Definitions Flashcards
1
Q
Absolute Threshold
A
The minimum stimulus energy necessary for an observer to detect a stimulus
2
Q
Action
A
Motor activities such as moving the head or eyes and locomoting through the environment. Action is one of the major outcomes of the perceptual process.
3
Q
Bottom-up processing (data-based)
A
Processing that is based on the information on the receptors.
4
Q
Classical psychophysical methods
A
The methods of limits, adjustment, and constant stimuli, described by Fechner, that are used for measuring thresholds.
5
Q
Cognitive influences on perception
A
How the knowledge, memories, and expectations that a person brings to a situation influence his or her perception.
6
Q
Difference threshold
A
The minimal detectable difference between two stimuli
7
Q
Environmental stimulus
A
The stimulus “out there” in the external environment
8
Q
Frontal love
A
Receiving signals from all of the senses, the frontal lobe plays an important role in perceptions that involve that coordination of information received through two or more senses. It also serves functions such as language, thought memory, and motor functioning.
9
Q
Knowledge
A
Any information that the perceiver brings to a situation. (Top-down)
10
Q
Magnitude estimation
A
A psychophysical method in which the subject assigns numbers to a stimulus that are proportional to the subjective magnitude of the stimulus.
11
Q
Method of adjustment
A
descending or ascending, observer adjusts knob. The method of adjustment is faster because observers can determine their threshold in just a few trials by adjusting the intensity themselves.
12
Q
Method of constant stimuli
A
Random order, most accurate because it involves many observations and stimuli presented in random order, which miniizes how presentation on one trial can affect the observers judgment of the stimulus presented on the next trial. The disadvantage of this method is that it is time-consuming.
13
Q
Method of limits
A
descending or ascending, average of crossover
14
Q
Neural processing
A
Operations that transform electrical signals within a network of neurons or that transform the response of individual neurons.
15
Q
Oblique effect
A
Enhanced sensitivity to vertically and horizontally oriented visual stimuli compared to obliquely oriented (slanted) stimuli. This effect has been demonstrated by measuring both perception and neural responding.
16
Q
Occipital lobe
A
A lobe at the back of the cortex that is the site of the cortical receiving area for vision
17
Q
Parietal lobe
A
A lobe at the top of the cortex that is the site of the cortical receiving area for touch and is the termination point of the dorsal (where or how) stream for visual processing.
18
Q
Perceived magnitude
A
A perceptual measure of stimuli such as light or sound that indictaes the magnitude of experience
19
Q
Perception
A
Conscious sensory experience
20
Q
Perceptual process
A
A sequence of steps leading from the environment to perception of a stimulus, recognition of the stimulus, and action with regard to the stimulus.
21
Q
Phenomenological method
A
Method of determining the relationship between stimuli and perception in which the observer describes what he or she perceives.
22
Q
Physiological approach to perception
A
Analyzing perceptino by determining how a peron’s perception is related to physiological processes that are occuring within the person. This approach focuses on determining the relationship between stimuli and physiological responding and between physiological responding and perception
23
Q
Power function
A
A mathematical function of the form P=KSn, where P is perceived magnitude, K is a constant and S is the stimulus intensity, n is an exponent
24
Q
Primary receiving area
A
Areas of the cerebral cortex that first receive most of the signals initiated by a sense’s receptors. Ex. the occipital cortex is the site of the primary receiving area for vision, and the temporal love is the site of the primary receiving area for hearing.
25
Principle of representation
A principle of perception that evertyhing a person perceives is based not on direct contact with stimuli but on representations of stimuli on the receptors and in the peron's nervous sytem.
26
Principle of transformation
A principle of perception that stimuli and responses created by stimuli are transformed, or changed, between the environmental stimulus and perception
27
Psychophysical approach to perception
Analyzing perception by determining how a person's perception is related to stimuli in the environment. This approach focuses on determining the relationship between stimuli in the environment and perceptual responding.
