single-cell recordings (electrophysiology)
• fMRI
• Lesion studies
• ERP from EEG
• optical imaging/near infra-red spectroscopy (NIRS)
• psychophysics
• illusions and introspection
• computational modelling
• single-cell recording

Question 19

single-cell recording

Answer 19

• action potentials of neurons are recorded with microelectrodes inserted close to cell
• requires section of skull to be removed
• useful for identifying cells which are selective for certain features

Question 20

virtual lesions - TMS

Answer 20

• pulses of magnetic energy disrupt activity in a small part of the brain for a short period

Question 21

psychophysics

Answer 21

quantifying the relationship between physical stimuli and the psychological response

absolute/detection threshold vs difference threshold

Question 22

absolute/detection threshold

Answer 22

smallest stimulus needed for detection

e.g., min concentration of flavour you can taste

Question 23

difference threshold

Answer 23

smallest difference between two stimuli that can be detected - the ‘just-noticeable difference (JND)’

e.g. the min diff between 2 colours that you can see

Question 24

global form task

Answer 24

which quadrant has a shape in it

Question 25

biological motion task

Answer 25

videos of dots moving - does it or does it not look like a person walking

autistic children find this harder