Term
| advantages of TMS over organic lesion |
|
Definition
no reorganization
can be used to determin timing of cognition
lesion is focal
lesion can be moved within the same participant
can study functional connectivity |
|
|
Term
| advantages of organic lesion over TMS |
|
Definition
subcortical lesions can be studied
lesions can be accurately localized
changes in behavior/cognition are more obvious |
|
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Term
| event-related potentionals |
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Definition
measurements of electrical signals generated by the brain through electrodes placed on different points on the scalp
reduced signal to noise ratio
look at timing and amplitute of peaks
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Term
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Definition
| Properties of the world that are manifested in cognitive systems (mental representation) and neural systems (neural representation). |
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Term
| Single-cell recordings (or single-unit recordings) |
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Definition
| Measure the responsiveness of a neuron to a given stimulus (in terms of action potentials per second). Placed in the axon or outside membrane |
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Term
| Multi-cell recordings (or multi-unit recordings) |
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Definition
| The electrical activity (in terms of action potentials per second) of many individually recorded neurons. |
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Term
|
Definition
| The informational content of a neuron may be related to the number of action potentials per second. |
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Term
|
Definition
| The synchrony of firing may be used by a population of neurons to code the same stimulus or event. |
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Term
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Definition
| The study of the time course of information processing in the human nervous system. Changes in information processing will manifest in time takes to complete a task. |
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Term
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Definition
| The problem of how a physical substance (the brain) can give rise to our feelings, thoughts and emotions (our mind). |
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Term
|
Definition
| A general method for dividing reaction times into different stages devised by Sternberg. |
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Term
|
Definition
| encoding, comparing, decision, responding |
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Term
|
Definition
related to properties of the stimulus.
tent to be earlier than endogenous |
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Term
|
Definition
| related to properties of the task |
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Term
|
Definition
The difficulty of locating the sources of electrical activity from measurements taken at the scalp (in ERP research).
could calculate backwards from magnitude and location |
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Term
|
Definition
| 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. |
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Term
|
Definition
measuring the magnetic field generated from brain currents
unaffected by skull
poor detecting deep dipoles
millisecond temporal resolution
potentially good spatial
expensive |
|
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Term
|
Definition
a whole group of neurons have to fire, but nto cancel out each other
affected by the skull
detects all dipoles
sensitive to gyri and sulci activity
millisecodn temporal resolution
poor spatial
cheaper
no vocal |
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Term
|
Definition
| electrode in the axon itself |
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Term
|
Definition
|
|
Term
| 3 tpyes of representations found at the neural level |
|
Definition
local representation (one neuron/grandmother cell)
fully distributed: inofrmation is in all neurons of a given population
sparse distributed representation: distributed representation in which a small portion of the neurons carry information about an event/stimulus |
|
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Term
| sparse distributed coding |
|
Definition
sparse distributed representation: distributed representation in which a small portion of the neurons carry information about an event/stimulus
high memory cpacity
conserves energy
protects against information loss
allows us to generalize and categorize |
|
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Term
|
Definition
| peaks and troughs of the ERP |
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Term
|
Definition
| Reaction times are faster to a stimulus if that stimulus is preceded by a stimulus of similar meaning (this is also known as semantic priming). |
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Term
|
Definition
excellent temporal resolution
continous measurement over time
easier to link to neural processes
electrophysiological changes to unattended stimuli |
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Term
|
Definition
Measures of the spatial configuration of different types of tissue in the brain (principally CT and MRI).
