exam 2 - bio psych

pupil

the hole found within the iris where light can enter

Size of pupil is regulated by this

iris

gives eye its color

lens

behind the pupil, focuses incoming light on the retina

Focus occurs through what process

accommodation

ciliary muscle

When focused on something far away, lens is flattened

Heterochromia

A condition where two irises are different in colors

vertical pupils

helps to maintain sharp focus across horizontal fields (allows to more accurately judge their prey)

Horizontal pupils

sacrifice sharpness for a wider peripheral view

cornea

the outermost surface of the eye in the front it is clear and dome shape

sclera

the outermost surface of the eye excluding the cornea

iris

a thin layer behind the cornea

ligament

they hold the lens in place are connected to the ciliary muscles on the top and bottom

retina

the part of the eye beyond the lens

light sensitive tissue located at the back of the eye

optic nerves

they line the retina at the top and bottom and leave together at the back of the eye

fovea

the indentation at the center of the retina

The fovea is the only part capable for mediating high acuity (mainly because the RG cells are thinnest over the fovea and light is less distorted)

five layers of the retina: Retinal Ganglion Cells

over 30 different types within the retina

The cells are horizontally arranged in parallel, with their axons to the left are dendrites to the right. The axons join together to form a long bundle that moves down to the optic nerve and the blind spot

five layers of the retina: Amacrine cells

communicates laterally across major channels of sensory input

these intermingle with the bipolar cells and connect to both bipolar cells and ganglions

five layers of the the retina: bipolar cells

two sides

these exist to the right of ganglions as horizontally arranged parallel cells

five layers of the retina: Horizontal cells

communicates laterally across major channels of sensory input

these intermingle with the bipolar cells and connect to both bipolar cells and receptors, which form the final layer

five layers of the retina: receptor

(farthest from the light) incoming light is distorted by four layers.

these neurons come in two shapes. On the left side of the cell body they connect to bipolar cells and horizontal cells. On the right, the cell is shaped either like a rod or cone. To the right of these receptors is the back of the eyeball

optic disk

is where the axons of retinal ganglion cells penetrate the retina and exit the eye (this area has no receptors creating a blind spot)

cones

cone shaped receptors in the retina, less sensitive to light and responsible for detailed vision.

these cells work well in the bright light and help you see more of the shades of color and acuity of what you are looking at.

three types of cones

s-cones: short, more sensitive to blue

m-cones: medium, more sensitive to green

l-cone: long, more sensitive to red light

rod

rod shaped receptors, highly sensitive to light and help with vision in dim light, less color and acuity

these help you see in black and white they help you see more shaped and movement when it is dim or dark out.

more sensitive to blue-green (peak sensitivity around 498 nanometers)

duplexity theory

the conceptualization of the retina as containing two different type of photoreceptors

photopic vision

(cone mediated vision) good lighting and high acuity, allows for color to be more present

scotopic vision

(rod mediated vision) lacks in detail and color but increases light

Spectral sensitivity curve

explained how sensitive our eyes are to different colors of light across a visible spectrum (the rainbow) this is done in wavelengths

color blindness

a condition where a person has difficulty distinguishing certain colors (this has to do with missing one or more of the cone systems)

Ishihara Plate:

tests for red green color blindness

trichromatic theory

First proposed in 1820 by Thomas Young and refined by Von Helmholtz in 1852.

One of the three different types of photopigments coats each cone; each photopigment reacts optimally to a particular part of the spectrum of electromagnetic energy.

The ratio of cones activated at a particular part of the color spectrum

opponent process theory

Was first proposed by Hering in 1878. Opponent processing occurs at all levels of the visual system beyond the receptors.

Three classes of cells: one that becomes more active to red and less active to green; one that becomes more active to blue and less active to yellow; and one that becomes more active to bright and less active to dark areas

color consistency

Perceive same color despite changes in wavelengths of the light

visual cortex

The part of the brain that will process the visual information (turns vision from your eyes into images in your mind)

