Term
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Definition
Scotopic system
No color
dim light
outside fovea
low accuity
monochromatic |
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Term
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Definition
Photopic system
Thrichromatic
color
bright light
inside fovea
high accuity |
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Term
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Definition
Discriminate different forms of energy
Discriminate different intensities of energy
Reliability
Rapid Response
Suppress extraneous info |
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Term
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Definition
Membrane potentials in receptors
Typically excitatory post synaptic potential EPSPs
May yield AP
Graded to reflect the intensity of stimulus
Sometimes synaptic
provides local intensity info |
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Term
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Definition
| Using big groups of neurons with different firing thresholds in order to account for a wide range of intensities yet be able to detect acute differences |
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Term
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Definition
| Can identify faces but can't recognize to whom they belong |
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Term
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Definition
| Receptors lose sensitivity with sustained stimulation. Allows receptors to respond to changes. Eliminates extraneous info that doesn't provide important news about the world. Can be neural or non-neural. |
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Term
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Definition
| Increases contrast. Ability to 'inhibit' surrounding cells in order to enhance the stimulus. |
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Term
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Definition
| All cells in a column respond to the same body region and sub-modality. Different columns for different body regions. Different columns for tonic and phasic receptors |
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Term
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Definition
Suppression of Pain. Can be adaptive. Fear, stress, and painful stimuli can induce Analgesia.
Prevents recuperative behaviors |
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Term
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Definition
Initiated by tissue damage
Chemical substances activate nerve terminals (substance P, histamine, prostaglandins, serotonin). Slow un-mylenated axons (C-fibers) carry pain info to the spinal cord. Pain info asends to somatosensory cortex via spinothalamic tract |
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Term
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Definition
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Term
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Definition
| Located in PAG (midbrain grey matter) activate serotonergic neurons in the Medulla. Medulla neurons shut down spinal neurons, close gate. |
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Term
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Definition
| Can gate pain because the excited neurons can inhibit and shut off the pain projection neurons. |
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Term
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Definition
1) Pinna acts to funnel sound in
2) Middle ear bones increase the amplitude of vibrations to the oval window.
3) Oval window presses on the gelatenous matrix
4) Causes the Basilar membrane to vibrate
5) This pushes the stereocilia on the inner ear to bend and depolarize
6) Hair cells release glutamate
7) Glutamate excites sensory neuron |
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Term
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Definition
| Basilar membrane is stiff and narrow at the proximal end and flixible and wide at the distal end. Therefore certain frequencies cause it to vibrate more or less. The brain responds to these different frequencies. |
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Term
| Vibration of Basilar membrane |
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Definition
| Causes displacement of hair cells |
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Term
| Displacement of hair cells |
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Definition
| Causes tip links to pull channels open and depolarize. Voltage gated calcium channels open causing vesicle fusion at the base of the hair cell. |
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Term
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Definition
Both ears in superior olivary nucleus
Inferior colliculus |
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Term
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Definition
| The ability to localize sound comes from small time differences from when a sound reaches the brain from each ear. |
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Term
| Photoreceptor Transduction |
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Definition
1) Light photon strikes discs in rod or cone
2) Cleaves rhodospin into retinal and opsin
3) Opsin activates G-protein (transducin)
4) Transducin closes Na channels, hyperpolarizes rod/cone |
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Term
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Definition
| There are three populations of cones. Red, Green, and Blue. Combined they form all colors |
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Term
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Definition
Based on psychology
Neurons color as binary opposits
Afterimages |
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Term
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Definition
1) Retinal ganglion cells
2) LGN
3) Primary Visual cortex
4) Secondary visual cortex |
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Term
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Definition
1-2
Bottom
magnocellular BIG neurons
Motion and dim light sensitive
poor color and resolution
input from rods
3-6
top
parvocellular Small cells
Color and detail resolution
Input from cones
All the layers stack up
Layers 1,4,6 from contralateral nasal retina
Layers 2,3,5 from ipsilateral temporal |
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Term
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Definition
Circular - center surround organization
Larger than Retinal Ganglion Fields |
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Term
| LGN projects directly to... |
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Definition
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Term
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Definition
(area 17)
Bar shaped receptive fields
+/- organization
Binocular
Responds to spot within field
Cell is orientated selectively |
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