Brain and Behavior 2

Receptor

cell, often specialized neuron, suited by its structure to respond to specific form of energy, such as vibration of sound

Sensation

acquisition of sensory information

Perception

interpretation of sensory information

Frequency

number of cycles or waves of alternating compression and decompression of vibrating medium per second

Pitch

psychological perception of frequency of a sound

Intensity

physical energy in a sound, influenced by the wave’s amplitude

Loudness

our perception of a sound’s intensity

Pure tones

waveforms with a very regular (sine) wave, which have only one frequency

Complex sounds

sounds that mix several frequencies, showing combination of frequencies and amplitudes: musical tone or random noise

Pinna

flap of the ear on the side of the head, also called the outer ear

Tympanic membrane

very thin membrane stretched across end of the auditory canal

Ossicles

tiny bones in the middle ear that operate in lever fashion to transfer vibrations from tympanic membrane to the cochlea

malleus

hammer

incus

anvil

stapes

stirrup

Eustachian tube

middle ear structure that connects middle ear to the back of the mouth, equalizing air pressure of middle ear with the outside world

Cochlear canal

location of auditory receptors which vibrate due to activity in vestibular and tympanic canals

Organ of Corti

sound-analyzing structure that rests on basilar membrane which consists of four rows of specialized cells called hair cells

Inner hair cells

sensory cells that receive 90–95% of auditory neurons

Outer hair cells

increase cochlea’s sensitivity both by amplifying its output and sharpening frequency tuning at location of peak vibration

Frequency theory

assumes neurons from adjacent receptor locations project to adjacent cells

Telephone theory

early form of frequency theory developed by William Rutherford that posited individual neurons in auditory nerve fired at save frequency as rate of vibration of sound source

Volley theory

groups of neurons follow frequency of sound at higher frequencies when single neuron cannot

Place theory

any one of a group of theories that states that encoding sound frequency depends on location of maximal vibration

Frequency-place theory

combination theory stating frequency following by individual neurons accounts for frequencies up to about 200 Hz and all remaining frequencies are represented by place of greatest activity

Interaural level difference

locating sounds caused when sound interference of head causes near ear to receive more intense sound

Interaural timing difference

a sound directly to person’s left or right takes about 0.5 milliseconds to travel additional distance to second ear

Head-related transfer function (HRTF)

frequency alterations to sound as it passes through pinna and auditory canal, as well as through the head and other parts of body

Coincidence detectors

neurons that fire most when they receive input from both ears at the same time

Echolocation

a sort of sonar typically used by animals like bats, dolphins, and cave-dwelling birds, animals use sound localization to avoid obstacles in total darkness

Language

structured system of communication with common set of grammatical and organizational rules

Grammar

consistent set of language rules

Aphasia

language impairment caused by damage to the brain

Broca’s aphasia

language impairment caused by damage to Broca’s area and surrounding cortical and subcortical areas

Four primary qualities of Broca’s aphasia

non-fluent, anomia, difficulty articulation, agreammatic

Wernicke’s aphasia

language impairment where person has difficulty understanding and producing sensical spoken and written language

alexia

inability to read

agraphia

inability to write

angular gyrus

brain pathway that connects visual projection area with auditory and visual association areas in temporal and parietal lobes

97 million

light receptors in the human eye

electromagnetic spectrum

variety of energy forms, ranging from gamma rays at one extreme of frequency to the radiations of alternating current circuits at the other

retina

light sensitive tissue at the rear of the eye, made up of two main types of light-sensitive receptor cells, called rods and cones, and neural cells connected to them.