28
Psychophysics
Traditionally, the term psychophysics refers to quantitative methods for measuring the relationship between properties of the stimulus and the subject's experience.
29
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. (Effect of top down processing)
30
Reaction time
The time between presentation of a stimulus and an observer's or listener's response to the stimulus. Reaction time is often used in experiments as a measure of speed of processing.
31
Recognition
The ability to place an object in a category that gives it meaning. Ex. red object = tomato
32
Response compression
The result when doubling the physical intensity of a stimulus less than doubles the subjective magnitude of the stimulus. Exponents less than 1.0 are associated with response compression (as occurs for the brightness of a light)
33
Response criterion
In a signal detection experiment, the subjective magnitude of a stimulus above which the participant will indicate that the stimulus is present.
34
Response expansion
The result when doubling the physical intensity of a stimulus more than doubles the subjective magnitude of the stimulus. Exponents greater than 1.0 are associated with response expansion (sensing shocks)
35
Sensory receptors
Cells specialized to respond to environmental energy, with each sensory system's receptors specialized to respond to a specific type of energy.
36
Signal detection theory
A theory stating that the detection of a stimulus depends both on the participant's sensitivity to the stimulus and on the participant's response criterion
37
Steven's power law
A law concerning the relationship between the physical intensity of a stimulus and the perception of the subjective magnitude of the stimulus. The law states that P=KSn, where P is perceived magnitude, K is a constant, S is the stimulus intensity, and n is an exponent.
38
Temporal lobe
A lobe on the side of the cortex that is the site of the cortical receiving area for hearing and the termination point for the ventral, or what, stream for visual processing. A number of areas in the temporal lobe, such as the fusiform face area and the extrastriate body area, serve functions related to perceiving and recognizing objects.
39
Top down processing
Processing that starts with the analysis of high-level information, such as knowledge.
40
Transduction
In the senses, the transformation of environmental energy into electrical energy. Ex. the retinal receptors transduce light energy into electrical energy. The transformation of one form of energy (light energy ) to another form (electrical energy)
41
Visual form agnosia
The inability to recognize objects
42
Visual pigment
A light-sensitive molecule contained in the rode and cone outer segments. The reaction of this molecule to light results in the generation of an electrical response in the receptors.
43
Visual search
A procedure in which a person's task is to find a particular element in a display that contains a number of elements.
44
Weber fraction
The ratio of the difference threshold to the value of the standard stimulus in Weber's law
45
Weber's law
A law starting that the ratio of the difference threshold to the value of the stimulus is constant. Doubling the value of a stimulus will cause a doubling of the difference threshold. DL/S
46
Absorption Spectrum
A plot of the amount of light absorbed by a visual pigment versus the wavelength of light. A pigment's absorption spectrum is a plot of the amount of light absorbed versus the wavelength of the light. The rod pigment absorbs best at 500nm, the blue-green area.
There are three absorption spectra for the cones because there are three different cone pigments, each in its own receptor.
The short-wavelength pigment absorbs light best at about 419nm. The medium at 531nm and long 558nm.
47
Accommodation
In vision, bringing objects located at different distances into focus by changing the shape of the lens. Accommodation is the change in the len's shape that occurs when the ciliary muscles at the front of the eye tighten and increase the curvature of the lens to that it gets thicker. This increased curvature increases the bending of the light rays passing through the lens so the focus point is pulled back to create a sharp image on the retina.
48
Action potential
Rapid increase in positive charge in a nerve fiber that travels down the fiber. AKA nerve impulse
49
Amacrine cell
A neuron that transmits signals laterally in the retina. Amacrine cells synapse with bipolar cells and ganglion cells.
50
Axial myopia
Myopia (nearsightedness) in which the eyeball is too long. (refractive myopia)
51
Axon
The part of the neuron that conducts nerve impulses over distances (nerve fiber)
52
Bipolar cell
A retinal neuron that receives inputs from the visual receptors and sends signals to the retinal ganglion cells.
53
Blind spot
The small area where the optic nerve leaves the back of the eye. There are no visual receptors in this area, so small images falling directly on the blind spot cannot be seen.
