Exam 1 Flashcards
Conscious sensory experience =
Perception
Often identified with elementary processes that occur at the begining of a sensory system
Sensation (also see structuralism)
A sequence of steps leading from the envrironment to perception of a stimulus, recognition of the stimulus, and action with reguard to the stimulus
perceptual process
The stimulus “out there” in the external envrionment
Distal stimulus
The stimulus on the receptors. In vision, this would be the image on the retina
Proximal stimulus
What Principle states that stimuli and responses created by stimuli are transformed, or changed between the environmental stimulus and perception. An example is when light reflected from a tree a person is looking at is transformed at it is focused in the eye’s optical system
Principle of Transformation
= Stimuli and responses created by stimuli are changed between the environmental stimulus and perception
What Principle is the second principle of perception. It emphasizes that an image that has been transformed from light is then represented as something in the person’s eyes. For example, an image of a tree is transformed into the image on the retina, and this image represents the tree in the person’s eyes.
Principle of Representation
= Everything a person perceives is based not on direct contact with stimuli, but on representations of stimuli that are formed on the receptors and on the activity in the person’s nervous system
Cells specialized to respond to envriomental energy, with each sensory system’s receptors specailized to respond to a specific type of energy
Sensory receptors
In the senses, the transformation of envrionmental energy into electrical energy. For exaple, the retinal receptors transduce light energy into electrical energy.
Transduction
Operations that transform electrical signals within a network of neurons or that transform the response of individual neurons
Neural processing
Area of the cerebral corten that first receives most of the signals initiated by a sense’s receptors
Primary receiving area
The primary receiving area for vision
Occipital cortex
The primary receiving area for hearing
Temporal lobe
The 2mm-thick layer that covers the surface of the brain and contains the machinery for creating perception, as well as for other functionc, such as language, memory, and thinking
Cerebral cortex
A lobe at the back of the cortex that is the site of the cortical receiving area for vision
Occipital lobe
A lobe one the side of the corten that is the site of the cortical receiving area for hearing and the termination point for the ventral, or WHAT, stream for the visual processing. A number of areas in this lobe, such as the fusiform face area and the extrastriate body area, serve fuctions related to perceiving and recognizing objects
Temporal lobe
A lobe at the top of the cortex that is the site of the cortical recieving area for touch and is the termination point of the doral (WHERE or HOW) stream for visual processing
Parietal lobe
Receiving signals from all of the senses, what lobe plays an important role in perceptions that involove the coordination of info received through 2 or more senses. It also serves functionc such as language, thought, memory, and motor functioning
Frontal lobe
The ability to place an object in a category that gives it meaning
Recognition
- for ex. recognizing a perticular red object as a tomato
The inability to recognize objects
Visual object agnosia
Motor activites in response to a stimulus
Action
Any info that the perceiver brings to a situation
Knowledge
-also see Top-down processing
Rat-man demonstration
The demonstration in which presentation of a “ratlike” or “manlike” picture influences an observer’s perception of a second picture, which can be interpreted either as a rat or as a man. This demonstration illistrates an effect of top-down processing on perception
Placing objects into categories, such as “tree,” “bird,” “car”
Categorize
Processing that is based on the info on the receptors (based on incoming data)
Bottom-up processing
AKA data-based processing
Processing that starts with the analysis of high-level info, such as knowledge a person brings to a situation (based on prior knowledge)
Top-down processing
AKA kowledge-based processing
Enhanced sensitivity to vertically and horizontally orientated visual stimuli compared to obliquely orientated (slanted) stimuli. This effect has been demonstrated by meaning both perception and neural responding
Oblique effect
The relationship between stimuli and behavioral responses, where behavioral responses can be perception, recognition, or action
Stimulus-behavior relationship
Traditionally, this term refers to the quatitative methods for measuring the relationship between properties of the stimulus and the subject’s experience. In this book, all methods that are used to determine the relationship between stimuli and perception will be broadly referred to as this method
Psychophysics
The narrowest spacing of a grooved surface on the skin for which orientation can be accurately judged
Grating acuity
-also see 2-point threshold
The relationship between stimuli and physiological responses
Stimulus-psychology relationship
Relationship between physiological responses and behavioral responses
Physiology-behavior relationship
The smallest stimulus level that can just be detected
Absolute threshold
The minimum stimulus energy necessary for an observer to detect a stimulus
Thresholds
The methods of limits, adjustments, and constant stimuli, described by Fechner, that are used for measuring thresholds
Classical psychological methods
a psychophysical procedure for determining the sensory threshold by gradually increasing or decreasing the magnitude of the stimulus presented in discrete steps. That is, a stimulus of a given intensity is presented to a participant; if it is perceived, a stimulus of lower intensity is presented on the next trial, until the stimulus can no longer be detected. If it is not perceived, a stimulus of higher intensity is presented, until the stimulus is detected. The threshold is the average of the stimulus values at which there is a detection-response transition (from yes to no, or vice versa)
Method of limits
a psychophysical procedure for determining the sensory threshold by randomly presenting several stimuli known to be close to the threshold. The threshold is the stimulus value that was detected 50% of the time
Method of constant stimuli
- AKA constant stimulus method; method of right and wrong cases
a psychophysical technique in which the participant adjusts a variable stimulus to match a constant or standard. For example, the observer is shown a standard visual stimulus of a specific intensity and is asked to adjust a comparison stimulus to match the brightness of the standard.
