Human Behaviour - Sensation And Preception

Front 1

What is Sensation?

Back 1

The process by which the body gathers information about the environment and transmits it to the brain for initial processing.

Front 2

What is Perception?

Back 2

The process by which the brain selects, organises and interprets the sensations.

Front 3

It is useful to distinguish between initial processing (sensation) and interpretative processing (perception), but really the line between them is what?

Back 3

Artificial

Front 4

Both work together to produce what?

Back 4

Both work together to produce an integrated translation of physical reality into a psychological reality.

Front 5

What are the three principles that underlie both sensation and perception?

Back 5

1) There is no one-to-one correspondence between physical and psychological reality.

2) Sensation and perception are active (and not passive) processes.

3) Sensation and perception are adaptive (they facilitate survival and reproduction).

Front 6

There is no one-to-one correspondence between physical and psychological reality.

Back 6

Although there is a relationship between physical stimulation and psychological experience, what happens “out there” (in the physical world) is not exactly what is reproduced “in here” (in the psychological world).

Front 7

Sensation and perception are active (and not passive) processes.

Back 7

▪The psychological experience of physical stimulation does not just occur automatically.

▪Sensation is the process of translating physical energy into neural impulses.

▪Perception is the process of translating neural impulses into psychologically meaningful. interpretations

Front 8

Sensation and perception are adaptive (they facilitate survival and reproduction).

Back 8

▪The evolutionary perspective argues that human behaviour has evolved in ways that help promote the survival of the species.

▪We have developed particular senses (e.g. the ability to see, hear, touch etc.) because these senses help us survive.

▪We have developed the ability to perceive (or interpret) the facial expressions of other people as this helps us survive (e.g. recognising fear in another person).

Front 9

Although we have different (or specialised) sensory systems (e.g. sight, smell), What do they all have in common?

(5)

Back 9

1) Transduction

2) Absolute Threshold

3) Signal detection

4) Difference Threshold

5) Sensory adaption

Front 10

What is Transduction?

Back 10

They translate physical energy (stimulus information) into sensory signals (neural impulses).

Front 11

What are the types of Transduction?

(3)

Back 11

1) Sensation begins with stimulation from the environment in the form of physical energy.

2) Sensory receptors in the eyes, nose, mouth, ears and skin transform the physical energy into neural impulses that the brain can interpret.

3) The brain receives a ‘neural code’ and based on this, it interprets the (i) quality and (ii) intensity of the sensation.

Front 12

1) What is Absolute Threshold?

2) How much do we sense around us?

3) How is the absolute threshold determined?

4) What is the absolute threshold for:

(a) Hearing

(b) Smell

(c) Taste

(d) Touch

(e) Vision

Back 12

1) They have a minimum point of physical energy that is usually required to ‘register’ or detect the external stimulus.

2) We only sense a small amount of what is actually occurring around us.

3) Is experimentally determined by measuring the amount of stimulation a person needs to detect the stimulus about 50% of the time.

4) (a) the ticking of a watch six metres away in a quiet place.

(b) one drop of perfume in a large house.

(c) one teaspoon of sugar dissolved in 10 L of water.

(d) the wing of a fly falling on the cheek from a height of 1 cm.

(e) the flame of a candle 50 km away on a dark, clear night.

Front 13

1) What is Signal Detection?

2) What are the judgements based on?

Back 13

1) Psychological judgements are still required to make decisions about whether a stimulus has been detected. Since there is no real absolute threshold of physical energy, we detect the presence of a stimulus based on judgments.

2) (a) Stimulus sensitivity: How well a person sees, hears, feels etc. The stimulus.

(b) Response bias: How ready we are to report detecting a stimulus when we are not sure (and is affected by expectations and motivation).

Front 14

Table for Signal Detection

Back 14

Front 15

1) What is Difference Threshold?

2) What is a type of Difference Threshold?

3) What is it?

4) What does it depend on?

Back 15

1) Psychological judgements are required to make decisions about whether a change in the level of the stimulus has been detected.

2) Just Noticeable Difference (JND)

3) The psychological equivalent of the difference threshold.That is, (psychologically) noticing when a change has occurred in an existing sensation.

