Ch. 2 Psychophysics Of Sensation And Perception

Front 1

psychophysics

Back 1

the study of the relation between variation in specified characteristics of the physical stimulation and the attributes and magnitude of subjective experience. this would be the relationship between events and things in the ‘world out there’ and the perceptual models and representations ‘in your brain’

Front 2

Psycho vs. Physics

Back 2

Events occuring in the physical world are sensed and through neural activity in the brain perceived. What we perceive is not always entirely accurate.

Front 3

Range vs. Resolution

Back 3

"AKA detection and difference

Front 4

Detection/Range

Back 4

Methods to measure DECTECTION are used to define the RANGE of a particular sensory system. The first part of Chapter 2 presents several methods we might use to make this determination.

Front 5

Difference/Resolution

Back 5

The last part of Chapter 2 discusses methods to measure the resolution of a sensory system. The resolution of sensory systems can be shown graphically in a nice way – See Fig 2.10. See the line for‘Brightness’

Front 6

Representations

Back 6

shortcuts that save neurons; do not resemble what is happening in outside world.

Front 7

Models

Back 7

in many ways, directly reflects outside world (only vision shape and touch perceive this way)

Front 8

‘Labeled Line’

Back 8

need a receptor for each stimulus value or can't sense (audition, touch, pain/temp)

Front 9

‘Across Fiber

Back 9

receptors are broadly tuned to multiple signals, i.e. 3 color receptors

Front 10

The structure and function of neurons

Back 10

Dendrites - receiving end; Axon hillock - decision center, electrical signal; Axon, axon terminals - sending end, neurotransmitter

Front 11

Neurons and neurotransmitters

Back 11

neurons have only one neurotransmitter to send so the decision is never which to send, it is simply YES - send it or NO - don't send it

Front 12

how ions (K+, Na+, Cl-) are used to generate

Back 12

K+ Potassium (some cases, a NO vote), Cl- Chloride (many cases, NO vote), Na+ Sodium (many cases, YES vote), Ca++ Calcium (not important for electrical)

Front 13

Neuron Voltage

Back 13

low -70mV because action potentials are regenerative but regeneration takes time

Front 14

Resting state of cell

Back 14

Inside usually carry negative charge naturally without ions; Sodium and chloride channels are closed; Potassium channels are open

Front 15

Resting potential

Back 15

Inside usually carry negative charge naturally without ions; Sodium and chloride channels are closed; Potassium channels are open

Front 16

Synaptic Potential

Back 16

1. Neurotransmitter attaches and opens a transmitter-gated channel: a. Na+ open YES (excitatory), b. Cl- opens NO (inhibitory); 2. Ion changes charge of cell and may begin action potential

Front 17

Action Potential

Back 17

1. Axon’s voltage-gated channels respond to the charge (about -50mV needed to open): a. Voltage opens, time closes (refractory period); 2. Na+ in sends K+ out (cell approaches Na+ equilibrium); 3. Na+/K+ pump restores ion concentrations; 4. Action potential passes down chain of axon

Front 18

Myelin and why it is that neurons can operate at such low voltages

Back 18

Layers of fat wrapped around axon that increase the speed of the neural impulse allowing it to travel all the way down the axon without letting any charge escape through top or bottom

Front 19

Why is Ca++ important?

Back 19

Initiates the chemical reaction; required for neurotransmitters to release (either naturally or through drugs but without neurons snooze)

Front 20

What do individual neurons do, and how are they used to sense and represent stimuli in the environment?

Back 20

Neurons are sensory transducers; they say Yes/No/Mo' ; stimuli encoded as 2D maps; sheets of receptors make up maps

Front 21

Functional architecture of the vertebrate CNS and of sensory pathways (from 2D sheets of receptors to 2D cortical maps)

Front 22

telencephalon

Back 22

pattern processing, motor control, memory, emotions, future plans, personality

Front 23

diencephalon

Back 23

thalamus (relay/gateway to telen.) & hypothalamus (regulatory center)

Front 24

midbrain

Back 24

object localization

Front 25

cerebellum

Back 25

movement, balance, posture

Front 26

hindbrain

Back 26

heart rate, breathing

Front 27

spinal cord

Back 27

reflexes

Front 28

‘Important Sub-Regions of the Telencephalon’ - functions associated with each sub-region and know the functions associated with layers 4,5,6 of cortex.

