PSY 10000 #2

sensation

simple stimulation of a sense organ

perception

organization, identification, and interpretation of a sensation in order to form a mental representation

transduction

process whereby sense receptors convert physical signals from the environment into neural signals that are sent to the central nervous system

sensory adaptation

sensitivity to prolonged stimulation tends to decline over time as an organism adapts to current (unchanging) conditions

psychophysics

methods that systematically relate the physical characteristics of a stimulus to an observers preception

absolute threshold

measure of psychophysics that determines minimal intensity needed to just barely detect the stimulus in 50% of trials

sensitivity

how responsive we are to faint stimuli (measured by absolute threshold)

just noticeable difference (JND)

measure of psychophysics that determines minimal change in a stimulus that can just barely be detected

acuity

how well we distinguish two very similar stimuli (measured by JND)

Weber's law

for every sense domain, the change in a stimulus that is just noticeable is a constant proportion despite variation in intensities

noise

all other stimuli coming from internal and external environments

signal detection theory

the response to a stimuli depends both on a person's sensitivity to the stimulus in the presence of noise and a person's detection criterion

cornea

clear, smooth outer tissue which bends light and sends it to the pupil; where light first passes through in vision process

pupil

a hole in the iris

iris

translucent, doughnut-shaped muscle that controls the size of the pupil and hence the amount of light that can enter the eye

lens

controlled by muscles inside the eye to bend light after passing though pupil and focus it into the retina

accomodation

process whereby the eye maintains a clear image onto the retina; lens becomes fatter for far objects and rounder for close objects

retina

layer of light-sensitive tissue lining the back of the eyeball

myopia

nearsightedness; eyeball too long and images focused in front of the retina

hyperopia

farsightedness; eyeball too short and images focused behind the retina

cones

photoreceptors cells in retinal that detect color, operate under typical daylight conditions, and allow us to focus on fine details; concentrated in the fovea and less common than rods

rods

photoreceptors cells in retinal that are active only under low-light conditions, for night vision; not in fovea and much more sensitive than cones

fovea

an area of the retina where vision is clearest and there are no rods at all; objects no focused in fovea are in peripheral vision

bipolar cells

conduct electrical signals from the rods and cones and transmits them to the RGC

retinal ganglion cells (RGCs)

organize the visual signals and send them to the brain

optic nerve

formed by axons of the RGCs and leave the eye through the blind spot (hole) of the retina

blind spot

location of the visual field that produces no sensation of the retina

area V1

part of occipital lobe which contains primary visual cortext

color-opponent system

pairs of cone types (channels) work in opposition; L-cone (sensitive to long wavelengths) vs. M-cone (sensitive to medium wavelengths) channel and S-cone (sensitive to short wavelengths) vs. M-cone channel; why color afterimage

two visual streams

(1) ventral (lower) stream = areas that represent object's shape and identity (WHAT) & (2) dorsal (upper) stream = areas that identify where object is and how it is moving (WHERE & HOW)

parallel processing

brain's capacity to perform multiple activities at the same time

binding problem

how the brain links features together so that we see unified objects in our visual world rather than free-floating or miscombined featers

illusory conjunction

perpetual mistake whereby the brain incorrectly combines features from multiple objects (binding problem)

feature-integration theory

focused attention not required to detect individual features but required to bind together (why have binding problem)

attention

active and conscious processing of particular information

perceptual constancy

even as aspects of sensory signal change, perception remains constant; how? conceptual knowledge = rich store of facts and meaningful information we have about familiar objects

modular view

specialized brain areas detect and represent specific objects

distributed representation

pattern of activity across multiple brain regions identifies objects

perceptual organization

process of grouping and segregation features to create whole objects organized in meaningful ways (Gestalt psychology) --> simplicity, closure, continuity, similarity, proximity, and common fate

monocular depth cues

aspects of a scene that yield information about depth when viewed with only one eye --> relative size, linear perspective, texture gradient, interposition, and relative heinght in the image

binocular disparity

differences in the retinal images of the two eyes that provides information about depth

apparent motion

perception of movement as a result of alternating signals appearing in rapid succession in different locations

biological motion perception

our ability to perceive biological motion critical for identifying individuals and socially relevant features, such as their emotional state, personality characteristics, and whether they are engaging in deceptive actions

change blindness

when people fail to detect change to the visual details of a scene

inattention blindness

failure to perceive objects that are not the focus of attention

classic model of perception

perception is direct and comes fully formed; eye like hole and projects image onto the brain similar to comera obscura

constructivist theory of perception

brain produces a continuous stream of unconscious predictions, engaging in "unconscious inferences" to evaluate those predictions and update them as needed

exteroception

neural system designed to process sensory input from the external world (vision, audition, touch)

interoception

neural systems designed to process sensory input from the body's internal world (temperature, pain, smell, taste, autonomic visceral function, autonomic vascular function, neuroendocrine fluctuations, neuroimmune functions); part of autonomic nervous system; afferent (body to brain processing) underlines interoception and enables inner state of bodily feeling perceives along valence and arousal dimension

light

critical stimulus for vision; both wave (wavelength correlated with color) and particle (photons correlated with brightness); visible light=portion of the elctromagnetic spectrum that is seen by humans

foveate

to place object in a fovea's area of focus to assess in detail

color

consequence of the perceptual representation of wavelength composition of the light reaching the eye; correspond to the summed activity of three types of cones: S-cones (blue), M-cones (green), and L-cones (red)

population coding

pattern of activation across different populations (types) of cones that determines color

agnosia

what happens when our what vs. where pathways are damaged (loss of knowledge)

apprerceptive agnosia

ventral lesions where patient is unable to recognize or draw objects from visual presentation; patient D.F.

