Cerebral Averaged Potentials Preceding Oral Movement

Abstract

The “readiness potential” is an event-related potential that shows increasing negativity at vertex and motor strip scalp recording sites prior to voluntary, unilateral limb movements. Though speech involves movement on both sides of the midline, recent recordings of prespeech potentials suggest a pattern of bilateral activation that lateralizes to the dominant hemisphere just prior to the onset of articulatory movement. To determine whether this pattern of dominant hemisphere activation is present prior to a stereotyped, nonspeech movement of the mouth, the averaged potentials preceding a lip protrusion task were recorded at the cranial vertex and over the right and left motor cortex. Results were compared to potentials preceding a right finger extension task performed by the same subjects. Both the finger and the lip movements were initially preceded by slow negative potentials. Prior to the finger extension task, the negative amplitude became greatest over the left motor cortex, contralateral to the side of movement. Prior to the lip protrusion task, the amplitude of the potential remained even over the right and left motor cortices. The results suggest that, for this nonspeech movement of a midline structure, bilateral cortical control takes place. Control of lip movement is apparently not necessarily a dominant hemisphere function, though dominance may become part of the motor control strategy for more complex movements such as those used during speech.

Audio-Vocal Monitoring System Revealed by Mu-Rhythm Activity

“…While many unresolved issues remain with respect to the control of tongue movements, the bilateral control has been consistently reported in earlier studies (e.g., Wohlert and Larson, 1991), in agreement with the prominent power change over the central regions of the motor cortex in the present study.…”

Movement related cortical potentials in a face naming task: Influence of the tip-of-the-tongue state

“…Since Kornhuber and Deecke (1965) recorded the Bereitschaftspotential (BP) or readiness potential (RP), related to simple and self-paced movements, several studies have been carried out in which four MRCPs have consistently been recorded: the first component of the readiness potential (1st-RP), the negative slope (NS'), the motor potential (MP) and the reafferent potential (RAP) (for a complete revision, see Shibasaki and Hallett, 2006). On the other hand, the speech MRCPs have been less well studied, and there is only conclusive data regarding the 1st-RP component (Brooker and Donald, 1980;Deecke et al, 1986;Grabow and Elliott, 1974;Grözinger et al, 1975Grözinger et al, , 1977Levy, 1977;McAdam and Whitaker, 1971;Tarkka, 2001;Wohlert, 1993;Wohlert and Larson, 1991).…”

The Possibility of Left Dominant Activation of the Sensorimotor Cortex During Lip Protrusion in Men

“…Lip protrusion is a midline movement, and therefore probably involves an equivalent contribution from the cerebral sensorimotor cortex of both sides. An electroencephalographic (EEG) study reported that non-speech movement of a midline structure was under bilateral cortical control, and that control of lip movement was apparently not necessarily a dominant hemisphere function (Wohlert and Larson 1991). Salmelin et al also reported in an MEG study that no interhemispheric correlations were found for the non-verbal mouth movements (Salmelin and Sams 2002).…”