Sensation and Perception

Question 1

Define sensation

Answer 1

registering stimulation of the senses

Question 2

Define perception

Answer 2

processing and interpreting sensory information

Question 3

Define cognition

Answer 3

using perceived information to learn, classify and comprehend

Question 4

Bottom-up processing

Answer 4

perception starts with physical characteristics of stimulus and basic sensory processes (feature detectors)

Question 5

Top-down processing

Answer 5

perceiver actively constructs perception based on cognition, knowledge and learning

Question 6

Gibson Theory of Direct Perception

Answer 6

information in sensory receptors and sensory context is enough for perception, cues in environment cue perception, complex thought is not required

Question 7

Gregory TD Processing

Answer 7

perception is not determined simply by stimulus patterns; rather it is a dynamic searching for the best interpretation of the available data

Question 8

Single cell recording

Answer 8

micro electrode stimulates an individual cell and records its action potential

Question 9

Quian Quiroga Experiment

Answer 9

showed individual neutrons can be responsible for recognising individual people in multiple sensory modalities

Question 10

Event related potentials

Answer 10

electrodes on the scale measure neural activity in response to a stimulus

Question 11

Functional MRI

Answer 11

looks at blood flow in the brain in response to a stimulus

Question 12

Lesions

Answer 12

cutting parts of the brain out with a knife or destroying nerve cells with a neurotoxin to look at brain changes in response to damage

Question 13

Transcranial Magnetic Stimulation

Answer 13

looks at the same idea as lesions but doesn’t cause permanent damage, magnetic stimulation disrupts biological motion

Question 14

Psychophysics

Answer 14

quantifies the relationships between physical stimuli and sensation/perception
Threshold; change from one perceptual experience to another
Absolute threshold; smallest stimulus intensity needed for detection
Differential threshold; smallest difference between two stimuli that can be detected

Question 15

Artificial Intelligence

Answer 15

computer models are used to simulate the output of human sensation to investigate the mechanisms taking place

Question 16

What do the cornea and the lens do?

Answer 16

Focus light on the retina

Question 17

Describe the process of accommodation

Answer 17

The ciliary muscles change the shape of the lens to bring objects at different distances into focus

Question 18

Where has the highest concentration of photoreceptors?

Answer 18

The fovea

Question 19

What do photoreceptors consist of?

Answer 19

Rods and cones

Question 20

Describe 3 things about rods and what they do

Answer 20

1. rods contain rhodopsin2. they respond to dim light3. the are not found in the fovea

Question 21

Describe 2 things about cones and what they do

Answer 21

1. there are three types which will respond to one of; short, medium or long wavelengths2. respond in bright light

Question 22

Name the 2 types of retinal ganglion cells

Answer 22

1. midget (parvocellular)2. parasol (magnocellular)

Question 23

What do midget (parvocellular) cells do?

Answer 23

They are retinal ganglion cells which are connected to cones, responsible for the finer details and colour in vision

Question 24

What do parasol (magnocellular) cells do?

Answer 24

They are retinal ganglion cells that are connected to rods, they are responsible for integrating information across lots of rods as well as recognising movements and flickers

Question 25

Describe retinotopy and where it occurs

Answer 25

This occurs in the calcurin sulcus; the visual field is mapped onto the cortex. Central vision is mapped at the occipital pole and the periphery towards the middle

Question 26

Describe how the cortex processes line orientation

Answer 26

Particular cells in the visual cortex are affected by certain orientations of lines, for every point in the visual field there is a cell for every possible orientation of line

Question 27

Is there a critical period involved in line orientation recognition? If so, describe it

Answer 27

An experiment using kittens found a critical period of 5 months. After this time kittens could only recognise the orientation of line they had been exposed to since birth - neural plasticity

Question 28

What is the McCollough effect?

Answer 28

after looking at a particular colour for a long period of time those neurons become fatigued so when it is replaced with white, you will see the opposite colour of what was there

Question 29

What is cerebral achromatopsia?

Answer 29

damage to small cortical region, loss of conscious colour perception, this can affect one visual field

Question 30

What is Protanopia?

Answer 30

lack the cone for red light

Question 31

What is Deuteranopia?

Answer 31

lack of the cone green light

Question 32

What is Tritanopia?

Answer 32

lack of the cone for blue light