Search

The Continuous Performance Test (CPT) is a valuable tool for assessing behavior in attention-deficit/hyperactivity disorder (ADHD). Quantitative electroencephalography (QEEG) is a promising tool for the diagnosis of ADHD. Recently, theta-phase gamma-amplitude coupling (TGC) measurement has received attention because it is a feasible method of assessing brain function. We investigated the relationship between CPT performance and EEG measures such as TGC and theta and gamma activity. EEGs were recorded from 68 volunteers from a camp for hyperactive children using a 19-electrode system. Their TGC, theta and 40 Hz gamma activity were estimated and compared with results obtained on the Korean ADHD Rating Scale (KARS) and the Intermediate Visual and Auditory (IVA) CPT. The results demonstrated significant negative partial correlations between TGC and the IVA CPT, such as the Response Control Quotient (RCQ) and Attention Quotient (AQ). TGC successfully identified the level of dysfunctional interaction of the attention/arousal system at a multi-scale large network level. It is thought that as the TGC increases, the efficacy of the system is very low or dysfunctional. Compensatory hyper-arousal patterns of the dysfunctional attention/arousal system may account for this effect. TGC is a promising neurophysiological marker for ADHD behavior in children. [ABSTRACT FROM AUTHOR]

Abstract: Theta–gamma coupling (TGC) is known to reflect working memory processes, but it is unclear whether TGC as measured by scalp electroencephalography (EEG) reflects working memory processes or nonspecific attentional processes. In this study, we examined the degree of TGC during a visuo-spatial working memory task (2-back task) vs. a simple vigilance task in 13 young participants. During the working memory task, TGC increased in the frontal area at approximately 40Hz. In addition, TGC was also significantly different at high-gamma frequency despite no differences in gamma power between the two tasks, and a correlation between TGC only during the working memory task and hit rate was observed. These results suggest that TGC reflects working memory processes and may be a useful bio-physiological marker of working memory. [Copyright &y& Elsevier]

Abstract: Although theta-gamma coupling is known to reflect memory-related processes, it is unclear whether it has a relationship with memory ability. Here, we investigated the relationship between theta phase and gamma power coupling (TGC) and scores obtained regarding memory tasks. Thirty-one older subjects performed a spatial delayed match-to-sample task (SDMST) during EEG recording. We also evaluated performance on the delayed figure recall (DFR) and delayed verbal recall (DVR) tasks regarding memory ability. Partial correlation analysis (controlled for age) demonstrated that increases in TGC in the parietal area were significantly correlated with increases in the DFR scores obtained. In addition, TGC was significantly correlated with the accuracy rate of the SDMST. Our results indicate that TGC could be a useful biophysiological marker of memory ability. [Copyright &y& Elsevier]