Sex differences in sensorimotor mu rhythms during selective attentional processing

• Published in: Neuropsychologia Vol. 48; no. 14; pp. 4102 - 4110
• Main Authors: Popovich, C., Dockstader, C., Cheyne, D., Tannock, R.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.12.2010; Elsevier
• Subjects: Adult; Adult and adolescent clinical studies; Attention; Attention - physiology; Biological and medical sciences; Brain Mapping; Contingent Negative Variation; Electric Stimulation - methods; Electroencephalography - methods; Evoked Potentials, Somatosensory - physiology; Female; Forearm - innervation; Humans; Magnetoencephalography; Magnetoencephalography - methods; Male; Median Nerve - physiology; Medical sciences; Mu rhythm; Organic mental disorders. Neuropsychology; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Reaction Time - physiology; Self Report; Sensorimotor; Sex Characteristics; Sex differences; Somatosensory cortex; Somatosensory Cortex - physiology; Young Adult; Somatosensory cortex; Sex differences; Magnetoencephalography; Attention; Mu rhythm; Sensorimotor; Human; Central nervous system; Sex; Cognition; Encephalon; Selective attention; Somesthetic pathway
• ISSN: 0028-3932; 1873-3514
• DOI: 10.1016/j.neuropsychologia.2010.10.016

We used magnetoencephalography to investigate the effect of directed attention on sensorimotor mu (8–12Hz) response (mu reactivity) to non-painful electrical stimulation of the median nerve in healthy adults. Mu desynchronization in the 10–12Hz bandwidth is typically observed during higher-order cognitive functions including selective attentional processing of sensorimotor information (Pfurtscheller, Neuper, & Krauz, 2000). We found attention-related sex differences in mu reactivity, with females showing (i) prolonged mu desynchrony when attending to somatosensory stimuli, (ii) attentional modulation of the mu response based on whether attention was directed towards or away from somatosensory stimuli, which was absent in males, and (iii) a trend for greater neuronal excitability of the primary somatosensory region suggesting greater physiological responsiveness to sensory stimulation overall. Our findings suggest sex differences in attentional control strategies when processing somatosensory stimuli, whose salience may be greater for females. These sex differences in attention to somatosensory stimuli may help elucidate the well-documented sex biases in pain processing wherein females typically report greater sensitivity to experimental and clinical pain.