64 Multiple choice questions
- Multiple pulses with rates up to 50hz.
summed or superimposed signal of the postsynaptic electrical fields of
similarly aligned neuronal dendrites. Signals are recorded as a waveform
with each potential having its own particular voltage (size) and
frequency (oscillation rate).
- - Must always be used to compare two conditions
-Cannot measure neuronal response directly, rather it indexes a hemodynamic response of the vascular system to the increased need for oxygen in neurons in the local area.
-Provides only gross information on the location of these substances within the brain
-The concentration of the biologically active substances must be relatively high.
in neuron A is consistently associated with the firing of neuron B, a
change occurs such that the influence of neuron A on neuron B is
use of magnetic fields to distort the behavior of protons. The length
of time the protons take to recover from the distortion is used to
create an image of the anatomy of the brain.
absence or suppression of alpha activity. The degree of suppression is
used to determine how active the brain is under different conditions
(depression, greater suppression of R hemi).
high energy ionizing radiation emitted by a substance introduced into
the body. The radioactive substance emits positrons which collide with
electrons and produce photons of light. Higher metabolic activity
produces more light which can than be extrapolated to create an image of
It is the preferred technique for examining neurotransmitter function int he brain.
- The hemisphere receiving sensory information processes it.
differ not so much in what type of information they process, but rather
in how they process information. L hemi processes information in a
piecemeal and analytic fashion (temporal emphasis), whereas the R hemi
processes information in a gestalt and holistic fashion (spatial
- Examining whether all the answers obtained from a set of interrelated experiments lead to the same conclusion.
measure of brain activity in reference to a specific event. Provides
some idea of when processes occur in the brain. The common alignment and
firing of dendrites creates a dipole which can then be detected by
electrodes placed on the scalp.
Useful because they provide information about the time course with which information is processed in the brain.
provides information about the structural integrity of brain regions as
well as about the anatomical connectivity between different brain
regions. Could be used to investigate the effects of demyelinating
disorders and examine changes in white matter tracts during childhood.
be used to confirm findings from the lesion method and implicate a
brain region as playing a critical role in a specific mental function.
Can provide insights into how the brain reorganizes, and provide
information about whether a behavior is critically dependent on a
particular brain region or whether it results from the interaction
between brain regions.
Can also be used therapeutically.
- Reduced spatial resolution compared to the PET.
The overall picture of brain activity is less precise because it is averaged over a much longer time interval than PET.
keep researchers honest and provide systematic ways of manipulating
lesions that may not occur in real life which than provides researchers
with novel predictions about the relationship between the brain and
magnetic potentials produced by brain activity. The strength of the
magnetic field recorded on the outside of the head can help provide some
information about how deep within the brain the source is located.
- Using small sets of tests to generate hypotheses and then evaluating these hypotheses using more specific tests.
- Delta - Present during sleep, slow frequencies of 1-4hz.
Alpha - Present when relaxed, frequencies of 9-12hz
Beta - Present when awake and alert, frequencies >15hz
Gamma - Synchronous oscillations between groups of neurons; may play an important role in perceptions and attention.
to record electrical activity of the brain. Compared to brain imaging
techniques, ERM's are relatively poor at pinpointing the location of
electrical activity in the brain. However, it does provide an accurate
measure of brain activity.
changes in physiological functions can be used to infer the activity
levels of different brain regions. The BOLD (blood oxygen level
dependent) method takes advantage of the fact that oxygenated and
deoxygenated blood have different magnetic properties.
- The concept that one hemisphere dominates or leads mental function. Introduced by John Hughlings Jackson
stimulating coils only affect the region of the brain closest to the
surface. It is also not possible to control what regions of the brain
are affected by TMS.
information is presented simultaneously to each ear so that each
hemisphere receives two competing pieces of information.
- That is, a reasonable guess as to how well the person was performing before the inquiry.
- relies on both localization of function and on distributed processing.
localize the source of epileptic activity and to locate primary sensory
cortices. Also used to understand a variety of cognitive processes, and
the neurophysiology underlying psychiatric disorders.
advantage of the fast signal to record information locked to an event.
In this way it helps provide information about he source of activity
within millimeters while providing temporal information on the order of
milliseconds. However it cannot be used to obtain information about the
tools of cognitive neuroscience used to provide information about the
integrity of brain structures and the electrical and metabolic activity
of specific brain regions.
of scans an individual can undergo per year is limited, therefore
studies requiring multiple scans to determine changes over time are
-Temporal and spatial resolution is poorer than fMRI's.
-Requires ongoing ability to create a radioactive isotope.
regions of brain tissue are responsible for specific functions. The
site of brain damage, not just the extent of the damage, will predict
the nature and degree of deficit observed.
forth the idea that all pieces of brain contribute to all functions.
The nature of cognitive deficits following brain damage hinged not on
which region of the brain was destroyed but rather on the extent of the
- Does not involve transmitting high energy ionizing radiation through the body.
