Behavioral Neuroscience exam 2

Study guide: Describe the connection from the eyes to the brain and explain how they produce the blind spot of the eye. explain blind spots

messages go from the receptors at the back of the head to the bipolar cells, located closer to the center of the eye.

Bipolar cell sends their messages to the ganglion cells, located still closer to the center of the eye

Ganglion cells’ axons unite and travel back to the brain as the optic nerve.

Additional cells called amacrine cells get info from bioploar cells and send it to other bipolar cells and, ganglion cells, and even other amacrine cells. amacrine cells refine the response of bipolar and ganglion cells, giving certain ones jobs to see shapes or color, or direction of movement

a consequence of this anatomy is the ganglion cell axons join to form the optic nerve that exits through the back of the eye. the point at which it exits is a blind spot because it has no receptors

`properties of cones

gives you 95% of information because of the Fovea and how it is built. we have great color vision in the Fovea, but not in the periphery, or side of your eye, because there aren’t any ___

abundant in the fovea (center of the cornea)

we have 6 million ___

properties of rods

most abundant  in the peripheral  120 million

respond to faint light but are less useful in daylight because bright light bleaches them 

color vision

perception depends on the wavelength of light.

350 wavelength range= violet 700 wavelength range= red

the more spread out the wavelengths are determines the color you see.

we have three different cone type: short, medium, and long wavelength

Law of specific nerve energy

All of our senses have specialized receptors made.

Principle of vision

we only see something when light effects it

1. enters eye through pupil

2. it gets focused by cornea and lens

3. focuses it then to the retina

4. light from above hits bottom of the retina & light from the left goes through the right

blind spot

consequence of no receptors where ganglion cells form optic nerve. their axons block it

Horizontal cells

inhibitory contact onto bipolar cells.

important for knowing where the boundaries of shapes are.

there is a sharpness at the boundaries where objects end, and these cells help you see that

Amacrine

Disperse information it gets from bipolar cells to other bipolar, ganglia, other amacrine cells

the fovea

the most central area of the retina. Tightly packed visual receptors, and different than the other visual receptors we see.

each receptor here attaches to 1 bipolar and 1 single midget ganglion cell

way more detailed in the center of our eye

vision is dominated by the ___

midget ganglion cells

ganglion cells in the fovea of humans and other primates. each are small and responds to just a single cone. each cone in the fovea has a direct route to the brain.

these cells provide 70% of the input to the brain so, your vision is nominated by what you see in and near the fovea

The opporant process theory: punnet process theory

see color spectrum red green and yellow blue

the example with the inverted colored fruit

or looking at the sun and closing your eyes and the imprint

retinex theory

How we recognize color consistently

the idea that context matters e.i the black and gray block

color vision deficiency

impairment in perceiving color differences

Gene responsible for it is contained on the x chromosomes.

when women have the gene on one of their x’s they usually have the other x as a spare and it cancels it out. men only have XY so they have no fail safe

most common form is (red/green) long/medium wavelength cones

Mammalian  vision

Vision is crossed , so right goes to left side of the brain, and vise versa

Reduction  in one neuron by activity  in the neighboring neurons

• cookie anology in text book

how does mammalian vision work

1. we have light coming in hitting back of the receptor

2. receptors sends excitory to bipolar and horizontal cell.

3. horizontal send inhibitory messages to previously stated bipolar cell

4. (look at chart in slides) only the number matching up to triggered receptor the most, bipolar cells near by are getting left overs

5. sharpens the edges or what you see

more processing of vision

ANOLOGY— receptors are students, bipolar cells are school of discipline, ganglions are the university presidents and deans.

tons of receptors, talk to bipolar cells, which we have less of, talk to ganglion, we have significantly (compared to the other) less, but they are most important

in the occipital lobe

lateral geniculate → primary visual cortex

VI

is making your vision when you are literally just looking around. some are impaired (blind people)

Responsible for generating view of world

VI causes

Aphanstasia → too little imagery

Hyperphantasia → too much image

The primary cortex

simple cells

complex cells

end stopped/ hypercomplex

develop visual cortex

1. Work involving animal study helps understanding

2. Lack of stimulation → receptors synapses looses sensitivity

3. Sensitive period ends w/ onset of chemicals that inhibit axonal sprouting

4. Worked w/ kittens so they could only recognize patterns and wouldn’t well IRL

Impaired infant vision

Vision can be restored

difficultly recognize objects

unable to tell components are part of a whole

early correction is best fixed

ventral and dorsal stream

Generally, the majority v1 v2 v3 are in the occipital but not all of them are exclusive to occipital

ventral stream

the ‘what’

Important  for identifying  and recognizing objects

Dorsal Stream

the ‘how’

tracking movement → you cant identify where the fly is

Visual agnosia

pattern pathway ventral stream→ temporal cortex

direction doral stream → parietal lobe

Recognize faces = fusiform gyrus

Fantz (1963)

1. young infant study 10 hours to 5 days old

2. had to be young and keep eyes open for image

3. showed images in slide show

4. found fixiated on faces (they did like patterns)

