PNB 2XA3 - Cognition Ch 1,3-5 Midterm Term Review

Introspection

the process through which one "looks within" to observe and record the contents of one's own mental life

Behaviourist movement

a methodological perspective that dominated American psychology for many years. This perspective emphasized broad principles concerned with how behaviour changes in response to different configurations of stimuli (including stimuli that are often called "rewards" and "punishments"). In its early days, behaviourists sought to avoid mentalistic terms (terms that referred to representations or processes inside the mind).

Transcendental method

A type of theorizing proposed by the philosopher Immanuel Kant. To use this method, an investigator first observes the effects or consequences of a process and then asks: What must the process have been to bring about these effects?

Response time

the amount of time (usually measured in milliseconds) needed for a person to respond to a particular event (such as a question or a clue to press a specific button).

Cognitive neuroscience

the effort towards understanding humans' mental functioning through close study of the brain and nervous system

Clinical neuropsychology

the study of brain function that uses, as its main data source, cases in which damage or illness has disrupted the working of some brain structure

Neuroimaging techniques

non-invasive methods for examining either the structure of the activation pattern within a living brain

Cornea

the transparent tissue at the front of each eye that plays an important role in focusing the incoming light

Lens

the transparent tissue located near the front of each eye that (together with the cornea) plays an important role in focusing incoming light. Muscles control the degree of curvature of the lens, allowing the eye to form a sharp image on the retina

Retina

the light-sensitive tissue that lines the back of the eyeball

Photoreceptors

cells on the retina that are sensitive to light and that respond (i.e., send a signal to adjacent cells) when they are stimulated by light

Rods

photoreceptors that are sensitive to very low light levels but that are unable to discriminate hues and that have relatively poor acuity. Often contrasted with cones

Cones

photoreceptors that are able to discriminate hues and that have high acuity. Cones are concentrated in the retina's fovea and become less frequent in the visual periphery. Often contrasted with rods

Acuity

the ability to see fine detail.

Fovea

the centre of the retina and the region on the eye in which acuity is best; when a person looks at an object, they are lining up that object with the fovea.

Bipolar cells

a type of neuron in the eye. Bipolar cells receive their input from the photoreceptors and transmit their output to the retinal ganglion cells

Ganglion cells

a type of neuron in the eye. The ganglion cells receive their input from the bipolar cells, and then the axons of the ganglion cells gather together to form the optic nerve, carrying information back to the lateral geniculate nucleus

Optic nerve

the bundle of nerve fibres, formed from the retina's ganglion cells, that carries information from the eyeball to the brain

Lateral geniculate nucleus (LGN)

an important way station in the thalamus that is the first destination for visual information sent from the eyeball to the brain

Lateral inhibition

a pattern in which cells, when stimulated, inhibit the activity of neighbouring cells. In the visual system, lateral inhibition in the optic nerve creates edge enhancement

Edge enhancement

a process created by lateral inhibition in which the neurons in the visual system give exaggerated responses to edges of surfaces

Mach band

a type of illusion in which one perceives a region to be slightly darker if it is adjacent to a bright region, and also perceives a region to be slightly brighter if it is adjacent to a dark region. This illusion, created by lateral inhibition, contributes to edge enhancement.

Single-cell recording

A technique for recording the moment-by-moment activation level of an individual neuron within a healthy, normally functioning brain.

Receptive field

The portion of the visual field to which a cell within the visual system responds. If the appropriately shaped stimulus appears in the appropriate position, the cell's firing rate will change. The firing rate will not change if the stimulus is of the wrong form or is in the wrong position

Centre-surround cells

a type of neuron in the visual system that has a "donut-shaped" receptive field. Stimulation in the surrounding ring has the opposite effect.

Area V1

the site on the occipital lobe where axons from the LGN first reach the cerebral cortex. This site is (for one neural pathway) the location at which information about the visual world first reaches the brain

Parallel processing

A system in which many steps occur at the same time. Usually contrasted with serial processing

Serial processing

A system in which only one step happens at a time (and so the steps occur in a series). Usually contrasted with parallel processing

What system

The system of visual circuits and pathways leading from the visual cortex to the temporal lobe and especially involved in object recognition. Often contrasted with the where system

Where system

the system of visual circuits and pathways leading from the visual cortex to the parietal lobe and especially involved in the spatial localization of objects and in the coordination of movements. Often contrasted with the what system

Binding problem

the problem of reuniting the various elements of a scene, given that these elements are initially dealt with by different systems in the brain

Neural synchrony

A pattern of firing by neurons in which neurons in one brain area fire at the same time as neurons in another area; the brain seems to use this pattern as an indication that the neurons in different areas are firing in response to the same stimulus

Conjunction error

An error in perception in which a person correctly perceives what features are present but misperceives how the features are joined, so that (for example) a red circle and a green square might be misperceived as a red square and a green circle.

