Neural correlates of motor performance in target sports: The model of movement-related alpha gating [Powerpoint]

What determines optimal motor performance? Scientists have addressed this question through various approaches. One such approach involved the measurement of brain activity during performance of aiming motor tasks by using electroencephalography (EEG). This research field has produced compelling evidence that a particular type of brain activity involved with neuronal inhibition – oscillations within the alpha frequency (8-12 Hz) – is associated with successful motor performance (e.g., a holed putt in golf). Our programme of research evaluated the utility of examining EEG alpha activity from multiple brain regions while relatively-inexperienced recreational golfers putted golf balls to a hole or a series of targets. Our findings revealed that motor execution was accompanied by a regional pattern – alpha gating – whereby neuronal activation was diverted away from movement-unrelated regions of the brain exhibiting enhanced alpha activity (temporal and occipital), and gated towards movement-related regions exhibiting diminished alpha activity (central). Greater inhibition of movement-unrelated regions was associated with greater movement accuracy and improved performance after skill practice, provided that an adequate level of neuronal activation was maintained in movement-related regions. In addition, a disturbance to the alpha gating, induced by randomly varying target location, resulted in impaired performance and greater perceived task difficulty. The main theoretical contribution of this research programme lies in the proposal of the movement-related alpha gating model of motor performance in target sports. These findings lay out the foundations for future applied work aimed at teaching athletes to self-regulate their brain activity to recreate the alpha gating pattern for optimal performance at will

Pain-related evoked potentials are modulated across the cardiac cycle

Evidence suggests that the arterial baroreceptors modulate pain. To examine whether cortical processing of nociception is modulated by natural variations in arterial baroreceptor stimulation during the cardiac cycle, peak-to-peak amplitudes of the N2–P2 pain-related potential and pain ratings were recorded in response to noxious laser stimulation at different times during the cardiac cycle in 10 healthy males. Significant variations in the N2–P2 amplitudes occurred across the cardiac cycle, with smaller amplitudes midcycle, indicating that cortical processing of nociception was attenuated during systole compared to diastole. Pain ratings did not vary across the cardiac cycle. These data support the hypothesis that arterial baroreceptors modulate the processing of nociception during each cardiac cycle

The advantage of a quiet eye: visual processing or postural stability?

The quiet eye phenomenon describes the performance advantage conferred by a steady ocular fixation on the critical target of an action (e.g., the ball in golf putting) immediately prior to and during movement execution. Remarkably, the mechanisms underlying the quiet eye-performance association are still the subject of debate. This study adopts a novel multi-measure psychophysiological approach to shed light on the mechanisms behind the quiet eye phenomenon. We tested key predictions of two competing mechanisms: that longer quiet eye is associated with enhanced visual processing (visual hypothesis) or with greater postural-kinematic stability (postural-kinematic hypothesis). Thirty-two recreational golfers putted 20 balls to a 2-m distant target on a flat surface. We examined quiet eye durations using electrooculography, visual processing using electroencephalography, and swing duration using kinematic sensors. Occipital alpha power, an inverse neural marker of visual processing, increased prior to and during swing execution, suggesting decreased visual processing compared to a pre-putt baseline. Importantly, quiet eye duration was strongly and positively correlated with swing duration. Our findings refute the claim for enhanced visual processing in the final moments of closed-loop aiming tasks and support the postural-kinematic account that the duration of the quiet eye is associated with a slow movement execution

A psychophysiological account of the quiet eye phenomenon: Novel methods and insights [Powerpoint]

Superior performance in target sports has been associated with a long quiet eye period, defined as a steady final fixation on the target of an action (e.g., the ball in golf putting). Despite extensive evidence showing that experts have a longer quiet eye than novices, scientists debate on the putative mechanisms that confer performance advantage to a long quiet eye. With the aim to stimulate this debate, this presentation discusses novel psychophysiological methods to examine eye movements (through electrooculography, EOG) alongside brain activity (through electroencephalography, EEG) and movement kinematics (through movement sensors). Recent research adopting this multi-measure approach has generated a series of findings that shed light on the function of the quiet eye (Gallicchio, Cooke, & Ring, 2018; Gallicchio & Ring, 2018). First, expertise and performance effects emerged mostly for the quiet eye component beginning after movement initiation, hence downplaying the role of cognitive mechanisms related to movement planning. Second, visual processing decreased before and during movement execution, thereby challenging the dominant interpretation of the quiet eye as a period of enhanced visual attention to the target. Finally, the finding that post-movement initiation quiet eye duration was strongly and positively associated with movement duration suggests that the quiet eye-performance effect may be due to a stable posture, ensuring a steady visual reference for a smooth execution, hence better performance. These findings encourage a radical re-interpretation of the quiet eye as postural-kinematic phenomenon and, moreover, demonstrate the utility of adopting a psychophysiological approach in the study of the quiet eye

Effects of essential hypertension on short latency human somatosensory-evoked potentials

Reduced perception of somatosensory stimulation in patients with essential hypertension may be due to deficits in the ascending somatosensory pathway. Function in the ascending somatosensory pathway was assessed bymeasuring N9, N13, and N20 somatosensory-evoked potentials in 14 unmedicated essential hypertensives and 22 normotensives. N9 amplitudes were smaller and N13 amplitudes marginally smaller in hypertensives than normotensives. N9 amplitudes were inversely associated with blood pressure. N20 amplitudes and N9, N13, and N20 latencies did not differ between groups. In addition, plexus-to-cord, cord-to-cortex, and plexus-to-cortex conduction times were not different between groups. These data suggest that hypertension affects the peripheral nervous system by reducing the number of active sensory nerve fibers without affecting myelination. However, hypertension does not seem to affect the afferent somatosensory pathway within the brain

Sensory detection thresholds are modulated across the cardiac cycle: evidence that cutaneous sensibility is greatest for systolic stimulation

The visceral afferent feedback hypothesis proposes that sensorimotor function is impaired by cortical inhibition associated with increased baroreceptor activation. This study is the first to examine the effects of naturally occurring variations in baroreceptor activity across the cardiac cycle on cutaneous sensory detection thresholds. In each trial, an electrocutaneous stimulus was delivered to the index finger at one of three intervals (0, 300, 600 ms) after the R-wave of the electrocardiogram. Separate interleaving up-down staircases were used to determine the 50% detection threshold for each R-wave to stimulation interval. Cutaneous sensory detection thresholds were lower for stimuli presented at R+300 ms than R+0 ms or R+600 ms. The finding that cutaneous sensibility was greater when stimulated during systole than diastole may be accounted for by a modified afferent feedback hypothesis. Copyright © 2009 Society for Psychophysiological Research