The unusual symmetry of musicians: Musicians have equilateral interhemispheric transfer for visual information

Abstract

Previous behavioural research has shown that spatial attention is bilaterally represented in musicians, possibly reflecting more equal neural development between the hemispheres. We investigated this theory electrophysiologically with another measure that has shown asymmetry, interhemispheric transfer time (IHTT). Sixteen right-handed musicians and 16 matched non-musicians responded to stimuli presented to the left and right visual fields while 128-channel EEG was recorded. IHTT was calculated by comparing the latencies of occipital N1 components between hemispheres. Non-musicians showed significantly faster IHTT in the right-to-left direction than in the left-to-right direction and a shorter N1 latency in the left than in the right hemisphere. In contrast, the musician group showed no directional difference between hemispheres in IHTT, and no hemispheric difference in latency. These results indicate that musicians have more bilateral neural connectivity than non-musicians, reflected in an unusual lack of asymmetry. It is suggested that plastic developmental changes caused by extended musical training in childhood result in equally efficient connections to both hemispheres.

Musical expertise modulates the effects of visual perceptual load

“…On the other hand, the heterogeneous range of musical instruments that we used suggests that the expertise effects measured in this study are unlikely to be based on the presence of specific local visual features, but rather indicate a more general and global level of perceptual expertise for musical instruments of various kinds. This suggestion is in line with previous findings that, relative to nonmusicians, musicians generally are faster and more accurate in tests of visual spatial perception and mental imagery (Brochard, Dufour, & Després, 2004;Patston, Hogg, & Tippett, 2007), have faster interhemispheric visual transfer times (Patston, Kirk, Rolfe, Corballis, & Tippett, 2007), and have larger cortical motor representations (Elbert, Pantev, Wienbruch, Rockstroh, & Taub, 1995). Note that these findings were not confined to the representations of musical instruments.…”

Sex hormonal modulation of interhemispheric transfer time

“…At least this is the case for right-handed males. Left-handers (Iwabuchi & Kirk, 2009), musicians (Patston et al, 2007), those with a variety of neurological disorders Rolfe et al, 2007), and, of particular relevance here, females (Moes et al, 2007;Norwicka & Fersten, 2001) differ from this pattern and show more symmetrical IHTTs. This fits with numerous reports of less FCA in these groups (e.g.…”

“…Previous work employing visual-evoked potentials to measure IHTT, revealed a directional asymmetry in conduction velocities between hemispheres (e.g. Barnett, Corballis, & Kirk, 2005;Brown, Larson, & Jeeves, 1994;Iwabuchi & Kirk, 2009;Moes, Brown, & Minnema, 2007;Nowicka & Fersten, 2001;Patston, Kirk, Rolfe, Corballis, & Tippett, 2007;Rolfe, Kirk, & Waldie, 2007;Saron & Davidson, 1989; see also Marzi, 2010, andTacikowski, 2011, for reviews). The transfer of neural information from the right hemisphere to the left is faster than transfer from the left hemisphere to the right.…”

Effects of trifluoromethylphenylpiperazine (TFMPP) on interhemispheric communication

“…However, it also seems that it is only true for right-handed males. Lefthanders (Iwabuchi and Kirk 2009), females (Nowicka and Fersten 2001) and musicians (Patston et al 2007) show less asymmetry in IHTT direction. This fits with numerous reports of less lateralisation in these groups (Knecht et al 2000;Potter and Graves 1988;Shaywitz et al 1995).…”