Necker cube

one of the classic reversible (or ambiguous) figures; the figure is a two-dimensional drawing that can be perceived as a cube from above or as a cube viewed from below.

Reversible (or ambiguous) figure

drawings that can be readily perceived in more than one way. Classic examples include the vase/profiles, the duck/rabbit, and the Necker cube

figure/ground organization

the processing step in which the perceiver determines which aspects of the stimulus belong to the central object (or "figure") and which aspects belong to the background (or "ground")

Gestalt principles

a small number of rules that seem to govern how observers organize the visual input, grouping some elements but perceiving other elements to be independent of one another

Visual features

the elements of a visual pattern: vertical lines, curves, diagonals, and so on, that together form the overall pattern.

Perceptual constancy

the achievement of perceiving the constant properties of objects in the world (e.g., their size, shape, and colour) despite changes in the sensory information we receive that are caused by changes in our viewing circumstances

Size constancy

the achievement of perceiving the constant size of objects despite changes in the size of the retinal image that result from variations in viewing distance

Shape constancy

the achievement of perceiving the constant shape of objects despite changes in the shape of the retinal image that result from variations in viewing angle

Brightness constancy

the achievement of perceiving the constant brightness of objects despite changes in the light reaching the eye that result from variations in illumination

Unconscious inference

the hypothesized steps that perceivers follow to take one aspect of the visual scene (e.g., viewing distance) into account in judging another aspect (e.g., size)

Distance cues

information available to the perceiver that allows the perceiver to judge how far off a target object is

Binocular disparity

a distance cue based on the differences between the two eyes' views of the world. This difference becomes less pronounced the farther away an object is from the observer

Monocular distance cues

features of the visual stimulus that indicate distance even if the stimulus is viewed with only one eye

Pictorial cues

patterns that can be represented on a flat surface to create the sense of a three-dimensional object or scene

Interposition

a monocular distance cue that relies on the fact that objects farther away are blocked from view by closer objects that happen to be in the viewer's line of sight

Linear perspective

a cue for distance based on the fact that parallel lines seem to converge as they get farther away from the viewer

Motion parallax

a distance cue based on the fact that as an observer moves, the retinal images of nearby objects move more rapidly than do the retinal images of objects farther away

Optic flow

the pattern of change in the retinal image in which the image grows larger as the viewer approaches an object and shrinks as the viewer retreats from it

Bottom-up processing

A sequence of events that is governed by the stimulus input itself.

Top-down processing

A sequence of events that is heavily shaped by the knowledge and expectations that the person brings to the situation.

Visual search task

An often-used laboratory task in which research participants are asked to search for a specific target (e.g., a shape, or a shape of a certain colour) within a field of other stimuli; usually, the researcher is interested in how quickly the participants can locate the target

Tachistoscope

A device that allows the presentation of stimuli for precisely controlled amounts of time, including very brief presentations

Mask

A visual presentation that is used to interrupt the processing of another visual stimulus

Priming

A process through which one input or cue prepares a person for an upcoming input or cue.

Repetition priming

A pattern of priming that occurs simply because a stimulus is presented a second time; processing is more efficient on the second presentation

Word-superiority effect (WSE)

The data pattern in which research participants are more accurate and more efficient in recognizing letters if the letters appear within a word (or a word-like letter string) than they are in recognizing letters appearing in isolation

Well-formedness

A measure of the degree to which a string of symbols (usually letters) conforms to the usual patterns (for letters: the rules of spelling); for example, the nonword "FIKE" is well formed in English, but "IEFK" is not

Feature nets

Systems for recognizing patterns that involve a network of detectors, with detectors for features serving as the initial layer in each system

Activation level

A measure of the current status for a node or detector. Activation level is increased if the node or detector receives the appropriate input from its associated nodes or detectors; activation level will be high if input has been received frequently or recently

Response threshold

The quantity of information or activation needed to trigger a response in a node or detector, or, in a neuroscience context, a response from a neuron

Bigram detectors

Hypothetical units in a recognition system that respond, or fire, whenever a specific letter pair is in view

Local representation

A mode of representation in which information is encoded in a small number of identifiable nodes. Local representations are sometimes spoken as "one idea per node" or "one content per location.:

Distributed representation

A mode of representing ideas or contents in which there is no one node (or specific group of nodes) representing the content and no one place where the content is stored. Instead, the content is represented via a pattern of simultaneous activity across many nodes within a network. The same nodes will also participate in other patterns, so those nodes will also be part of other distributed patterns

Excitatory connection

A link from one node, or one detector, to another such that activation of one node activates the other.

