Identifying the Benefits of Observational Practice in the Acquisition of a Novel Coordination Skill

The experiment undertaken was designed to reveal how split attention within an observational learning context influences perception and production processes. The task was producing a bimanual coordination pattern with a 90˚ relative phase lead of one hand over the other hand. Multi-resource observer group watched both of the model’s arms and training animation. Single-resource observer groups watched either model’s arm movements or a training animation. In the pre- and post-scanning trials, participants performed the task with pendula animation. After each trial, they performed a perceptual test. In the pre- and post-baseline trials, participants watched the pendula animation and then, re-produce the pattern. During the practice session, models tracked the training animation and their yoked observer saw this. The physical practice model improved at both physical performance and perceptual discrimination of the practiced task. The observer groups showed better performance in perceptual and physical performance test compared to the control group. This implies that observer’s ability of extracting the relative phase information indicates a link from perceiving the model’s movement to the coordination process required to producing the observed action. As a theory of observational learning, the visual perspective theory specifically accounts for the pick-up relative motion information (relative phase) through observation

Cortical Excitability Changes Emerge in M1 Following Training With a Novel Bimanual Coordination Pattern

Conceptually, motor skill memory has been divided into two distinct forms, which are explicit and implicit memory representations. These two memory components have distinct neural processing pathways. Extensive studies focusing on discrete and serial reaction time tasks (SRTT) have been done to explore these processing pathways to establish a link between memory consolidation processes and cortical excitability changes in motor cortex (M1) after training. Research has revealed distinct cortical excitability changes in M1 that differentiate a SRTT as either implicit or explicit. In the area of motor skill/learning, rhythmic bimanual coordination tasks are often treated as different from SRTT for a variety of reasons. The primary goal of this study was to determine if cortical excitability changes in M1 following training with a 90° bimanual coordination pattern would be more like changes observed after training with an SRTT in an implicit or explicit context. To accomplish the goal, transcranial magnetic stimulation (TMS) was used to probe M1 excitability before and after training. A secondary goal of this study was to examine whether or not training altered participants’ ability to perceptually discriminate aspects of the trained coordination pattern. A feature of explicit representation is the ability to recall the sequence after training, a feature not characteristic of an implicit representation. A recognition test introduced after a delayed-retention test of the trained 90° pattern was used to determine if training and delay interval interacted to establish changes in perceptual discrimination ability. The bimanual task required participants to produce the 90˚ relative phase pattern with finger abduction/adduction motions. Training was facilitated by using a Lissajous plot to provide concurrent feedback. Before training and at 6 and 21 minutes after training motor evoked potentials (MEPs) were measured from the first dorsal interosseous (FDI) muscle. Participants had either a 30 minute or 6-hour delay after training before performing a set of retention test trials of the 90° bimanual pattern and then performing a recognition test of the finger motions used to produce the 90° pattern. At the end of training participants produced the 90˚ phase pattern with smaller error and variability compared to the beginning of training, and maintained the skill level gained at the end of practice until the delayed retention test. Cortical excitability increased above baseline at the 6 min and 21 min TMS probes after training, consistent with the pattern observed following training with an implicit SRTT. Participants were able to perceptually discriminate finger motions of the trained 90° pattern during the recognition test. The results suggest that participants’ developed an explicit representation of the bimanual 90˚ pattern. However, the ability to both produce and perceptually discriminate coordination patterns based on relative phase also suggest that relative phase as an order parameter links perception to action and thereby constrains and facilitates both action and perception processes in a similar manner

Cortical Excitability Changes Emerge in M1 Following Training With a Novel Bimanual Coordination Pattern

Conceptually, motor skill memory has been divided into two distinct forms, which are explicit and implicit memory representations. These two memory components have distinct neural processing pathways. Extensive studies focusing on discrete and serial reaction time tasks (SRTT) have been done to explore these processing pathways to establish a link between memory consolidation processes and cortical excitability changes in motor cortex (M1) after training. Research has revealed distinct cortical excitability changes in M1 that differentiate a SRTT as either implicit or explicit. In the area of motor skill/learning, rhythmic bimanual coordination tasks are often treated as different from SRTT for a variety of reasons. The primary goal of this study was to determine if cortical excitability changes in M1 following training with a 90° bimanual coordination pattern would be more like changes observed after training with an SRTT in an implicit or explicit context. To accomplish the goal, transcranial magnetic stimulation (TMS) was used to probe M1 excitability before and after training. A secondary goal of this study was to examine whether or not training altered participants’ ability to perceptually discriminate aspects of the trained coordination pattern. A feature of explicit representation is the ability to recall the sequence after training, a feature not characteristic of an implicit representation. A recognition test introduced after a delayed-retention test of the trained 90° pattern was used to determine if training and delay interval interacted to establish changes in perceptual discrimination ability. The bimanual task required participants to produce the 90˚ relative phase pattern with finger abduction/adduction motions. Training was facilitated by using a Lissajous plot to provide concurrent feedback. Before training and at 6 and 21 minutes after training motor evoked potentials (MEPs) were measured from the first dorsal interosseous (FDI) muscle. Participants had either a 30 minute or 6-hour delay after training before performing a set of retention test trials of the 90° bimanual pattern and then performing a recognition test of the finger motions used to produce the 90° pattern. At the end of training participants produced the 90˚ phase pattern with smaller error and variability compared to the beginning of training, and maintained the skill level gained at the end of practice until the delayed retention test. Cortical excitability increased above baseline at the 6 min and 21 min TMS probes after training, consistent with the pattern observed following training with an implicit SRTT. Participants were able to perceptually discriminate finger motions of the trained 90° pattern during the recognition test. The results suggest that participants’ developed an explicit representation of the bimanual 90˚ pattern. However, the ability to both produce and perceptually discriminate coordination patterns based on relative phase also suggest that relative phase as an order parameter links perception to action and thereby constrains and facilitates both action and perception processes in a similar manner