54
Cell body
The part of a neuron that contains the neuron's metabolic machinery and that receives stimulation from other neurons.
55
Cone
Cone shaped receptors in the retina that are primarily responsible for vision in high levels of illumination and for color vision and detail vision. Cones results in better detail vision that the rods (less convergence, more private lines) Better visual acuity.
56
Cone spectral sensitivity curve
A plot of visual sensitivity versus wavelength for cone vision. Often measure 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.
57
Convergence (neural)
When many neurons synapse onto a single neuron. Convergence occurs when a number of neurons synapse onto a single neuron (like a manager) Many of these foveal cones have private lines to ganglion cells, so that each ganglion cell receives signals from only one cone, with no convergence. High convergence results in high sensitvity but poor acuity (the rods). Low convergence results in low sensitvity but high acuity (cones)
58
Cornea
The transparent focusing element of the ye that is the first structure through which light passes as it enters the eye. The cornea is the eye's major focusing element.
59
Dark adaptation
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.
60
Dark adaptation curve
The function that traces the time course of the increase in visual sensitivity that occurs during dark adaptation.
61
Dark adapted sensitivity
The sensitivity of the eye after it has completely adapted to the dark
62
Dendrites
Nerve processes on the cell body that receive stimulation from other neurons
63
Depolarization
When the inside of a neuron becomes more positive, as occurs during the initial phases of the action potential. Depolarization is often associated with the action of excitatory neurotransmitters.
64
Detached retina
A condition in which the retina is detached from the back of the eye.
65
Electromagnetic spectrum
Continuum of electromagnetic energy that extends from very short wavelength gamma rays to long wavelength radio waves. Visible light is a narros band within this spectrum
66
Excitatory response
The response of a nerve fiber in which the firing rate increases
67
Eye
The eyeball and its contents, which include focusing elements, the retina, and supporting structures
68
Falling phase of the action potential
In the axon, or nerve fiber, the increase in negativity from +40mV back to -70mV that occurs during the action potential. This increase in negativity is associated with the flow of positively charge potassium ions out of the axon.
69
Far point
As a light is moved toward the eye, the distance at which the light becomes focused on the retina
70
Farsightedness
A condition causing poor vision in which people can see objects that are far away but do not see near objects clearly. (Hyperopia)
71
Fovea
A small area in the human retina that contains only cone receptors. The fovea is located on the line of sight, so that when a person looks at an object, the center of its image falls ont he fovea.
72
Ganglion cell
A neuron in the retina that recives 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.
73
Horizontal cell
A neuron that transmits signals laterally across the retina. Horizontal cells synapse with receptors and bipolar cells.
74
Hyperopia
Farsightedness. Causing poor vision in which people can see objects that are far away but not near objects
75
Hyperpolarization
When the inside of a neuron becomes more negative. Hyperpolarization is often associated with the action of inhibitory neurotransmitters.
76
Inhibitory response
Occurs when a neuron's firing rate decreases due to inhibition from another neuron.
77
Ions
Charged molecules. Sodium (Na+), potassium K+, and chlorine Cl- are the main ions found within nerve fibers and in the liquid that surrounds nerve fibers.
78
Isomerization
Change in shape of the retinal part of the visual pigment molecule that occurs when the molecule absorbs a quantum of light. Triggers the enzyme cascade that results in transduction from light energy to electrical energy in the retinal receptors.
79
Laser assisted in situkeratomileusis
LASIK. A process in which the cornea is sculpted with a laser in order to achieve clear vision by adjusting the focusing power of the cornea so it focuses light onto the retina.
80
Lens
The transparent focusing element of the eye through which light passes after passing through the cornea and the aqueous humor. The len's change in shape to focus at different distances is called accommodation.
81
Light adapted sensitivity
The sensitivity of the eye whe int he 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.
82
Macular degeneration
A clinical condition that causes degeneration of the macula, an area of the retina that inclues the fovea and a small surrounding area.