Method of adjustment
-AKA adjustment method; error method; method of average error; method of equivalents
The minimum difference that must exist between 2 stimuli before we can tell the difference between them
Difference threshold
A psychophysical method in which the subject assigns numbers to a stimulus that are proportional to the subjective magnitude of the stimulus
Magnitude estimation
A perceptual measure of stimuli, such as light or sound, that indicates the magnitude of experience
Perceived magnitude
The time between presentation of a stimulus and an observer’s or listener’s response to the stimulus. Often used in experiements as a measure of speed of processing
Reaction time
Method of determining the relationship between stimuli and perception in which the observer describes what he or she perceives
Phenomenological report
Continuum of energy that extends from very-short-wavelength gamma rays to long-wavelength radio waves. Visible light is a narrow band within this spectrum
Electromagnetic spectrum
The structure that transmits electrical signals in the body. Key components of neurons are the cell body, dendrites, and the axon or nerve fiber
Neurons
The part of a neuron that contains the neuron’s metabolic machinery and that recieves stimulation from other neurons
Cell body
Nerve processes on the cell body that recieve stimulation from other neurons
Dendrites
The part of the neuron that conducts nerve impulses over distances
Axon
- AKA nerve fiber
In most sensory neurons, the long part of the neuron that transmits electrical impulses from one point to another
Nerve fiber
- AKA the axon
The difference in charge, between the inside and the outside of the nerve fiber when the fiber is not conducting electrical signals
Resting potential
= most nerve fibers have resting potentials of about 270 mV, which means the inside of the fiber is negative relative to the outside
Rapid increase in positive charge in a nerve fiber that travels down the fiber
Action potential
-AKA the nerve impulse
A response such as a nerve impulse, that travels all the way down teh nerve fiber without decreasinng in amplitude
Propagated response
The time period of about 1/1,000th of a second that a nerve fiber needs to recover from conducting a nerve impulse. No new nerve impulses can be generated in the fiber unti this period is over
Refractory period
Nerve firing that occurs in the absence of environmental stimulation
Spontaneous activity
Charged molecules. Sodium, potassium, and chlorine are the main ions found within nerve fibers and in the liquid that surrounds nerve fibers
Ions
Charged molecules. Sodium, potassium, and chlorine are the main ions found within nerve fibers and in the liquid that surrounds nerve fibers
Ions
A property of a membrane that refers to the ability of molecules to pass through it
Permeability
-high permeability = easy for molecules to pass through the membrane
When the inside of a neuron becomes more positive, as occurs during the initial phase of the action potential. This is often associated with the action of the excitatory neurotransmitters
Depolarization
In the axon, or nerve fiber, the decrease in negativity from 270 mV to 140 mV (at the peak of potential level) that occurs during the action potential. This increase is caused by an in flow of sodium (Na+) ions into the axon
Rising phase of the action potential
When the inside of a neuron becomes more negative. This is often associated with the action of inhibitory neurotransmitters
Hyperpolarization
In the axon, or nerve fiber, the increase in negativity from 140 mV back to 270 mV (the resting potential level) that occurs during the action potential. This increase in negativity is associated with the flow of positively charged potassium (K+) out of the axon
Falling phase of the action potential
A small space between the end of one neuron (the presynaptic neuron) and the cell body of another neuron (the postsynaptic neuron)
Synapse
A chemical stored in synaptic vesicles that is released in response to a nerve impluse and has an excitatory or inhibitory effect on another neuron
Neurotransmitters
Small area on the postsynaptic neuron that is sensitive to specific neurotransmitters
Receptor sites
The response of a nerve fiber in which the firing rate increases
Excitatory response
Occurs when a neuron’s firing rate decreases due to inhibition from another neuron
Inhibitory response
How neurons represent various characteristics of the environment
Sensory coding
-Also see: Population coding; Sparse coding; Specificity coding
The type of neural code in which different perceptions are signaled by activity in specific neurons
Specificity coding
-also see: Distributed representation
A highly specific type of neuron that fires in response to a specific stimulus, such as a person’s grandmother
Grandmother cell
The idea that a particular object is represented by the firing of a relatively small number of neurons
Sparse coding
Representation of a particular object or quality by the pattern of firing of a large number of neurons
Population coding
Belief that different mental faculties could be mapped onto different brain areas based on the bumps and contours on a person’s skull
Phrenology
The idea that specific areas of the cortex are specialised to respond to specific types of stimuli
Modularity
A structure that processes info about specific behavior or perceptual quality. Often identified as a structure that contains a large proportion of neurons that respond selectively to a particular quality, such as the fusiform face area, which contains many neurons that respond selectively to faces
Module
An area in the frontal lobe that is important for language pereception and production. One effect of damage is difficulty in speaking
Broca’s area
An area in the temporal lobe involved in speech perception. Damage to this area causes aphasia, which is characterizes by difficulty in understanding speech
Wernicke’s area
The study of the behavioral effects of brain damage in humans
Neuropsychology
Procedures that make it possible to visualize areas os teh human brain that are activated by different types of stimuli, tasks, or behaviours. The most common technique used in perception research is functional magnetc resonance imaging (fMRI)
Brain imaging
Procedures that make it possible to visualize areas os teh human brain that are activated by different types of stimuli, tasks, or behaviours
Brain imaging
The most common brain imaging technique used in perception research
functional magnetc resonance imaging (fMRI)
Brain scannign technique that makes it possible to create images of structures within the brain
Magnetic Resonance Imaging (MRI)
A brain imaging technique that indicates brain activty in awake, behaving organisms. The image occurs when the response to a magnetic field changes in respose to changes in blood flow in the brain
functional magnetc resonance imaging (fMRI)
Occurs when a stimulus causes neural activity in a number of different areas of the brain, so the activity is distributed across the brain
Distributed representation
The “road map” of fibers connecting different areas of the brain
Structural connectivity
The “road map” of fibers connecting different areas of the brain
Structural connectivity
Neural connectivity between 2 areas of the brain that are activated when carrying out a specific function
Functional connectivity
fMRI measured as a person is engaged in a specific task
task-related fMRI
The signal recorded usubg functional magnetic resonance imaging when the brain is not involved in a specific task
resting-state fMRI
A method in which which fMRI is used to dtermine functional connectivity
Resting-state functional connectivity
A method in which which fMRI is used to dtermine functional connectivity
Resting-state functional connectivity
A method in which which fMRI is used to dtermine functional connectivity
Resting-state functional connectivity
Laction on the brain that is involved in carrying out a specific task and which is used a reference point when measuring resting-state functional connectivity
Seed location
Resting-state fMRI measured at a loction other than the seed location
Test loaction
One of the most famous problems in science: How do physical processes such as nerve impulses or sodium and potassium molecules flowing across membranes (the body part of the problem) become transformed into the richness of perceptual experience (the mind part of the problem)?