Back 28

see handouts

Front 29

basal ganglia

Back 29

maintains telencephalon

Front 30

hippocampus

Back 30

involved in the complex processes of forming, sorting, and storing memories

Front 31

amygdala

Back 31

emotion

Front 32

Differences between brain regions that answer ‘where’ the stimulus is vs. ‘what’ the stimulus is.

Back 32

Telencephalon answers WHAT is the object? Midbrain answers WHERE is the object?

Front 33

frequency

Back 33

characterization of sound waves by the number of cycles of pressure changes completed in a second, usually specified in units called Hertz (Hz) (physical side of pitch)

Front 34

intensity

Back 34

a general term that refers to the magnitude of the physical energy stimulating an organ (physical side of loudness)

Front 35

complexity

Back 35

the acoustic dimension of sound produced by vibrating bodies that do not vibrate at a single frequency. The psychological dimension of the resultant complex waveform is termed timbre. (physical side of timbre)

Front 36

pitch

Back 36

the psychological attribute of a tone that is described as high or low. Pitch is primarily mediated by the frequency of the tone (psychological side of frequency)

Front 37

loudness

Back 37

the attribute of an auditory sensation in which tones are ordered from soft to loud. Loudness is primarily determined by the amplitude of a sound wave (psychological side of intensity)

Front 38

timbre

Back 38

an attribute of auditory sensation that corresponds to the physical complexity of a tone (psychological side of complexity)

Front 39

How does ‘noise cancellation’ work?

Back 39

a technical means of canceling repetitive noise (created by a complex sound wave by generating and identical sound wave that is 180° out of phase

Front 40

How do ‘density’ and contribute to our perception of sound?

Back 40

a tonal quality that refers to the compactness or tightness of a sound. Generally, greater density occurs with higher-frequency tones.

Front 41

How do ‘volume’ and contribute to our perception of sound?

Back 41

a tonal quality that refers to the size and expansiveness of a tone. Various combinations of frequency and intensity produce different volumes

Front 42

How do ‘dissonance’ and contribute to our perception of sound?

Back 42

in audition, those combinations of tones that sound discordant or harsh

Front 43

How do ‘consonance’ and contribute to our perception of sound?

Back 43

in audition, those combinations of tones that appear to blend well and sound pleasant together

Front 44

What is Fourier Analysis and what does it have to do with audition?

Back 44

the breakdown of a complex waveform into its component simple sine waves based on the mathematical theorem devised by the nineteenth-century French scientist Jean Baptiste Fourier

Front 45

What is Fourier Synthesis and what does it have to do with audition?

Back 45

the physical construction of a complex waveform from a series of simple sine waves

Front 46

What is a ‘Frequency Spectrogram’ and why is it useful for understanding how sound is coded by the auditory system?

Back 46

a graphic reproduction of the frequency spectrum, intensity, and duration of a pattern of acoustic signals

Front 47

Your knowledge of the basic structure and function of the human auditory system, from outer, to middle, to inner ear.

Front 48

Know what is happening in each region, and how: outer, middle, inner ear

Back 48

outer ear acts as amplifier, collects sound waves; air in external auditory canal compresses and becomes more dense

Front 49

In other words, know the sequence of events that begins with vibrating air and ends with Na+ channels being opened on the tips of inner hair cells.

Front 50

basiliar membrane "

Back 50

a membrane on which lies the hair cells of the organ of Corti

Front 51

tectorial membranes"

Back 51

membrane extending along the top of the organ of Corti; outer hair cells bring tectorial membrane in closer in order to amplify sound; useful in 'tuning in'