4) Depends on the existing level of stimulation. E.g. The higher the current intensity, the larger the change required to notice a change.

Front 16

1) What is Sensory adaptation?

2) Sensory receptors have a tendency to do what?

Back 16

1) They are able to ‘tune out’ redundant stimulation.

2) Have the tendency and capacity to respond less to stimuli that continues without change.

Front 17

What are the six main sensory systems?

Back 17

1) Vision

2) Hearing

3) Smell

4) Taste

5) Touch

6) Proprioceptive senses

Front 18

Vision

1) What is required for the sensation of vision?

2) What do we only see?

3) What is it?

Back 18

1) Light is the physical energy required for sensation of vision.

2) White light

3) Light particles whose wavelengths oscillate (‘go up and down’) between 400 and 700 nanometres (nm).

ROY G BIV (Red, Orange, Yellow, Green, Blue, Indigo, Violet)

Front 19

Vision

The eye is the sense organ required for transduction. What are the two main steps?

Back 19

1) Light enters the eye and is focused onto the retina.

2) The retina transduces the light falling on it into neural impulses.

Front 20

Vision: Light enters the eye and is focused onto the retina.

What happens here?

Back 20

▪Light first enters the eye through the cornea.

▪Then passes through the aqueous humour, pupil (and iris), lens and vitreous humour.

▪And then lands on the retina.

Front 21

Vision: The retina transduces the light falling on it into neural impulses.

1) What is a retina?

2) What happens here?

Back 21

1) Is a thin layer of tissue at the back of the eye sensitive to light.

2) - Cells in the retina transduce the light into neural impulses.

- The neural impulses are relayed to the brain for interpretation via the optic nerve.

- The central area of the retina is called the fovea, which is sensitive to small detail.

- Thus, vision is sharpest for stimuli directly in sight (i.e. in front of the fovea)

Front 22

Vision

What are the parts of the eyes?

(6)

Back 22

1) Cornea

2) Aqueous humour

3) Pupil and Iris

4) Lens

5) Vitreous humour

6) Retina

Front 23

Vision

Cornea

Back 23

A tough, transparent tissue covering the front of the eyeball.

Front 24

Vision

Aqueous humour

Back 24

A fluid containing nutrients such as oxygen that supply the eye.

Front 25

Vision

Pupil and Iris

Back 25

1) An opening in the [coloured] iris.

2) Muscles in the iris control the size of the pupil to regulate the amount of light entering the eye.

Front 26

Vision

Lens

Back 26

1) An elastic, disc-shaped structure that changes the focus the eyes based on the distance of the object.

2) Becomes flatter for faraway objects and rounder for nearer objects.

Front 27

Vision

Vitreous humour

Back 27

A clear, gelatinous liquid.

Front 28

Vision

1) Where does Transduction occur?

2) Is the retina multilayered?

3) Where does the light land first in the eye?

4) What are the two types of photoreceptors?

5) What do Rods do?

6) What do Cones do?

7) What do they generate?

8) Where does it pass through?

9) What forms the optic nerve?

10) What is the spot called where the optic nerve leaves the eye?

Back 28

1) In the retina.

2) Yes.

3) Inner layer of the retina.

4) Rods and Cones.

5) Produces the visual sensations of black, white and grey only. Concentrated on the periphery of the retina. More sensitive to light (120 million per retina), providing vision in dim light.

6) Produces the visual sensations of colour and black and white. Concentrated in the centre of the retina (in the fovea). More light required (8 million per retina), providing little vision in dim light.

7) Electrical Impulses.

8) Bipolar cells and then ganglion cells.

9) Axons of the ganglion cells.

10) 'Blind spot' because there are no photoreceptors there.

Front 29

Vision

1) For humans where is the sensation of vision?

2) For the colours we see, what do we depend on? (2)

3) Therefore, what does 'colour' actually belong to?

4) The colour of an object is not an inherent property of the object. What is it then?

5) Grass does not appear green to us because grass is green, but because of …

Back 29

1) In colour.

2) On how our brain interprets it.

