Electrophysiological correlates of motor and sensory behavior PP Flashcards
Limitation of optical imaging techniques
Limited penetration into brain tissue - prevents measurement from more than 5 cm away from area
What kind of imaging technique is near infrared spectroscopy (NIRS)
Optical imaging
What can NIRS image?
Both neuronal and blood volumes changes and even anatomical details
What can NIRS be combined with
fMRI
EEG
What is NIRS based on?
The tie required for near-infrared light to move through the head
Does NIRS offer good or bad temporal and spatial resolution?
Good
2 NIRS approaches to measure infant brain
Optical topography
Optical tomography
What is biomagnetism?
Study of magnetic fields with origin in specific biological systems
What has the SQUID been used to measure the magnetic fields produced by?
Heart
Lung
Brain
Which imaging modality is most suitable for biofeedback application?
NIRS
What does observed MEG represent?
Combined activity of millions of neurons
When using biofeedback to induce a relaxed physical state, which EEG waves are modulated?
Alpha waves
Measure of relationship between 2 areas of EEG recording
Coherence function (COH)
What does the sites with highest COH scores correspond with?
Areas with greatest anatomical connections
Which hemisphere of the brain is involved in analytical part of tasks?
Left
Which hemisphere of the brain is involved in spatial/visual part of tasks?
Right
Which wave is enhanced a few seconds before performance of various skilled aiming tasks? and what does that suggest?
Alpha
Suggest that left-hemisphere processes are suppressed
What does intention refer to?
Selection of an output (action)
What does attention concern?
Selection of input (stimuli)
What is the suppression of EEG activity (mostly in the alpha range) called?
Event-related desynchronization (ERD)
3 criteria for ERD
Circumscribed
Phasic
Focused over specific cortical areas
Does EEG reflect intelligence?
No
Which EEG wave does memory load have an effect on?
Gamma
Which has longer reaction time (RT) scores, low or high memory load?
High memory load
What dies ERD in the lower alpha band reflect?
Attention
What dies ERD in the upper alpha band reflect?
Stimulus encoding
Where do stimuli creating positive feelings produce more activity?
Left hemisphere in frontal lobes
What kind of brain activity does EEG represent?
Spontaneous
What are ERP (event related brain potential) generated as a response to?
Specific stimuli
What are long latency potentials?
The positive or negative components of the ERP that occur at 250 to 750 sec after an event
What do long latency potentials reflect?
Subjective responses to expected or unexpected stimuli (including orienting response)
What does N400 occur in response to?
Unexpected endings of sentences (related to semantic deviation)
Example of steady potential shift (SPS)
Contigent negative variation (CNV)
When can continent negative variation be observed?
When subjects are told that they have to respond to an event some time after a warning signal is given
When does readiness potential (RP) build up?
Just before the onset of voluntary movement
What are brain stem potentials?
Low amplitude responses reflecting electrical activity in various brain stem structures
What are ERPs recorded simultaneously to?
PET or fMRI
Where is the N1-P2 complex generated?
Auditory cortex in temporal lobes
Where is the negative wave occurring at 55ms generated?
Postcentral gyrus
What is N1 related to?
Attention
In who is the latency of the N1 component delayed?
4 to 8 year olds
What are long latency potentials strongly influenced by?
Subjective factors
What are the long latency potentials N400 and P600 related to?
Memory processes
Where are continent negative variation (CNV) found?
Maximal over the central cortex and less pronounced at frontal and parietal areas
Where has readiness potential (RP) been recorded?
Areas of brainstem and midbrain
What are ERP (event related brain potentials) derived from?
The EEG
What are faster RTs associated with?
Higher amplitude ERPs
When are P300 response latencies and RTs longer?
When auditory discriminations are more difficult
What are bisensory stimulation associated with?
Faster RTs, shorter ERP latencies and greater ERP amplitudes
What does pre motion MPs (movement-related potentials) represent?
Preparation for voluntary movements
What does error related negativity (ERN) allow for the study of?
How errors in motor response is monitored
What is non-REM sleep described as?
Stages 1 to 4
Changes of ERPs during sleep
Delay of brain auditory evoked potential wave latencies
Amplitude of the N! ERP starts to decrease and disappears when stage 2 sleep is established
What do the P300 results indicate regarding sleeper?
That the sleeper is capable of discriminating among stimuli if they are loud, meaningful or novel enough
Unique ERP of the sleep state
N350
N550
