Week 4 Flashcards
1
Q
Sensation
A
The process where the senses pick up visual, auditory and other sensory stimuli and transmit them to the brain
2
Q
Perception
A
The process where the brain actively organises and interprets sensory information
3
Q
Basic Principles of Sensation and Perception
A
- There is not one-to-one correspondence between physical and psychological reality
- Sensation and Perception are active Processes
- Sensation and Perception are adaptive and support survival and reproduction
4
Q
Sensation and Perception: Top Down and Bottom Up Processing
A
Top Down: driven by context and interpretation
Bottom up: Driven by the properties of the stimulus
5
Q
Sensory Systems: Photic
A
Modality: Vision
Stimuli: Light
6
Q
Sensory Systems: Mechanical – Hearing
A
Modality: Hearing
Stimuli: Vibration
7
Q
Sensory Systems: Mechanical - Touch
A
Modality: Touch
Stimuli: Contact
8
Q
Sensory Systems: Chemical - Smell
A
Modality: Smell
Stimuli: Substance in mucus in nasal cavity
9
Q
Sensory Systems: Chemical – Taste
A
Modality: Taste
Stimuli: Substances in saliva on tongue
10
Q
Sensory Systems: Other
A
- Thermal
- Joint
- Muscle
- Vestibular (Inner Ear & Balance)
11
Q
What is Light?
A
Light is electromagnetic radiation in a combination of waves
- amplitude (brightness)
- Wavelength (colour & hue)
- Purity (saturation)
12
Q
What are the eyes two main purposes?
A
- Provide housing for neural tissue that receives light
- Channelling light towards the sensory receptors in retina – Rods and Cones
13
Q
Eye Structure:
A
- Cornea – light rays enter here
- Pupil: opening just behind cornea
- Iris: gives eye colour, assist pupil to adjust to amount of light
- Lens: behind pupil, focuse light rays on to retina
- Retina: back of the eye where images are focused and processed, sends visual information to brain
14
Q
Photoreceptors
A
- Found in the Retina
- there are millions of receptor cells that are sensitive to light
- Innermost layer of the receptors
- Two types of receptors: Rods and Cones
15
Q
Receptor Cells - Cones
A
- Detect color and fine detail - Function best in adequate light - Colour vision - Short, Medium & Long - Daytime vision - Have poor response to dim light - Better visual acuity - Fovea: only cones
16
Q
Receptor Cells – Rods
A
- Extremely sensitive - Enable vision in dim light - Movement - Outnumber Cones - Night vision - Peripheral vision - Outside of fovea
17
Q
Fovea
A
- A tiny pit located in the macula of the retina and provides the clearest vision of all
18
Q
What is colour vision?
A
- Colour is a psychological interpretation not a property of light
19
Q
Two theories of colour vision
A
- Trichromatic
- Opponent processes
20
Q
Trichromatic Theory
A
- Young and later Helmholtz - Specialised receptors sensitive to wavelengths associated with red, green, blue - Eye does its own colour mixing by varying these wavelengths
21
Q
What is colour blind Dichromacy?
A
Most colour blind people can see two types of colour receptors
22
Q
What is Monochromacy?
A
Inability to distinguish any colours and perceive only variations in brightness
23
Q
Protanopia
A
- 1% of males lack the long wavelength cones - Brightness of red, orange and yellow are reduced
24
Q
Dueteranopia
A
- 1% of males - Lacking in medium-wavelength cones
25
Tritanopia
- Less than 1% of males and females - Lacking in short-wavelength cones - Colours like blue indigo and violet as greenish and drastically dimmed. - Some colours even perceived as black
26
Trichromacy
Three types of cones within the Retina
27
Pigment Epithelium
a layer of pigmented cells in the retina of the eye, overlying the choroid.
28
Opponent Processes Theory
Colour Perception depends on receptors that make antagonistic responeses to three pairs of colours
- Complementary Colours; that produce gray tones when mixed together
- Afterimage; a visual image that persists after the stimulus is removed
29
- Complementary Colours that produce gray tones when mixed together
- Afterimage - an image that persists after a stimulus is removed
Opponent Process Theory
30
Receptor Stage
Neural Stage
Model for normal human colour vision
31
Visual Pathways to the Brain
- Axons leaving back of each eye form the optic nerves
- Axons travel to the Optic Chiasm
32
Optic Chiasm
- The point where the axons from the eye cross over and become contralateral
- Signal from the left optic nerve are now trasmitted to the right hemisphere
- also allows signals from both eyes to go to both hemispheres of the brain
33
Information processing in the Visual Cortex
- Visual input ultametely arrives at primary visual cortex in the occipital lobe
- cells in Visual Cortex are highly specialised
- Are Feature detectors - neurons that respond selectively to very specific complex stimuli
34
What is Light
- Electromagnetic Radiation
- Wavelength
- Amplitude
- Purity
35
Describe Eyesight
- Retina consists of photoreceptors
- information to visual system via optic nerve
- long wave = red
- medium wave = green
- short wave = blue
36
Colour Theories
- Trichromatic Theory = mixing of red green and blue
- Opponent Processes = anatgonistic colour pairs
- both contribute at different stages
37
What and Where pathways
- Ventral stream: What (form and colour)
- Dorsal stream: where (motion and depth)
38
Perceiving form: Hubel and Wiesel
Cells, and columns of cells, within the visual system detect specific particular orientations
- Builds up to detection of specific shapes
- From shapes we can detect objects
after this the options for detection become endless
39
Sensation and Perception are not always neat
The diret senstion of the world does not always match up with our perception of it.
