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Correlated neuronal activity and the flow of neural information. Jaeseung Jeong, Ph.D Department of Bio and Brain Engineering. Nonlinear information transmission of the cerebral cortex. Conventional measure: cross-correlation.
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Jaeseung Jeong, Ph.D
Department of Bio and Brain Engineering
Conventional measure: cross-correlation
Jelic V et al., Quantitative electroencephalography power and coherence in Alzheimer\'s disease and mild cognitive impairment. Dementia. 1996;7(6):314-23.
Definition of synchronization: two or many subsystems sharing specific common frequencies
Broader notion: two or many subsystems adjust some of their time-varying properties to a common behavior due to coupling or common external forcing
Jansen et al., Phase synchronization of the ongoing EEG and auditory EP generation. Clin Neurophysiol. 2003;114(1):79-85.
Le Van Quyen et al., Nonlinear interdependencies of EEG signals in human intracranially recorded temporal lobe seizures. Brain Res. (1998)Breakspear and Terry. Detection and description of non-linear interdependence in normal multichannel human EEG data. Clin Neurophysiol (2002)
as a reference baseline?
What does the brain do when not actively engaged in
goal-directed cognitive tasks –
when, for want of a better term, we might say it is at “rest”?
What functions does the ‘resting’ brain subserve
and how do these impinge on more general aspects of cognition?
resting human brain using MRI.
(Biswal B., Yetkin F., Haughton V. and Hyde J., (1995) Functional connectivity in the motor cortex of resting human brain using echo-planar MRI. Magn. Res. Med. 34, 537–541)
Biswal et al. (1995) were the first to observe the coherence between such low frequency oscillations and widely distributed neuro-anatomical networks.
Detection of functional connectivity using temporal correlations in MR images. Michelle Hampson, Bradley S. Peterson, Pawel Skudlarski, James C. Gatenby, John C. Gore, Human Brain Mapping 15(4):247 - 262, 2002
Chen et al. (2008) compared the spatial distribution and spectral power of seven bands of resting state EEG activity, in an eyes closed and eyes open condition:
The issue of how different brain regions are connected functionally, that is, how the interplay of different areas subserves cognitive function, has become a key concern in neuroscience.
This has led to a certain confusion with regard to terminology.
Should only the task-negative network be termed the DMN and contrasted with the task-positive network?
Or should both task-positive and task-negative networks be regarded as elements of the DMN?
In the context of DMN activity, MPFC is thought to mediate a dynamic interplay between emotional processing and cognition functions which map on to the ventral and dorsal regions, respectively ([Gusnard et al., 2001], [Raichle et al., 2001] and [Simpson et al., 2001]).
a | All input spike trains were independent. In the middle traces, both postsynaptic neurons are shown to fire at about 30 spikes s-1.
The y axis indicates the rate of spike coincidences when the spike trains from the two neurons are shifted in time by the amount shown on the x axis. These correlograms have been normalized so that a zero rate corresponds to independent spike trains. The three panels correspond to three different pairs.
In the top two examples, more synchrony was observed when attention was focused on the tactile stimuli; this was the more prevalent effect. An example of lower synchrony with attention on the tactile stimulus — the less frequent effect — is shown in the lower plot.
Monkeys were trained to fixate on a central spot and to attend to either of two stimuli presented simultaneously and at the same eccentricity.
a and b | The continuous traces show the stimulus-driven local field potentials (LFPs). The spikes below were recorded simultaneously from different electrodes.