week 1

Question 1

why study perception

Answer 1

• understand how to best move about and interact with our environment
• evolution, higher chance of survival

Question 2

analog representation of the world from a digital signal

Answer 2

• assumption from the brain to perceive missing information
• experience/ expectation instead of perception

Question 3

importance of knowing how stimuli are encoded and perceived

Answer 3

• help create technology designed to restore those with sensory loss
• brain computer interfaces, brain signals = stimuli = perception
• computer vision, self driving vehicles

Question 4

bottom up information

Answer 4

• shape
• color
• motion

Question 5

top down information

Answer 5

• theory
• knowledge
• context

Question 6

cognitive penetration

Answer 6

• cognitive factors shaping perception ie everything seeming brighter and hard tasks being easier when you are in a good mood, placebo
• debated whether perception is different or the description is affected

Question 7

vestibular sense

Answer 7

• where we are orientated in the world

Question 8

proprioception

Answer 8

• where our limbs are positioned

Question 9

sensation and perception

Answer 9

• physical stimulus
• stimuli reach the sensory organ, bind to receptors
• sensory cells translate stimulus into a code to be interpreted by the brain (transduction, involving action potential)
• interact with experience, different perceptions from the same stimuli

Question 10

method of limits

Answer 10

• stimuli presented sequentially either increasing or decreasing

Question 11

method of constant stimuli

Answer 11

• stimuli of varying levels presented randomly, above and below threshold

Question 12

method of adjustment

Answer 12

• participants adjust stimuli to find their own threshold value

Question 13

absolute threshold

Answer 13

• how much pressure or how bright or loud a stimulus must be to perceive it

Question 14

difference threshold

Answer 14

• how much a stimuli needs to be changed to notice a difference

Question 15

point of subjective equivilance

Answer 15

• point at which two stimuli are judged to be perceptually identical

Question 16

what theory to use to account for possible bias during self report method

Answer 16

signal detection theory
- our ability to be accurate
- greater sensitivity, greater chance of being accurate

hit
correct rejection
false alarm
miss

more correct responses, curved upward to the left

Question 17

electrical stimulation

Answer 17

Question 18

neuroimaging EEG
electroencephalogram

Answer 18

• up to 128 electrodes placed on the scalp
• measuring electrical potential generated by the brain
• continuous signal
• hard to tell where in the brain the activity is coming from, can’t move

Question 19

neuroimaging MEG
magnetoencephalogram

Answer 19

• measures magnetic field distortions caused by the electrical activity in the brain
• less portable and more expensive but better at determining where in the brain

Question 20

neuroimaging MRI/ fMRI
functional magnetic resonance imaging

Answer 20

• very detailed images of brain processes
• expensive, non portable
• scary, claustrophobic
• not suitable for some populations ie pacemakers

Question 21

hubel and wiesel

Answer 21

• using animal models to record electrical outputs of individual neurons
• lowered an electrode so it was adjacent to neurons in the primary visual cortext in a cat
• work helped describe orientation columns in the visual cortex
• neurons are tuned to specific stimulus features

Question 22

neuropsychological studies

Answer 22

• patients with focal damage in a small region of the brain, strange patterns of perceptual behaviour
• documenting their behaviour and damage site, infer the role of the damaged area in perception

Question 23

lesion studies

Answer 23

• in animals creating specific lesion models and testing for perception
• permenant damage to neural tissue or reversible approaches such as cortical cooling
  cortical cooling
• certain brain areas turned off by cooling them off so action potentials can’t be generated, recovered by warming

Question 24

transmagnetic stimulation (TMS)

Answer 24

• group of technologies
• stimulate the brain via electric current
• magnetic field generator (coil) on the head of participants
• coil induces an electrical current in the particular brain region beneath the coil, induces changes in how the region functions which can be perceptual or behavioural
• temporary experimental analyses
• on the optical nerve can result in temporary blindness