- Visual Illusions
- Blue/ Black vs Gold/White Dress
40
What things influence visual perception?
* Reversible figure
* Perceptual Set
* Inattentional Blindness
41
Reversible figure
A drawing that is compatible with two differnt interpretations and can shift back and forth between two images
42
Perceptual Set
Readiness to perceive something in a particular way
43
Inattentional Blindness
The failure to see fully visible objects or events in a visual disply because your attention is focused elsewhere
44
What things influence visual perception?
- Bottom up processing; progression from individual aspects to the whole
- Top down processing; progression from the whole to individual elements
- Subjective Contours (Assumptions)
45
Gestalt Principles of perception
- Proximity:
- Closure
- Similarity
- Simplicity
- Continuity
46
Gestalt Principles:
Proximity
the closer the objects or events are the more likely they are to be perceived as belonging together
47
Gestalt Principles - Closure
people tend to fill in missing contours to form a complete object
48
Gestalt Principles: Similarity
similar elements are perceived to be part of a group
49
Gestalt Principles: Simplicity
People group stimuli to provide the simplest interpretation of the world
50
Gestalt Principles: Continuity
Sensations that appear to create a continuous form are perceived as belonging together
51
Depth Perception
Interpretation of visual cues that indicte how near or far away objects are
52
Binocular Cues
- Binocular Depth Cues
- Retinal Disparity
53
Binocular depth cues
Cues about distance based on the differing views of both eyes
54
Retinal Disparity
A cue depth perception when objects within 25 feet project images to slightly different locations on the right and left retina
the right and left eyes see slightly different views of the object
55
Monocular Cues
- Monocular depth cues
- Pictorial depth cues
56
Monocular depth cues
Clues about distance based on image from either eye alone
57
Pictorial Depth Cues
Cues about distance that can be given in a flat picture
58
Monocular Cues: Interposition
One object blocks another
59
Monocular Cues: Linear Perspective
Lines coverage
60
Monocular Cues: Texture Gradient
Distant objects finer
61
Monocular Cues: Shading
3D objects cast shadows
62
Monocular Cues: Aerial Perspective
Far objects are fuzzy
63
Monocular Cues: Familiar size
Familiar objects that apper small are inferred to be distant
64
Monocular Cues: Relative size
the smaller of two objects is seen as further away
65
Vibration of sound molecules
- Wavelenth/Frequency: pitch
- Amplitude: loudness
- Purity: Timbre
66
Human Hearing Capacities
- Wavelengths of sound are described in terms of their frequency and measured in hertz
- humans can only hear a portion of the available sounds
- Both these characteristics are simmilar to light
67
The Ear
- Air is collected by the **pinna**
- These vibrations are projected to the ear drum
- Ear drum vibrations cause movement of the anvil, hammer & stirrup (ossicles)
- ossicles cause the chochlear to produce fluid movement
- Basilar membrane stimulates hair cells at auditory receptors
68
Theories of Audition: Place Theory
Specific sound frequencies vibrate specific portions of the basiliar membrane (von Helmholtz, 1863)
69
Theories of Audition: Frequency Theory
Specific sound frequencies vibrate the basilir membrane at different rates
70
Theories of Audition: Combination Theory
Place Theory and Combination Theory work together to create audition
71
Ascending Auditory Pathways
- Ear (via chochlear)
- to thalamus
- to Auditory Cortex
72
Perception of sound: localisation
- Time and intensity difference at each ear gives us localisation
73
Gustatory System:
The sense of Taste
Perceptions
1. Sweet
2. Sour
3. Bitter
4. Salty
5. Umami
74
How is taste adaptive?
Salt = NaCl: Na deficiency which can lead to death
Sour = acidic: high concentrations tissue damage
Bitter = often poisonous
Sweet = essential to metabolism
75
NaCl
Sodium Chloride
76
Taste Buds
- taste receptors in the mouth
- trigger neural impulses sent to thalamus and to the cortex
- projects on tonuge that contain taste buds
77
What/Where are the receptors for smell?
Olfactory Receptors = olfactory cilia in your nose
350 types of olfactory receptors (taste)
78
Olfactory Cilia
dendrites of olfactory sensory neurons
79
Olfactory System is non-verbal
- smell is attached to emotion and memory
- Olfactory bulb closely connected to amygdala and hippocampus
80
The Olfactory System
* Nasal Passage
* Olfactory Axons
* Odor Receptors
* Olfactory Bulb
81
Flavour Perception
- Gustation + Olfaction
- Taste + Smell
82
What kind of energy do touch sensors in the skin respond to?
- Pressure
- Temperature
- Pain
83
What type of stimuli does touch respond to
- Mechanical
- Thermal
- Chemical-
84
Pain Perception
Pain perception changes with:
- Time
- Cognition/emotion cells in the spinal cord allow sensory information but block pain from transmission to the brain
- beleifs/attitudes
- mood/emotion
85
Endorphons and pain perception
- Endorphins natural morphine-like pain killers
- descending neural pathway mediates pain
86
Pain Therapy
The four elements of pain treatment
## Footnote
- Drugs that create a bottleneck at the"gate"
- Injection therapies such as nerve blocks and epidurals
- physical therapy and exercise
- behavioural techniques:
-- Progressive muscle relaxation
-- Psychotherapy (CBT)
87
Speech Perception
Speech perception is multimodal
- Auditory
- Visual
- Percept