83
Monochromatic light
Light that contains only a single wavelength.
84
Myopia
An inability to see distant objects clearly. Nearsightedness
85
Near point
The distance at which the lens can no longer accommodate enough to bring close objects into focus. Objects nearer than the near point can be brought into focus only by corrective lenses.
86
Nearsightedness
An inability to see distant objects clearly. Myopia
87
Nerve fiber
In most sensory neurons, the long part of the neuron that transmits electrical impulses from one point to another. Axon
88
Neural circuit
A number of neurons that are connected by synapses
89
Neural convergence
Synapsing of a number of neurons that are connected by synapses
90
Neural convergence
Synapsing of a number of neurons onto one neuron
91
Neuron
The structure that transmits electrical signals in the body. Key components of neurons are the cell body, dendrites, and the axon or nerve fiber.
92
Neurotransmitter
A chemical stored in synaptic vesicles that is released in response to a nerve impulse and has an excitatory or inhibitory effect on another neuron.
93
Optic nerve
Bundle of nerve fibers that carry impulses from the retina to the lateral geniculate nucleus and other structures. Each optic nerve contains about 1 million ganglion cell fibers.
94
Outer sgment
Part of the rod and cone visual receptors that contain the light sensitive visual pigment molecules.
95
Peripheral retina
The peripheral retina, which includes all of the retina outside of the fovea, contains both rods and cones. Contains many more rods than cones.
96
Permeability
A property of a membrane that refers to the ability of molecules to pass through it. If the permeability to a molecule is high, the molecule can easily pass through the membrane.
97
Preferential looking technique
A technique used to measure perception in infants. Two stimuli are presented, and the infant's looking behavior is monitored for the amount of time the infant spends viewing each stimulus.
98
Presbyopia
The inability of the eye to accommodate due to a hardening of the lens and a weakening of the ciliary muscles. It occurs as people get older.
99
Propagated response
A response, such as a nerve impulse, that travels all the way down the nerve fiber without decreasing in amplitude.
100
Pupil
The opening through which light reflected from objects in the environment enters the eye
101
Purkinje shift
The shift from cone spectral sensitivity to rod spectral sensitivity that takes palce during dark adaptation.
102
Receptor site
Small area on the postsynaptic neuron that is sensitive to specific neurotransmitters
103
Refractive myopia
Myopia in which the cornea and/or the lens bends the light too much.
104
Refractory period
The time period of about 1/1000th of a second that a nerve fiber needs to recover from conducting a nerve impulse. No new nerve impulses can be generated in the fiver until the refractory period is over.
105
Resting potential
The difference in charge between the inside and the outside of the nerve fiber when the fiber is not conducting electrical signals. Most nerve fibers have resting potentials of about -70mv which means the inside of the fiber is negative relative to the outside.
106
Retina
A complex network of cells that covers the inside back of the ey. These cells include the receptors, which generate an electrical signal in response to light, as well as the horizontal, bipolar, amacrine, and ganglion cells.
107
Retinitis pigmentosa
A retinal disease that causes a gradual loss of vision, beginning in the peripheral retina.
108
Rising phase of the action potential
In the axon, or nerve fiber, the decrease in negativity from -70v to +40mv (the peach action potential level) that occurs during the action potential. This increase is caused by an inflow of NA+ ions into the axon.
109
Rod
A cylinder-shaped receptor in the retina that is responsible for vision at low levels of illumination. The rods results in better sensitivity than the cones.
110
Rod monochromat
A person who has a retina in which the only function receptors are rods
111
Rod spectral sensitivity curbe
The curve plotting visual sensitivity versus wavelength, for rod vision. This function is typically measured when the eye is dark adapted by a test light presented to the peripheral retina.
112
Rod cone break
The point on the dark adaptation curve at which vision shifts from cone vision to rod vision.
113
Sensory receptors
Cells specialized to respond to environmental energy, with each sensory system's receptors specialized to respond to a specific type of energy.
