Neural correlates underpinning synchronized movement of double scull rowers.

We investigated the neural correlates underpinning synchronized movement in rowers using a neural index for social interaction termed the phi complex. Phi 1 and phi 2 indicate the enhancement and reduction of mirror neuron activation, respectively. We hypothesized that in a leader-follower relation, followers would exhibit a larger phi 2 power than leaders due to enhanced mirror neuron activation by the followers to accurately mimic their partner's movements. We also expected that brain activation underlying social interaction would be enhanced during synchronization. Although phi 2 was not modulated by role (leader vs. follower) or condition (usual-pair vs. unusual-pair), the statistical analysis suggested the relationship between the magnitude of phi 2 and empathetic ability in followers in the usual-pair condition. Given that the activation of the mirror neuron system underlies empathic ability, it is plausible that the participants used the mirror neuron system to follow the movement of a usual partner. In other words, the leader in the synchronization did not need to use the mirror neuron system, which was consistent with the result of a larger phi 1 for leading than following the movement. These results suggest that the neural correlates of empathy may be used to synchronize with partners as the follower.

Medial frontal negativities predict performance improvements during motor sequence but not motor adaptation learning.

Alterations in our environment require us to learn or alter motor skills to remain efficient. Also, damage or injury may require the relearning of motor skills. Two types have been identified: movement adaptation and motor sequence learning. Doyonet al. (2003, Distinct contribution of the cortico-striatal and cortico-cerebellar systems to motor skill learning. Neuropsychologia, 41(3), 252-262) proposed a model to explain the neural mechanisms related to adaptation (cortico-cerebellar) and motor sequence learning (cortico-striatum) tasks. We hypothesized that medial frontal negativities (MFNs), event-related electrocortical responses including the error-related negativity (ERN) and correct-response-related negativity (CRN), would be trait biomarkers for skill in motor sequence learning due to their relationship with striatal neural generators in a network involving the anterior cingulate and possibly the supplementary motor area. We examined 36 participants' improvement in a motor adaptation and a motor sequence learning task and measured MFNs elicited in a separate Spatial Stroop (conflict) task. We found both ERN and CRN strongly predicted performance improvement in the sequential motor task but not in the adaptation task, supporting this aspect of the Doyon model. Interestingly, the CRN accounted for additional unique variance over the variance shared with the ERN suggesting an expansion of the model.

The Effects of Computer-Based and Motor-Imagery Training on Scoring Ability in Lacrosse.

Previous studies have confirmed that the temporal attentional control created by the repetition of stimulus-response compatibility (SRC) tasks was transferred to shooting skills in lacrosse players. In the current study, we investigated whether combining motor imagery training with SRC tasks could enhance the scoring ability of lacrosse players. We grouped 33 male lacrosse players into three groups: an SRC task and motor imagery group (referred as to SRC + Image), an SRC task group, and a control group. Players in the first two groups underwent five sessions of 200 SRC task trials. In addition, the SRC + Image group completed five sessions of motor-imagery training. The control group underwent no training interventions. All three groups performed a lacrosse shooting test and a Simon task before and after training sessions to assess the magnitude of the interference effects of the various types of training they underwent. The results of the Simon task showed that repetition of 1,000 trials was enough to create a short-term representation with the incompatible special mapping being transferred to a dynamic activity like lacrosse shooting. Moreover, a combination of a computer-based Type 2 task and motor-imagery training could effectively increase players' scoring abilities in a field of large spatial conflict.

Difference in Interoception between Long-Distance Runners and Sprinters: An Event-related Potential Study.

PURPOSE: Interoception is a sense of the physiological state of one's body. Interoception that is generated by processing physiological information in the insular cortex plays an important role in achieving optimal performance in competitive sports. This study aimed to reveal the difference in interoceptive ability between long-distance runners and sprinters and its neural correlates by recording the stimulus-preceding negativity (SPN) that is generated from the insular cortex. Based on previous findings, we predicted that long-distance runners would show better interoceptive ability and larger SPNs compared with sprinters. METHOD: We used a questionnaire and a heartbeat counting task to evaluate the interoceptive sensitivity and accuracy, respectively, of both long-distance runners and sprinters. We recorded SPNs during the execution of a time estimation task where participants estimate 3 s by pressing a button. RESULTS: Results of the questionnaire revealed that sprinters exhibited a higher interoceptive ability associated with attention control of their own bodies than did long-distance runners. Sprinters also showed a larger SPN over the left centroparietal regions compared with long-distance runners. CONCLUSION: In contrast to our prediction, sprinters exhibited a superior interoceptive ability and a greater activity of the insular cortex relative to long-distance runners. These results suggest that sprinters might be more susceptible to their internal bodily signals compared with long-distance runners, exhibiting greater activation of the anterior insula.

Anterior insula activity and the effect of agency on the Stimulus-Preceding Negativity.

If you know that you are the author of a freely chosen action and that you bear responsibility for its outcome, then you are said to have "a sense of agency." When there is a delay between action and outcome, this response must be remembered if you are to learn from the experience. Previous studies have shown that the Stimulus-Preceding Negativity (SPN) recorded during the delay interval is larger under conditions that foster a sense of agency. In an EEG experiment (N = 27), we confirmed that the SPN is larger when participants have a choice between two responses in a gambling task as compared to when there is only a single button and the computer determines the monetary outcome. This SPN agency effect was largest over right prefrontal cortex and it did not vary significantly between trial blocks in which only gains or only losses were possible. Participants in a second experiment (N = 26) performed the same task while activity in anterior insular cortex, a known SPN generator, was measured via functional magnetic resonance image (fMRI). An essentially identical pattern of results was obtained: Activity was greater on choice than no-choice trials, especially for the right hemisphere, and no effect of contextual valence was observed. Although parallel observations such as these cannot warrant causal inference, our findings are consistent with the assumption that anterior insular cortex contributes to the effect of agency on the SPN.