This is where the optic nerve sends its signals

V1: (primary cortex) processes basic features like edges, shapes and contrasts

sensation

the process of detecting the presence of a stimuli

perception

the higher order process of integrating recognizing and interpreting patterns of sensations

primary sensory cortex

received the majority of the input from the thalamic relay nuclei of the system

thalamic relay nuclei

are a specific region within the thalamus that transmit sensory information to the appropriate cortex

secondary sensory cortex

receives most of the input from the primary sensory cortex of that system

association cortex

any area of the cortex that receives input from many sensory systems, most come from the secondary sensory cortex

hierarchical organization

input is assigned to specific levels or ranks in relation to one another

functional segregation

this refers to the idea that different parts of the brain process distinct types of sensory information separately (different kind of analysis done at each cortex)

parallel processing

simultaneous analysis of a signal in different ways by multiple parallel pathways of a neural network

physical aspects (ears)

are objective, measurable and describe the properties of sound waves themselves

what the ear does

perceptual aspect

are subjective, experiences through our senses, and describe how we interpret the physical properties of sound

what the brain does

auditory cortex

the part of the brain responsible for processing sound information

located in superior temporal gyrus

damage to the anterior cortex

(what pathway) results in trouble identifying sounds

damage to the posterior auditory cortex

(where pathway) results in difficulty locating sounds

somatosensory system: exteroceptive system

external stimuli applied to the skin

mechanical stimuli

thermal stimuli

nociceptive stimuli (pain)

somatosensory system: proprioceptive system

position of the body that comes from signals sent by muscles, joints and organs of balance

somatosensory system: interoceptive system

general info about conditions within the body (temperature and blood pressure)

two major somatosensory pathways

1. Dorsal column medial meniscus system: this tends to carry information about touch and proprioception (position of body)

2. Anterolateral system: tends to carry information about pain and temperature

Neuroplasticity

the brain's ability to change and adapt due to experience. It is an umbrella term referring to the brain's ability to change, reorganize, or grow neural networks. This can involve functional changes due to brain damage or structural changes dues to learning

gliomas

tumors starting from glial cells

are the most abundant type of of malignant tumors

metastatic

transmission of disease from one organ to another

originated in the lungs

infarct

The area of the dead or dying tissue produced by a stroke

cerebral hemorrhage

bleeding in the brain

This occurs when a blood vessels breaks in the brain and seeps into the surrounding neural tissue causing damage to it

cerebral Ischemia

disruptions of the blood supply to an area of the brain

thrombosis

blocks the blood flow to an area

embolism

carried in the bloodstream from a larger vessel to a smaller one causing it to become lodged

arteriosclerosis

the wall of a blood vessel thickens and the channels narrow which leads to blockage

contusions

are closed head TBI's that involve damage to the cerebral circulatory system

chronic traumatic encephalopathy

occurs due to a serious blow to the head and or repeated blows to the head

types of seizures

tonic - rigid

clonic - convulsions

focal seizures

does not involve the entire brain

a pinpoint

generalized seizures

involve the entire brain

can begin focal but spread to the entire brain

Parkinson's disease

A movement disorder that can start around mid to old age

Symptoms include tremors, muscle rigidity, difficulty initiating movement, slowness of movement and a mask like face

Lack of dopamine can play a major role

Huntingtons disease

Similar to PD as it is a motor disorder but it is much more rare

progresses to major motor problems and cognitive deterioration.

progresses until death

multiple sclerosis

is a slow progressive disease that attacks the myelin of axons in the CNS

Alzheimers disease

Stage one: preclinical stage involves pathological changes in the brain without any symptoms

Stage two: prodromal stage involves mild cognitive impairment

Stage three: dementia stage involves a progressive decline in memory, deficits in attention, and personality changes. These are usually followed by marked confusion, irritability and deterioration of speech

learning

how experience changes the brain

memory

how these changes are stored and subsequently reactivated

amnesia

any pathological loss of memory

what procedure did HM have

bilateral medial temporal lobectomy

suffered from severe epilepsy

retrograde amnesia

memories for events before surgery

anterograde amnesia

no memory of new events

explicit memories

experiences; learning

implicit memories

unconscious memories

muscle memory

episodic

type of long term memory that involves conscious recollection of previous experiences together with their context in terms of time, place, associated with emotions

semantic

type of long term memory involving the capacity to recall words, concepts, or numbers which is essential for the use of understanding of language

Deficits in episodic more severe in bilateral temporal lobe amnesia

reasoning of Korsakoff Syndrome

results in B1 deficiency (thiamine)

infantile amnesia

we remember virtually nothing events in our infancy

reconsolidation

the process where reactivated long term memories become temporarily unstable and susceptible to modification before being restabilized essentially allowing for the updating of stored memories

five brain area implicated in memory

1. Inferotemporal cortex: (complex visual functions) helps to store memory from visual input

2. Amygdala: emotionally significant memories (rats and shock) the amygdala has not been shown to store the memory but increase the emotional significance

3. Prefrontal cortex: deficits in working memory can occur with damage to this area

4. Cerebellum: works in the storage of memories of learned sensorimotor skills

5. Striatum: habit forming memories