114
Spectral sensitivity
The sensitivity of visual receptors to different parts of the visible spectrum.
115
Spectral sensitivity curve
The function relating a subject's sensitivity to light to the wavelength of the light. The SSC for rod and cone vision indicate that the rods and cones are maximally sensitive at 500nm and 560nm respectively.
116
Spontaneous activity
Nerve firing that occurs in the absence of environmental stimulation
117
Synapse
A small space between the end of one neuron (the presynaptic neuron) and the cell body of another neuron (the postsynaptic neuron)
118
Visible light
The band of electromagnetic energy that activates the visual system and that, therefore, can be perceived. For humans visible light has wavelengths between 400 and 700 nanometers.
119
Visual acuity
The ability to resolve small details
120
Visual evoked potential
An electrical response to visual stimulation recorded by the placement of disk electrodes on the back of the head. This potential reflects the activity of a large population of neurons in the visual cortex.
121
Visual pigment
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.
122
Visual pigment bleaching
The change in the color of a visual pigment that occurs when visual pigment molecules are isomerized by exposure to light.
123
Visual pigment regeneration
Occurs after the visual pigment's two components-opsin and retinal have become separated due to the action of light. Regeneration, which occurs in the dark, involves a rejoining of these two components to reform the visual pigment molecule. This process depends on enzymes located int eh pigment epithelium.
124
Wavelength
For light energy, the distance between one peak of a light wave and the next peak.
125
Area V1
The visual receiving area of the brain, called area V1 to indicate that is is the first visual area in the cortex. Striate cortex.
126
Belongingness
The hypothesis that an area's appearance is influenced by the part of the surroundings that the area appears to belong to. This principle has been used to explain the perception of lightness in the Benary cross and White's illusion.
127
Center-surround antagonism
The competition between the center and surround regions of a center-surround receptive field, caused by the fact that one is excitatory and the other is inhibitory. Stimulating center and surround areas simultaneously decreases responding of the neuron, compared to stimulating the excitatory area alone
128
Center-surround organization
Arrangement of a neuron's receptive fields in which one area is surrounded by another area, like the hole in a donut (corresponding to the center) and the donut (the surround). Stimulation of the center and surround causes opposite responses.
129
Cerebral cortex
The 2mm thick layer that covers the surface of the brain and contains the machinery for creating perception, as well as for other functions such as language memory and thinking.
130
Complex cell
A neuron in the visual cortex that responds best to moving bars with a particular orientation
131
Contrast threshold
The intensity difference that can just barely be seen between two areas. For vision this is often measured using gratings with alternating light and dark bars.
132
Distributed coding
Typer of neural code in which different perceptual qualities are signaled by the pattern of activity across many neurons. This contrasts with specificity coding, in which qualities are signaled by activity in a specific type of neuron.
133
Easy problem of consciousness
The problem of determining the relationship between physiological processes like nerve firing and perceptual experience. Note that this involves determining a relationship, not a cause.
134
End stopped cell
A cortical neuron that responds best to lines of a specific length that are moving in a particular direction.
135
Excitatory center, inhibitory surround receptive field
A center-surround receptive field in which stimulation of the center area causes an excitatory response, and stimulation of the surround causes an inhibitory response.
136
Experience dependent plasticity
A process by which neurons adapt to the specific environment within which a person or animal lives. This is achieved when neurons change their response properties so they become tuned to respond best to stimuli that have been repeatedly eperienced in the environment.
137
Feature detector
A neuron that responds selectively to a specific feature of the stimulus such as orientation or direction of motion.
138
Fusiform face area
An area in the hman inferotemporal cortex that contains neurons that are specialized to respond to faces
139
Grandmother cell
A hypothesize type of neuron that responds only a very specific stimulus such as a peron's grandmother (specificity coding)
140
Hard problem of consciousness
The problem of determining how physiological processes, such as ion flow across nerve membranes, cause different perceptual experiences.
141
Hermann grid
A display that results in the illusion of dark areas at the intersection of two white corridors. This perception can be explained by lateral inhibition.
