COGS 17 Homework 22

• When a stimulus is coded through the RATIO of response across multiple cells.
• i.e. temperature, hot respond more to hot cold to cold, etc.

When MULTIPLE pre-synaptic cells all communicate to ONE post-synaptic cell

When ONE pre-synaptic cell communicates to many post-synaptic cells.

Set of receptors whose activity influences the activity of target cell.

Type of Receptive Field: stimulating center increases target response, non-center decreases it.

Type of map that preserves spatial relationships (as along a sensory surface).

• In cortex, disproportionate enlargement of the representation of a sensory area of low convergence.
• (Cortical cells with small Receptive Fields fill a disproportionally large area of the visual projection areas)

An area of the brain specialized for processing one particular type of information

• The problem posed by having several modules, and yet perceiving wholes.
• i.e. red square

Rear layers of neurons in the eyeball

Cells that respond to light

Visual receptor that are (HIGH) convergent, sensitive to motion and low light, mainly in periphery.

Visual receptor that connect few to 1 (LOW Convergent), sensitive to color and detail, dispersed plus concentrated in center.

Central area of cone receptors, connected 1:1 for highest acuity.

(Postsynaptic to Receptors) Next cell in pathway, spontaneous firing, graded potentials, release excitatory NT.

Inter-neurons that modify reaction of bipolars, implicated in color opponency.

(Postsynaptic to Bipolars) Next cell in pathway, shows action potentials, release excitatory NT. The axon of this cell forms the Optic Nerve.

Ganglions cell axon form this.

Place where optic nerve leaves eye for brain, also called "blind spot"

• Inter-neurons that modify reaction of optic disc (ganglions), implicated in contrast effects.
• Graded Potentials, mostly Inhibitory NT, modify interface of Bipolars and Ganglions

Level of light that results in greatest release of NT from Receptors

Level of light that results in greatest release of NT from Bipolars

High-detail discrimination, as from low convergence, that retains info on differences from rods and cones.

High likelihood of detection, as from high convergence that crosses next cell's threshold.

• Cell activity resulting in release of inhibitory NT to cells orthogonal to info pathway
• - Functions mainly to exaggerate differences

Illusion created by lateral inhibition that alters perception of central grey depending on its surrounding.

Direction of inhibition in direction-sensitive motion circuit.

Nucleus in Thalamus that processes most visual information from eye.

In cortex, set of cells, in 6 layers, that all respond to the same preferred stimulus.

In cortex, set of cells that all have the same Receptive Fields and include set of orientation columns & blobs.

Topological map that preserves spatial relationships found on retina

Primary projection area for vision in occipital lobe of cortex.

Visual pathway specialized for color and detail, that "flows" along bottom of cortex.

Parvocellular Pathway is also call what because it terminates in the lobe of this cortex.

Parvocellular Pathway also calls what because it conveys information that helps you to identify a stimulus or individual

Small ganglion cells that begin parvocellualr pathways, with small Receptive Fields and sustained response.

Visual pathway specialized for motion and localization, "flows" along top part of cortex.

Magnocellular Pathway also calls what because it Terminates in this lobe of the cortex

Parietal Pathway also calls what because it Conveys info that helps locate and interact with stimuli

Large ganglion cells that begin Magnocellular pathway, with large Receptive Fields and transient response.

Nucleus in Midbrain in Magnocellualar path, processes some visual (esp motion) info from eye

Though visual cortex damaged and no visual experience, mid-brain enables some visual localization.

Color coding per ratio of activity of 3 cone types responding to 3 overlapping ranges of frequencies.

Recoding of Trichromatic Color Vision, via lateral inhibition from Horizontal cells, into red/green and blue/yellow

LGN or Ganglions with R+G-, G+R-, B+Y-, or Y+B- receptive fields

V4 mediated processes that enables identification of color under different light conditions (AKA "retinex theory")

Cells in V1 that respond to line, or gradient, oriented in particular direction

Cells in V2 that best response to moving lines of particular direction

Number of dark/light changes per degree of visual angle

Frequency gradients that V1 cells in Parvo path are most sensitive to

Frequency gradients that V1 cells in Magno path are most sensitive to

End of parvo pathway, includes cells that prefer hand, face, or other complex stimulus.

