Biopsychology Exam 2 UW

Sensation

Detection of our environment by our bodies and brains

Perception

The subjective experience of our environment

Transduction

Translation of external stimulus into a neural signal

Touch: Mechanical pressure

Taste and Smell: Chemical molecules

Sound: Vibrations of air molecules

Sight: Photons

Retina

A layered structure, composed of five layers of cells

Photoreceptors

These capture the photons of light and covert the light into neurochemical activity through a biochemical process known as phototransduction

Rods

Highly sensitive to light, therefore ideal for vision in dim environments. They simply detect degrees of light and dark. NO response to color. More of them in the human eye.

Cones

Less sensitive to light. Best suited for vision in bright environments. Detects color. More concentrated in the fovea.

Bipolar Cells

They carry information from the photoreceptors to the ganglion cells

Ganglion Cells

On side closest to the lens. Passes information from the eye to the brain.

Fovea

Where cones are most concentrated

On Center Cell

Responds to light that stimulates center region

Off Center Cell

Responds to light that stimulates outer region

Optic Nerve

Signals move toward the brain via axons of the retinal ganglion cells, which converge to form the...

Blind Spot

There can be no photoreceptors at the point where the optic nerve leaves the eye, so this is known as the...

Optic Chiasm

Where the optic nerve from the left and right eye come together

Lateral Geniculate Nucleus (LGN)

A portion of the thalamus that processes electrical signals carrying information about the visual scene

Striate Cortex

Another name for primary visual cortex

Simple Cortical Cells

Respond to a line at a preferred orientation AND particular location

Complex Cortical Cells

Respond to a line of the preferred orientation at ANY location in the receptive field

Ventral Stream

Deciphers WHAT objects are--how to identify and categorize them

Dorsal Stream

Deciphers WHERE objects are and how to interact with them

Motion Blindness

Can still see objects and their positions, but can no longer see motion (snapshots)

Blindsight

A part of the primary visual cortex is damaged, but some part of the brain is still seeing unconsciously

Glutamate

Sent from: Everywhere

Sent to: Everywhere

Major role: Most predominant excitatory NT in the brain

GABA

Sent from: Everywhere

Sent to: Everywhere

Major role: Most predominant inhibitory NT in the brain

Alcohol

Acts on both GABA and Glutamate (increases GABA activity, decreases Glu activity)

Acetylcholine

Sent from: Basal forebrain

Sent to: Cortex, amygdala, hippocampus, skeletal muscles, PNS

Major role: In CNS: learning and memory modulation; in PNS: motor control, parasympathetic activity

Dopamine

Sent from: Substantia nigra, ventral tegmental area

Sent to: Cortex, basal ganglia, nucleus accumbens

Major roles: Reward, learning, memory, and movement

Norepinephrine

Sent from: Brainstem (locus coeruleus), and midbrain

Sent to: Cortex, thalamus, limbic system

Major roles: Alertness, mood, sexual behavior

Serotonin

Sent from: Midbrain and brainstem (raphae nuclei)

Sent to: Throughout forebrain

Major roles: Sleep and wakefulness, mood, anxiety, hunger, lots!

Psychoactive Drugs

A chemical substance that alters perceptions and/or mood (affects consciousness)

NT production, release, clearance

postsynaptic--receptors, cellular processes

How drugs can interfere with NT functioning

Frequency

The number of high/low-pressure cycles that that occur per second is referred to as...

Pitch

Our perception of a sound's frequency

Amplitude

The size of the pressure change from peak to the trough is called...

Loudness

Our perception of amplitude

Outer vs. middle vs. inner ear

1) Pinna, ear canal, tympanic membrane

2) Ossicles (oval window is a gateway)

3) Cochlea, semicircular canals

Pinna

The folds of the outer ear that selectively amplify certain frequencies

Eardrum

Sound waves hit this membrane, deepest part of the outer ear

Ossicles

Three tiny bones in the middle ear that transfer energy from the eardrum to the oval window

Oval window

Gateway to the inner ear

Cochlea

Spiral structure in the inner ear filled with fluid

Basilar membrane

Running along the length of the cochlea, is exposed to the fluid waves triggered by the vibrations of the oval window

Tonotopic map

Fluid vibrations of different frequencies will cause different parts of the basilar membrane to vibrate, effectively creating a...

