Correlation between performance and quantity/variability of leg exploration in a contingency learning task during infancy

Quantity and quality of motor exploration are proposed to be fundamental for infant motor development. However, it is still not clear what types of motor exploration contribute to learning. To determine whether changes in quantity of leg movement and/or variability of leg acceleration are related to performance in a contingency learning task, twenty 6–8-month-old infants with typical development participated in a contingency learning task. During this task, a robot provided reinforcement when the infant’s right leg peak acceleration was above an individualized threshold. The correlation coefficient between the infant’s performance and the change in quantity of right leg movement, linear variability, and nonlinear variability of right leg movement acceleration from baseline were calculated. Simple linear regression and multiple linear regression were calculated to explain the contribution of each variable to the performance individually and collectively. We found significant correlation between the performance and the change in quantity of right leg movement (r = 0.86, p < 0.001), linear variability (r = 0.71, p < 0.001), and nonlinear variability (r = 0.62, p = 0.004) of right leg movement acceleration, respectively. However, multiple linear regression showed that only quantity and linear variability of leg movements were significant predicting factors for the performance ratio (p < 0.001, adjusted R² = 0.94). These results indicated that the quantity of exploration and variable exploratory strategies could be critical for the motor learning process during infancy.     

Gender stereotypes and motor performance: How explicit and implicit stereotypes influence girls standing long jump and anxiety

ObjectivesInducing a negative stereotype toward women usually leads to a decrease in women's motor performance. Given that most studies have focused on explicit stereotype induction among adults, the main aim of this study was to investigate the effects of explicit and implicit gender stereotypes on standing long jump performance in children. The second aim was to investigate the effects of these same manipulations on children’s state anxiety.DesignA mixed model design with within-between-subject was used with standing long jump performance and state anxiety as dependent variables.MethodTwo hundred and four children (Mage = 10.95 years, SDage = 0.85) participated in this study and were randomly assigned, after baseline measurement, into four different groups (i.e., explicit/implicit vs. explicit vs. implicit vs. control). Specifically, participants performed 8 trials of standing long jump (4 trials during the baseline phase and 4 trials during the experimental phase). Children also completed the competitive state Anxiety Inventory at baseline as well as immediately after the trials.ResultsFor motor performance, children in the explicit/implicit group and in the implicit group were negatively affected by the stereotype manipulation during all trials whereas participants in the explicit group were only negatively impacted during the last two trials. However, regarding state anxiety, children were negatively affected after both explicit only and implicit only manipulations and more significantly after explicit/implicit manipulation.ConclusionsThe present research showed that the explicit and implicit manipulations influenced motor performance differently, but that these two manipulations increased state anxiety in the same way. Moreover, the combination of the explicit and implicit inductions leads to a greater significant negative influence on state anxiety but not motor performance.     

The role of somatosensory stimulation in social phobia—An analysis of hand coordination in patients and therapeutic dyads during psychodynamic psychotherapy

In the psychotherapeutic treatment of social phobia, the hand movement behaviour exhibited during the interaction provides information about the success of the therapy. In particular, the degree of mutual somatosensory stimulation of the hands (hands moving on each other, as a unit, apart) appears to be relevant regarding the patient's mental state. To test this hypothesis, the present study investigates hand coordination in the course of psychotherapy in patients with and without symptom improvement and in the corresponding therapeutic dyads. Forty-two videos of patient–therapist dyads consisting of 21 patients (n = 11 non-improved; n = 10 improved; according to Liebowitz Social Anxiety Scale self-assessment) from the Social Phobia Research Network project were investigated in early psychotherapy sessions and in pre-last sessions. Hand movements of four randomised video sequences per dyad were analysed with NEUROGES^®-ELAN. Patients with non-improved symptoms displayed shorter act apart coordination and more act on each other coordination than patients with improved symptoms. Patients displayed more act apart and act on each other and less act as a unit coordination than therapists. In therapeutic dyads, act on each other coordination in early sessions, as well as short act apart coordination, was significantly related to non-improvement. Patients with non-improved symptoms are characterised by more hand coordination associated with a high degree of somatosensory stimulation serving self-regulation (act on each other), as well as short complex gestural expressions (act apart). Thus, hand coordination constitutes a progression and outcome parameter informing on somatosensory stimulation.     

