Brain, Body, Behavior 0HV40 exam

Covert orienting

The movement of attention from one location to another without moving the eyes/the body

Cognition

A variety of higher mental processes such as thinking, perceiving, imagining, speaking, acting and planning

Cognitive neuroscience

Aims to explain cognitive processes in terms of brain-based mechanisms

Mind-body problem

The problem of how a physical substance (the brain) can give rise to our feelings thoughts and emotions (our mind)

Dualism

The belief that mind and brain are made up of different kinds of substance

Dual-aspect theory

The belief that mind and brain are two levels of description of the same thing.

Reductionism

The belief that mind-based concepts will eventually be replaced by neuroscientific concepts

Phrenology

The failed idea that individual differences in cognition can be mapped on to differences in skull shape

Functional specialization

Different regions of the brain are specialized for different functions

Cognitive neuropsychology

The study of brain-damaged patients to inform theories of normal cognition

Information processing

An approach in which behaviour is described in terms of a sequence of cognitive stages.

Interactivity

Later stages of processing can begin before earlier stages are complete

Top-down processing

The influence of later stages on the processing of earlier ones (e.g. memory influences on perception)

Parallel processing

Different information is processed at the same time (i.e. in parallel)

Neural network models

Computational models in which information processing occurs using many interconnected nodes

Nodes

The basic units of neural network models that are activated in response to activity in other parts of the network.

Temporal resolution

The accuracy with which one can measure when an event (e.g. a physiological change) occurs

Spatial resolution

The accuracy with which one can measure where an event (e.g. a physiological change) is occurring.

Modularity

The notion that certain cognitive processes (or regions of the brain) are restricted in the type of information they process

Domain specificity

The idea that a cognitive process (or brain region) is dedicated solely to one particular type of information (e.g. colors, faces, words)

Neuron

A type of cell that makes up the nervous system and supports, among other things, cognitive function

Cell body

Part of the neuron containing the nucleus and other organelles

Dendrites

Branching structures that carry information from other neurons

Axon

A branching structure that carries information to other neuros and transmits action potential

Synapse

The small gap between neurons in which neurotransmitters are released, permitting signalling between neurons

Action potential

A sudden change (depolarization and repolarization) in the electrical properties of the neuron membrane in an axon

Neurotransmitters

Chemical signals that are released by one neuron and affect the properties of other neurons

Myelin

A fatty substance that is deposited around the axon of some neurons that speeds conduction

Gray matter

Matter consisting primarily of neuronal cell bodies

White matter

Tissue of the nervous system consisting primarily of axons and support cells

Glia

Support cells of the nervous system involved in tissue repair and in the formation of myelin (amongst other functions)

Corpus callosum

A large white matter tract that connects the two hemispheres

Ventricles

The hollow chambers of the brain that contain cerebrospinal fluid

Anterior/Rostral

Towards the front

Posterior/caudal

Towards the back

Superior/dorsal

Towards the top

Inferior/ventral

Towards the bottom

Lateral

The outer part

Coronal section

Vertical slices through both hemisphere

Sagittal section

Vertical slice through one hemisphere

Midline or medial section

Sagittal section between the hemispheres

Axial section

Section in the horizontal plane

Gyri

The raised folds of the cortex

Sulci

The buried grooves of the cortex

Neocortex

New cortex, where there are six main cortical layers

Mesocortex

Includes cingulate gyrus and insula

Allocortex

Includes the primary olfactory cortex and hippocampus

Sylvian fissure

Divides frontal and temporal lobes

Brodmann's areas

Regions of cortex defined by the relative distribution of cell types across cortical layers (cytoarchitecture)

Basal ganglia

Regions of subcortical grey matter involved in aspects of motor control and skill learning; they consist of structures such as the caudate nucleus, putamen and globus pallidus

Limbic system

A region of subcortex involved in relating the organism to its present and past environment; limbic structures include the amygdala, hippocampus, cingulate cortex and mammillary bodies.