associative agnosia

ventral lesions where patient can perceive intact objects and draw them but is unable to name objects from visual presentations

prosopagnosia

ventral lesions where patient is unable to identify faves through they can still recognize other types of objects

Balint's syndrome

dorsal lesions where patinet has poor control of visually guided movements and is unable to identify two objects at once

sound waves

changes in air pressure unfolding over time; what hearing depends on

pure tone

simple sound wave that consists of regularly altering regions of higher and lower air pressure, radiating outward in all directions from the source

3 physical dimensions of sound waves

frequency determines pitch=how high or low a sound is; amplitude determines loudness=perception of a sound's intensity; complexity (mixture of frequencies) determines timbre=quality of sound that allows you to distinguish two sources with the same pitch and loudness

outer ear

collects sound waves and funnels them to the middle ear (pinna, auditory canal, eardum)

middle ear

transmits vibrations to inner ear (ossicles, oval window)

inner ear

where vibrations are transduced into neural signals (cochlea basilar membrane, inner hair cells)

cochlea

fluid-filled tube that contains cells that transduce sound vibrations into neural impulses

basilar membrane

structure in the inner ear that moves up and down in time with the vibrations relayed from the ossicles and transmitted through the oval window

inner hair cells

specialized auditory receptor neurons embedded in the basilar membrane; bending generated action potential in the auditory nerve axons

area A1

primary auditory cortex in the temporal lobe

place code

brain uses information about the relative activity (what cells are or aren't active) of hair cells across the whole basilar membrane to help determine pitch perceived

temporal code

brain uses the timing of the action potentials in the auditory nerve to help determine pitch perceived

machine learning

form of artificial intelligence in which a computer program learns from data that is input to the program and uses that information to process new data

conductive hearing loss

damage to eardrum or ossicles that inhibit sound wave conduction to cochlea

sensorineural hearing loss

damage to the cochlea, hair cells, or auditory nerve

somatosenses

body senses

haptic perception

active exploration of the environment by touching and grasping objects with our hands (receptors in muscles, tendons, joints, and skin)

touch

transduction of skin sensations into neural signals; receptors sense pain, pressure, texture, pattern, and vibrations with each sensitive to small patch of skin (most of tactile brain devoted to skin parts with highest sensitivity to spacial details --> acuity)

pain

sensation which indicates damage or potential danger to the body

referred pain

sensory information from internal and external areas converge on the same nerve cells in the spinal cord

gate-control theory

signals arriving from pain receptors in the body can be stopped, or gated, by interneurons in the spinal cord via feedback from the skin or brain

proprioception

your sense of bodily position

vestibular system

three fluid-filled semicircular canals and adjacent organs located next to the cochlea in each inner ear that maintain balance

olfaction

sense of smell; odorant molecules make way into the nose through air and trigger olfactory receptor neurons which stimulate the olfactory bulb; enters forebrain DIRECTLY so not regulated by the thalamus

olfactory receptor neurons (ORNs)

receptor cells that transduce odorant molecules into neural impulses (bind only to certain molecules)

olfactory bulb

brain structure located above the nasal cavity beneath the frontal lobes

pheromones

biochemical odorants emitted by other members of an animals' species that can affect its behavior or physiology

taste (gustation)

tongue covered in thousands of small bumps (papillae) which contain hundreds of taste buds; salt, sour, bitter, sweet, and umami (savory)

taste buds

organs of taste transduction; tastant molecule in food react with taste buds' receptor cells (microvilli)

homeostatic self

inner state of "bodily feelings"; sense of feeling alive informed by valence and arousal dimensions

dorsal column-media leminsical pathway

tactile information that crosses when gets to the brain

spinothalamic pathway

carries information for thermoreceptors and nocioreceptors (pain) that crosses in spinal cord; both go to ventral posterior nucleus of thalamus then somatosensory cortex (and insula)

thermoreceptors

communicate information about core temperature vs skin temperature; perception of temperature arises when outside challenges core; core body temperature is usually > skin temperature and body gets really concerned when reversed (pain)

emotion

temporary state that prepares people for actions and is characterized by a distinct subjective experience and pattern of physiological activity; subjective experience, physiological activity, and preparation for action

appraisal

conscious or unconscious evaluations and interpretations of the emotion-relevant aspects of a stimulus or event; emotions response to evaluation of events not events themselves

action tendencies

a readiness to engage in a specific set of emotion-relevant behaviors; response of either approach or avoidance

valence

how positive or negative the experience is (pleasant vs. unpleasant)

arousal

how calm or energetic the experience is

James-Lange theory

subjective experience of emotion FOLLOWS our body's SPECIFIC response to stimulus

Cannon-Bard theory

subjective experience of emotion ACCOMPANIES our body's SPECIFIC response to stimulus

Two-Factor theory

subjective experience of emotion depends on how we LABEL our body's GENERAL response to a stimulus

amygdala

plays a central role in producing emotions; information arrives to amygdala through fast and slow (cortex) pathways