Line Bisection Task Performance and Resting Eeg Alpha Power

Abstract

Neurologically normal subjects generally err to the left of veridical center when performing a line bisection task, a phenomenon termed "pseudoneglect." We hypothesized that resting electroencephalogram (EEG) alpha oscillations may show relationships with attentional mechanisms and give some clues about the underlying mechanisms of pseudoneglect. We recorded resting EEGs of 41 subjects and tested them with a paper-pencil line bisection task. Our results showed that line bisection scores of men (n=18) were less biased and their performance was higher compared to those of women (n=20), but these differences only approached significance. The eyes open resting EEG alpha power of women was significantly and positively correlated with their line bisection performance. In general, significant relationships were related to the left hand performance when the lines were presented in the left hemispace. Greater resting alpha power was correlated with lower absolute bisection score or, in other words, higher bisection performance. Greater alpha power also correlated with diminished leftward bisection bias (or reduced pseudo-neglect). The resting EEG alpha of men was weakly associated with bisection performance. Results discussed in terms of Kinsbourne's activation-orientation theory and Basar's view on brain oscillations.

Go with the flow

“…Moreover, there was a significant main e ect of "hemisphere" (F (1,19) = 12.75, p = .002), with alpha power being higher in the left hemisphere as compared to the right hemisphere (mean di erence = 8.97, SE = 2.51). This finding is the opposite of two previous reports (Çiçek et al, 2003;, but note that looked at alpha power at a specific, short time window during an attention task. There were no significant main or interaction e ects including the factor "brain stimulation" (p's > 0.10).…”

Increased Alpha-Rhythm Dynamic Range Promotes Recovery from Visuospatial Neglect: A Neurofeedback Study

“…Secondly, lateralized entrainment of alpha oscillations via TMS causally inhibits visual detection within the contralateral hemifield [29]. Likewise, the degree of pseudoneglect in the healthy population appears to correlate with individual variations in posterior alpha amplitude [30]. These effects may be explained by a mechanism where localized alpha oscillations act as an inhibitory gate for sensory processing [31].…”

Effects of musical expertise on line section and line extension

“…The prevailing explanation for these leftward biases is the notion of right hemispheric dominance for spatial attention (Fink et al, 2000). According to this theory, spatial information is predominantly processed in the right hemisphere, as supported by imaging studies (Witelson, 1976;Ratcliff, 1979;Cicek et al, 2003Cicek et al, , 2007Cicek et al, , 2009. Consequently, there is an attentional preference and overestimation for stimuli presented in the left hemispace since they are processed in the right hemisphere due to the optic chiasm.…”