142
Inferotemporal cortex
An area of the brain outside Area V1 (the striate cortex) involved in object perception and facial recognition
143
Inhibitory area
Area of a receptive field that is associated with inhibition. Stimulation of this area causes a decrease in the rate of nerve firing.
144
Inhibitory-center, excitatory-surround receptive field
A center-surround receptive field in which stimulation of the center causes an inhibitory response and stimulation of the surround causes an excitatory response
145
Lateral geniculate nucleus LGN
The nucleus in the thalamus that recives inputs from the optic nerve and, in turn, communicates with the cortical receiving area for vision.
146
Lateral inhibition
Inhibition that is transmitted laterally across a nerve circuit. In the retina, lateral inhibition is transmitted by the horizontal and amacrine cells.
147
Lightness
The perception of shades ranging from white to grey to black.
148
Mind-body problem
How do physical processes such as nerve impulses or sodium and potassium molecules flowing across membranes (body) become transformed into the richness of perceptual experience (mind)
149
Neural correlate of consciousness
Connections between the firing of neurons and perceptual experience.
150
Neural plasticity
The capacity of the nervous system to change in response to experience. Examples are how early visual experience can change the orientation selectivity of neurons in the visual cortex and how tactile experience can change the sizes of areas in the cortex that represent different parts of the body.
151
Neural processing
Operations that transform electrical signals within a network of neurons or that transform the response of individual neurons
152
Occipital lobe
A lobe at the back of the cortex that is the site of the cortical receiving area for vision.
153
Ommatidium
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. The limulus eye has been used for research on lateral inhibition because its receptors are large enough so that stimulation can be applied to individual receptors.
154
Orientation tuning curve
A function relating the firing rate of a neuron to the orientation of the stimulus.
155
Prosopagnosia
A form of visual agnosia in which the person can't recognize faces.
156
Receptive field
A neuron's receptive field is the are on the receptor surface (the retina for vision, the skin for touch) that, when stimulated, affects the firing of that neuron. The definition became the retinal region over which a cell in the visual system can be influenced (excited or inhibited) by light. The region of the retina that must receive illumination in order to obtain a response in any given fiber. The fiber responds only when a small area of the retina is illuminated. A fiber's receptive field covers a much greater area than a single rod or cone receptor. It covers hundreds or even thousands of receptors meaning that the fiber is reciving converging signals from all of these receptors. (hartline.) receptive fields overlap.
157
Selective adaptation
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.
158
Selective rearing
A procedure in which animals are reared in special environments. Ex. kittens in vertical striped to determine the effect on orientation selectivity of cortical neurons.
159
Simple cortical cells
A neuron in the visual cortex that responds best to bars of a particular orientation
160
Simultaneous contrast
The effect that occurs when surrounding one color with another changes the appearance of the surrounded color. Occurs for chromatic and achromatic stimuli.
161
Sparse coding
The idea that a particular object is represented by the firing of a relatively small number of neurons
162
Specificity coding
Type of neural code in which different perceptions are signaled by activity in specific neurons.
163
Striate cortex
The visual reciving area of the cortex, located in the occipital lobe
164
Superior colliculus
An area in the brain that is involved in controlling eye movements and other visual behaviors. This area receives about 10% of the ganglion cell fibers that leave the eye in the optic nerve.
165
Visual receiving area
The area of the occipital lobe wehre signals from the retina and LGN first reach the cortex
166
White's illusion
A display in which two rectangles are perceived as differing in lightness even though they both reflect the same amount of light and even though the rectangle that is perceived as lighter receives more lateral inhibition than the one perceived as darker.
167
Ablation
Removal of an area of the brain. This is usually done in experiments on animals to determine the function of a particular area. Lesioning.
168
Action pathway
Pathway that conducts signals from the striate cortext to the parietal lobe.
169
Brain imaging
Procedures that make it possible to visualize areas of the human brain that are activated by different types of stimuli, tasks, or behaviors. The two most common techniques used in perception research are positron emission tomography and functional magnetic resonance imaging.