Inhibitory connection

A link from one node, or one detector, to another, such that activation of one node decreases the activation level of the other.

Prosopagnosia

A syndrome in which individuals lose their ability to recognize faces and to make other fine-grained discriminations within a highly familiar category, even though their other visual abilities seem intact

Inversion effect

A pattern typically observed for faces in which the specific face is much more difficult to recognize if the face is presented upside-down; this effect is part of the evidence indicating that face recognition relies on processes different from those involved in other forms of recognition.

Holistic perception

a process in which the ability to identify an object depends on the whole, or the entire configuration, rather than on an inventory of the object's parts. In holistic perception, the parts do play a role, but by virtue of creating the patterns that are critical for recognition.

Selective attention

The skill through which a person focuses on one input or one task while ignoring other stimuli that are also on the scene

Dichotic Listening

A task in which research participants hear two simultaneous verbal messages, one presented via headphones to the left ear and a second one presented to the right ear. In typical experiments, participants are asked to pay attention to one of these inputs (the attended channel) and are urged to ignore the other (the unattended channel).

Attended channel

A stimulus (or group of stimuli) that a person is trying to perceive. Ordinarily, information is understood or remembered from the attended channel.

Unattended channel

a stimulus (or group of stimuli) that a person is not trying to perceive. Ordinarily, little information is understood or remembered from the unattended channel

Shadowing

A task in which research participants repeat back a verbal input, word for word, as they hear it

Filter

A hypothetical mechanism that would block potential distractors from further processing

Fixation target

A visual mark (e.g., a dot or a plus sign) at which research participants point their eyes, or fixate. Fixation targets help research participants to control their eye position

Inattentional blindness

A pattern in which perceivers seem literally not to see stimuli right in front of their eyes; this pattern is caused by the participants focusing their attention on some other stimulus and not expecting the target to appear

Change blindness

a pattern in which perceivers either do not see or take a long time to see large-scale changes in a visual stimulus. This pattern reveals how little people perceive, even from stimuli in plain view, if they are not specifically attending to the target information

Early selection hypothesis

A proposal that selective attention operates at an early stage of processing, so that the unattended inputs receive little analysis

Late selection hypothesis

A proposal that selective attention operates at a late stage of processing, so that the unattended inputs receive considerable analysis

Biased completion theory

A proposal that attention functions by shifting neurons' priorities, so that the neurons are more responsive to inputs that have properties associated with the desired or relevant input

Spatial attention

the mechanism through which people allocate processing resources to particular positions in space, so that they more efficiently process any inputs from that region in space

Limited-capacity system

a group of processes in which mental resources are limited, so that extra resources supplied to one process must be balanced by a withdrawal of resources somewhere else, with the result that the total resources expended do not exceed the limit of what is available

Mental resources

some processes or some capacity needed for performance, but in a limited supply

Endogenous control of attention

a mechanism through which a person chooses (often, on the basis of some meaningful signal) where to focus attention

Exogenous control of attention

a mechanism through which attention is automatically directed, essentially as a reflex response, to some "attention-grabbing" input

Feature integration theory

a proposal about the function of attention in "gluing" together elements and features that are in view

Divided attention

the skill of performing multiple tasks simultaneously

Executive control

the mental resources and processes that are used to set goals, choose task priorities, and avoid conflict among competing habits or responses

Perseveration error

A pattern of responding in which a person produces the same response over and over, even though the person knows that the task requires a change in response. This pattern is often observed in patients with brain damage in the frontal lobe

Goal neglect

A pattern of behaviour in which people fail to keep their goal in mind, so that, for example, they rely on habitual responses even if those responses will not move them toward the goal

Automaticity

a state achieved by some tasks and some forms of processing, in which the task can be performed with little or no attention. In many cases, automatized actions can be combined with other activities without interference. Automatized actions are also often difficult to control, leading many psychologists to refer to them as "mental reflexes"

Stroop interference

A classic demonstration of automaticity in which research participants are asked to name the colour of ink used to print a word, and the word itself is the name of a different colour. For example, participants might see the word "YELLOW" printed in blue ink and be required to say "blue." Considerable interference is observed in this task, with participants apparently being unable to ignore the word's content even though it is irrelevant to their task