2 - SENSORY PERCEPTION

Question 1

sensory perception

Answer 1

= experimential knowing from our sensory mechanisms and processes which allow us to know and experience what is in the world

• knowing by sensing
• ‘when we are consciously aware of the things that we know by sensing, then our knowing involves sensations’
• ‘these sensations are not the sensory knowledge itself, rather they are the means by which that knowledge is presented to us’

sensations are the medium, knowledge/perception is the message

JAMES’ PREFERRED DEFINITION👇🏻
‘process of obtaining information or knowledge (about the environment or body) from sensory stimulation and making it available for doing things (eg planning actions, controlling their execution, creating memories, thinking and reasoning - anything you can do with knowledge, really’
- making knowledge available to use

Question 2

sensations

Answer 2

= the qualities of experience that one can perceive or understand which correspond to the physical properties of the object

• conscious experiences and serve as the means by which sensory knowledge is presented to the conscious mind

eg size, colour, texture etc

eg sensations of hearing = loudness, pitch, timbre
eg sensations of taste = sweetness, sourness, and bitterness

Question 3

sensory knowing

Answer 3

knowing what’s out there

sensory perception

Question 4

qualities of sensory experience

Answer 4

eg sensations like colour, shape etc

Question 5

distinction between sensory knowing and qualities of sensory experience

Answer 5

• has been recognised for hundreds of years
• sensations are the medium
• knowledge/perception is the message

Question 6

subliminal perception

Answer 6

non-conscious form of perception

• sensory knowing without sensations
• goes against what Thomas Reid said - he said you can’t have one without the other
• another example of knowing without sensations is blindsight
• the knowing is either:
  ~ experienced as a kind of feeling (know something but don’t know where from)
  ~ or it is demonstrated behaviour (correctly answer a question you claim to have not seen/heard/sensed)

Question 7

the two aspects of conscious sensory experiences

Answer 7

1 - knowing about the world (perception)

2 - qualities of experience (sensations)

Question 8

having knowledge but no sensory perception

Answer 8

subliminal perception or blindspot

• you can have knowledge of something without having any conscious awareness of that thing
• it’s non-conscious perception

Question 9

proximal stimulation

Answer 9

= ‘physical energy or force (electromagnetic, mechanical, acoustic or chemical) that impinges upon sensory receptors and evokes a change in their membrane potential’

‘can also be characteristics or features of this energy, such as its strength, a change in its strength or the rate at which strength is changing’

• stimulates sensory receptors
• eg light energy stimulating photoreceptors in the eye
• actually the images formed by the optical apparatus of the eyes is the proximal stimulation

Question 10

distal stimulus

Answer 10

= a perceived/perceptible object, structure, substance, state of affairs or event in the environment or the body. these are sources or causes of proximal stimulation (&/or of its features and patterns)

‘determine the strength and type of proximal stimulation, how it changes over time and how it is patterned’

Question 11

how proximal stimulation contains information about distal stimuli

Answer 11

‘because the characteristics of proximal stimulation are determined by distal stimuli’

Question 12

the problem of sensory perception

Answer 12

‘getting information about distal stimuli out of the proximal stimulation’

Question 13

sensory receptors

Answer 13

• found almost everywhere in the body
• ‘cells or parts of cells that change their electrochemical state when they absorb energy from their surroundings’
• do something in response to stimulation
• eg photoreceptors absorb light which alters the electrochemical state via cell membrane potential

Question 14

stimulus energy

Answer 14

energy that receptors absorb

Question 15

stimulation

Answer 15

exposing a receptor to stimulus energy

Question 16

response

Answer 16

‘a change in electrochemical state (membrane potential) produced by stimulation’

• eg ‘retinal photoreceptors response to light energy is a decrease in membrane potential (hyper-polarisation)’ = unusual as they don’t generate APs
• ‘almost all other receptor cells respond to stimulation with an increase in membrane potential (depolarisation), to evoke APs’

Question 17

where are auditory receptors found?

Answer 17

cochlea of the ear

Question 18

where are the vestibular receptors found?

Answer 18

vestibular organs of the inner ear

Question 19

where are somatosensory receptors found?

Answer 19

• not associated with a particular sensory organ or location
• distributed throughout the body
• eg skin and epithelial tissue
• eg muscles, joints, bones, ligaments, tendons
• eg lungs, GI tract walls, blood vessels

Question 20

visual perception

Answer 20

‘when we are stimulated by light and perceive things’

‘the process of obtaining information and knowledge (about the environment and body) from light stimulation (and maybe other sources) and making it available for doing things’

Question 21

visual brain

Answer 21

• substantial portions of the cerebral cortex
• thalamic nuclei
• nuclei in the midbrain and the brainstem
• LGN (lateral geniculate nucleus) of the thalamus = cone opponency
• ‘fibres forming the optic radiation = spread out and terminate in the occipital lobe visual area’

Question 22

cerebral cortex

Answer 22

responsible for conscious seeing

• includes, occipital lobes, substantial portions of parietal lobes and parts of the temporal lobes
• the representation of surface spectral reflectances is computed here

Question 23

visual brain

Answer 23

• substantial portions of the cerebral cortex
• thalamic nuclei
• LGN = ‘earlier stage of visual processing - could be wavelength selective (e.g cones) but they do not ‘see’ colour’
• nuclei in the midbrain and the brainstem

Question 24

cerebral cortex

Answer 24

responsible for conscious seeing

• includes, occipital lobes, substantial portions of parietal lobes and parts of the temporal lobes

Question 25

sensing colour

Answer 25

• colour is a property of conscious experience, not of the world
• you can dream in colour, and therefore are experiencing colour without any stimulation by light

Question 26

synesthesia

Answer 26

‘people experience the sensations characteristics of one sense when a different sense is stimulated’

Question 27

‘if we look at a single patch of surface in isolation (surroundings = darkness) it’s colour will change as its illumination changes’

‘but it won’t if it’s part of a visible scene’

‘thus the brain uses light in many different regions of the retinal image in order to assign colour to any particular region’

‘proven by the fact we are NOT ‘blue blind’ in central vision, despite having no S-cones

Answer 27

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Question 28

V1 and V2

Answer 28

‘sorting house, segregating information about different aspects of the stimulus and distributing these to areas specialised to processing them’

eg motion, wavelength/colour, light/dark, lines, edges, binocular differences etc

Question 29

V4

Answer 29

‘area that deals with processing wavelength-related signals to generate perceived colours’

‘first area where colour constancy is found’