mind-body problem
For light energy, the distance between one peak of a light wave and the next peak
Wavelength
The band of electromagnetic energy that activates the visual system and that, therefore, can be percieved.
Visible light
= for humans, is between 400-700 nM
The eyeball and its contents, which include focusing elements, the retina, and suporting structures
Eyes
The opening through which light reflected from objects in the environment enters the eye
Pupil
The transparent focusing element of the eye that is the first structure through which light passes as it enters the eye. This is the eye’s major focusing element
Cornea
The transparent focusign element of the eye through which light passes after passing through the cornes and the aqueous humor. This change in shape to focus at different distances is called accomodation.
Lens
A complex network of cells that cover the inside back of the eye. These cells include the receptors, which generate an electrical signal in response to light, as well as the horizontal, bipolar, amacrine, and ganglion cells
Retina
The receptors for vision
Photoreceptors
Receptor in the retina that is responsible for vision at low levels of illumination
Rods
Receptors in the retina that are primarily responsible for vision in high levels of llumination and for colour vision and detail vision
Cones
Part of the rod and cone visual receptors that contains the light-sensitive visual pigment molecules
Outer segments
A light-sensitive molecule contained in the rod and cone outer segments. The reaction of this molecule to light results in the generation of an electrical response in the receptors
Visual pigments
Bundle of nerve fibers that carry impulses from teh retins to the lateral geniculate nucleus (LGN) and other structures. Each of these contains about 1 million ganglion cell fibers
Optic nerve
A small area in the humsn retina that contains only cone receptors. This ares is located on the line of sight, so that when a person looks at an object, the center of its image fall on it
Fovea
A small area in the humsn retina that contains only cone receptors. This ares is located on the line of sight, so that when a person looks at an object, the center of its image fall on it
Fovea
The area of the retina outside of the fovea
Peripheral retina
A clinical condition that causes degeneration of the macula, and area of the retina that includes the fovea and a small surrounding area
Macular degeneration
A retinal disease that causes a gradual loss of vision, begining in the peripheral retina
Retinitis pigmentosa
The small area where the optic nerve leaves the back of the eye. There is no visual receptors in this area, so small images falling directly on this area cannot be seen
Blind spot
In vision, bringing object located at different distances into focus by changing the shape of the lens
Accomodation
Errors that can affect the ability of the cornes and/or lens to focus incoming light onto the retina
Refractive errors
The inability of the eye to accomodate due to a hardening of the lens and a weakening of the ciliary muscles. It occurs as people get older
Presbyopia
The inability of the eye to accomodate due to a hardening of the lens and a weakening of the ciliary muscles. It occurs as people get older
Presbyopia
An inability to see distant objects clearly. AKA nearsightedness
Myopia
Myopia (nearsightedness) in which the cornea and/or the lens bends the light too much
Refractive myopia
(also see Axial Myopia)
Myopia (nearsightedness) in which the eyeball is too long
Axial Myopia
A condition causing poor vision in which people can see objects that are far away but not see near objects clearly. AKA farsightedness
Hyperopia
Change in shape of the retinal part of the visual pigment molecule that occurs when the molecule absorbs a quantum of light. This triggers the enzyme cascade that results in transduction from light energy to electrical enery in the retinal receptors
Isomerization
Visual adaptation that occurs in the dark, during which the sensitivity to light increases. This increase in sensitivity is associated with regeneration of the rod and cone visual pigments
Dark adaptation
The function that traces the time course of the increase in visual sensitivity that occurs during dark adaptation
Dark adaptation curve
The sensitivity of the eye when in the light-adapted state. Usually taken as the starting point for the dark adaptation curve because it is the sensitivity of the eye just before the lights are turned off
Light-adapted sensitivity
The sensitivity of the eye after it has completely adapted to the dark
Dark-adaptive sensitivity
A person who has a retina in which the only functioning receptors are rods
Rod monochromats
The point on the dark adaptation curve at which vision shifts from cone vision to rod vision
Rod-cone break
The change in the colour of a visual pigment that occurs when visual pigment molecules are isomerized by exposure to light
Visual pigment bleaching
Occurs after the visual pigment’s 2 components- opsin and retinal- have become separated due to the action of light. Regeneration, which occurs in the dark, involves a rejoining of these 2 components to reform the visual pigment molecule. This process depends on enzymes located in the pigment epithelium
Visual pigment regeneration
A condition in which the retins is detached from the back of the eye
Detatched retina
The sensitivity of visual receptors to different parts of the visible spectrum
Spectral sensitivity
-also see Spectral sensitivity curve
The function relating a subject’s sensitivity to light to the wavelength of the light. This curves for rod and cone vision indicate that the rods and cones are maximally sensitive at 500 nm and 560 nm, repectively
Spectral sensitivity curve
also see Purkinje shift
Light that contains only a single wavelength
Monochromatic light
A plot of visual sensitivty verses wavelength for cone vision. Often measured by presenting a small spot of light to the fovea, which contains only cones. Can also be measured when the eye is light adapted, so cones are the most sensitive receptors
Cone spectral sensitivity
The curve plotting visual sensitivity vs wavelength for ___ vision. This function is typically measured when the eye is dark adapted by a test light presented to the peripheral retina
Rod spectral sensitivity curve
The shift from cone spectral sensitivity to rod sensitivity that takes place during dar adaption
Purkinje shift
-also see Spectral sensitivity
A polt of the amount of light absorbed by a visual pigment vs the wavelength of light
Absorption spectrum
A number of neurons that are connected by synapses
Neural circuits