170
Cortical magnification
Occurs when a disproportionately large area on the cortex is activated by stimulation of a small area on the receptor surface. One example of cortical magnification 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 is activated by stimulation of the lips and fingers. Even though the fovea accounts for only 0.01 percent of the retina’s area, signals from the fovea account for 8 to 10 percent of the retinotopic map on the cortex
171
Dorsal pathway
Pathway that conducts signals from the striate cortex to the parietal lobe. The dorsal pathway has also been caledd the where, the how, or the action pathway.
172
Double dissociation
In brain damage, when function a is present and function b is absent is one person, and function a is absent and function b is present in another. Presence of a double dissociation means that the two functions involved different mechanisms and operate independently of one another.
173
Expertise hypothesis
The idea that human proficiency in perceiving certain things can be explained by changes in the brain caused by long exposure, practice or training
174
Extrastriate body area
An area of the temporal lobe that is activated by pictures of bodies and parts of bodies
175
Functional magnetic resonance imaging
A brain imaging technique that indicates brain activity in awake, behaving organisms. The fMRI response occurs when the response to a magnetic field changes in response to changes in blood flow in the brain.
176
Fusiform face area
An area in the hyman inferotemporal cortex that contains neurons that are specialized to respond to faces.
177
How pathway
Pathway that conducts signals from the striate cortext to the parietal lobe
178
Hypercolumn
In the striate cortex - unit proposed by Hubel and Wiesel that combines location, orientation, and ocular dominance columns that serve a specific area on the retina.
179
Landmark discrimination problem
The behavioral task used in Ungerleider and Mishkin's experiment in which they provided evidence for the dorsal, or where, visual processing stream. Monkeys were required to respond to a previously indicated location. Landmark discrimination: pick the food well closer to the cylinder. Lesioning the parietal lobe makes this task difficult.
180
Location column
A column in the visual cortex that contains neurons with the same receptive field locations on the retina. Location columns that are perpendicular to the surface of the cortex, so that all of the neurons within a location column have their receptive fields at the same location on the retina The location columns are 1mm. containing orientation columns that cover all possible orientations. One location column is one location on the retina.
181
Module
A structure that processes information about a 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. A structure that is specialized to process information bout a particular type of stimulus is called a module.
182
Neuropsychology
The study of the behavioral effects of brain damage in humans
183
Ocular dominance
The degree to which a neuron is influenced by stimulation of each eye. A neuron has a large amount of ocular dominance if it responds only to stimulation of one eye. There is no ocular dominance if the neuron responds equally to stimulation of both eyes.
184
Ocular dominance column
A column in the visual cortext that contains neurons that respond best to stimulation of the same eye
185
Orientation column
A column in the visual cortext that contains neurons with the same orientation preference.
186
Parahippocampal place area
An area in the temporal lobe that is activated by indoor and outdoor scenes.
187
Positron emission tomography
A brain mapping technique that is used in awake human subjects to determine which brain areas are activated by various tasks.
188
Retinotopic map
A map on a structure in the visual system, such as the lateral geniculate nucleus 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 retina are usually represented by locations that are adjacent to each other on the structure.
This organized spatial map means that two points that are close together on an object and on the retina will activate neurons that are close together in the brain
189
Spatial organization
How different locations in the environment and on the receptors are represented in the brain. Refers to the way stimuli at specific locations in the environment are represented by activity at specific locations in the nervous system.
190
Tiling
The adjacent (and often overlapping) location columns working together to cover the entire visual field. (similar to covering a floor with tiles)
191
Ventral pathway
Pathway that conducts signals from the striate cortex to the temporal lobe. What pathway, involved in recognizing objects.
192
Apparent movement
An illusion of movement that occurs when two objects separated in space are presented rapidly, one after another, separated by a brief time interval.
193
Bayesian inference
A statistical approach to perception in which perception is determined by taking probabilities into account. These probabilities are based on past experiences in perceiving properties of objects and scenes.