(i).The type and amount of reflected light entering the eye, and..

(ii).The type and amount of activity in our cones.

3) 'Colour' belongs to the person and not the stimulus.

4) But a psychological experience of the object.

5) ▪The type and amount of light wavelengths reflected off grass and onto our eye, and

▪The type and amount of activity in retinal cones sensitive to these wavelengths

Front 30

Hearing

1) What is required for the sensation of hearing?

2) What does sound refer to?

3) How does sound occur?

4) How many properties does acoustic energy have?

5) What are they?

Back 30

1) Sound is the physical energy that is required for this.

2) Rhythmic pulsations of acoustic energy.

3) In form of air particles, and is emitted outward from vibrating object.

4) Three.

5) Frequency, Complexity, and Amplitude.

Front 31

Hearing: Frequency

1) What is it's definition and how is it measured?

2) What psychological property is it related to?

Back 31

1) How often a sound wave cycles (or ‘oscillates’) per second. Hertz (Hz): 1 Hz = 1 cycle/sec.

2) Pitch: The quality of a tone, from low to high

•The higher the frequency, the higher the pitch

•We can hear a large range of frequencies (approx. 15 – 20 000 Hz), but our capacity decreases with age

Front 32

Hearing: Complexity

1) Definition.

2) What psychological property is it related to?

Back 32

1) The extent to which a sound is composed of multiple frequencies.

2) Timbre: The characteristic texture of a sound.

Front 33

Hearing: Amplitude

1) Definition, and what's its measurement?

2) What psychological property is it related to?

Back 33

1) The height and depth of one oscillation. Decibels (dB).

2) Loudness

•The greater the amplitude, the louder the sound.

Front 34

Hearing

1) What organ is required for the transduction of hearing?

2) What are the parts of the ear? and what are the sub-parts of each? (3)

Back 34

1) The ear.

1) Outer ear (Pinna and Auditory canal), Middle ear (Eardrum (or tympanic membrane), and Ossicles), Inner ear (Cochlea, Hair cells, Auditory nerve)

Front 35

Hearing: Outer ear

1) What is its function?

2) What is the function of Pinna?

3) What is the function of the Auditory canal?

Back 35

1) Collects and amplifies sounds in the air.

2) Funnels sound waves into the ear.

3) Carries and amplifies sound waves to the middle ear.

Front 36

Hearing: Middle ear

1) What is its function?

2) What is the function of the eardrum (or tympanic membrane)?

3) What is the function of Ossicles?

Back 36

1) Converts waves of air pressure into movements of the ossicles.

2) Reproduces the cyclical vibration of the object that created the sound on a microcosmic scale, causing the ossicles (tiny bones) to vibrate and the sound to amplify.

3) Malleus (hammer), incus (anvil) and stapes (stirrup).

Front 37

Hearing: Inner ear

1) What is its function?

2) What is the function of a Cochlea?

3) What is the function of the Hair cells?

4) What is the function of the Auditory nerve?

Back 37

1) Transforms the ossicle movements into waves (in cochlear fluid) that generate neural impulses.

2) Transduces physical energy into neural impulses.

3) Transmits neural impulses to the auditory nerve.

4) Transmits neural impulses to brain for processing.

Front 38

Taste

1) What is it useful for?

2) Where are the taste receptors found on the tongue?

3) What are they sensitive to?

4) What are they specific tastes?

5) When are they replaced?

6) Why is regeneration essential?

Back 38

1) - It protects a person from ingesting spoilt food.

- Allows for the intake and regulation of nutrients (e.g. salt and sugar).

2) Inside you tastebuds.

3) Molecules soluble in saliva.

4) Mainly sweet, sour, salty, and bitter.

5) Every 10 – 11 days.

6) For avoiding permanent loss of taste.

Front 39

Touch

1) What are the receptors for touch located?

2) What is useful about it?

3) What can we learn?

4) How many receptors are their in our skin?

5) While they can respond to all, they are usually specialised to respond to one of three qualities of touch. What are they?

Back 39

1) Skin: 2m^2

2) - Protect the body from injury.

- Aid in identifying objects.

- Help maintain body temperature.