A retinal neuron that recieves inputs from the visual receptors and sends signals to the retinal ganglion cells
Bipolar cells
A neuron in the retina that receives inputs from bipolar and amacrine cells. The axons of the ganglion cells are the nerve fibers that travel out of the eye in the optic nerve
Ganglion cells
A neuron that transmits signals laterally across the retina. These cells synapse with receptor and bipolar cells
Horizontal cells
A neuron that transmits signals laterally in the retina. These cells synapse with bipolar cells and ganglion cells
Amacrine cells
Synapsing a number of neurons onto one neuron
Neural convergence
Convergence
-see Perspective convergence
The ability to resolve small details
Visual acuity
A neuron’s _____ is the area on the receptor surface (the retina for vision; the skin for touch) that, when stimulated, affects the firing of that neuron
Receptive field
A receptive field that has a center-surround organization
Center-surround receptive fields
Area of a receptive field that is associated with excitation. Stimulation of this area causes an increase in the rate of nerve firing
Excitatory area
Area of a receptive field that is associated with inhibition. Stimulation of this area causes a decrease in the rate of nerve firing
Inhibitory area
A center-surround receptive field in which stimulation of the center area causes an excitiatory response and stimulation of the surround causes an inhibitory response
Excitatory-center, inhibitory-surround receptive field
A center-surround receptive field in which stimulation of the center causes an inhibitory response and stimulation of the surround caused an excitatory response
Inhibitory-center, excitatory-surround receptive field
The competition between the center and the surround regions of a center-surround receptive field, caused by the fact that one is ecitatory and the other is inhibitory. Stimulating center and surround areas simultaneously decreases responding of the neuron, compared to stimulating the excitatory area alone
Center-surround antagonism
Inhibition that is transmitted laterally across a nerve circuit. In the retins, lateral inhibition is transmitted by the horizontal and amacrine cells
Lateral inhibition
A structure in the eye of the Limulus that contains a small lens, located directly over a visual receptor. The Limulus eye is made up of hundreds of these ommatidia. It has been used for research on lateral inhibition because its receptors are large enough so that stimulation can be applied to individual receptors
Ommatidia
An increase in percieved contrast at boarders between regions of the visual field
Edge enhancement
Occurs when areas of different lightness are positioned adjacent to one another to create a boarder. The illusion is the perception of a light band on the light side of the boarder and a dark band on the dark side of teh boarder, even though these bands do not exist in the intensity distribution
Chevreul illusion
Light and dark bands percieved at light-dark borders
Mach bands
A technique used to measure perception in infants. 2 stimuli are presented, and the infant’s looking behavior is monitored for the amount of time the infant spends viewing each stimulus
Preferential looking (PL) technique
An electrical response to visual stimulation recorded by the placement of disk electrodes one the back of the head. This potential reflects the activity of a large population of nerons in the visual cortex
Visual evoked potential
A receptive field that has a center-surround organization
Center-surround receptive field
An x-shaped bundle of fibers on the underside of the brain, where nerve fibers activated by stimulation of one side of the visual feild cross over to the opposite side of the brain
Optic chiasm
Side of the body opposite to the side on which a particular condition occurs
Contralateral
The nucleus in the thalamus that recieves inputs from the optic nerve and, in turn, communicates with the cortical receiving ares for vision
Lateral geniculate nucleus (LGN)
An area in the brain that is involved in controlling eye moevements and other visual behaviours. This area receives about 10% of the ganglion cell fibers that leave the eye in the optic nerve
Superior colliculus
The area of the occipital lobe where signals from the retina and LGN first reach the cortex
Visual receiving area
The visual receiving area of the cortex, located in the occipital lobe. AKA V1
Striate cortex
The visual receiving area of the brain, and it is the 1st visual area in the cortex. AKA striate cortex
Area V1
A neuron in the visual cortex that responds best to bars of a particular orientation
Simple cortical cells
A function relating the firing rate of a neuron to the orientation of the stimulus
Orientation tuning curve
A neuron in the visual cortex that responds best to moving bars with a particular orientation
Complex cells
A cortical neuron that responds best to lines of a specific length that are moving in a particular direction
End-stopped cells
A neuron that responds selectively to a specific feature of the stimulus such as orientation or direction of motion
Feature detectors
A procedure in which a person or animal is selectively exposed to one stimulus, and then the effect of this exposure is assessed by testing with a wide range of stimuli. Typically, sensitivity to the exposed stimulus is decreased
Selective adaptation
The intensity difference between 2 area that can just barely be seen. This is often measured using gratings with alternating light and dark bars
Contrast threshold
A procedure in wihch animals are reared in special environments. An example is the experiment in which kitten were reared in an environment of vertical stripes to determine the effect on orientation selectivity of cortical neurons
Selective rearing
The capacit of the nervous system to change in response to experience. Examples are how early visual experiences can change the orientation selectivity of neurons in the visual cortex and now tactile experience can change the sizes of areas in the cortex that represent different parts of the body
Neural plasticity
-also see: Experience-dependent plasticity; Selective rearing
A process by which neurons adapt to the specific envrionment within chich a person or animal lives. This is achieved when neuronschange their response properties so they become tuned to respond best to stimuli that have been repeatedly experienced in the emvironment
Experience-dependant plasticity
-also see Neural plasticity; selective rearing