5. had a preference for too heavy configuration. diff between it and normal was very small

motion perception

implied movement → you see a pic and you can guess how it will move

when everything moves (your head) it is less responsive

when damaged, you can tell things exist, but can’t see them movement

implied movement

you see an object in a picture and you can guess how it will move

First sensory system

Was chemical. it is imprtant because it helps us detects toxins

taste

to determine if you should consume something

perception of flavor is both taste and smell.

perception of flavor

we have 5 or 6 taste receptors and thats taste only, but in order to perseve flavor, like cherry vs, strawberry, it’s mostly up to the olfactory system

taste receptors

modified skin cells located in papillae

salty, sweet, bitter, sour, umami, and olegostus

change perception in stimuli

adaptation. your receptors can get tired ( like when you eat something sweet and keep going and the taste dwindles)

taste coding

most if not all respond to one taste

bitter receptors could send it to neurons specilized in bitter or not

touch aspect of taste → somatosensory cortex

insula

‘disgust’ primary cortex “blech”

variation in taste sensitivity

olfaction

detect and chemicals

critical in most mammals

olfactory have hairs too, close to the nasal massage way, called cillea

physics of sound

Sound waves displace air molecules

Amplitude

How loud something is. the lower the bumps of the sound waves, the quieter.

Frequencies

pitch. the deeper the sound, the more spread out the waves

Children vs. adults

____ can hear more frequencies than ____

Prosody

Communicating emotional information through tone of voice

outer ear

pinna

pinna

The outside of an ear

helps locate sound, like if sound was a ping pong ball and the pinna is the blocks in that one arcade game

Middle ear

Tympanic membrane/ ear drum

Malleus/ Hammer

Incus/ anvil

Stapes/ stirrup

what does the middle ear do?

Transfers sound waves to bigger waves in ear

Inner Ear

*NOTES UNCLEAR

Pitch perception

frequency theory

place theory

Frequency theory

Basicylar membrane in synchrony  with sound, so auditory nerve axons to produce APs at the same frequeny

place theory

areas on basilar membrane only on frequency of sound waves. so, we’d have different hairs for different frequencies  frequencies like cones.

Auditory cortex

control ateral

Primary auditory cortex= in the temporal lobe

you have to hear things in order for auditory to develop

• “what” vs “where pathways”

• parallels visual cortex

  • Like language, phonemes. SOme sounds, if you never hear them while you are developing, you don’t know what they are

Before it goes to primary auditory cortex, it goes in the hypothalamus

A1

(primary cortex) more responsive to preferred sound(??? unclear if it’s sound)

damage to a1 doesn’t cause deafness like v1 causes blindness

sound localization

compare responses on the three cues

1. Sound of arrival

2. sound shadow

3. phase difference

sound of arrivals

how quick it reaches the ear

sound shadow

where does the sound become deafened

phase difference

where in the cycle if wavelength is hitting the ear.

synesthesia

you have two things that become tied like associating number w/ color

happens in family with perfect pitch

muscle contraction

movement depends on ____

smooth muscles

control the digestive system other organs

skeletal muscles

movement attached to bones

cardiovascular muscle

muscles controlling heart organ (??)

types of muscles

smooth

skeletal muscles

cardio vascular

muscles and movements

muscles of comprised of many fibers, and each fiber has a 1:1 ratio with axons. this causes movements to be more precise.

movement

requires alternating contraction of opposing set of muscles 

flexor muscle

flexes raises

Extensor muscle

Extends straightened

fast twitch

anerobic → behaviors requiring quick movements. Like a health bar— you use all your oxygen and have to gain it back after

Slow twitch

aerobic → laid back activities. you replace as you go

proprioceptors

critical for walking on uneven ground, detects the position or movement of a part of the body

muscle spindles 

 proprioceptors parallel to the muscle that respond to a stretch; causes a contraction of the msucles

Golgi tendon organ

another type of proprioceptors that responding to increases in muscle tension is a “brake” so you dont over extend

Combo of voluntary and involuntary

Most movements are a ___ ___ ___ ________ movements, like walking

Ballistic

once you start to intitiate, you cannot finish

other movements not Ballistics

guided by feedback

central pattern generator

neural mechanisms in spinal cord or else where that generate rythmic patterns of motor output

sequence of behavior

sequence is fixed from beginning to end. like yawning or sneezing . and if you think about it, you’ll start to suck.

pathway of movement

frontal lobe has a precentral gyrus

in that precentral gyrus, there is a

primary motor cortex, axons connect to the brainstem and the spinal cord, which generate impulses that control the muscles

planning movement

specific areas of the primary cortex are responsible for control of specific areas of the opposite side of the body.

• Some overlap does exist

We have some much movement in our face and fingers because we use them so much

Primary motor cortex

active in planning of movements

outcome movements= what do I want to do

movement= actually executing it.

posterior parietal cortex

keeps track of position of body

• so you don’t hurt yourself and are aware of surrounding

subblementary (??) motor cortex

second before you move

• errors

• initial voluntary movement

prefrontal cortex

route of movement

• preperation of movement

• receives info about target and current body position

prefrontal cortex

delay before movement

• considers the probability of the movements outcome

• relevant sensory information