Spatial resolution of the image is superior
differ in their ability to process a particular attribute of visual
information (spatial frequency). R hemi more adept at low spatial
frequency, L hemi more adept at high spatial frequency.
obtain information about the source of neural activity as well as its
time course. Measures the absorption of light through the slow signal,
which is thought to reflect increased blood flow to areas engaged by
Measures the scattering of light which is related to the swelling of glia and neurons that are associated with neuronal firing (fast signal).
main nerve fiber tract that transfers information between the cerebral
hemispheres. Different types of information are transferred across
different parts of the callosum.
It is the major conduit for higher-order information.
- Simulates the action of the brain and its processes (computational models)
aspects of the approaches used in ERP's and EEG's. The activity is
examined over time, but the signals are not summed, instead the strength
of activity in different EEG frequencies is computed.
- Hemispheres of the brain are equipotential at birth. Lateralization increases until puberty after which it remains constant.
up of components which are characteristic portions of the wave.
Components are usually given names that have two parts (P,N) (number of
milliseconds after stimulus to presentation of component).
~100ms -linked to sensory processing
~N200 - mismatch negativity → individual presented with an item that is physically deviant from that of the prevailing context.
~P300 - related to attention and memory, oddball paradigm
~N400 - occurs when individuals detect semantic anomalies. Increases with the deviance of the word.
portion of a processing system that is dedicated to a single function
not performed elsewhere within that system (localization of function).
- Stimulation is delivered at a precise time during performance of a task.
an individual engages in a particular type of process, a greater
activation occurs in the hemisphere best suited to the task.
basic component of most computational models which exhibits behavior
like a neuron. Units are wired together in layers. These layers consist
of an input layer that simulates the receipt of information from the
outside world, an output layer that simulates the response of the system
and a "hidden" layer that is involved in the transformation necessary
to perform the computation under investigation.
- In the L hemisphere, important for language comprehension.
carried by the fibers of passage cannot be transmitted from one brain
region to another because of damage to the fibers. Not the result of
damage to neurons responsible for the behavior itself.
tool used to record and amplify the electrical signals of the brain.
Electrodes are placed on the scalp with one being placed on an
electrically inactive site such as the mastoid bone to provide a
- Static - A constant magnetic field
Pulse Sequence - Oscillating magnetic field
Gradient Field - Variates intensity over the area being imaged
to determine the degree to which damage to the CNS may have compromised
a person's cognitive, behavioral, and emotional functioning.
- Used to determine which hemisphere is responsible for speech output.
- The information received by the hemisphere less adept at a given task is transferred to the opposite hemisphere.
by placing an electrode into the brain region of interest. The
electrical output of the cell is then recorded. Researchers determine a
baseline of cell firing, and then find the properties of a stimulus that
causes the cell to fire maximally above that baseline.
Helpful in providing information about the organization of many brain regions, but studies in humans are limited.
opposite of the MEG. Imposes a pulsed magnetic field over the scalp
which induces an electrical field that alters the pattern of brain
activity in the underlying tissue. Causes a reversible lesion by
scrambling neuronal activity (making neurons fire in a random pattern
rather than coherent). Can facilitate or disrupt brain activity.
- -Detects the increase in the signal due to decreased presence of deoxygenated blood.
-A widely available method.
-Noninvasive technique with no high energy radiation involved.
-Allows scientists to examine changes in the brain over time and has high temporal resolution
- An amino acid with the second highest concentration in the nervous system.
specific brain functions by looking at or damaging a particular area
which results in the loss of specific brain functions.Emphasizes neural
substrates by asking "what functions are supported by a particular piece
of brain tissue?" Can test this by either looking at individuals with
similar brain damage or individuals with similar observed deficits.
be used on everyone because of magnetic fields interfere with
pacemakers and can be harmful to individuals with metal in their body
not connected to hard tissue.
whether two cognitive functions are independent of one another (i.e.
disruptions on speech output are independent of disruptions in speech
us to see the internal structure of the brain which is useful for
identifying damaged structures and also for assessing the size and shape
of neural structures in neurologically intact people.
not because of changes in the activation function of the units
themselves, but rather because of the changes in the interrelationships
between and among units.
down version of the PET scan which allows researchers to examine how
the brain uses specific molecules and also provides information on the
absolute levels of brain metabolism.
- The degree of influence that a unit in one level has on a unit in another level (-1 to 1).
use of x-rays to determine the density of brain structures. Higher
density areas are white (bone) and lower density areas are dark (CSF).
Old trauma is dark because of the CSF. These scans are relatively
inexpensive and have no restrictions on who can receive them.
to specify with certainty the location of the dipole. Any given pattern
of activity on the scalp could mathematically be produced by a variety
of generators within the brain (inverse problem).
- Multiple tests used to detect any typed of brain dysfunction.