A map on a structure in the visual system, such as the lateral geniculate nuclus or the cortex, that indicates locations on the structure that correspond to locations on the retina. In retinotopic maps, locations adjacent to each other on the retins are usually represented by locations that are adjacent to each other on the structure
Retinoptic map
Occurs when a disproportionately large area on the cortex is activated by stimulation of a small area on the receptor surface. One example is the relatively large area of visual cortex that is activated by stimulation of the fovea. An example in the somatosensory system is the large area of somatosensory cortex activated by stimulation of the lips and fingers
Cortical maginifcation
The size of the cortical maginifcation effect
Cortical magnification factor
A column in the visual cortex that contais neurons with the same receptive field locations on the retina
Location columns
A column in the visual cortex that contains neurons with the same orientation preference
Orientation columns
In the striate cortex, unit proposed by Hubel and Wiesel that combines location, orientation, and occular dominance columns that serve a specific area on the retina
Hypercolumn
The adjacent (and often overlapping) location columns working togeter to cover the entire visual field (similar to covering a floor with tiles)
Tiling
Collective term for visual areas in the occipital lobe and beyond known as V2, V3, V4, and V5
Extrastriate cortex
Removal of an area of the brain. This is usually done in experiments on animals to determine the function of a particular area. AKA lesioning
Ablation
The behavioral task used in Ungerleider and Mishkin’s experiment in wihch they provide eveidence for the ventral (or WHAT) visual processing stream. Monkeys were required to respond to an object with a particular shape
Object discrimination problem
The behavioral task used Ungerleider and Mishkin’s experiment in wihch they provide eveidence for the dorsal (or WHERE) visual processing stream. Monkeys were required to resond to a previously indicated location
Landmark discrimination problem
Pathway that conducts signals from the striate cortex to teh temporal lobe. AKA the WHAT pathway because it is involved in recognizing objects
Ventral pathway
Pathway that conducts signals from the striate cortex to the parietal lobe. AKA the WHERE, the HOW, or the ACTON pathway by different investigators
Dorsal pathway
In brain damage, when fundtion A is present and function B is absent in one person, and function A is absent and function B is present in another. Presence of a double dissociate means that the 2 functions involove different mechanisms and operate independently of one another
Double dissociations
An ares of the brain outside V1 (the striate cortex), involved in object perception and facial recognition
Inferotemporal (IT) cortex
Subcortical structure in the brain that is associated with forming and storing memories
Hippocampus
Change in response to a stimulus presented within a neuron’s receptive field caused by stimmulation outside of the receptive field
Contextual modulation
Change in response to a stimulus presented within a neuron’s receptive field caused by stimmulation outside of the receptive field
Contextual modulation
A cortical neuron that responds best to lines of a specific length that are moving in a particular direction
End-stopped cell
A neuron in the visual cortex that responds best to bars of a particular orientation
Simple cortical cell
A condition in which damage to an area of the cortex involved in motion perception causes blindness to motion
Akinetopsia
A segment of time at a particular location that is perceived by observers to have a begining and an ending
Event
The point in time when one event ends and another begins
Event boundary
A biological motion stimulus created by placing lights at a number of places on a person’s body and having an observer view the moving-light stimulus that results as the person moves in the dark
Point-light walkers
The physical movement of a stimulus. Contrasts with ‘apparent motion’
Real motion
Perception of motion when there actually is none
illusory motion
-also see Apparent motion
Perception of motion when there actually is none
illusory motion
-also see Apparent motion
Apparent motion
- see apparent movement
The illusory movement of one object that is caused by the moevement of another object that is nearby
Induced motion
An illusion that occurs after a person views a moving stimulus and then sees movement in the opposite direction when viewing a stationary stimulus immediately afterwards
Motion aftereffects
-also see Waterfall illusion
An aftereffect of movement that occurs after viewing a stimulus moving in one direction, such as a waterfall. Viewing the waterfall makes other objects appear to move in the opposite direction
Waterfall illusion
-also see Movement aftereffect
The structured pattern of light created by the presence of objects, surfaces, and textures in the environment
Optic array
Occurs when one object moves relative to the environment, so that the stationary background is covered and uncovered by the moving object. This indicates that the object is moving relative to the envrionment
Local disturbance in the optic array
Info for movement that occurs when all elements in a scene move. The perception of this indicates that it is the observer that is moving and not the scene
Global optic flow
Info for movement that occurs when all elements in a scene move. The perception of this indicates that it is the observer that is moving and not the scene
Global optic flow
A neural circuit proposed by Werner, in which signals caused by movement of a stimulus across the receptors are processed by a delay unit and an output unit so that signals are generated by movement in one direction but not in the opposite direction
Reichardt detector
A component of the Reichardt detector that compares signals recieved from 2 or more neurons. According to Reichardt’s model, activity in the _____ is necessary for motion perception
Output unit
A component of the Reichardt detector that compares signals recieved from 2 or more neurons. According to Reichardt’s model, activity in the _____ is necessary for motion perception
Output unit
A component of the Reichardt detector proposed to explain how neural firing occurs to different directions of movement. The ____ delays the transmission of nerve impulses as they travel from the receptors towards the brain
Delay unit
Brain region in the temporal lobe that contains many directionally selective neurons
Middle temporal (MT) area
In research on movement perception in which arrays of moving dots are used as stimuli, the degree of correlation between the direction of the moving dots. 0% ______ mean all of the dots are moving independently; 100% means all the dots are moving in the same direction