Feedback-Related Electroencephalogram Oscillations of Athletes With High and Low Sports Anxiety.

We investigated the relationship between performance-related anxiety and the neural response to error feedback that was delivered during the execution of a time estimation task. Using the Sport Anxiety Scale (SAS-2), we selected university athletes high and low in sports anxiety. Participants executed a time estimation task where they were instructed to estimate 1 s by pressing a button after a sound cue. They performed this task while their performance was being evaluated by an experimenter (evaluation condition) and also while alone (in a no-evaluation condition). We tested whether feedback-related brain activities may increase in amplitude in the evaluation condition compared to the control condition - especially for athletes who report high performance-related anxiety. We focused on oscillations of sub-delta, delta, and theta frequency bands phase-locked to the feedback onset. Time-frequency analyses revealed that the magnitude of both the sub-delta component (0.3-1.2 Hz) and the theta component (4-8 Hz) were larger in incorrect than correct trials. In addition, the theta component was smaller for athletes high in sports anxiety than for athletes low in sports anxiety. The delta component was overall larger for correct than incorrect feedback. Further, athletes high in sports anxiety exhibited a larger delta component (1.5-3.5 Hz) for correct feedback in the evaluation condition than in the no-evaluation condition. Our results suggest that evaluation by others may increase the delta oscillation associated with correct feedback processing - especially among athletes high in sports anxiety.

Brain activities associated with learning of the Monty Hall Dilemma task.

The Monty Hall Dilemma (MHD) poses a counterintuitive probabilistic problem to the players of this game. In the MHD task, a participant chooses one of three options where only one contains a reward. After one of the unchosen options (always no reward) is disclosed, the participant is asked to make a final decision: either change to the remaining option or stick with their first choice. Although the probability of winning if they change is higher (2/3) compared to sticking with their first choice (1/3), most people stick with their original selection and often lose. In accordance with previous research, repetitive exposure to the MHD task increases the change behavior without any obvious understanding of the mathematical reasons why changing increases their chance of being rewarded. We recorded the stimulus-preceding negativity (SPN), an ERP that might reflect the informative value of the feedback. In the second half of the task, feedback was predicted to be less informative because learning had taken place. Indeed, the SPN amplitude became smaller over the frontal region. Also, the SPN amplitude was larger for change than for stick trials. These results suggest that learning in the MHD might be manifest in affective-motivational anticipation as indicated by the SPN.

Modulation of Spatial Attentional Allocation by Computer-Based Cognitive Training during Lacrosse Shooting Performance.

It has been reported that repetitive execution of a stimulus-response compatibility (SRC) task attenuates the interference effect of a choice reaction time task, known as a Simon task. We investigated whether attentional control, enhanced by repetitive execution of an SRC task, would reduce the interference effect of a Simon task and could be transferred to lacrosse shooting skills, increasing the likelihood that players would shoot in the direction opposite to the goalie's initial movement. Female lacrosse players who were matched in terms of age, handedness score, competitive lacrosse playing experience, and playing position, were allocated to the SRC task group (n = 15) or the 2-back training group (n = 14). Participants underwent 10 sessions of 180 trials of a computer-based version of either a Type 2 SRC task or the 2-back task, within four consecutive weeks. Eight practice trials were completed prior to the execution of each task in every training session, during which feedback was provided to confirm accurate mapping between the stimulus and response. Before and after the training phase, both the magnitude of the Simon effect and the lacrosse shooting performance were assessed. After participating in computer-based cognitive training, players did indeed increase the number of shots toward the direction opposite to that of the movement of the goalie. In conclusion, these findings indicate that computer-based cognitive training is beneficial for improving the shooting ability of lacrosse players.

Stimulus-preceding negativity represents a conservative response tendency.

Humans tend to be conservative and typically will retain their initial decision even if an option to change is provided. We investigated whether the stimulus-preceding negativity (SPN), an event-related potential associated with the affective-motivational anticipation of feedback in gambling tasks, represents the strong response tendency to retain an initial decision. We compared SPNs in three different card-gambling tasks wherein the participants were given the opportunity to change their initial decision after they chose one of three cards. In two of these tasks, the winning probability was equiprobable (1/3 and 1/2, respectively) whether or not the participants changed their initial decision. However, in the Monty Hall dilemma task, changing the initial decision stochastically doubled the probability of winning (2/3) compared with retaining (1/3). In this counterintuitive probabilistic dilemma task, after the participant chose an option among three cards, a nonreward (losing) option is revealed. Then, the participants are offered a chance to change their mind and asked to make their final decision: to retain their initial choice or change to the alternate option. In all tasks, maintenance of previous behaviors was observed, although the rate of retaining earlier choices tended to be lower in the Monty Hall dilemma task than in the other two tasks. The SPNs were larger on retain trials than on change trials irrespective of task. These results suggest that underlying brain activities associated with the strong tendency to retain the initial decision can be observed by the SPN and thus it reflects expectancy of outcomes in terms of self-chosen behaviors.