based on the fact that tissue has different physical properties |
|
|
Term
|
Definition
| Measures temporary changes in brain physiology associated with cognitive processing; the most common methods of PET and fMRI are based on a hemodynamic measure. |
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Term
| Computerized tomography scans |
|
Definition
constructed according to the amount of x-ray absorption in different types of tissue
amount of absorption is related to tissue density
cannot distinguish between white and gray matter like mri |
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|
Term
|
Definition
safe
great spatial
dsicrimitnation in matter
can be adopted in blood oxygenation |
|
|
Term
| functional imaging is designed to |
|
Definition
| measure the moment to moment variable characteristics of the brain associated with change sin cogntiive processing |
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Term
|
Definition
| A technique for segregating and measuring differences in white matter and gray matter concentration. |
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|
Term
| Diffusion tensor imaging (DTI): |
|
Definition
| Uses MRI to measure white matter connectivity between brain regions. |
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|
Term
|
Definition
| Blood oxygen-level-dependent contrast; the signal measured in fMRI that relates to the concentration of deoxyhemoglobin in the blood. |
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Term
|
Definition
| Stimuli from a given condition are presented consecutively together. |
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Term
|
Definition
| Stimuli from two or more conditions are presented randomly or interleaved. |
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|
Term
| Hemodynamic response function (HRF) |
|
Definition
| Changes in the BOLD signal over time. |
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|
Term
| Pure insertion (also pure deletion) |
|
Definition
| The assumption that adding a different component to a task does not change the operation of other components. |
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Term
|
Definition
| The effect of one variable upon another. |
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Term
|
Definition
| The way in which different regions communicate with each other. |
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Term
|
Definition
| Event-related functional magnetic resonance imaging. |
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|
Term
| Stereotactic normalization |
|
Definition
| The mapping of individual differences in brain anatomy onto a standard template. |
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Term
|
Definition
| Redistributing brain activity from neighboring voxels to enhance the signal-to-noise ratio. |
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Term
|
Definition
| A volume-based unit (cf. pixels, which are 2D); in imaging research the brain is divided into many thousands of these. |
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Term
|
Definition
| Locations in the brain defined relative to the atlas of Talairach and Tournoux. |
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Term
|
Definition
| A reduction/suppression of the activity of a brain region (or a cognitive process), triggered by activity in another region/process. |
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Term
|
Definition
| An increase of the activity of a brain region (or a cognitive process), triggered by activity in another region/process. |
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|
Term
|
Definition
| An increase in physiological processing in one condition relative to some other condition(s). |
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Term
|
Definition
| A decrease in physiological processing in one condition relative to some other condition(s). |
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Term
|
Definition
| Over-elastic region of artery that is prone to rupture. |
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|
Term
|
Definition
| One task is performed worse than another because the task is performed sub-optimally (but not because some aspect of the task is compromised). |
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Term
|
Definition
| If two tasks share the same neural/cognitive resource but one task uses it more, then damage to this resource will affect one task more than the other. |
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Term
|
Definition
| difficulties in spelling and writing |
|
|
Term
|
Definition
| Lesions affect one or more components within the pre-existing cognitive system but do not result in a completely new cognitive system being created. |
|
|
Term
|
Definition
| A process of interaction between environment and multiple brain-based constraints that leads to the mature cognitive system emerging out of transformations of earlier ones. |
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Term
|
Definition
| The embryos precursor to the central nervous system, consisting of a set of cells arranged in a hollow cylinder. |
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Term
|
Definition
|
|
Term
|
Definition
| Support cells that guide neurons from the neural tube to final destination. |
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Term
|
Definition
| A time window in which appropriate environmental input is particularly important (but not necessarily essential) for learning to take place. |
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Term
|
Definition
| The theory that common phobias are biologically determined from evolutionary pressures. |
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Term
|
Definition
| An impaired ability to perform the coordinated movements that are required for speech. |
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Term
|
Definition
| layers on neurons, differr in thickness |
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Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| columns and layers function |
|
Definition
pass through all layers of cortex
Layer 4: input
Layers 1-3: local processing & Interneurons
Layers 5-6: Output |
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|
Term
| Approaches to studyingneurotransmitter systems |
|
Definition
Tracer Studies in slices
PET (Positron Emission Tomography)
Pharmaceuticals
Gene studies |
|
|
Term
| interactions between systems |
|
Definition
inhibitation and excitation
different levels: synapses, regions, neuromodulators
methods don't always show this |
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|
Term
| three components of methods/techniques |
|
Definition
temporal
spatial
invsiveiness |
|
|
Term
|
Definition
single cell recordings
eeg/erp
MEG |
|
|
Term
|
Definition
| functional and anatomical imaging |
|
|
Term
|
Definition
| human lesion, animal, teporary, and pharmacological |
|
|
Term
|
Definition
measures action potential
good spatial and temporal localization
not for high processing
can't generalize
not on humans, no language |
|
|
Term
| single unit recordings design issues |
|
Definition
species
task appropriate
individual cells as subjects |
|
|
Term
| direct electrical recording in humans |
|
Definition
pre/during surgery
why? Eplypsy and tumors
implanting electrodes |
|
|
Term
|
Definition
sensitive to neural activity in the dendrites
neural bassis is of electric dipoles in axons |
|
|
Term
|
Definition
overall pictures of brain activity
temporal localization
mental states |
|
|
Term
|
Definition
bad spatial localization
data is noisy |
|
|
Term
|
Definition
| Component sensitive to novelty |
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|
Term
|
Definition
| Component sensitive to semantic errors |
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|
Term
|
Definition
|
|
Term
|
Definition
| Component sensitive to faces |
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|
Term
|
Definition
|
|
Term
|
Definition
Mental chronometry: when are two processes diverge in time?
different timing = different processes
scalp topography |
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|
Term
| Interpretation traps in EEG |
|
Definition
Negative =/= inhibition; positive =/= excitation
All pyramidal cells are excitatory
Amplitude: Higher doesnt always mean more activity.