Influence of perceived emotion and gender on social motor coordination

Theorists have long postulated that facial properties such as emotion and sex are potent social stimuli that influence how individuals act. Yet extant scientific findings were mainly derived from investigations on the prompt motor response upon the presentation of affective stimuli, which were mostly delivered by means of pictures, videos, or text. A theoretical question remains unaddressed concerning how the perception of emotion and sex would modulate the dynamics of a continuous coordinated behaviour. Conceived in the framework of dynamical approach to interpersonal motor coordination, the present study aimed to address this question by adopting the coupled-oscillators paradigm. Twenty-one participants performed in-phase and anti-phase coordination with two avatars (male and female) displaying three emotional expressions (neutral, happy, and angry) at different frequencies (100% and 150% of the participant's preferred frequency) by executing horizontal rhythmic left-right oscillatory movements. Time to initiate movement (TIM), mean relative phase error (MnRP), and standard deviation of relative phase (SDRP) were calculated as indices of reaction time, deviation from the intended pattern of coordination, and coordination stability, respectively. Results showed that in anti-phase condition at 150% frequency, MnRP was lower with the angry and the female avatar. In addition, coordination was found to be more stable with the male avatar than the female one when both displaying neutral emotion. But the happy female avatar was found to elicit more stable coordination than the neutral female avatar. These results implied that individuals are more relaxed to coordinate with the female than the male, and the sensorimotor system becomes more flexible to coordinate with an angry person. It is also suggested social roles influence how people coordinate, and individuals attend more to interact with a happy female. In sum, the present study evidenced that social perception is embodied in the interactive behaviour during social interaction.     

Planned Straight or Biased to Be So? The Influence of Visual Feedback on Reaching Movements

Abstract

Behavioral studies consistently find that subjects move their hand along straight paths despite considerations that suggest reaches should be curved. Literature on this topic makes it clear that the experimentally displayed feedback influences how subjects reach. Could the standard visual feedback, a displayed cursor, explain the lack of path curvature in experimental results? To address this question, we conducted three experiments to examine reach behavior in the absence of the standard visual feedback. In the first experiment, we found significant increases in curvature as visual feedback was progressively extinguished across groups. A second experiment revealed that practiced reaches became curved after the standard visual feedback was removed. A final experiment found that subjects’ reaches made before and after a brief display of visual feedback were similar, indicating a preference for specific curved trajectories. Our results suggest that the consistently straight reaches often observed could be due to a bias to move the displayed cursor straight, which when removed reveal subject-specific preferences for reaches that are often curved.     

Effect of Stroke on Joint Control during Reach-to-Grasp: A Preliminary Study

Abstract

We investigated changes in control of inter-segmental dynamics underlying upper extremity dyscoordination caused by stroke. Individuals with stroke and healthy individuals performed a natural reach-to-grasp movement. Kinetic analysis revealed that both groups rotated the shoulder by muscle torque and used interaction torque to rotate the elbow. However, individuals with stroke used interaction torque less than healthy individuals, actively suppressing a substantial portion of it. This resulted in inefficient use of active control and dyscoordination of the upper extremity. The degree of interaction torque suppression and inefficiency of active control at the elbow positively correlated with stroke severity. The increased interaction torque suppression can be a strategy used by individuals with stroke to compensate for deficient feedforward control of this torque.     

Eighteen-month-olds integrate verbal cues into their action processing: Evidence from ERPs and mu power

Behavioral research has shown that infants use both behavioral cues and verbal cues when processing the goals of others’ actions. For instance, 18-month-olds selectively imitate an observed goal-directed action depending on its (in)congruence with a model’s previous verbal announcement of a desired action goal. This EEG-study analyzed the electrophysiological underpinnings of these behavioral findings on the two functional levels of conceptual action processing and motor activation. Mid-latency mean negative ERP amplitude and mu-frequency band power were analyzed while 18-month-olds (N = 38) watched videos of an adult who performed one out of two potential actions on a novel object. In a within-subjects design, the action demonstration was preceded by either a congruent or an incongruent verbally announced action goal (e.g., “up” or “down” and upward movement). Overall, ERP negativity did not differ between conditions, but a closer inspection revealed that in two subgroups, about half of the infants showed a broadly distributed increased mid-latency ERP negativity (indicating enhanced conceptual action processing) for either the congruent or the incongruent stimuli, respectively. As expected, mu power at sensorimotor sites was reduced (indicating enhanced motor activation) for congruent relative to incongruent stimuli in the entire sample. Both EEG correlates were related to infants’ language skills. Hence, 18-month-olds integrate action-goal-related verbal cues into their processing of others’ actions, at the functional levels of both conceptual processing and motor activation. Further, cue integration when inferring others’ action goals is related to infants’ language proficiency.     