Coherence
Presenting a strong magnetic feild to the head that temporarily disrupts the functioning of a specific area of the brain
Transcrainal magnetic stimulation (TMS)
A procedure in which a small electrode is inserted into the cortex and an electrical current is passed through the electrode activtes neurons near the tip of the electrode. This procedure has been used to determine how activating specific groups of neurons affects perception
Microstimulation
Occurs when only a portion of a moving stimulus canbe seen, as when the stimulus is viewed through a narrow aperature or though the “field of view” of a neurons’ receptive field. This can result in misleading info about the direction in which the stimulus is moving
Aperature problem
In the perception of apparent motion, the principle that apparent movement tends to occur along the shortest path betwen 2 stimuli
Shortest path constraint
Motion produced by biological organisms. Most of the experiments on this motion have used walking humans with lights attached to their joints and limbs as atimuli
Biological motion
-also see Point-light walker
When a still picture depicts an action that involves motion, so that an observer could potentially extend the action depicted in the picture in his or her mind based on what will most likely happen next
Implied motion
Occurs when motion depicted in a still picture continues in an observer’s mind
Representational momentum
An illusion that occurs after a person views a moving stimulus and then sees movement in the opposite direction when viewing a stationary stimulus immediately afterwards
Motion aftereffect
-also see Waterfall illusion
A loss of colour vision caused by damage to the cortex
Cerebral achromatopsia
Condition (sometimes incorectly called colour blindness) in which people see fewer colours than people with normal colour vision and need to mix fewer wavelengths to match any other wavelength in the spectrum
Colour deficiency
Colour with hue, such as blue, yellow, red, or green
Chromatic colours
When an object reflects some wavelengths of the spectrum more than others
Selective reflection
A plot showing the % of light reflected from an object vs wavelength
Reflectance curves
When some wavelengths pass through visually transparent objects or substances and others do not. This is associated with the perception of chromatic colour
Selective transmission
Plots of the % of light transmitted through a liquid or object at each wavelength
Transmission curves
Involves the absorption and selective transmission or reflection of light. It occurs when colorants (such as pigments or dyes) are mixed or when several coloured filters are inserted into a single beam of white light.
Subtractive colour mixture
creating a new color by a process that adds one set of wavelengths to another set of wavelengths. This happens when lights of different wavelengths are mixed. When we add all of the different wavelengths of sunlight, we see white light rather than many individual colors. All of the wavelengths still reach our eyes. It is the combination of different wavelengths that creates the diversity of colors.
Additive colour mixture
Colours that appear in the visible spectrum
Spectral colours
Colours that do not appear in the spectrum because they are mixtures of other colours. An example is magenta, which is a mixture of red and blue
Nonspectral colours
The experience of a chromatic colour such as red, green, yellow, or blue, or combo of these colours
Hues
The relative amount of whiteness in a chromatic colour. The less whiteness a colour contains, the more ______ it is
Saturation
Low stauration in chromatic colours as would occur when white is added to a colour. For example, pink is not as saturated as red
Desaturated
The light-to-dark dimension of colour
Value
The perception of shades ranging from white to gray to black
Lightness
A solid in which colours are arranged in an orderly way based on their hue, saturation, and value
Colour solid
Depiction of hue, saturation, and value developed by Albert in the early 1900s in which different hues are arranged around the circumference of a cylinder with perceptually similar hues placed next to each other
Munsell colour system
The idea that our perception of oclour is determined by the ration of activity in 3 receptor mechanism with different spectral sensitivities
Trichromacy of colour vision
Trichromacy of colour vision
Young-Helmholtz theory
A procedure in which observers are asked to match the colour in on field by mixing 2 or more lights in another field
Colour matching
A technique in which a narrow beam of light is directed into a single visual receptor. This technique makes it possible to determine the pigment absorption spectra of single receptors
Microspectrophotometry
A technique that makes it possible to look into a person’s eye and take pictures of the receptor array in the retina
Adaptive optical imaging
Imperfections on the eye’s cornea and lens that distort light on its way to the retina
Aberrations
Arragement of short-, medium-, and long-wavelength cones in a particular area of the retina
Cone mosaic
The situation in which 2 physically different stimuli are perceptually indentical. In vision, this refers to 2 lights with different wavelength distributions that are percieved as having the same colour
Metamerism
2 lights that have different wavelength distributions but are perceptually identical
Metamers
Rare form of colour blindness in which the absence of cone receptors results in perception only of shades of lightness (white, gray, black), with no chromatic colour present
Monochromatism
A person who is completely colour-blind and therefore sees everything as black, white, or shades of gray. They can match any wavelength in the spectrum by adjusting the intensity of any other wavelength. They generally have only one type of functioning receptors, usually rods
Monochromats
A person who is completely colour-blind and therefore sees everything as black, white, or shades of gray. They can match any wavelength in the spectrum by adjusting the intensity of any other wavelength. They generally have only one type of functioning receptors, usually rods
Monochromats
A condition in which a person perceives no chromatic colour. This can be caused by absent or malfunctioning cone receptors or by cortical damage
Colour blind
any single cone system is color blind in the sense that different combinations of wavelength and intensity can result in the same response from the cone system. This implies that color vision depends critically on the comparative inputs of the different cone systems.
