A Quantitative Electroencephalographic Correlate of Sustained Attention Processing

Abstract

The objective of the present investigation was to develop a quantitative electroencephalographic measure (qEEG) that is sensitive and specific to changes in sustained human performance. A principal components analysis (PCA) was performed on the qEEG obtained from participants during a continuous performance test. Measures of sensitivity (proportion of correctly identified correct responses, or hits) and specificity (proportion of correctly identified incorrect responses, or misses) were calculated to assess the classification accuracy of each newly derived component. PCA solutions produced a right hemisphere component comprised of beta-wave activity measured from four unipolar sites (F8, C6a, C6, and T4) that appeared to be sensitive and specific to changes in human performance. Results provide evidence for the validity of a right hemisphere qEEG measure that is sensitive and specific to changes in sustained human performance. Consistent with the findings of previous research, the present findings implicate the right cerebral hemisphere in the sustained attention process.Despite recent advances in functional neuroimaging and other neurophysiological techniques very little research has been dedicated to the identification and the development

Rhythmic Oscillations in Quantitative EEG Measured During a Continuous Performance Task

“…Periodicities ranging from 1.00 to 2.00 min and from 4.70 to 5.70 min with amplitudes greater than would be expected due to chance were retained (Smith et al 2003). The results of the present investigation validate the existence of cyclic variations in human performance that have been identified previously (Smith et al 2003) and extend those findings by implicating right-hemisphere mediated arousal in the process (Arruda et al 1996(Arruda et al , 1999(Arruda et al , 2007. Significant cyclic variations in left-hemisphere betawave activity were not observed.…”

“…Absolute power in the beta frequency range (12-25 Hz) was then calculated for each of the 1,800 segments using a Fast Fourier Transformation (FFT) algorithm introduced by Brigham (1974), producing a near continuous 30 min record of absolute beta power for each of the 58 active electrode recording sites. Absolute beta power measured from four unipolar recording sites (i.e., F8, C6a, C6, and T4) was then averaged to form a single right-hemisphere composite variable that has proven to be both sensitive and specific to changes in sustained human performance (Arruda et al 2007). The beta frequency bandwidth and the EEG recording sites used were selected to closely approximate that used by Arruda et al (1996Arruda et al ( , 1999Arruda et al ( , 2007.…”

“…For example, research suggests that performance on sustained attention tasks is marked by brief cyclical or ''molecular'' variations that may be obscured by neuroimaging techniques with poor temporal resolution (Conte et al 1995;Gilden and Wilson 1995;Lovett Doust et al 1978;Smith et al 2002;Smith et al 2003). Given the documented role of the right hemisphere in mediating sustained attention (Arruda et al 1996;Arruda et al 1999;Arruda et al 2007), it is likely that cyclic changes in performance are accompanied by cyclic changes in right hemisphere brain activity that may be difficult to detect using traditional neuroimaging techniques.…”

“…Arruda et al (1996Arruda et al ( , 1999Arruda et al ( , 2007 have developed a right-hemisphere qEEG measure comprised of beta power that appears to index a right lateralized arousal system. The identification of cyclic variations in right hemisphere activity would support the findings of previous research that has already identified cyclic variations in human performance (Smith et al 2003) and would further support the theory that the right hemisphere mediates specific cyclic changes in arousal (Tucker and Williamson 1984;Posner and Petersen 1990;Pardo et al 1991;Arruda et al 1999) during a sustained attention task.…”

Vertical scanning biases and their possible influence on reading direction: Celtic wisdom or folly?

“…Line bisection is a spatial task that requires the use of Vertical scanning 107 global (vs. focal) attention and requires continuous (vs. categorical) processing. Studies in normal subjects have demonstrated that it is the right hemisphere that is dominant for global attention (Robertson et al, 1988), continuous processing (Arruda et al, 1996(Arruda et al, , 2007, and spatial computations (Jager & Postma, 2003). Thus, when performing the routine line bisection task, normal subjects should initially orient to the left side of the line.…”