Methodological considerations for longitudinal investigations of young drivers

IntroductionMotor vehicle crashes (MVCs) are the leading cause of mortality among teenagers. Teen driving research has a longstanding history; however, much of this work is cross-sectional. The Eunice Kennedy Shriver National Institute for Child Health and Human Development funded a study, REACT (Roadway Experiences and Attentional Change in Teens) which combined factorial and longitudinal designs to investigate the independent and joint effects of age and driving experience on driving attention over time among young drivers.MethodLongitudinal methods offer important contributions to teen driving research by enabling characterization of driving trajectories. This paper describes methodological considerations for longitudinal studies of teen drivers. Such considerations are organized into overarching themes, including population, recruitment, enrollment, and retention, throughout this paper. These considerations were compiled as a combination of our own experiences in REACT and previous literature. We elaborate on these considerations below to illustrate the value of each consideration.ResultsIssues encountered are discussed and strategies for dealing with various issues are described. Transportation barriers, scheduling difficulties, and skipped study milestones were among the most frequent challenges; we outline these and other issues encountered in REACT and corresponding considerations for such issues in Table 2. Sharing these experiences should aid future longitudinal investigations of young drivers, which are critically needed to reduce teen MVCs.ConclusionsStudies similar to REACT are considerable undertakings due to the comprehensive nature of longitudinal design. Such investigations must maintain a delicate balance between appropriate amounts of rigor and flexibility in the development of thoroughly defined research questions and theoretically driven frameworks. Key considerations that have contributed to the success of REACT are outlined, challenges encountered throughout data collection are documented, and recommendations based on choices made and lessons learned to inform future longitudinal investigations on young drivers are provided.     

Processing deceptive information in sports: Individual differences for responding to head fakes depends on the attentional capability of the observer

In team sports, players sometimes try to deceive their opponents by providing misleading information in order to gain a temporal advantage. Head-fakes are often applied when a player gazes in one direction, while passing/shooting the ball in another direction. The opponent is challenged to focus attention on the relevant information (i.e., pass direction), while ignoring the conflicting information (i.e., gaze direction). The present study aimed to identify the link between attentional capabilities and the effectiveness of head fakes. Twenty-seven novices performed in a basketball-specific head-fake task and in the attention-window task. A correlation between performances in both tasks revealed that participants with higher attentional capabilities were better able to focus their attention on the relevant feature (pass direction), when judging basketball situations, than participants with lower attentional capabilities. The results emphasize the relevance of high attentional capabilities in team sports and indicate that focusing one’s attention to the pass direction poses a possibility of reducing the effects of head fakes.     

Generate,maintain, manipulate? Exploring the multidimensional nature of motor imagery

Motor imagery (MI), the mental rehearsal of a motor task, is thought to be a synergistic interaction between processes that allow for the generation, maintenance, and manipulation, of motor images. While our understanding of the multidimensional nature of MI stems from research examining various methods to assess MI ability, limited research has been conducted employing multiple assessments across participants to probe the underlying dimensions of MI. Accordingly, the current study sought to explore the multidimensional nature of MI using an exploratory approach that would allow for the dimensions of imagery to be examined and linked to each assessment measure. Specifically, participants (N = 81) underwent a battery of MI-assessments (including questionnaires, mental chronometry, a hand laterality judgment task, and a MI-based learning task), and data was analyzed via principal component analysis (PCA). Three components resulted, which were named based on which outcome measures loaded on to the component: generation, maintenance, and manipulation of motor images. We further discuss a fourth component, named ‘temporal sequencing’ of motor images, identified via the initial component solution. Concordant with previous research, we highlight the importance of employing multiple measures when assessing imagery ability prior to its use in training. Notably, this work allowed us to link assessments of MI to the different dimensions of MI, informing on the nature of MI.