LU4: Sensation & Perception

Question 1

Define Psychophysics

Answer 1

Studies how a physical stimulus within the environment is converted into perceptions and psychological experiences. Paved way in including the significance of depth, amplitude & perceptual illusions.
Eg) Gustav Fechner & Wilhelm Wundt.

Question 2

Define stimulus

Answer 2

Sensory input. Eg) our sensory organs: mouth, ears & eyes. Organize and interpret sensory input so we can attach meaning develop a response to input through 2 separate but interacting stages of perception &sensation. We often view this as one process.

Question 3

Define sensation

Answer 3

The psychological process of taking in raw, physical energy from stimuli (light) through the sensory receptors of our different sensory organs.

Question 4

Define transduction

Answer 4

Sub- process that occurs during sensation.
It’s the conversion of raw, physical energy into sensory neurological signals.

Question 5

Define perception

Answer 5

The psychological process of selecting, organizing & interpreting the sensory neurological signals that reach the brain so we can make sense of and attach meaning to sensations.

Question 6

Define agnosia

Answer 6

Auditory: Inability to recognise an object by listening.
Visual: Inability to recognise various sights.
Form: Inability to recognise an object by the whole picture.
Tactile: Inability to perceive forms through touch.
Olfactory: Inability to recognise an object by listening.
Gustatory: inability to recognize an object through smell.

Question 7

Define threshold

Answer 7

A point at which a stimulus triggers a response.

Question 8

Define stimulus intensity

Answer 8

How intense a stimulus has to be in order to be detected.

Question 9

Define absolute threshold

Answer 9

The weakest detectable stimulus. The level at which the stimulus’ intensity is detected for a specified period of time (usually 50%).

Question 10

Define the Just Noticeable Difference (JND)

Answer 10

Aims to identify the lowest intensity of stimulation needed to create a noticeable difference between stimuli or difference threshold. More apparent at greater levels of intensity.

Question 11

Define the signal detection theory

Answer 11

This proposes that the detection of stimuli involves a decision making process as well as sensory processes, both of which are influenced by a variety of factors besides stimulus intensity.
Eg) personal experience, bias etc.

Question 12

Define subliminal perception (below threshold)

Answer 12

The registration of sensory input without conscious awareness. Subconscious perceptions can influence a persons initiative, experiences & resistance.

Question 13

Define sensory adaptation

Answer 13

A gradual decline sensitivity to prolonged stimulation. Things we become used to throughout the day. Eg) your clothes.
Allows people to identify changes in their environment more easily.
Eg) smelling smoke.

Question 14

What is influenced by visual systems?

Answer 14

Influenced by the contexts we operate in, & meanings attached to what we see.

Question 15

What is the stimulus of visual systems?

Answer 15

Light

Question 16

Light travels in waves with 2 important properties, what are they?

Answer 16

1. Wavelength
2. Amplitude

Question 17

What is wavelength?

Answer 17

The difference between successive peaks of waves perceived as colour.

Question 18

Define amplitude:

Answer 18

The height, perceived as brightness.

Question 19

What is saturation?

Answer 19

Used to identify the perception of colour. The purer the light wave the more saturated the colour. The same color can be perceived as different shades. (As whiteness declines, saturation increases).

Question 20

The eye has 2 main functions, what are they?

Answer 20

1. Transport stimuli to necessary receptors (sensations).
2. Forms part of process of creating images of visual world (perceptions).