Principle of univariance
A person who has form a of colour deficiency. They can match any wavelength in the spectrum by mixing 2 other wavelengths
Dichromats
A person with normal colour vision. They can match any wavelength in the spectrum by mixing 3 other wavelengths in various proportions
Trichromats
A display of coloured dots used to test for the presence of colour deficiency. The dots are colured so that people with normal (trichromatic) colour vision can perceive numbers in the plate, but people with colour deficiency cannot perceive these numbers or perceive different numbers than someone with trichromatic vision
Ishihara plates
A display of coloured dots used to test for the presence of colour deficiency. The dots are colured so that people with normal (trichromatic) colour vision can perceive numbers in the plate, but people with colour deficiency cannot perceive these numbers or perceive different numbers than someone with trichromatic vision
Ishihara plates
A person who has dichromatic vision in one eye and trichromatic vision in the other eye. People with this (rare) condition have been tested to determine what colours dichromats perceive by asking them to compare the perceptions they experience with their dichromatic eye and thier trichromatic eye
Unilateral dichromat
A form of colour deficiency in which a person has just 2 types of cone pigment and so can see chromatic colours but confuse soem colours and trichromats can distinguish
Dichromatism
A form of colour deficiency in which a person has just 2 types of cone pigment and so can see chromatic colours but confuse soem colours and trichromats can distinguish
Dichromatism
A form of dichromatism in wihch a protanope is missing the long-wavelength pigment, and perceives short-wavelength light as blue and long-wavelength light as yellow
Protanopia
A form of dichromatism in wihch a protanope is missing the long-wavelength pigment, and perceives short-wavelength light as blue and long-wavelength light as yellow
Protanopia
The wavelength at which dichromat percieves gray
Neutral point
A form of dichromatism in which a person is missing the medium-wavelength pigment. They perceive turquoise at short-wavelengths, sees yellow at long-wavelengths, and has a neutral point at about 498 nm
Deuteranopia
A form of dichromatism in which a person is missing the medium-wavelength pigment. They perceive turquoise at short-wavelengths, sees yellow at long-wavelengths, and has a neutral point at about 498 nm
Deuteranopia
A form of dichromatism in which a person is missing the short-wavelength pigment. They see blue at short-wavelengths, red at long wavelengths
Tritanopia
A form of dichromatism in which a person is missing the short-wavelength pigment. They see blue at short-wavelengths, red at long wavelengths
Tritanopia
A type of colour deficiency in wihch a person needs to mix a minimum of 3 wavelengths to match any other wavelength in the spectrum but mixes thses wavelengths in different proportions than a trichromat
Anomalous trichromatism
A theory originally proposed by Hering, which claimed that our perception of color is determined by the activity of two opponent mechanisms: a blue–yellow mechanism and a red–green mechanism. The responses to the two colors in each mechanism oppose each other, one being an excitatory response and the other an inhibitory response. In addition, this theory also includes a black–white mechanism, which is concerned with the perception of brightness
Opponent-process theory of colour vision
-also see Opponent neuron
Perceptually similar colors located next to each other and arranged in a circle
Colour circle
Procedure in which participants are given colours from around the hue circle and told to indicate the proportions of red, yellow, blue, and green that they perceive in each colour
Hue scaling
Name given by Ewald Hering to what he proposed were the primary colors: red, yellow, green, and blue
Unique hues
Procedure in which a subject is shown a monochromatic reference light and is asked to remove, or “cancel,” the one of the colors in the reference light by adding a second wavelength. This procedure was used by Hurvich and Jameson in their research on opponent-process theory
Hue cancellation
A neuron that has an excitatory response to wavelengths in one part of the spectrum and an inhibitory response to wavelengths in the other part of the spectrum
Opponent neurons
The effect in which the perception of an object’s hue remains constant even when the wavelength distribution of the illumination is changed. Partial colour constancy occurs when our perception of hue changes a little when the illumination changes, though not as much as we might expect from the change in the wavelengths of light reaching the eye
Colour constancy
Exposure to light in a specific part of the visible spectrum. This adaptation can cause a decrease in sensitivity to light from the area of the spectrum that was presented during adaptation
Chromatic adaptation
A type of colour constancy that occurs when changing an object’s illumination causes a change in perception of the object’s hue, but less change than would be expected based on the change in the wavelengths of light reaching the eye. Note that in complete colour constancy, changing an object’s illumination causes no change in the object’s hue
Partial colour constancy
The idea that an object’s characteristic colour influences our perception of that object’s colour
Memory colour
The online address for a picture of a dress that is seen as alternating blue and black stripes by some people and as alternating white and gold stripes by others
TheDress
The constancy of our perception of an object’s lightness under different intensities of illumination
Lightness constancy
The percentage of light reflected from a surface
Reflectance
A principle stating that two areas that reflect different amounts of light will have the same perceived lightness if the ratios of their intensities to the intensities of their surroundings are the same
Ratio principle
An edge between two areas where the reflectance of two surfaces changes
Reflectance edge
The border between two areas created by different light intensities in the two areas
illumination edge
Procedure in which a person pays less attention when the same stimulus is presented repeatedly. For example, infants look at a stimulus less and less on each successive trial
Habituation procedure
-see also Dishabituation
An increase in responding that occurs when a stimulus is changed. This response is used in testing infants to see whether they can differentiate two stimuli
Dishabituation
A procedure used to study infant colour vision in which two side-by-side squares of different colours are presented and the infant’s looking time to the two squares is measured to determine whether they can tell the difference between them
Novelty-preference procedure
Imperfections on the eye’s cornea and lens that distort light on its way to the retina
Abberation
Jack observes a dog. According to the principle of ____, fundamental changes in the stimulus occur between the actual dog and Jack’s perception of the dog
transformation
Kate walks up to an automated teller machine and pushes a button. The pressure exerted by her finger is transformed into electrical energy, which causes a device that uses mechanical energy to push her money out of the machine. This process is called _____.
