Asymmetrical Visual Deprivation: A Technique to Differentially Influence Lateral Hemispheric Function

Abstract

This article describes a contact-lens method to sustain asymmetry in visual deprivation and the use of this method to test the general hypothesis that asymmetry in input deprivation can shift activation balance in the integrated brain, differentially influencing lateral hemispheric function. Effects of asymmetrical visual deprivation were as predicted on lateral asymmetry of EEG theta, producing more theta over the deprived hemisphere. Cross-modal influence of such visual deprivation was found in the perception of pleasantness of odors. An interaction was found between side of visual deprivation and performance on verbal reasoning and spatial orientation tasks. A line-bisection test of visual attention was not sensitive to the effects. Fatigue as rated on the Profile of Mood States was greatest when the left hemisphere was deprived.

Left hemisphere specialization for response to positive emotional expressions: A divided output methodology.

“…The findings of Experiments 1 and 2 are consistent with existing evidence for left hemisphere specialization for positive stimuli and right hemisphere superiority for negative stimuli. More generally, they are consistent with studies that find a relation between rightward direction of attention and positive affect (Beaumont, 1985; Dimond, Farrington, & Johnson, 1976; Drake, 1987; Levick et al, 1993; Nisbett & Wilson, 1977). The results are also consistent with electrophysiological evidence that the left and right hemispheres become differentially activated in the presence of positive and negative emotion respectively (Bennett, Davidson, & Saron, 1981; Davidson, Ekman, Saron, Senulis, & Friesen, 1990; Davidson & Fox, 1982, 1989; Davidson, Schwartz, Saron, Bennett, & Goleman, 1979; Schaffer, Davidson, & Saron, 1983; Tucker, Stenslie, Roth, & Shearer, 1981), and with a subset of relevant neuroimaging studies, which find differential lateralized contributions in the processing of emotion categories (Wager, Phan, Liberzon, & Taylor, 2003).…”

Olfactory Discrimination and Transient Mood Change in Young Men and Women: Variation by Season, Mood State, and Time of Day

“…Schiffman et al (1995a) found significantly more tension, depression, anger, fatigue, and confusion and less vigor in subjects exposed to unpleasant swine odors. Therefore, lavender may have been perceived as unpleasant in this study, at all doses, even though it is rated as neutral to mildly pleasant and neutral on ratings of familiarity, intensity, and irritability (Knasko, 1992;Levick et al, 1993;Millot and Brand, 2001;Millot et al, 2002;Royet et al, 2000;Savic and Berglund, 2000;Savic and Gulyas, 2000;Zatorre et al, 1992). Indeed, although we did not assess the hedonics of lavender in this study, it has been rated as intense and pleasant as peppermint in another study from our laboratory (Goel, unpublished).…”

Determination of hemispheric emotional valence in individual subjects: A new approach with research and therapeutic implications

“…This evidence includes studies using theta EEG [57,98], lateral ear temperature [57], BOLD fMRI [58,99], and PET [100]. The combination of lateralized psychological and physiological responses, leads Schiffer to hypothesize that LVFS might preferentially activate the contralateral hemisphere [101] and produce an associated mental state that is consistent with that hemisphere's emotional valence.…”