Balanced brains: an investigation of visuospatial ability and lateralization in musicians

Abstract

Musicians comprise a unique population whereby persistent musical practice involving complex cognitive and motor tasks dates back to childhood when the potential for neural plasticity is at its highest. Accordingly, it has been speculated that musical training results in neural structural and functional differences between musicians and non-musicians. In particular, there is evidence to indicate parietal regions are more equally lateralized in musicians, but research investigating visuospatial abilities and lateralization in musicians is scarce. Studies 1 and 2 aimed to assess the visuospatial ability and cognitive processing speed of adult musicians versus ‪demographically and educationally matched non-musicians. ‪Musicians performed more quickly and more accurately than non-musicians in two tasks of visuospatial ability, and completed more items than non-musicians in three tasks of processing speed, suggesting ‪musicians had better ‪visuospatial ability and a faster speed of processing. Studies 3 and 4 aimed to investigate ‪visuospatial attention in ‪these groups using a line-bisection task and a visual discrimination task. On both tasks musicians demonstrated more balanced visuospatial attention with a slight bias to the right hemispace, which was in contrast to the non-musicians’ bias to the left hemispace, a natural phenomenon known as ‘right pseudoneglect’. In Study 5, the laterality of visual processing in musicians and non-musicians was further investigated by comparing electrophysiological interhemispheric transfer time (IHTT) of lateralized visual stimuli across the corpus callosum. Non-musicians had faster right-to-left than left-to-right IHTT consistent with previous research, whilst musicians had more balanced IHTT in both directions and faster left-to-right transfer than non-musicians. Absolute latency patterns revealed similar results and consistently demonstrated more balanced visual processing in musicians. The behavioural data, analysed in Study 6, revealed a tendency (n.s.) for the ‪musician group to respond more quickly to stimuli presented in the right visual field than to stimuli presented in the left visual field, whilst ‪non-musicians did not show this pattern. Overall, the results indicate that musicians have enhanced visuospatial ability and are less lateralized for visuospatial attention and perception than non-musicians. The results are discussed in relation to plastic developmental changes that may be caused by extended musical training from childhood. Specifically, it is proposed that musical training in early life may elicit a process of myelination that is more bilaterally distributed than myelination in non-musicians.