Posner task
Task: participants decide if two letters are in the same category
Effect: longer RT for accessing more abstracted representations
Main idea: different response times reflect degrees of processing required
Stroop task
Task: subjects instructed to name the color of a word
Effect: slower to name colors for mismatched colors and words
Main idea: task-irrelevant information interferes with processing
serial processing
sequential, “step-by-step” processing
slow, recognizes bottlenecks
parallel processing
simultaneous processing
faster, requires effective resource allocation
Steinberg memory paradigm
Task: identify if a “probe” letter was part of a set of letters
Effect: RT increases with number of items, no difference for “yes” or “no”
Main idea: comparison process acts in a sequential manner
Word superiority: serial vs. parallel
Task: decide which of two target letters were embedded in a word, nonsense string, or surrounded by Xs
Effect: most accurate when identifying target embedded in a word
Main idea: context affects performance - we activate individual letters and words in parallel
Shephard Mental Rotation
Task: asked whether two (rotated) images match
Effect: RT increases with amount of rotation needed
Main idea: takes time to form a mental image and perform transformations
parametric manipulation
varying the amount of a given process
cognitive subtraction
add or remove a process from the processing stream
Donder’s Method
Task: hit a button in response to a light under various conditions
Effect: RT increases with number of processes executed
Main idea: processes are additive
causal methods
“poking” the brain - interrupting or modifying brain function to see what happens (lesioning, transcranial magnetic stimulation)
correlational methods
“listening” to the brain (fMRI, EEG, single-unit recordings)
stroke
disruption to blood flow in the brain; damage at specific anatomical locations
traumatic brain injury (TBI)
often result from accidents or blows to the head, can cause physical damage and may lead to long-term impairments
neurodegenerative disorders
progressive conditions characterized by gradual loss of neurons and brain function; widespread brain damage
examples: Alzheimer’s, Parkinson’s, Huntington’s
single dissociation
patient group shows impairment on one task, but not another
double dissociation
one patient group shows impairment on one task, second patient group shows impairment on a separate task
provides stronger evidence for selective impairment than single dissociation
deep brain stimulation (DBS)
causal method
implantation of electrodes in the brain and delivering of electrical impulses to modulate neural activity in targeted areas
optogenetics
causal method
uses light to control neurons that have been genetically modified to express light-sensitive ion channels, precise control of neuronal activity
transcranial magnetic stimulation (TMS)
causal method
utilizes magnetic fields to induce electrical currents in specific brain areas, non-invasive modulation of neuronal activity
electrophysiology
correlational method
records electrical activity from individual neurons or groups of neuron at a highly detailed level
electrocorticography (ECoG)
captures electrical activity from surface of the brain using electrodes on the cortex, high spatial and temporal resolution
used to identify epileptic zones, map critical brain functions
electroencephalography (EEG)
measures electrical activity through the scalp, noninvasive
used to diagnose epilepsy, sleep disorders, and brain activity in response to tasks
Event-Related Potentials (ERP)
brain responses tied to specific sensory, cognitive, or motor events; insight into brain function and timing
magnetoencephalography (MEG)
detects magnetic fields produced by neuronal electrical activity, allows for noninvasive study of brain function with good spatial, excellent temporal resolution
computed tomography (CT)
uses X-rays to create detailed images of the brain
used to diagnose injuries, tumors, structural abnormalities
positron emission technology (PET)
visualizes metabolic processes in the brain by detecting radioactive tracers, useful for studying brain function and disorders
magnetic resonance imaging (MRI)
provides high-resolution images of the brain’s structure and anatomy using magnetic fields and radio waves, no exposure to ionizing radiation
diffusion tensor imaging (DTI)
type of MRI that maps diffusion of water molecules in brain tissue, reveals microstructural organization of white matter
functional magnetic resonance imaging (fMRI)
measures brain activity by detecting changes in blood flow, offers insight into brain’s functional areas during tasks or rest
BOLD (blood-oxygen-level-dependent) signal
detected in fMRI, reflects changes in blood oxygenation