The imaged brain Flashcards
Measures of the spatial configuration of different types of tissue in the brain (principally CT and MRI)
Structural imaging
Measures temporary changes in brain physiology associated with cognitive processing; the most common method is fMRI and is based on a hemodynamic measure
Functional imaging
A technique for segregating and measuring differences in white matter and gray matter concentration
Voxel-based morphometry (VBM)
Uses MRI to measure white matter connectivity between brain regions
Diffusion tensor imaging (DTI)
A volume-based unit; in imaging research the brain is divided into many thousands of these
Voxel
A measure of the extent to which diffusion takes place in some directions more than others
Fractional anisotropy (FA)
The signal measured in fMRI that relates to the concentration of deoxyhemoglobin in the blood.
BOLD: Blood-oxygen-level-dependent contrast
Changes in the BOLD signal over time
Hemodynamic response function (HRF)
A type of experimental design in functional imaging in which activity in a control task is subtracted from activity in an experimental task
Cognitive subtraction
The assumption that adding a different component to a task does not change the operation of other components
Pure insertion
The effect of one variable upon another
Interactions
A motor signal used to predict sensory consequences of an action
Efference copy
The way in which different regions communicate with each other
Functional integration
A technique for measuring functional connectivity in which correlations between several regions (networks) are assessed while the participant is not performing any tasks
Resting state paradigm
A set of brain regions that is more hemodynamically active during rest than during tasks
Default mode network
The mapping of individual differences in brain anatomy onto a standard template
Stereotactic normalization
Redistributing brain activity from neighboring voxels to enhance the signal-to-noise ratio
Smoothing
Locations in the brain defined relative to the atlas of Talairach and Tournoux
Talairach coordinates
An approach for correcting many statistical comparisons based on the number of tests being conducted
Family Wise Error (FWE)
An approach for correcting for many statistical comparisons based on the number of positive results obtained
False Discovery Rate (FDR)
A reduction/suppression of the activity of a brain region (or a cognitive process), triggered by activity in another region/process
Inhibition
An increase of the activity of a brain region (or a cognitive process), triggered by activity in another region/process
Excitation
An increase in physiological processing in one condition relative to some other condition(s)
Activation
A decrease in physiological processing in one condition relative to some other condition(s)
Deactivation
A progressive loss of information from semantic memory
Semantic dementia
Conceptually based knowledge about the world, including knowledge of people, places, the meaning of objects and words
Semantic memory
An fMRI analysis method in which distributed patterns of activity are linked to cognitive processes
Multi-voxel pattern analysis (MVPA)
A disorder of consciousness in which patients with severe brain damage are in a state of partial arousal
Vegetative state