Deficit from damage to Fusiform Gyrus, patient cannot recognize familiar faces.

Cortical area with direction-sensitive cells, responds best to stimulus moving across retina.

Cortical area with optic-flow detectors, respond best to contraction/expansion of whole scene.

Area in anterior Temporal lobe that response to Biological Motion

In V2 or MT, cells that respond to degrees of difference between location of an image on 2 retina

Cells in higher parietal cortex that respond to the affordances of an object

Parietal cells (also found in Premotor Cortex) that respond to seeing self or other perform task.

Membrane vibrated by air molecules moving down Auditory Canal

Three tiny bones (Malleus/Hammer, Incus/Anvil, Stapes/Stirrup) linked into lever system, amplify vibrations of Tympanic Membrane

Membrane vibrated by the third ossicle bone, initiating vibration of (Endolymph) Cochlear Fluid.

Thick, incompressible, potassium-rich fluid that fills cochlea.

snail-like Coiled, three chambered tube [top (Scala Vestibuli), mid (S. Media), bottom (S. Tympani)] in Inner Ear which contains Organ of Corti

Section of central chamber of Cochlea where Receptor Cells are found

Membrane that runs along floor of Organ of Corti, moves up and down.

Membrane that runs along the roof of Organ of Corti, moves forward and back.

Auditory receptor cells that are deformed between Basilar and Tectorial Membrane

Tiny "hairs" extending from hair cells whose deformation initiates transduction.

Ion that enters receptor, decreasing its polarity (Audition)

Ion that enters the receptor, causing chain reaction that results in release of excitatory NT (Glutamate)

NT released by auditory receptors

Type of change in polarity in auditory receptors

Cells to which auditory Receptors communicate, whose axons exit to brain.

Type of change in polarity in spiral ganglions.

Relative levels of activity across diffferentially-resonsating basilar membrane code frequency.

Rate of oscillation of Bas. Membrane codes frequency per rate of Auditory Nerve Firing

Time during which Auditory Nerve Fibers cannot fire next action potential.

Since each cell can only fire 1/1000 sec, must work together at alt. intervals.

Ganglions involved in Volley Principle can only all fire at the same phase (e.g.) peak of input wave

• Differences used for localization, caused by "head shadow" attenuating high frequencies.
• Sound at ear closer to source is slightly more intense (louder) than at other ear, because of Head Shadow.
• -Works best for higher frequencies, since these most likely to be absorbed by head

• Differences used for localization, comparing peak and trough of lower frequencies reaching both ears
• - Peak = oscillating molecules most condensed
• -Trough = oscillating molecules most rarefied - widely spread out

Differences used for localization, per race of left vs. right. Onset signals to superior olive.

Receptor cells that show divergent connectivity, for detail freq discrimination.

Receptor cells that show convergent connectivity, for loudness discrimination.

Axons of spiral ganglion in auditory path form this nerve

Auditory Nerve is part of this cranial nerve

Next synapse in Medulla, beginning of separate information pathways.

Cells in Cochlear Nucleus that duplicated incoming signal

Primary Like Cells helps generate what kind of map that represents low>high frequency across cell array

Cell in Cochlear Nucleus that transforms incoming signal into a transient burst.

Cell in Cochlear Nucleus that transforms incoming signal into one of graded, increasing amplitude.

When information from only one ear is involved.

When information from both ears is combined, good for localization as in superior olive.

Next auditory site (after cochlea nucleus), also in Medulla, repsonsible for Orienting Reflex

Next auditory site (after superior olive), in MIDBRAIN, where info is integrated with visual at nearby site

Next auditory site (after inferior colliculus), in Thalamus, site of among other things, A1

Primary Projection Area for Audition, along Lateral Sulcus of Temporal Cortex

• Secondary auditory area in cortex
• Most respond best to complex sounds (familiar noises, speech sounds)

Area with critical role in comprehension of speech, in left hemisphere

Type of complex auditory input processed by higher auditory centers in right hemisphere.

Type of receptor cells in Vestibular System

Which Ion, when not/allowed to enter cell, changes receptors polarity

Changes in velocity & orientation alter this kind of firing rate.

