Predictability of the target stimulus for sensory-guided movement modulates early somatosensory cortical potentials

• Published in: Clinical neurophysiology Vol. 117; no. 6; pp. 1345 - 1353
• Main Authors: Legon, Wynn, Staines, W. Richard
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 01.06.2006; Elsevier Science
• Subjects: Adult; Aged; Attention; Attention - physiology; Biological and medical sciences; Electric Stimulation; Electrodiagnosis. Electric activity recording; Evoked Potentials, Somatosensory - physiology; Female; Fundamental and applied biological sciences. Psychology; Humans; Investigative techniques, diagnostic techniques (general aspects); Male; Median Nerve - physiology; Medical sciences; Middle Aged; Motor control; Motor control and motor pathways. Reflexes. Control centers of vegetative functions. Vestibular system and equilibration; Motor Neurons - physiology; Movement - physiology; Nervous system; Neurons, Afferent - physiology; Psychomotor Performance - physiology; Reaction Time; Sensorimotor integration; Sensory gating; Somatosensory evoked potentials; Touch - physiology; Vertebrates: nervous system and sense organs; Sensorimotor integration; Sensory gating; Somatosensory evoked potentials; Motor control; Attention; Human; Stimulus frequency; Frequency modulation; Stimulus movement; Electrical stimulus; Central nervous system; Electrophysiology; Isometric muscular contraction; Amplitude modulation; Encephalon; Electrodes; Predictability; Somesthetic pathway; Median nerve; Performance; Somatosensory evoked potential
• ISSN: 1388-2457; 1872-8952
• DOI: 10.1016/j.clinph.2006.02.024

To investigate the role of sensory modulation in the control of sensory-guided behaviour. Specifically, we hypothesized that early somatosensory evoked potentials (SEPs) would be facilitated during performance of continuous sensory-guided movement requiring sustained attention. Median nerve SEPs were elicited via electrical stimulation and recorded from scalp electrodes while subjects performed tasks requiring continuous sensory–motor transformations. Subjects received a predictable (rhythmic amplitude modulation) or unpredictable (random amplitude modulation) amplitude varying tactile stimulus (frequency constant at 20 Hz) delivered to the tip of the index finger either alone or with the requirement to track it by modulating the isometric grip force produced by the opposite hand. Early SEP (N20-P27) amplitudes were differentially modulated during unpredictable tracking compared to sensory–motor controls. Specifically, N20 amplitudes were attenuated and P27 amplitudes were enhanced during sensory-guided tracking. Sustained attention to task-relevant sensory stimuli differentially modulates areas within primary somatosensory cortex (S1) during a continuous sensory–motor transformation. These data have implications for understanding the role of attention in regulating somatosensory cortices during sensory–motor behaviour.