transduction
____ is one of the behavioral responses in the perceptual process.
Perception
Dr. Sanchez uses _________, which is an approach that measures the relationships between the physical and the psychological response.
psychophysics
Dr. Jones is conducting an experiment in which the participants’ brain activity is measured in a brain scanner as they try to detect lines with different orientations. This best illustrates the _____ relationship.
stimulus–physiology
Sherri is getting her hearing tested. The quietest sound she can hear is known as the _____.
absolute threshold
Dr. Fechner conducts an experiment in which he presents a series of sounds that gradually get louder in order to identify each participant’s threshold for hearing the tones. What does Dr. Fechner call this method?
method of limits
An experimenter is showing mammograms (images of breast tissue) to radiologists and asking them to categorize the lesions as malignant or benign. The experimenter is using a ____ test.
recognition
Dr. Electra conducts an experiment in which participants press a blue button when they see a red light flash and a red button when they see a blue light flash. Dr. Electra is best described as studying _____.
reaction time
José is participating in an experiment where he is asked to describe what he is perceiving when he is tasting various foods. This is best described as the _____ report approach to studying perception.
phenomenological
Perception is identified as _____.
complex processes that involve higher-order mechanisms
Corollary discharge model. When a bird flies by, but the eye is stationary, what happens?
Movement is perceived because an image movement signal is generated without a motor signal.
Corollary discharge model. When we scan our eyes across a stationary scene, why don’t we perceive movement?
Because there is an image movement signal and a motor signal at the same time
When we see the color of an object, our brains are perceiving:
The wavelengths of light that are not absorbed by the object
The cones in our retinas are sensitive to the wavelengths of light that correspond to:
Blue, green, and red
A 3-dimensional object casts its shadow on a surface covered with checkered black and white squares. With respect to Question 1, why does the lower square appear to be lighter than the upper square?
Because the visual system takes into account the shadow cast by the cylinder
A 3-dimensional object casts its shadow on a surface covered with checkered black and white squares. With respect to Question 2, why does the left segment appear darker than the right square?
Because the left segment appears to have light shining on it, while the right square is in the shadow of the cylinder
Mia is an art teacher who is teaching about the effects of mixing white into other colors. Mia is teaching her students about _____.
Saturation
Amy is examining how certain wavelengths of light pass through various fruit juices to create color. What concept is illustrated in this process?
Selective transmission
Chad is an art teacher who is teaching his students to mix paint to create different colors. He explains that each blob of paint absorbs wavelengths and these wavelengths are still absorbed by the mixture. Chad is teaching his students about _____.
Subtractive color mixture
According to the ____ theory of color perception, color vision depends on the activity of three different receptor mechanisms.
Trichromatic
In a ____ experiment, subjects reproduce a reference color by mixing different wavelengths of light.
Color-matching
Jerry sees everything in shades of lightness (white, gray, and black). Which of the following best describes Jerry’s condition?
Monochromat
____ neurons in the retina and lateral geniculate nucleus respond with an excitatory response to light from one part of the spectrum and with an inhibitory response to light from another part
Opponent
The finding that _____ supports the idea that there are specialized areas in the brain for color perception
Lesions in certain areas of the brain result in achromatopsia
Shana admires the redness of her sweater while seated in a dark restaurant. She goes outside into the bright sunlight and again notices how red her sweater is. Shana’s perception of the color of her sweater reflects the experience of color _____.
Constancy
Brent is conducting an experiment where he has participants look at a red square with one eye for 30 to 45 seconds. He then has them look at various colored objects in the environment. They report differences in the saturation of red and orange objects based on which eye they use. What phenomenon is Brent studying?
Chromatic adaptation
Why is it important for the points of the point-light walker to be placed at the person’s joints?
Because those locations provide information about the placement and movement of the limbs
What is different about the male and female point-light walkers that provides information about the walker’s gender?
Position and movement of the elbows and knees
Rick, a 48-year-old male, has recently suffered a stroke. He has difficulty following conversations in part because he can’t see the motions of a speaker’s face and mouth. Rick is most likely to have ____.
akinetopsia
Doug is watching television. Out of the corner of his eye he sees something moving, and realizes it is his dog coming into the room. What process is best illustrated in this scenario?
attentional capture
Blake is outside on a windy night and sees that the clouds are moving past the moon. He perceives that the moon appears to be racing through the clouds. What is this phenomenon called?
induced motion
Pedro visits Niagara Falls and watches the water pour over the cliff. He then looks off to the side at the rocks and foliage, and they appear to move up for a few seconds. What is this effect called?
waterfall illusion
Dr. Saunders is conducting an experiment that focuses on how movement of the observer causes changes in the structure created by the surfaces, textures, and contours of the environment. What is the term for this structure?
optic array
Sam watches his cat walk across the room. What signal is sent from the brain to Sam’s eye muscles as he moves his eyes to follow his cat walking across the room?
motor signal
According to ____ theory, an image displacement signal occurs when an image moves across receptors in the retina; a motor signal occurs when a signal is sent from the brain to the eye muscles; and a copy of the motor signal is sent to the brain where it is compared to the image displacement signal to determine whether movement has occurred.
corollary discharge
Carrie is a graduate student who studies parts of the brain that play important roles in the perception of motion. Which area of the brain does Carrie study?
middle temporal area
Apparent motion follows a principle called the _____, which states that apparent movement tends to occur along the shortest path between two stimuli
shortest path constraint
Kris looks at a photo of a person diving into a pool, with water splashing up around him. He imagines the diver plunging into the pool as the picture is taken. What type of motion is illustrated in this photo?
implied
