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

doi:10.1016/j.neuropsychologia.2007.02.001

Neuropsychologia

Volume 45, Issue 9, 2007, Pages 2059-2065

https://doi.org/10.1016/j.neuropsychologia.2007.02.001 Get rights and content

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.

Section snippets

Participants

Two groups of adults, musicians (N = 16, 8 female) and non-musicians (N = 16, 8 female), participated in this experiment, which was approved by the University of Auckland Human Participants Ethics Committee. All participants had normal or corrected-to-normal vision and provided written informed consent prior to testing. The musician group had a mean age of 25.31 years (S.D. = 5.92) and all members had received at least 8 years of music lessons (M = 13.44 years, S.D. = 4.07) and could read music. All

Stimuli and apparatus

Stimuli were circular white/black checkerboards with a diameter of 3° of visual angle that appeared for 100 ms against a grey background. The stimuli had 17 checkerboard squares at the widest diameter of the circle. Stimuli were presented to the left visual field (LVF) and right visual field (RVF), with their centre 6° from a central fixation cross.

EEG was recorded continuously at a 1 kHz sampling rate (0.1–100 Hz bandpass) with a high-density 128-channel Ag/AgCl electrode net (Electrical

Procedure

Participants were tested in a quiet, electrically shielded Faraday chamber and were seated 57 cm from a 15 in. SVGA computer monitor (640 × 480 pixel resolution) on which stimuli were presented. A fixation cross persisted throughout the experiment and participants were instructed to maintain their gaze on the cross at all times during the stimulus blocks. A brief block of 17 practice trials preceded four experimental blocks in which either the left (LH) or right hand (RH) was used in a

Interhemispheric transfer time

Effects for IHTT were analysed using a repeated-measures ANOVA with direction (right-to-left and left-to-right) as the within-subjects factor, and group (musicians and non-musicians) as the between-subjects factor. Data were averaged across hands.

The grand mean waveforms for N1 elicited to LVF and RVF stimuli are shown in Fig. 2 for musicians and non-musicians. The ANOVA for IHTT did not reveal a significant main effect of group, F(1,30) = 2.28, p = .14, but a main effect of direction showed

Discussion

Using the latencies of N1 responses to measure IHTT, we found that musicians did not exhibit the usual directional asymmetry. As expected from previous studies (Barnett & Corballis, 2005; Barnett et al., 2005; Barnett & Kirk, 2005; Brown & Jeeves, 1993; Brown et al., 1994; Larson & Brown, 1997), the non-musicians showed faster IHTT from the right to the left hemisphere than from left-to-right. In contrast, the musicians showed no directional advantage, indicating the speed of transfer for

Competing interests

The authors declare that they have no competing financial interests.

Acknowledgments

This research was supported by a grant from the University of Auckland Psychology Department Research Expenses for Doctoral Students Fund. We thank Sarah Hogg and Sarina Iwabuchi for their assistance in data collection.

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

Abstract

Section snippets

Participants

Stimuli and apparatus

Procedure

Interhemispheric transfer time

Discussion

Competing interests

Acknowledgments

Brain Research

Neuroscience Letters

Schizophrenia Research

Clinical Neurophysiology

Brain and Cognition

Neuropsychologia

Neuropsychologia

Neuropsychologia

Psychiatry Research

Neuroscience Letters

Brain Cognition

Neuropsychologia

Biological Psychiatry

Brain Research

NeuroImage

Behavioral Brain Research

Neuropsychologia

Neuropsychologia

Neuropsychologia

Neuropsychologia

Neuropsychologia

Motor cortex and hand motor skills: Structural compliance in the human brain

Human Brain Mapping