Chapter 2: Memory and the brain Flashcards
traumatic brain injury (TBI)
caused by a blow or jolt to the head, or a penetrative head injury. Normal brain function disrupted
The more severe the injury, longer unconsciousness or amnesia, more brain damage, poorer chance of recovery
why doesn’t TBI lead to theoretical conclusions about nature of memory
because it is hard to separate memory deficits from other factors
Alcoholic Korsakoff syndromes
drinking too much, eating too little, memory deficits prominent
Henry Molaison HM
most influential neuropsychological case
Temporal lobe epilepsy/ surgically removed parts of the hippocampus
New information retention damage
HM’s deficits were limited to episodic long term memory
double dissociation
a term particularly used in neuropsychology when two patient groups show opposite patterns of deficit
Ex: STM normal and impaired LTM, or normal LTM and impaired STM
converging operations
carrying out a whole series of operations and experiments using different methods and different participant groups, all focused on the same theoretical question
Computerized tomography (CT)
rotating an x-ray tube around head, provides multiple viewpoints of brain fed into computer for 3D representation of the brain
Magnetic resonance imaging (MRI)
places head in strong magnetic field, scammer emits radio waves
Grey matter (neuronal cell bodies), white matter (axons- linking different brain areas), and cerebrospinal fluid all emit different energy due to different absorption so provides 3D image
No radiation, more precise images than CT
Diffusion tensor imaging (DTI)
takes advantage of myelin sheaths which around white matter are relatively fatty, causing water within to flow along that fiber. Allows mapping of important white matter bundles that transfer information from one area of the brain to another
Transcranial magnetic stimulation (TMS)
a less invasive method of influencing the brain, a current is passed through a set of coils held close to the participants head
Causes magnetic field that can temporarily polarize or depolarize the brain area
Limited to areas of the brain near surface, discomfort
Electroencephalography (EEG)
recording the ongoing electrical activity of the human brain. Noninvasive, picks up electrical activity of the brain through electrodes on the scalp
Used to detect epileptic foci that can result in seizures
Event related potentials (ERPs)
more precise way of evaluating the brain’s response to specific cognitive activities through the pattern of EEG activity obtained by averaging the brain responses to the same stimulus presented repeatedly. Precise timing, most sensitive to gyri- peaks
Magnetic encephalography (MEG)
a system whereby the activity of neurons within the brain is detected through the tiny magnetic fields that their activity generates. Most sensitive to the activity in sulci- the valleys within in the folds of the brain
Positron emission tomography (PET)
method where radioactively labeled substances are introduced into the bloodstream and subsequently monitored to measure physiological activation. Injected into the bloodstream, carried to brain
Functional magnetic resonance imaging (fMRI)
measures the flow of oxygen within different areas of the brain, on assumption the active area of the brain will utilize more oxygen
When oxygen is depleted hemoglobin magnetic resonance signal charge, better spatial resolution, poor temporal resolution
Multivoxel pattern analysis (MVPA)
a scan results in visual representation of the brain that can be divided into an array of tiny spatial areas known as voxels. Look for cross voxel regularities. “Mind reading”- lying isn’t detected but the cognitive and emotional processes associated with lying are detected
Long term potentiation (LTP)
a process whereby synaptic transmission becomes more effective following a cells recent activation
patient studies main advantages
Naturally, potentially
Strongly implicate particular brain area
patient studies main disadvantages
Complex
Varies in extent and location
Not specific networks or temporal resolution
Patients rare and effects may change during recovery
Transcranial magnetic stimulation (TMS) main advantages
Specific brain region
Reversible
Inexpensive
Temporal specitivity
Transcranial magnetic stimulation (TMS) main disadvantages
Spatial resolution limited
Confined to surface of cortex
Discomfort
Safety concerns
Electroencephalography (EEG) main advantages
Rapid and inexpensive
Good temporal resolution
Noninvasive
Electroencephalography (EEG) main disadvantages
Poor spatial resolution
Not clearly specific to cognitive function
Event related potentials (ERPs) main advantages
Fast and inexpensive
High temporal resolution
Noninvasive
Event related potentials (ERPs) main disadvantages
Poor spatial resolution
Hard to separate influence of different components
Correlation, may be present but not essential to a task
Magnetoencephalography (MEG) main advantages
High temporal resolution
Noninvasive
Better localization than ERPs
Magnetoencephalography (MEG) main disadvantages
Limited spatial localization
Relatively inexpensive
Susceptible to interfering noise
Correlational
Positron emission tomography (PET) main advantages
Good spatial resolution
Can identify network of regions
Positron emission tomography (PET) main disadvantages
Poor temporal resolution Invasive Need radioactive injection Expensive Needs cyclotron indirect Relies on assumption about blood flow Correlational
Functioning magnetic resonance imaging (fMRI) main advantages
Good spatial resolution Reasonably good temporal resolution Can identify networks Noninvasive Relatively inexpensive
Functioning magnetic resonance imaging (fMRI) main disadvantages
Temporal resolution fairly low, in seconds
Depends on indirect measure of blood flow
Correlational
henry M neurologically finding benefits
Neurologically- demonstrated the importance of anatomical location
Henry M psychological finding benefits
Psychologically- supported separation of functions between memory and intelligence, between short term and long term
