Dynamic Sculpting of Brain Functional Connectivity Is Correlated with Performance

In this study, we examined the relationship between cortical coupling, reflected in event related partial coherence (ERPC) and cognitive processing speed while subjects performed a set of Raven's Progressive Matrices (RPM), a task used to measure IQ. Fifty-five participants (29 males) performed a computerized version of the RPM where they were required to identify the shape (probe) that is consistent with a matrix of displayed shapes. Participants indicated a match or non-match by pressing a micro-switch with either the right or left hand. The steady state visually evoked potential (SSVEP) was elicited by a 13 Hz uniform visual flicker superimposed over the visual fields and the SSVEP event-related coherence (SSVEP-ERPC) calculated for all 2016 unique electrode pairs. The linear correlation between SSVEP-ERPC and processing speed (the inverse of reaction time) was calculated for all electrode pairs for all time points during the 3 sec interval that the probes were on the screen. Using correlation coefficient thresholds corresponding to p=0.001 we identified those electrode pairs where SSVEP-ERPC or neural synchronization was significantly correlated with processing speed. At a point 0.8 sec before the appearance of the probe we observed that the synchronization between specific prefrontal, frontal and central sites was correlated with processing speed. We suggest that this relationship may reflect the efficiency of working memory processes and speed of information processing.

[1]  D. Tucker,et al.  EEG coherency II: experimental comparisons of multiple measures , 1999, Clinical Neurophysiology.

[2]  D. P. Russell,et al.  Increased Synchronization of Neuromagnetic Responses during Conscious Perception , 1999, The Journal of Neuroscience.

[3]  R. Coppola,et al.  Functional and effective frontotemporal connectivity and genetic risk for schizophrenia , 2003, Biological Psychiatry.

[4]  Paul L Nunez,et al.  Fronto-Parietal Evoked Potential Synchronization is Increased During Mental Rotation , 2003, Neuroreport.

[5]  P. Goldman-Rakic.  Regional and cellular fractionation of working memory. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[6]  R. Knight,et al.  Prefrontal modulation of visual processing in humans , 2000, Nature Neuroscience.

[7]  G Pfurtscheller,et al.  Event-Related changes of band power and coherence: methodology and interpretation. , 1999, Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society.

[8]  H. Petsche,et al.  Synchronization between prefrontal and posterior association cortex during human working memory. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[9]  M. Hallett,et al.  Integrative visuomotor behavior is associated with interregionally coherent oscillations in the human brain. , 1998, Journal of neurophysiology.

[10]  Hualou Liang,et al.  Short-window spectral analysis of cortical event-related potentials by adaptive multivariate autoregressive modeling: data preprocessing, model validation, and variability assessment , 2000, Biological Cybernetics.

[11]  J. Desmond,et al.  Neural Substrates of Fluid Reasoning: An fMRI Study of Neocortical Activation during Performance of the Raven's Progressive Matrices Test , 1997, Cognitive Psychology.