Psychological Skills Training for Athletes in Sports: Web of Science Bibliometric Analysis

Psychological Skill Training (PST) for optimal performance in sports has received extensive attention from athletes, coaches, and experts, and numerous studies have been conducted, but despite this interest, it has not been the subject of any bibliographic analysis. The analysis covered 405 articles and reviews that were located in the Thomson Reuters Web of Science (Core CollectionTM) between 1992 and 2021. These papers were published by 1048 authors from 543 different universities across 54 countries in 107 different journals. The fundamental bibliometric calculations and co-word networks were completed. As a result, the following thematic elements were grouped into four clusters: (1) PST for stress, mental toughness, and coping, (2) PST for anxiety, motivation, self-confidence, and self-efficacy, (3) PST for flow and mindfulness, and (4) PST for emotions. From the results of this study, it was confirmed that the topic of PST is converging toward the best performance, with various approaches, such as stress management, anxiety control, and coping as techniques for PST. Furthermore, mindfulness and positive psychology studies emphasize athletes’ quality of life, so coaches and experts should pay more attention to improving athletes’ quality of life in future research

“Coach Really Knew What I Needed and Understood Me Well as a Person”: Effective Communication Acts in Coach–Athlete Interactions among Korean Olympic Archers

The purpose of this study is to qualitatively explore situations in which athletes perceived communication with their coach to be important and determine the effect of this communication on the athletes. Literature on the communication process in sports emphasizes the distinct characteristics of each sports and its setting. However, previous research has not studied various settings in detail, and archery is yet to be explored. The qualitative process included an in-depth, semi-structured interview with eight Olympic archers. Thematic analysis was used to interpret the data. Athletes perceived communication with coaches to be important during their performance, while dealing with psychological crises, and during their training. Our analysis suggests that, depending on the communicative actions, a coach may positively or negatively impact an athlete’s self-awareness, self-confidence, anxiety, autonomy, and motivation. A noteworthy finding of this study is that archers perceive communication with coaches about the selection and management of equipment as important. This study emphasizes the critical role of an athlete’s communication with the coach in various situations and discusses the theoretical and practical implications in the context of sports performance

Examining the effect of transcranial direct current stimulation on the dominant motor cortex in the indirect measurement of physical ability

Background: The effects of transcranial direct current stimulation (tDCS) on specific sports skills have received extensive attention, however, it is difficult to accurately determine its effect on physical performance due to the complexity of the tasks. The objective of this study was to investigate the effects of uni-hemispheric anodal tDCS of the motor cortex (M1) on the indirect measurement of physical ability in healthy men. Methods: Thirteen healthy, right-leg-dominant men aged between 21 and 32 years (26.53 ± 2.73 years) participated in two different experimental conditions in a randomized, single-blinded crossover design: anodal stimulation (a-tDCS) and sham-tDCS (2 mA for 20 minutes targeting the left M1 contralateral to dominant leg). Before and immediately after the tDCS stimulation, participants completed the standing long jump (SLJ) and sidestep test (SST), and their blood pressure and heart rate were checked for the safety of tDCS application. Results: No significant difference was observed between a-tDCS and sham-tDCS (F(1,24) = 0.02, p = 0.86, ηp2 = 0.001) on SLJ. Also, no significant changes in SLJ were observed between pre- and post-stimulation sessions for both conditions (F(1,24) = 1.18, p = 0.28, ηp2 = 0.047). Similarly, SST scores were not significantly different from a-tDCS and sham-tDCS condition (F(1,24) = 0.57, p = 0.45, ηp2 = 0.024). Significant changes in SST were not observed throughout the experiment sessions for both stimulation conditions (F(1,24) = 0.12, p = 0.73, ηp2 = 0.005). Conclusions: The uni-hemispheric a-tDCS applied over the M1 for 20 minutes may not be a valuable tool to obtain the physical performance benefits from the tasks that require bilateral lower limb power output, such as SLJ and SST

Functional expression and characterization of a cytosolic copper/zinc-superoxide dismutase of Spirometra erinacei

