Chapter 5: Psych

Sensation

The brain receives input from the sensory organs

Transduction

The process by which receptor cells (sensory cells) produce an electrical change (action potential) in response to physical stimulation

Absolute threshold

Minimum amount of stimulus/sensation needed for detection (50% of the time)

Subliminal messages

Messages below the threshold of conscious awareness

Difference Threshold/just noticeable difference

Difference in stimuli required to detect a difference between stimuli (perception)

Weber’s Law

Two stimuli must differ by a constant minimum proportion (if stronger, it is harder to tell the difference)

Perception

The brain makes sense out of the input from sensory organs. Consciously experienced

bottom-up processing

Analysis that begins with sensory receptors and works up to the brain’s integration of sensory information→ small to large

Top-down processing

Information processing guided by higher-level mental processes aka use context → big (knowledge) to small

Sensory adaptation

The change in sensitivity that occurs when a given set of sensory receptors and neurons is either strongly stimulated or relatively unstimulated for a length of time

Inattentional blindness

Failure to notice something added because you are so focused on another task

Signal detection theory

Detection depends on experience, expectations, alertness etc. (more likely to notice a door slam when waiting for someone)

Amplitude

Wave height

Wavelength

Length of wave from a peak to the next

Frequency

\# of waves that pass a given point in a given time period

Hertz (Hz)

cycles per second; measure of frequency

Visible spectrum

Large portion of electromagnetic radiation

Red

Long wavelengths

Green

Medium waves

Blue and violets

Shorter waves

Pitch

Frequency of sound wave associated with our perception

Decibels (dB)

logarithmic unit of sound intensity

Timbre

Sound’s purity

Cornea

Transparent tissue on the front of the eyeball that helps focus light that passes through

Pupil

The hole through which light can pass into the eyeball. Black appearing center of iris

Iris

Provides color of the eye. located behind the cornea. controls size of pupil

Lens

Helps the focusing process, and forms images on the retina. Behind iris and pupil

Fovea

small indentation in the retina that contains cones

Retina

Membrane lining the rear interior of the eyeball where photoreceptors (rods and cones) lie. Images formed here. Transduction occurs here.

Photoreceptor cells

Light-detecting cells that lie in the retina (rods and cones)

Cones

Photoreceptor cell which permits sharply focused color vision (detail-oriented). \~ 6 million

Rods

Photoreceptor cells which permit vision in dim light (black and white) \~120 million. sensitive to light

Optic nerve

Runs from back of eye to the brain

Blind spot

Point at which axons of the neurons converge to form the optic nerve, therefore, there is an absence of receptor cells (where optic nerve leaves the eye)

Optic chiasm

Where the optic nerve from each eye merges just below the brain

Trichromatic theory of color vision

Color vision emerges from the combined activity of 3 different types of receptors, each most sensitive to a different range of wavelengths

\-Three cones receive color

\-Missing one cone type explains colorblindness

Opponent-Process Theory

Complimentary colors are processed in ganglion cells, which explains why we see an afterimage. (green red, blue yellow)

Afterimage

Colors of this are the compliments of original→ explained by opponent process theory

Depth perception

How we see objects in a distance from our eyes. Can see this better with both eyes than one

Binocular cues

Rely on use of both eyes

Binocular disparity

Slightly different views that the 2 eyes have of the same object or scene

Monocular cues

Cues that only rely on one eye

Linear perspective

We perceive depth when we see 2 parallel lines that seem to converge

Pinna

Outer ear funnel for receiving sound waves. gives monaural cues

Tympanic membrane

Eardrum/middle ear.

Ossicles

Hammer anvil and stirrup in the middle ear that increase the amount of pressure that sound waves exert so transduction can occur

malleus

Hammer

Incus

Anvil

Stapes

Stirrup

Cochlea

fluid-filled, snail-shaped structure that contains the sensory receptor cells of the auditory system

Hair cells

Receptor cells for hearing located in basilar membrane

Basilar membrane

In the cochlea that contains the hair cells. Sound frequencies are traanslated

Temporal theory

Pitch perception asserts that frequency is coded by the activity level of a sensory neuron

Place Theory

Different portions of the basilar membrane are sensitive to sounds of different frequencies

Monaural

One-eared cues to localize sound

Binaural

2-eared cues to localize sound

Interaural level difference

The sound coming from the right side of your body is more intense in your right ear than left because of the attenuation of the sound wave as it passes through your head

Interaural timing difference/sound localization

Small difference in time at which a given sound wave arrives at each ear

Deafness

Partial or complete inability to hear

Congenital deafness

Born without hearing

Conductive hearing loss

Problem delivering sound energy to the cochlea→ ossicles are rigid and don’t carry the sound inward

Sensorineural hearing loss

Failure to transmit neural signals from the cochlea to the brain→ hair cell damage

Ménière’s Disease

Degeneration of inner ear structures that can lead to hearing loss, tinnitus, vertigo and inner ear pressure

Vertigo

Sense of spinning

Cochlear implants

Electronic devices that consist of a microphone, speech processor, and an electrode array→ sound info directly to the auditory nerve.

Umami

Manosodium Glutamate

Taste buds

Groups of taste receptor cells with hair-like extensions protrude into the central pore. Adapted to look and act like neurons

Olfactory receptor

In the mucous membrane at tope of nose

Meissner’s Corpuscles

Responds to pressure and lower frequency vibrations (receptors on skin)

Olfactory Bulb

tip of frontal lobe where olfactory nerve begins

Pacinian corpuscles

Somatosensory receptors in the skin are activated by vibration. Lets you feel objects through other objects (paper+pencil)

Markel’s disks

Respond to light pressure

Ruffini Corpuscles

Detect stretch

Thermoception

Sensory receptor for temperature and perception

Nociception

Sensory receptor for signaling an indication that there may be potential harm and pain

Inflammatory Pain

Signals some type of tissue damage

Neuropathic Pain

Damage to neurons so pain signals to brain are exaggereated

Congenital insensitivity to pain/congenital analgesia

Cannot experience pain

Vestibular sense

Ability to maintain balance and body posture

Proprioception

Perception of body position

Kinesthesia

Perception of the bodies movement through space

Pattern perception

ability to discriminate among different figures and shapes, occurs due to gestalt psychology

Perceptual Hypothesis

Educated guesses that we make while interpreting sensory information

fMRI

Taking image of where the blood is in the brain

MRI

photo of brain

Protenope

Red cone cells defective

Deuteranope

Green cone cells defective

Tritanope

Blue cone cells defective

Ventral vision stream

“what”: temporal cortex, connect to knowledge and language

Dorsol vision stream

“how/where”: connects to the action happening

Papillae

Gives texture to tongue

Gustation and olfaction

Processes that work like neurotransmitters

Additional salt

More action potentials

Salt and sour receptors

Normal ionotropic channel

Sweet, bitter, umami receptors

Metatrophic channel (more complicated)

Miraculin

Miracle berry→ bitter things taste sweet

Gustatopy

Parts of Insula activated in taste

Process of taste

1) Taste receptors

2) Gustatory nucleus of solitary tract

3) Thalamus

4) gustatory cortex-insula

5) orbitofrontal cortex

2 types of smell

1) from outside

2) from the mouth outwards

Support cells

Without, you lose the sense associated with them