Perception psych

midterm 1 (chapters 1,2,3)

frontal lobe

area of the brain that plays a key role in perceptions involving the coordination of sensory information

psychophysics

category of quantitative methods for measuring relationships between stimulus properties and subjects’ experiences

parietal lobe

cortical receiving area for touch and the termination point of visual processing’s dorsal stream

magnitude estimation

psychophysical approach where subject assigns numbers to a stimulus that are proportional to subjective degree

absolute threshold

smallest stimulus level that can just be detected

temporal lobe

cortical receiving area for hearing and the termination point for visual processing’s ventral stream

perception

conscious sensory experience

cerebral cortex

layer of the brain that contains the machinery for creating perception, language, memory, and thinking

principle of representation

perception that everything one perceives is based on representations of stimuli on the receptors

method of limits

psychophysical approach where experimenter presents sequences of stimuli in ascending and descending order

perceived magnitude

measure of stimuli, such as light or sound, that indicates the degree of experience

perceptual process

sequence leading to recognition of the stimulus and action with regard to the stimulus

transduction

transformation of environmental energy into electrical energy

sensory receptor

cell specialized to respond to a specific type of environmental energy

electromagnetic spectrum

continuum of energy that extends from very-short-wavelength gamma rays to long-wavelength radio waves

occipital lobe

site of the cortical receiving area for vision

phenomenological report

method of determining the relationship between stimuli and perception where the observer describes what they perceive

primary receiving area

area that first takes in most of the signals initiated by a sense’s receptors

top-down processing

processing that starts with the analysis of high-level information

proximal stimulus

in vision, the image on the retina

principle of transformation

perception that stimuli and responses created by stimuli are transformed between environmental stimulus and perception

oblique effect

enhanced sensitivity to vertically and horizontally oriented visual stimuli compared to obliquely oriented stimuli

visual form agnosia

inability to recognize objects

knowledge

any information that the perceiver brings to a situation

sensation

often identified with elementary processes that occur at the beginning of a sensory system

cell body

part of a neuron that contains the neuron’s metabolic machinery, receiving information stimulation from other neurons

receptor site

small area on the postsynaptic neuron that is sensitive to specific neurotransmitters

modularity

idea that specific areas of the cortex are specialized to respond to specific stimuli types

Broca’s area

area in the frontal lobe that is important for language perception and production

seed location

brain location involved in a specific task and a reference point when measuring resting-state functional connectivity

nerve fiber

long part of the neuron that transmits electrical impulses from one point to another

neuron

structure that transmits electrical signals in the body

module

structure that processes information about a specific behaviour or perceptual quality

axon

part of the neuron that conducts nerve impulses over distances

brain imaging

type of procedure used to visualize areas of the human brain activated by different types of stimuli

functional connectivity

neural connectivity between two areas of the brain activated when carrying out a specific function

structural connectivity

physical “road map” of fibers connecting different areas of the brain

action potential

rapid increase in positive charge in a nerve fiber that travels down the fiber

depolarization

occurrence where the inside of a neuron becomes more positive

sensory coding

how neurons represent various characteristics of the environment

Wernicke’s area

area in the temporal lobe involved in speech perception

ions

charged molecules, mainly sodium, potassium, and chlorine, within nerve fibers and in the surrounding

neurotransmitter

chemical stored in synaptic vesicles that is released in response to a nerve impulse

resting potential

charge difference between the inside and outside of the nerve fiber when not conducting signals

synapse

small space between the end of one neuron and the cell body of another neuron

refractory period

time needed by a nerve fiber to recover from conducting a nerve impulse

permeability

property of a membrane that refers to the ability of molecules to pass through it

propagated response

response that travels all the way down the nerve fiber without decreasing in amplitude

distributed representation

occurs when a stimulus causes neural activity in a number of different areas of the brain

spontaneous activity

nerve firing that occurs in the absence of environmental stimulation

light-adapted sensitivity

usually taken as the starting point for the dark adaptation curve

rod spectral sensitivity curve

curve plotting visual sensitivity versus wavelength for rod vision

cornea

transparent layer forming the front of the eye

visible light

band of electromagnetic energy that activates the visual system and that, therefore, can be perceived

lens

transparent focusing element of the eye

neural convergence

occurrence where many neurons synapse onto a single neuron

cone

receptor in the retina responsible for colour vision and detail vision

spectral sensitivity

acuteness of visual receptors to different parts of the visible spectrum

fovea

small area in the human retina that contains only cone receptors

dark adaptation

increase of eye’s sensitivity to light when light in the room decreases

wavelength

distance between one peak of a light wave and the next peak

macular degenteration

clinical condition that causes decay of an area of the retina that includes the fovea and a small surrounding area

receptive field

area on the receptor surface that, when stimulated, affects the firing of that neuron

accomodation

act of bringing objects located at different distances into focus by changing the lens shape

myopia

inability to see distant objects clearly (nearsightedness)

blind spot

small area where the optic nerve leaves the back of the eye

isomerization

change in shape of the retinal part of the visual pigment molecule; occurs when a quantum of light is absorbed

rod

receptor in the retina that is responsible for vision at low levels of illumination

refractive myopia

nearsightedness in which the cornea and/or the lens bends the light too much

hyperopia

condition in which people can see objects that are far away but do not see near objects clearly (farsightedness)

cone spectral sensitivity

plot of visual acuteness versus wavelength for cone vision

inhibitory area

area of receptive field that is associated with inhibition

axial myopia

nearsightedness in which the eyeball is too long

presbyopia

inability of the eye to accommodate due to hardening of the lens and weakening of the ciliary muscles

Purkinje shift

movement from cone spectral sensitivity to rod spectral sensitivity that takes place during dark adaptation

retinitis pigmentosa

retinal disease that causes a gradual loss of vision, beginning in the peripheral retina

optic nerve

bundle of nerve fibers that carry impulses from the retina to the lateral geniculate nucleus

retinal detachment

condition in which the retina is detached from the back of the eye

visual acuity

ability to resolve small details

spectral sensitivity curve

function relating a subject’s sensitivity to light to the wavelength of the light

rod spectral sensitivity curve

curve plotting visual sensitivity versus wavelength for rod vision

grandmother cell

highly specific type of neuron that fires in response to a specific stimulus

inhibitory response

occurrence where a neuron’s firing rate decreases due to restriction from another neuron

excitatory response

response of a nerve fiber in which the firing rate increases

dendrites

nerve processes on the cell body that receive stimulation from other neurons

neural processing

collection of operations that transform electrical signals within a network of neurons

difference threshold

minimum difference that must exist between two stimuli before we can detect a change between them

bottom-up processing

processing that is based on the information on the receptors

distal stimulus

something “out there” in the external environment

grating acuity

smallest width of lines that subjects can detect

sparse coding

stimulus is represented by a pattern of firing of only a small group of neurons

population coding

stimulus is represented by a pattern of firing of a very large group of neurons

Magnetic Resonance Imaging (MRI)

creates images of structures in the brain

Diffusion Tensor Imaging (DTI)

specialized type of MRI used to visualize white matter fiber tracts and to assess structural integrity

Functional Magnetic Resonance Imaging (fMRI)

measures localized increases in blood flow

photon

single particle of light

extraocular muscles

6 muscles that operate primarily in pairs to move the eyes vertically, horizontally, or torsionally in a twisting fashion

strabismus

a disorder of the extraocular muscles where the eyes are not aligned (lazy eye)

amblyopia

a condition in which both eyes develop normally but the neural signals from one eye aren’t processed properly, leading to legal blindness in the weak eye.

cataract

opacity of the lens that prevents clear vision