• Where receptors respond to head tilt via gravity induced deformation by crystals
• "Ear Stones"

Three fluid filled tubes that detect changes in angular acceleration

Effect when visual and/or motor feedback is inconsistant with vestibular info

Which Cranial nerve shared with audition

• Class of receptors that respond to temperature, pain, itch, and hair follicle movement
• -respond to change in Temperature (Thermoreceptors) and pain & itch (Nociceptors)

Receptors in Free Nerve Endings that respond to "noxious" (potentially damaging) stimuli

Class of receptors that respond to touch and internal movement

Detection of internal movement of muscles and organs

Type of response by above type of receptors (encapsulated endings)

Process by which one type of receptor is fatigues, showing its role in coding

Nucleus of Thalamus in somatosensory pathway

Path for pain and temperature info to brain, crossing over in Spinal Cord

Pathway for touch and internal motion info to brain, crossing over in brainstem

Pathway tending to be mylinated

• When damage to one side of spine results in different losses on ipsilateral vs contralateral sides
• -reduction/loss of touch and position sense on the ipsi-lateral (right) side below the point of injury
• -reduction/loss of temperature and pain detection on the contra-lateral (left) side below the point of injury

Location of primary projection area for somatosensory info (S1)

Name of topological map of body surface found Post Central Gyrus

Disproportionally fill Penfield Map.

NT released by pain receptors and other cells in pain pathway

Theory concerning top down blocking of pain info entering brain

Midbrain Area that is probaby the source of pain info blocking

"Endogenous morphines" released by Periaqueductal Grey Area

Type of interneuron in spine that responds to endorphin.

Opiate antagonist that reduces analgesic effects of morphine and acupuncture

Type of muscle, made of parallel fibers, attached by tendons to bones.

One type of Striate muscle, that moves bone towards body, in atagonistic pair with extensors

One type of Striate muscle, that moves bone away from body, in atagonistic pair with flexors

Where neuron releases NT that depolarizes muscle fiber cells > contraction

NT released by effector neurons to contract muscles

The contractile unit of a muscle fiber consisting of Myosin

Thick protein filament with knobby bead-like Cross Bridges along it,

Thin braided protein filament, anchored to muscle, that myosin hook into and tighten

a proprioceptor that detects passive stretch of a muscle, triggers Stretch Reflexx

A mono-synaptic reflex that contracts muscle to counter passive stretch

A reflex triggered by Tendon Organs detecting excessive contraction in muscle

A reflex triggered by pain detectors, rapidly removing skin from the source of pain

A reflex involving an Oscillator Circuit producing a fixed-rate rhythm

Reflexes, such as "rooting" or "grasping", found in newborns

Area of cortex that includes body map, sends movement commands to Stem and Cord

Location of the Primary Motor Cortex

Anterior to the Primary Motor Cortex, active during preparation to move, receives esp from visual-spacial areas

Premotor Cortex includes cells that respond to image of self, or other, performing familiar manual tasks

Lateral area that plans articulation, helps generate gramatical sentences (esp. in left hemisphere)

Dorsal to Broca's Area, also active during prep, esp. for rapid movements, receives from Parietal

Fast, crossing paths from Pyramids in cortex, esp. for precise control of peripheral moves

Cortico-Spinal Pathway stops at this Midbrain structure on the way from the Cortex to Medulla and Cord

Mainly ipsilateral pathways for posture & gross movement of neck, shoulders & trunk

"Little brain" involved esp in coordinated movement requiring aiming and timing

Movements that occur very rapidly and generally cannot be altered once begun

"Telephone poles" in cerebellar cortex that help code time as distance

"Wires" in Purkinje Cells whose action potentials release excitatory NT

Central areas that receive from Purkinje Cells ("Telephone Poles") and send output to brain/chord

Set of forebrain structures controlling posture, muscle tone, and smooth movement

Movement impairment, marked by rigidity, tremors, etc, for degeneration of Substantia Nigra

Midbrain structure whose dopaminergic axons synapse in Basal Ganglia

Precursor of dopamine, crosses blood-brain barrier, converted by neurons into dopamine