Chapter 3 Flashcards
Two concepts that under lie the cognitive approach
- Information processing depends on internal representations.
- These mental representations undergo internal transformations.
Transcranial magnetic stimulation (TMS)
Provides focal stimulation of brain noninvasively; directly stimulates neurons
- produced at either high (excitatory) or low (inhibitory) frequencies
What do CAT, MRI, and DTI all do?
Give information on structure of the brain
MRI
Maps brain areas in detail using magnetic properties of atoms that make up organic tissue
CAT
Inject dye into blood and pass x-rays through the head; allows 3D reconstruction
DTI
Neuroimaging that uses an MRI to image all white matter pathways (Myelination)
What do EEG, ECoG, Single-cell recording, and MEG have in common?
They all measure neural activity
Single-cell recording
Used to monitor the activity of individual neurons; measures change in membrane potential
-invasive technique using electrodes
MultiUnit recording
An array of electrodes is inserted into the brain to help understand the activity of many cells
ECoG
A grid of strip electrodes is inserted in the brain to help understand the activity of many cells
-invasive
Are single cell recordings, ECoG, and multiunit recordings invasive or noninvasive?
invasive
EEG
Surface recording made from electrodes placed on scalp; good for temporal resolution
MEG
Measures magnetic signals generated by the brain
- magnetic detectors are placed on the scalp that measure the electrical activity of neurons
- noninvasive
What is hemodynamic response?
Detect change in blood flow
PET
Measure metabolic activity or blood flow changes in the brain by monitoring the distribution of a radioactive tracker
fMRI
Utilizes an MRI to track blood flow changes in the brain that may be correlated with local neural changes
Event-related potentials-
A change in electrical activity that is time-locked to specific events such as the presentation of a stimulus or
onset of a response
- measured by EEG
What two imaging techniques exemplify hemodynamic response?
PET and fMRI
Block design
Experimental design that consist of blocks of multiple trials of the same type
DBS (deep brain stimulation)
Surgical implants of a microelectrode
directly in the brain.
- used for depression, OCD, other life altering disorders
- last resort
optogenetics
A technique (viral transduction) that allows researchers to turn on activity in targeted neurons by a device that shines a light within the brain by using a specially manipulated virus to insert light-sensitive proteins into
the membrane of a given type of neuron.
knockout procedure
Scientists manipulate a specific gene (or set of genes) such that it
does not express itself, and then study the knockout strains to explore the consequences of this change.
agonist
drug that binds to the receptor, producing a similar response to the intended chemical and receptor
antagonist
drug that binds to the receptor either on the primary site, or on another site, which all together stops the receptor from producing a response.
DAI (diffuse axonal injury)
The twisting, buckling, or distortion of the white matter that occurs with an injury disrupts the axonal cytoskeleton and thus also axonal transport.
What is the best way to diagnose neurodegenerative diseases?
fMRI
ischemia
-type of stroke
-caused by blood clot that prevents blood flow to the brain
hemorrhage
-type of stroke
-blood vessel ruptures that causes blood to leak into brain tissue
Word Superiority Effect
Reicher
- In this experiment, participants briefly see a stimulus and then decide which of two target letters (e.g., A or E) they saw. The stimulus is a word, a nonsense string, or a string in which every letter is an X except for the target letter.
- showed that it was most accurate for real words
mental representation
The way in which information is stored, processed, and used by the mind.
- Even with simple stimuli, the mind derives multiple representations.
ex) Letter matching task
Letter matching task
Posner
- Had participants look at two letters and then choose a button based on what category they thought they were in
- physical identity was the fastest and same category with both consonants was the longest
-illustrated mental representations/operations
Independent Variable
- variable that gets changed
- x axis
Dependent Variable
- variable that gets measured
- y axis
internal transformations
Mental representations undergo internal transformations.
* Memory alters how we perceive something.
* Info processing also subject to attentional constraints.
Sternberg’s Memory Comparison Task
Said that four primary mental operations are completed serially:
1. Encoding (identifying)
2. Comparing
3. Deciding
4. Responding
Serial Processing vs Parallel Processing
Serial is processing one thing at a time where parallel is processing multiple things at once
Stroop Task
colors and words
- trying to say the color of the word while the word is also a color; showed that reading interferes with other cognitive tasks
neuropsychologists
investigate the relationship
between brain function and behavior, often examining
how injuries, diseases, or other conditions affect cognitive processes and behavior.
How much oxygen does the brain use? How much mass does it take up?
20%; 2%
Is gray or white matter affected by TBIs
Both white and gray matter is affected
What are some consequences of TBI?
Edema (swelling) around the lesion (limited space within the skull causes an increase in the intracranial pressure, in turn reducing the perfusion pressure and flow of blood throughout the brain. This could result in ischemia or the emergence of secondary lesions.
What can TBI/concussions or even mild TBIs lead to ?
neurodegenerative diseases
Lesion studies
assume that brain injury disturbs or eliminates the
processing ability of the affected structure.
single vs double dissociations
Establishing a single dissociation between two functions provides limited and potentially misleading information, whereas a double dissociation can conclusively demonstrate that the two functions are localized in different areas of the brain.
Pharmacological study
An experimental method in which the independent variable is the administration of a chemical agent or drug
advantages and disadvantages of TMS
Advantages: Safe way to disrupt the activity of the brain, Within-subjects design
Disadvantages: Poor spatial resolution, Inconsistent results
When a brain area becomes more active, two relevant changes occur:
- Blood vessels dilate to allow more blood flow to the area.
- As the brain area uses oxygen, the percentage of hemoglobin
with oxygen decreases.