Depends on baseline -- which is arbitrary
Components dont correspond to single brain regions.
Most are a sum of contributions from many regions
Scalp location =/= brain location. |
|
|
Term
| Functional Brain Imaging: advatage and disadvantages |
|
Definition
Advantage of both methods: Good spatial
Disadvantages of both methods: Poor temporal resolution, but FMRI is better than PET |
|
|
Term
| brain activity correlates with |
|
Definition
|
|
Term
| why does a neuron needs blood? |
|
Definition
| dendrites need blood to focus and synaptic inputs and gated channels |
|
|
Term
| why is functional brain imaging poor? |
|
Definition
|
|
Term
|
Definition
|
|
Term
| Preprocessing data fMRI (4) and what they do |
|
Definition
Motion correction: Mathematical corrections of movement
Smoothing: removing noise for statistical analysis also helps for looking across people by allowing us to overlap
Normalization to template image: Morph subjects brain to match template
Averaging across subjects: average data to smooth out bumps in recording |
|
|
Term
|
Definition
| subtracted control activated areas or previous task |
|
|
Term
| fmri and brain area necessity |
|
Definition
cannot show if needed for a task
have to interrupt area to check performance' |
|
|
Term
| When is fMRI appropriate? |
|
Definition
When your experimental question is really about the brain.
When you can design appropriate tasks that can be done in the scanner, and will isolate your process of interest.
If a behavioral study will answer your question, then no need for fMRI.
Dont expect fMRI to provide the final answer; fMRI is best for hypothesis formation and development. Confirm results with another methodology |
|
|
Term
|
Definition
| look at smaller scale within regions, as activity is distributed across regions |
|
|
Term
|
Definition
fMRI not so good at indicating whether and how active regions interact
Seed region based models
Model Testing Methods |
|
|
Term
|
Definition
Start with one area of the brain (seed region)
See what interacts with it.
Exploratory method |
|
|
Term
|
Definition
Test a theory of how regions interact.
Mediation Effect Mapping
Reappraisal: think of a situation in other ways, not bad |
|
|
Term
| PET Imaging of Neurotransmitter systems |
|
Definition
Absolute measures of brain activity
Neurotransmitter systems |
|
|
Term
|
Definition
Planes of section
CT
MRI
Comparing groups using voxel based morphometry |
|
|
Term
| PET can give an absolute measure of neural activity |
|
Definition
Compare disease to controls
Rack time course of disease
FDG-PET= flurodeoxyglucose
Track changes in blood flow by tracking glucose |
|
|
Term
| Using PET to image NTs in vivo |
|
Definition
Classic PET measures blood flow by adding the radioactive tag to water, glucose, or oxygen.
Can also add the tag to other ligands
Can look at baseline binding (chemical anatomy)
Or at changes due to tasks (functional chemical anatomy) |
|
|
Term
| Performing MR anatomy studies |
|
Definition
Voxel Based Morphometry (VBM)
Multiple measures of gray matter: volume and morphology
can measure normal differences, not abnormalities |
|
|
Term
| applications MR anatomy studies |
|
Definition
Normal Individual differences
Development
Clinical studies |
|
|
Term
| White Matter Tract methods |
|
Definition
Tract tracing
Diffusion Tensor Imaging |
|
|
Term
|
Definition
| Label that spreads from axon terminal to cell body / dendrites. |
|
|
Term
|
Definition
| label that spreads from cell body to axon and axon terminal. |
|
|
Term
| Diffusion Tensor Imaging (DTI) |
|
Definition
Noninvasive study of white matter tracts
Measures direction of water flow. |
|
|
Term
| issues diffusion tensor imaging |
|
Definition
Uses standard MRI setup.
Often combined with MRI and fMRI
Doesnt show white matter
breaks in white matter affect cognition as it the disrupted connections |
|
|
Term
| Permanent lesions due to accidents or disease |
|
Definition
Brain tumor
Cerebrovascular disorders (stroke)
Traumatic brain injury (TBI)
Infection
Degenerative diseases
Anoxia or toxin exposure |
|
|
Term
| Adult versus developmental studies (lesions) |
|
Definition
| Changes and ability to overcome |
|
|
Term
| design issues in brain damage studies |
|
Definition
Case studies vs. group studies
Which disease to study?
