4 Visual Cortex Flashcards
Action pathway
Dorsal pathway
Ablation
Removal of an area of the brain. This is usually done experiments on animals, to determine the function of a particular area. Also call lesioning.
Brain imaging
Procedures that make it possible to visualize areas of the human brain that are activated by different types of stimuli, test, or behaviors. The most common techniques used in perception researcher positron emission tomography (PET) and functional magnetic resonance imaging (fMRI).
Complex cells
Neuron individual cortex that responds best to moving bars with a particular orientation.
Contralateral eye
Eye on the opposite side of the head from a particular structure.
Contrast threshold
Intensity difference that can just barely be seen between two areas. This is often measured using gradings with alternating light and dark arts.
Cortical magnification factor
Apportioning the small fovea with a large area on the cortex.
Dissociation
Situation that occurs as a result of brain damage in which one function is present in another is absent.
Dorsal pathway
Pathway that conducts signals from this try a quick text to the parietal lobe. This is also called the where, the how, or the action pathway to indicate its function.
Double dissociation
In brain damage, when function a is present in function b is absent in one person, and function a is absent and function b present another. Presence of the double dissociation means that the two functions involve different mechanisms and operate independently of one another.
End-stopped cells
Cortical neurons that responds best to lines of a specific length that are moving in a particular direction.
Experience-dependent plasticity
A process by which neurons adapted 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 experienced in the environment.
Extrastriate body area (EBA)
Area of the temporal lobe that is activated by pictures of bodies and parts of bodies.
Feature detectors
Neuron that response like to play to a specific feature of the stimulus.
Functional magnetic resonance imaging (fMRI)
Brain imaging technique that indicates brain activity in awake, awake, behaving humans in response to perceptual stimuli.
Fusiform face area (FFA)
Area in the human inferotemporal (IT) cortex that contains neurons specialized to respond to faces.
Grating stimuli
Stimulus pattern consisting of alternating bars with different lightnesses and colors.
How pathway
Dorsal pathway
Hypercolumn
In the striate cortex, unit proposed by Hubel and Wiesel that combines location, orientation, and ocular dominance columns the survey specific area on the retina.
Ipsilateral eye
Eye on the same side of the head as this structure to which the eye sends inputs.
Landmark discrimination problem
Behavior test used in later in Ungerleider and Mushkin’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.
Lateral geniculate nucleus (LGN)
Nucleus in the thalamus that receives inputs from the optic nerve and, in turn, since fibers to the cortical receiving area for vision.
Location column
Column in the visual cortex that contains neurons with the same except a few locations on the retina.
Module
Structure that processes information about a specific behavior horse perceptual quality. Often identified as a structure that contains a large proportion of neurons that respond selectively to a particular quality.
Neural plasticity
Capacity of the nervous system to change in response to experience. Examples are however visual experience can change the orientation selectivity of neurons in the visual cortex and how tactile experience can change the sizes of various and the cortex that represent different parts of the body.
Neuropsychology
Study of the behavioral effects of brain damage in humans.
Object discrimination problem
Behavioral task used in Ungerleider and Mishkin’s experiment in which they provided evidence for the eventual, or what, visual processing stream. Monkeys were required to respond to an object with a particular shape.
Ocular dominance
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 amount of dominance if the neuron responds equally to stimulation of both eyes.
Ocular dominance column
Column in the visual cortex that contains neurons the respond best to stimulation of the same.
Orientation tuning curve
Function relating the firing of a neuron to the orientation of the stimulus.
Parahippocampal place area (PPA)
Area in the temporal lobe that is activated by pictures of indoor and outdoor scenes.
Positron emission tomography (PET)
Brain mapping technique that is used in awake subjects to determine which brain areas are activated by various tasks.
Primary visual receiving area
Areas of the cerebral cortex that first receive most of the signals initiated by the sense’s receptor. For example, the occipital cortex is the site of the primary receiving area for vision, the temporal lobe is the site of the primary receiving area for hearing.
Prosopagnosia
Form of visual agnosia in which the person can’t recognize faces.
Retinotopic map
Map on structure in the visual system, such as the lateral geniculate nucleus for the cortex, that indicates locations on the structure that correspond to locations on the retina. Interesting topic maps, locations adjacent to each other on the retina are usually represented by locations that are adjacent to each other on the structure.
Rod and frame illusion
An illusion in which the perception of the orientation of a rod is affected by the orientation of surrounding frame.
Selective adaptation
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 ride range of stimuli. Exposing a person to vertical bars and then testing a person’s sensitivity to bars of all orientations is an example of selective adaptation to orientation.
Selective rearing
Procedure in which animals are reared in special environments. An example of selective rearing is the experiment in which kittens were reared in an environment of vertical stripes to determine the effect on orientation selected selectivity of cortical neurons.
Simple cortical cell
Neuron in the visual cortex that response best to bars of a particular orientation.
Single dissociation
When, as a result of brain damage, one function is present in another’s absence. Existence of a single dissociation indicates that the two functions involved different mechanisms but may not be totally independent of one another.
Striate cortex
Visual receiving area of the cortex, located in the occipital lobe.
Subtraction technique
Technique used to analyze the results of brain imaging experiments, and which brain activity elicited by a control condition is subtracted from the activity listed by experimental condition to determine the activity that can be attributed to the experimental condition alone.
Superior colliculus
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.
Theory of natural selection
Idea that genetically based characteristics that enhance an animal’s ability to survive, and therefore reproduce, will be passed on to future generations.
Ventral pathway
Pathway that conducts signals from the striate cortex to the temporal lobe. Also called the what pathway because it is involved in recognizing objects.
What pathway
Ventral pathway
Where pathway
Dorsal pathway
