Case 3 - Sensation and Perception

Question 1

what is sensation

Answer 1

the detection of simple properties of the stimuli.

• occur via our sensory organs, which sends information about the world to our brains
• stimuli may be distant or proximal events
• 5 sensory modalities

Question 2

what is transduction

Answer 2

a signal Is converted into another type of signal

Question 3

what is sensory transduction

Answer 3

refers to energy from environment is converted into neural activity which is done via receptor cells that stimulate other neurones via chemical transmission

Question 4

what are sensory nerves

Answer 4

bundles of axons that can only transmit action potentials

Question 5

what is sensory coding

Answer 5

the activity of axons in sensory nerves ‘codes’ from sense organs

Question 6

what are the two forms of sensory coding

Answer 6

• anatomical coding
• sensory coding

Question 7

what is anatomical coding

Answer 7

• different nerves represent different modalities
• distinctions between stimuli of the same modality e,g arising from different locations
• conveyed to different areas of the primary somatosensory cortex

Question 8

what is temporal coding

Answer 8

the rate of firing of axons represents ;encodes’ stimulus intensity

Question 9

what is the absolute threshold

Answer 9

the minimum level of a stimulus that can be detected

Question 10

what is the signal detection theory

Answer 10

level at which stimulus will be detected a % of the time

Question 11

what is the difference threshold

Answer 11

minimum detectable difference between two stimuli

Question 12

what is perception

Answer 12

our interpretation of what is represented by sensory input
- recognitions of objects, sounds and people
- occurs unconsciously but can be influenced by higher level cognitive processes such as expectations

Question 13

what is the Gestalt psychology

Answer 13

• foundation for modern study of perception
• Gestalt from German and is form or shape
• founded in early 20th century in Austria and Germany

Question 14

what does the Gestalt principle state

Answer 14

the whole is greater than the sum of the parts

Question 15

figure - ground principle

Answer 15

people instinctively perceive objects being in the foreground or the background

Question 16

the adjacency/proximity principle

Answer 16

elements of the visual scene that are close to each other appear to form groups

Question 17

the similarity principle

Answer 17

similar elements are perceived as belonging together

Question 18

the good continuation

Answer 18

elements that smoothly follow a line tend to belong together

Question 19

the law of closure

Answer 19

missing information is supplied to close of complete a figure

Question 20

the principle of common faith

Answer 20

elements on the same movement trajectory belong together

Question 21

how does the brain recognise objects so quickly?

Answer 21

• templates: stored visual memories of patterns compared with visual input
• prototypes: flexible, idealised stored patterns compared with visual input
• feature distinction models

Question 22

what is perception influenced by

Answer 22

pervious experience, assumptions and expectations, cultural factors, mood and attention

Question 23

what is perceptual set

Answer 23

selectivity bias with respect to what we perceive

Question 24

summary of sensation

Answer 24

• the detection if simple properties of stimuli
• sensory modalities
• sensory transduction
• sensory coding
• absolute and difference threshold

Question 25

summary of perception

Answer 25

• our interpretation of sensory input
• gestalt psychology and principles
• form perception - theories on recognition of the object
• top down influences on perception
• attention and perception