Spirometra erinacei is a pseudophyllidean tapeworm which inhabits the intestines of cats and dogs. The infections are usually asymptomatic in these animals, but the infection of the plerocercoid larvae of the parasite, spargana, cause sparganosis in other vertebrates, including human. In this study, we identified a gene encoding the copper/zinc-superoxide dismutase of S. erinacei (SeCuZnSOD) and partially characterized the biochemical and functional properties of the enzyme. The open reading frame of SeCuZnSOD was 465 bp that encodes 154 amino acids. The characteristic amino acid residues and motifs required for coordinating copper and zinc enzymatic function were well conserved. The genomic length of the SeCuZnSOD was 1,985 bp consisting of three exons that are separated by two introns. SeCuZnSOD is a typical cytosolic form which shares similar biochemical properties, including broad pH optima and inhibition profile by KCN and H2O2, with cytosolic Cu/Zn-SODs of other organisms. SeCuZnSOD was functionally expressed in both S. erinacei plerocercoid larvae and adult worms, and its expression level was significantly increased when the plerocercoid larvae were treated with paraquat. The enzyme may play essential roles for survival of the parasite not only by protecting itself from endogenous oxidative stress, but also by detoxifying oxidative killing of the parasite by host immune effector cells

IDENTIFICATION AND CHARACTERIZATION OF A MITOCHONDRIAL MANGANESE SUPEROXIDE DISMUTASE OF SPIROMETRA ERINACEI

A gene encoding the manganese superoxide dismutase (Mn-SOD) of Spirometra erinacei was identified, and the biochemical properties of the recombinant enzyme were partially characterized. The S. erinacei Mn-SOD gene consisted of 669 bp, which encoded 222 amino acids. A sequence analysis of the gene showed that it had typical molecular structures, including characteristic metal-binding residues and motifs that were conserved in Mn-SODs. An analysis of the N-terminal presequence of S. erinacei Mn-SOD revealed that it had physiochemical characteristics commonly found in mitochondria-targeting sequences and predicted that the enzyme is located in the mitochondria. A biochemical analysis also revealed that the enzyme is a typical Mn-SOD. The enzyme was consistently expressed in both S. erinacei plerocercoid larvae and adult worms. Our results collectively suggested that S. erinacei Mn-SOD is a typical mitochondrial Mn-SOD and may play an important role in parasite physiology, detoxifying excess superoxide radicals generated in the mitochondria

Identification and characterization of a cathepsin L-like cysteine protease from Taenia solium metacestode

Taenia solium metacestode, a larval pork tapeworm, is a causative agent of neurocysticercosis, one of the most common parasitic diseases in the human central nervous system. In this study, we identified a cDNA encoding for a cathepsin L-like cysteine protease from the T solium metacestode (TsCL-1) and characterized the biochemical properties of the recombinant enzyme. The cloned cDNA of 1216 bp encoded 339 amino acids with an approximate molecular weight of 37.6 kDa which containing a typical signal peptide sequence (17 amino acids), a pro-domain (106 amino acids), and a mature domain (216 amino acids). Sequence alignments of TsCL-1 showed low sequence similarity of 27.3-44.6 to cathepsin L-like cysteine proteases from other helminth parasites, but the similarity was increased to 35.9-55.0 when compared to mature domains. The bacterially expressed recombinant protein (rTsCL-1) did not show enzyme activity; however, the rTsCL-1 expressed in Pichia pastoris showed typical biochemical characteristics of cysteine proteases. It degraded human immunoglobulin G (IgG) and bovine serum albumin (BSA), but not collagen. Western blot analysis of the rTsCL-1 showed antigenicity against the sera from patients with cysticercosis, sparganosis or fascioliasis, but weak or no antigenicity against the sera from patients with paragonimiasis or clonorchiasis. (c) 2006 Published by Elsevier B.V.Taenia solium metacestode, a larval pork tapeworm, is a causative agent of neurocysticercosis, one of the most common parasitic diseases in the human central nervous system. In this study, we identified a cDNA encoding for a cathepsin L-like cysteine protease from the T solium metacestode (TsCL-1) and characterized the biochemical properties of the recombinant enzyme. The cloned cDNA of 1216 bp encoded 339 amino acids with an approximate molecular weight of 37.6 kDa which containing a typical signal peptide sequence (17 amino acids), a pro-domain (106 amino acids), and a mature domain (216 amino acids). Sequence alignments of TsCL-1 showed low sequence similarity of 27.3-44.6 to cathepsin L-like cysteine proteases from other helminth parasites, but the similarity was increased to 35.9-55.0 when compared to mature domains. The bacterially expressed recombinant protein (rTsCL-1) did not show enzyme activity; however, the rTsCL-1 expressed in Pichia pastoris showed typical biochemical characteristics of cysteine proteases. It degraded human immunoglobulin G (IgG) and bovine serum albumin (BSA), but not collagen. Western blot analysis of the rTsCL-1 showed antigenicity against the sera from patients with cysticercosis, sparganosis or fascioliasis, but weak or no antigenicity against the sera from patients with paragonimiasis or clonorchiasis. (c) 2006 Published by Elsevier B.V