Fovea

A 1.5-mm-diameter circle in the middle of retina that contains the greatest concentration of cones

Visual acuity

ability to distinguish details

Receptive field

area of the retina from which a ganglion cell receives its input

Axons of ganglion cells join into

optic nerves

Retinal disparity

discrepancy in location of an object’s image on the two retinas

primary visual cortex (occipital lobe)

visual information is processed

Trichomatic theory (Young-Helmholtz theory)

asserts that just three color processes account for all the colors we are able to distinguish

Opponent process theory

attempts to explain color vision in terms of opposing neural processes

Complementary colors

colors that cancel each other out to produce a neutral gray or white

Retinotopic map

layout of visual cortex, where adjacent retinal receptors activate adjacent cells in visual cortex

Form vision

detection of an object’s boundaries and features

Lateral inhibition

retinal boundary where each neuron’s activity inhibits the activity of its neighbors and in turn they inhibit its activity

Simple cells

cells that respond to line or edge at specific orientation and place on retina

Complex cells

cells that continue to respond when a line or edge moves to a different nearby location

Spatial frequency theory

visual cortical cells analyze luminosity variations in a scene

Modular processing

segregation of various components of processing into separate locations

Hierarchical processing

lower levels of nervous system analyze information and pass results on to the next higher level for further analysis

Parvocellular system

allows discrimination of fine detail and color

Magnocellular system

specialized for brightness contrast and movement

Ventral stream

stream from visual cortex into temporal lobes

Dorsal stream

stream from visual cortex to parietal lobes

Object agnosia

impaired ability to recognize objects

Fusiform face area (FFA)

part of fusiform gyrus located in inferior temporal cortex central to face recognition.

Prosopagnosia

impaired ability to visually recognize familiar faces

Blindsight

ability to respond to visual stimuli that are not consciously seen

Visual word form area (VWFA)

“object” recognition function that responds to written words as a whole

Color agnosia

loss of ability to perceive colors due to brain damage

Movement agnosia

impaired ability to detect movement

Binding problem

how the brain combines information from different areas into a unitary whole

Synesthesia

condition in which stimulation in one sense triggers an experience in another sense or a concept evokes an unrelated sensory experience

Somatosenses

Proprioception, skin senses, Interoceptive system, and vestibular system

Proprioception

The awareness of the position of our bodies in space

Skin senses

touch, warmth, cold, texture, and pain. Distinct with their own receptors and pathways

The Vestibular Sense

sense of balance, it provides information about head position. Maintained by fluid-filled vestibular organ of inner ear

Dermatome

an area of skin that is mainly supplied by afferent nerve fibers from the dorsal root of any given spinal nerve.

Somatotopic map

the point-for-point correspondence of an area of the body to a specific point on the central nervous system.

Primary versus secondary somatosensory
cortex

the primary somatosensory cortex receives sensory information from the ventral posterolateral nucleus of the thalamus, whereas the secondary somatosensory cortex processes sensory information delivered to the primary somatosensory cortex.  

Body integrity identity disorder (apotemnophilia)

a mental disorder characterized by a desire to have a sensory disability or physical disability or feeling discomfort with being able-bodied, beginning in early adolescence and resulting in harmful consequences.

pain

an unpleasant sensory and emotional experience

Inflammatory soup

Histamine, proteins, lipids, neurotransmitters, and cytokines

Substance P

a neuropeptide, belonging to the tachykinin family of neuropeptides that acts as a neurotransmitter and a neuromodulator

Endorphins

hormones that are released when your body feels pain or stress

Gate control theory

modulates sensory input from the skin before it evokes pain perception and response

Periaqueductal gray (PAG)

a brain region that plays a critical role in autonomic function, motivated behavior and behavioral responses to threatening stimuli

phantom pain

a painful perception that an individual experiences relating to a limb or an organ that is not physically part of the body, either because it was removed or was never there in the first place

Muscle spindles

stretch receptors within the body of a skeletal muscle that primarily detect changes in the length of the muscle

Golgi tendon organs

monitors muscle force and tension

Central pattern generators (CPGs)

self-organizing biological neural circuits that produce rhythmic outputs in the absence of rhythmic input

Premotor cortex

an area of the motor cortex lying within the frontal lobe of the brain just anterior to the primary motor cortex

Supplementary motor area

a part of the motor cortex of primates that contributes to the control of movement

Primary motor cortex

a brain region that in humans is located in the dorsal portion of the frontal lobe

Basal ganglia

a group of subcortical nuclei (cluster of neurons) found in the brains of vertebrates.

Parkinson’s disease

Affects the basal ganglia, in particular the substantia nigra

Huntington’s disease

Damage starts in the striatum, moves on to rest of brain

Myasthenia gravis (MG)

Attacks acetylcholine receptors in muscles