- Facilitate social interaction (e.g. through hugs, kisses, holding and handshakes).

3) We can learn about how the brain processes sensory information and how we experience the sensation of touch, by looking at cases when skin is missing.

4) 5 million.

5) 1. Pressure

2. Temperature

3. Pain

Front 40

Touch: Pressure

1) What do they do?

2) What do the receptor activity allow to do?

3) Where on our body is the receptors for pressure sensitive?

Back 40

1) Register indentations on the skin produced by external stimulation (causing mechanical displacement).

2) For the psychological perception of texture.

3) In the hands.

Front 41

Touch: Temperature

1) What are the two types of Temperature receptors?

2) Type of physical energy transduced?

3) What do they respond to?

Back 41

1) Cold and Warm

2) Difference in temperature between body and environment/object.

3) Respond to temperatures of external objects.

Front 42

Touch: Pain

1) Is pain an important source of info?

2) What does it motivate us to do?

3) Receptors in the skin, which is sensitive to pain do not transduce physical energy into neural impulses. True or False.

4) Unlike pressure and temperature receptors, what do pain receptors respond to?

5) What is pain influenced by?

6) Therefore, the --------- of pain is strongly linked to the ----------- of pain.

Back 42

1) Yes.

2) To behave in ways that will terminate the source of the pain and thus prevent damage to skin tissue.

3) True.

4) Pain receptors respond instead to extreme levels of stimulation in the other senses.

5) By beliefs, expectations, emotional states and personality.

6) Sensation and Perception.

Front 43

Touch

1) What is a Phantom Limb?

2) Can a be sensed even though there is no skin to receive the sensory stimulation of touch from the environment?

3) Can phantom limb occur to someone born without the limb?

4) What does the Phantom limb teach us?

Back 43

1) The experience of the sensation of touch in a missing limb.

2) Yes.

3) Yes.

4) That our experiences of sensation do not just depend on stimulation from the environment, but are also influenced.

Front 44

1) What are Phantom limbs influenced by?

Back 44

1.Innate (or inborn) ‘pre-wiring’ of neurons

▪That is, neurons have a tendency to ‘expect’ and be sensitive to specific sensations (e.g. touch)

2.The ‘wiring’ between neurons in the body and parts of the brain

▪Thus, if damage has occurred to a sensory system, neurons can ‘re-wire’ their connections to others neurons in different parts of the brain

▪This re-wiring can create sensations in missing limbs

­E.g. Touching a person’s shoulder can cause a sensation in the “finger” of an amputated hand

Front 45

1) What are Proprioceptive senses comprised of? (2)

Back 45

1) Vestibular Sense

2) Kinaesthetic

Front 46

Proprioceptive Senses: Vestibular Sense

1) What does it provide?

2) Where are the receptors located? (2) What do they do?

3) What do the receptors transduce?

Back 46

1) Provides information about the position of your body in space by sensing gravity and movement.

2) In the inner ear.

▪Semicircular canals: sense acceleration/deceleration as the head moves

▪Vestibular sacs: sense gravity and the position of the head in space

3) Receptors in the inner ear transduce gravity (physical energy) into neural impulses for interpretation.

Front 47

Proprioceptive Senses: Kinaesthetic

1) What does it provide?

2) Where are the receptors located?

Back 47

1) Provides information about the movement and position of limbs and other parts of the body relative to one another.

2) In body joints and muscles.

Front 48

1) Perception refers to interpretative processing. But what are its weaknesses? (2) Provide an theory of psychology.

2) What is Gestalt Psychology?

3) Our perception is subject to illusion: What is it different to?

4) If we cannot form meaningful perceptions of our sensations, what can we do?

Back 48

1) ▪We do not interpret sensations to accurately reflect/replicate the physical world.

▪We interpret sensations according to what is meaningful to us.

▪Functionalism: the way the brain processes information depends on the function or purpose of processing the information.

2) A form of functionalism: “The whole is greater than the sum of its parts”.

3) It is different to the senses that gave rise to it.

4) We experience perceptual illusions.

In conclusion perception is interpretative and can be inaccurate, it is a subject to illusion.