Thalamus

A major subcortical relay centre; for instance, it is a processing station between all sensory organs (except smell) and the cortex

Hypothalamus

Consists of a variety of nuclei that are specialized for different functions that are primarily concerned with the body and its regulation

Superior colliculi

A midbrain nucleus that forms part of a subcortical sensory pathway involved in programming fast eye movement

Inferior colliculi

A midbrain nucleus that forms part of a subcortical auditory pathway

Cerebellum

Structure attached to the hindbrain; important for dexterity and smooth execution of movement

Pons

Part of the hindbrain; a key link between the cerebellum and the cerebrum

Medulla oblongata

Part of the hindbrain; it regulates vital functions such as breathing, swallowing, heart rate and the wake-sleep cycle

Representations

Properties of the world that are manifested in cognitive systems (mental representation) and neural systems (neural representation)

Single-cell recordings

Measure the responsiveness of a neuron to a given stimulus (in terms of action potentials per second)

Electroencephalography (EEG)

Measurements of electrical signals generated by the brain through electrodes placed on different points on the scalp

Event-related potential (ERP)

The average amount of change in voltage at the scalp that are linked to the timing of particular cognitive event

Reaction time

The time taken between the onset of a stimulus/event and the production of a behavioural response

Multi-cell recordings

The electrical activity (in terms of action potentials per second) of many individually recorded neurons

Grandmother cell

A hypothetical neuron that just responds to one particular stimulus(e.g. the sight of one's grandmother)

Rate coding

The informational content of a neuron may be related to the number of action potentials per second

Temporal coding

The synchrony of firing may be used by a population of neurons to code the same stimulus or event

Mental chronometry

The study of the time course of information processing in the human nervous system

Dipole

A pair of positive and negative electrical charges separated by a small distance

N170

An ERP component (negative potential at 170ms) linked to perceiving facial structure

Additive factors method

A general method for dividing reaction times into different stages devised by Sternberg

Associative priming

Reaction times are faster to a stimulus if that stimulus is preceded by a stimulus of similar meaning

Exogenous

Related to properties of the stimulus

Endogenous

Related to properties of the task

Inverse problem

The difficulty of locating the sources of electrical activity from measurements taken at the scalp (in ERP research)

Dipole modelling

An attempt to solve the inverse problem in ERP research that involves assuming how many dipoles (regions of electrical activity) contribute to the signal recorded at the scalp

Magnetoencephalography (MEG)

A non-invasive method for recording magnetic fields generated by the brain at the scalp

Structural imaging

Measures of the spatial configuration of different types of tissue in the brain (principally CT and MRI)

Functional imaging

Measures temporary changes in brain physiology associated with cognitive processing; the most common methods of PET and fMRI are based a hemodynamic measure

Voxel-based morphometry (VBM)

A technique for segregating and measuring differences in white matter and grey matter concentration

Diffusion tensor imaging (DTI)

Uses MRI to measure white matter connectivity between brain regions

Fractional anisotropy (FA)

A measure of the extent to which diffusion takes place in some directions more than others

BOLD

Blood oxygen-level-dependent contrast; the signal measured in fMRI that relates to the concentration of deoxyhemoglobin in the blood

Hemodynamic response function (HRF)

Changes in the BOLD signal over time

Cognitive subtraction

A type of experimental design in functional imaging in which activity in a control task is subtracted from activity in an experimental task

Pure insertion (pure deletion)

The assumption that adding a different component to a task does not change the operation of other components

Interactions

The effect of one variable upon another

Functional integration

The way in which different regions communicate with each other

Block design

Stimuli from a given condition are presented consecutively together

Resting state paradigm

A technique for measuring functional connectivity in which correlations between several region (network) are assessed while the participant in not performing any tasks

Default mode network

A set of brain regions that is more hemodynamically active during rest than during breaks

Event-related design

Stimuli from two or more conditions are presented or interleaved

efMRI

Event-related functional magnetic resonance imaging

Stereotactic normalization

The mapping of individual differences in brain anatomy onto a standard template

Smoothing

Redistributing brain activity from neighbouring voxels to enhance the signal-to noise ratio

Voxel

A volume-based unit (cf. pixels, which are 2D); in imaging research the brain is divided into many thousands of these

Talairach coordinates

Locations in the brain defined relative to the atlas of Talairach and Tournoux (x, y, z)

Family Wise Error (FWE)

An approach for connecting for many statistical comparisons based on the number of tests being conducted

False Discovery Rate (FDR)

An approach for correcting many statistical comparisons based on the number of positive results obtained.

Inhibition

A reduction/suppression of the activity of a brain region (or a cognitive process), triggered by activity in another region/process