Appropriate control groups
Single and double dissociations |
|
|
Term
| Associating location of brain damage with cognitive function |
|
Definition
Descriptive methods
Overlap methods
Voxel based Lesion Symptom Mapping |
|
|
Term
|
Definition
cognitive differentation (location irrelevant)
brain localization anatomical region and larger scale systems |
|
|
Term
|
Definition
white matter damage
plasticity |
|
|
Term
| lesions location and function (group sizes) |
|
Definition
description of lesions best for case studies or small groups
overlap method small to medium
voxel mapping, larg group |
|
|
Term
| Voxel based lesion symptom mapping (VLSM) |
|
Definition
lesion overlap
lesions locations correlated with performance |
|
|
Term
|
Definition
| See where the damage happens spatially |
|
|
Term
|
Definition
Aspiration
Transection
Chemical |
|
|
Term
|
Definition
| (cut through white matter tracts) |
|
|
Term
|
Definition
|
|
Term
| Two main maturational forces: |
|
Definition
Increased Mylenization
Synapse pruning |
|
|
Term
| Functional Consequences of maturation |
|
Definition
Increased interconnectivity between brain regions (related to Mylenization)
Increased specificity of cortical representations |
|
|
Term
| order of progression of mylenization |
|
Definition
1. Sensory and motor areas first
2. Parietal lobes and inferior temporal lobes later
3. Frontal lobes (tan) and corpus callosum last |
|
|
Term
| Synapse Generation and Pruning |
|
Definition
Synapse density in the visual and frontal cortex
Increases in dendrites and synapses across development
And then they are pruned down. |
|
|
Term
|
Definition
Gray matter increase and decreases across childhood/adolescence
Need to be pruned back if they are being used
Front cortex is the last in maturing |
|
|
Term
| Functional interconnections across age |
|
Definition
| Better integration and working together across age |
|
|
Term
| Physical brain changes with aging |
|
Definition
loss of myelin
synaptic degeneration
blood flow reduction, particularly anterior
similar to childhood |
|
|
Term
| Interpretation Issues in Developmental Studies |
|
Definition
anatomical imaging (volume isn't meaningful)
functional imaging patterns (decreased activity doesn't mean worse)
different pattern of activity |
|
|
Term
| Traumatic brain injury X age |
|
Definition
Complex interaction of age and recovery
phases in development that affects the relationship |
|
|
Term
| Factors contributing to functional impairment |
|
Definition
Highly specialized brain regions
Competitive processes across brain regions
"Teacher and student relationships between regions |
|
|
Term
|
Definition
code for proteins
generalists (used many areas)
switchable (on or off)< master genes |
|
|
Term
|
Definition
Code for traits or behaviors
Blueprints/0ne-2-one
insensitive to the environment
active only before birth |
|
|
Term
| How genes guide development |
|
Definition
code proteins necessary for the brain
when they should be developed
brain builds self from guidelines
adjust for environment from genes switching on or off |
|
|
Term
| Single nucleotide polymorphism |
|
Definition
Small differences in DNA can lead to small differences in proteins.
amino acids |
|
|
Term
| DA neurotransmission genes |
|
Definition
receptors
reuptake
synthesis enzymes
degradation enzymes
|
|
|
Term
|
Definition
|
|
Term
| issues in performing studies of genetic developmental disorders |
|
Definition
design issue: what is a comparision group?
interpretation issue: broad function of genes and developmental trajectory |
|
|
Term
| Amgydala changes associated with |
|
Definition
|
|
Term
| Parietal lobe changes associated with |
|
Definition
|
|
Term
| Adult phenotype may not reflect infant/child |
|
Definition
| Cant see nearly the difference as you see when they are older |
|
|
Term
|
Definition
|
|
Term
|
Definition
initial dip
overcompensation
undershoot |
|
|
Term
|
Definition
| the variable of interest is treated as a continuous dimension rather than a categorical distinction |
|
|
Term
|
Definition
| more power, detect small effects |
|
|
Term
| 3 assumptions in lesion studies |
|
Definition
factionation assumption
transparency assumption
universality assumption |
|
|
Term
|
Definition
| damage to brain can produce sleective cognitive lesions |
|
|
Term
|
Definition
| the universality assumption is that all congitive systems are basically identical |
|
|
Term
|
Definition
| a swelling of the brain following injury |
|
|
Term
| grouping of lesion patients |
|
Definition
syndrome
cognitive symptom
anatomical lesion
|
|
|
Term
|
Definition
| A discrete brain lesion can disrupt the functioning of distant brain regions that are structurally intact |
|
|
Term
|
Definition
| If there is a decrement in performance associated with doing two things at once, it suggests that these two tasks share cognitive processes. |
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