Inner hair cells

Transduce sound into electrical signals that will be interpreted by the central nervous system

Outer hair cells

Run parallel to inner hair cells, in response to the oscillating voltage, they physically shorten and lengthen, cycle for cycle, as fast as the sound itself, this allows them to mechanically amplify the incoming sound

Cochlear nerve

(Also known as the auditory nerve), consists of the fibers connecting the cochlear inner hair cells to the cochlear nuclei in the brainstem

Labeled line coding

A strategy found in several different sensory modalities: different neurons carry different specific information

Medial geniculate nuclei

(In the thalamus), relays the information to the primary auditory cortex

Interaural differences

Both ears are likely to sense a given sound, but depending on the relative position of that sound, each ear will receive a slighlty different signal. These ______ _______ provide information that the downstream auditory pathway can use to localize the source of the sound

Conduction deafness

Deafness resulting from damage to the outer or middle ear that prevents transmission of sound information to the cochlea

Sensorineural deafness

Deafness resulting from damage to the cochlea itself, which usually involves hair cells

Cochlear implants

These allow patients to completely bypass their own nonfunctioning cochleas and transmit sounds directly to the auditory nerve

Vestibular system

Provides important information about head movements, acceleration, and head position relative to gravity

Semicircular canals

(Three of them), part of the vestibular system, these sense head rotation and angular acceleration

Somatosensory system

Sensations of touch, temperature, pain, and body position are all part of the....

Mechanoreceptors

Detect pressure and vibration, acute sensitivity to physical distortions like stretching or bending

Thermoreceptors

Rely temperature information

Nociceptors

Perception of pain is mediated by specialized sensory receptors

Proprioception

The sense of position and movement of one's own body, provides a constant information stream of where we are in space

Muscle spindles

Report on the length of the muscle and the speed of any stretching

Golgi tendon organ

Seats itself where the tendons meet the muscle, transmit information about muscle tension

Gate control theory

This theory stipulates that pain results from the balance of activity in both nociceptive and nonnociceptive pathways

Taste receptor cell

Cells with receptors that facilitate the sensation of taste

Taste buds

Clusters of taste cells

Papillae

Taste buds cluster to form...

Sweet, sour, salty, bitter, savory

The 5 tastants

Pattern encoding

Sense of taste relies on population of neurons to encode the sensation.

Taste sensation vs. perception

Taste sensation begins with chemical compounds triggering responses in individual receptors, but taste perception involves many more sensory modalities (taste, smell, touch, thoughts, etc.)

Pheromones

Chemicals broadcast by a member of an animals species to transmit information (such as identity and sexuality) and trigger behaviors within other members of the same species

Synesthesia

(Joined sensation), is a harmless perceptual condition in which one hears colors, tastes, or shapes, or experiences other equally startling sensory blendings

Anosognosia

An absence of awareness about a physical impairment

EEG

The main technology used for studying sleep

REM

During this kind of sleep, brain waves become high frequency and low amplitude. The heart rate and breathing speed up, rapid eye movement occurs, and major muscle groups are paralyzed.

Slow-wave sleep

(Deepest sleep), brain's electrical activity oscillates at a low frequency with high amplitude, heart rate and breathing become slow and regular

Stage three, REM

There is more _____ sleep in the beginning of the night and more____ towards the end of the night

VLPO

A collection of neurons in the hypothalamus that promote sleep. These neurons release inhibitory neurotransmitters to several areas in the brainstem and forebrain that promote wakefulness and alertness.

Locus coeruleus (norephinephrine), raphe nucleus (serotonin), tuberomammillary nucleus (histamine), 2 groups of acetylcholinergic neurons

The arousal network includes several nuclei:

PGO waves

The appearance of these waves just precedes the appearance of REM sleep, and the density of the waves correlates with the amount of eye movement

Circadian rhythm

A natural internal rhythm that runs on an approximately 24-hour cycle and controls sleep wake cycles

Suprachiasmatic nucleus (SCN)

Located in the hypothalamus, receives light info directly from special ganglion cells, regulates sleep wake cycle

Pineal gland

Receives signals from SCN. Produces and releases melatonin into the cerebrospinal fluid

Melatonin

Related to sleep, but not directly. "Darkness" horomone. Influences wakefulness

Sleep deprivation

Irritability, muscle aches, yawning, difficulty maintaining attention, microsleeps, increase of stress, etc, are signs of...

Microsleeps

Brief sleep periods in the second or even subsecond range

Insomnia

Involves not getting enough sleep to feel rested, continuous state of hyperarousal

Hypersomnia

People with this condition suffer an excessive amount of sleepiness, typically in recurring episodes

Narcolepsy

Hypersomnia is the main symptom, experiences extreme fatigue at inappropriate times, can also suffer from muscle weakness and have poor nighttime sleep

Cataplexy

When muscles weaken suddenly. This can manifest as a slight sagging to a complete shutdown of the muscles leading to total collapse

Orexin

Narcolepsy results from a lower level of a hormone that promotes wakefulness

Sleepwalking, night terrors

NREM parasomnias

Sleep paralysis, REM sleep behavior disorder

REM parasomnias