What happens in the prefrontal cortex? Cognitive processing of novel and familiar stimuli in soccer: An exploratory fNIRS study.

The importance of both general and sport-specific perceptual-cognitive abilities in soccer players has been investigated in several studies. Although these perceptual-cognitive skills could contribute significantly to soccer players' expertise, the underlying cortical mechanisms have not been clarified yet. Examining activity changes in the prefrontal cortex under different cognitive demands may help to better understand the underlying mechanisms of sports expertise. The aim of this study was to analyse the prefrontal activity of soccer experts during general and sport-specific cognitive tasks. For this purpose, 39 semi-professional soccer players performed four perceptual-cognitive tests, two of which assessed general cognition, the other two assessed sport-specific cognition. Since soccer is a movement-intensive sport, two tests were performed in motion. While performing cognitive tests, prefrontal activity was recorded using functional near-infrared spectroscopy (fNIRS) (NIRSport, NIRx Medical Technologies, USA). Differences of prefrontal activity in general and sport-specific cognitive tasks were analysed using paired t-tests. The results showed significant increases in prefrontal activity during general cognitive tests (novel stimuli) compared to sport-specific tests (familiar stimuli). The comparatively lower prefrontal activity change during sport-specific cognition might be due to learned automatisms of experts in this field. These results seem in line with previous findings on novel and automated cognition, "repetition suppression theory" and "neural efficiency theory". Furthermore, the different cortical processes could be caused by altered prefrontal structures of experts and might represent a decisive factor for expertise in team sports. However, further research is needed to clarify the prefrontal involvement on expertise in general and sport-specific cognition.

This fNIRS study examines differences in the prefrontal activity of soccer experts during general and sport-specific cognitive tasks.In general cognitive tasks, increased prefrontal activity changes were detected, whereas lower cortical activity changes during sport-specific cognition were found.These findings support the "repetition suppression theory" and earlier findings on the processing of novel stimuli in the prefrontal cortex (PFC).The differences in the cortical processing of general and sport-specific tasks of soccer players might be caused by altered prefrontal structures of experts and could be of special importance for expertise in soccer.

Birds and bats enhance cacao yield despite suppressing arthropod mesopredation.

Bird- and bat-mediated biocontrol benefits the productivity of tropical commodity crops such as cacao, but the ecological interactions driving these ecosystem services remain poorly understood. Whereas birds and bats prey on herbivorous arthropods, they may also prey on arthropod mesopredators such as ants, with poorly understood consequences for pest biocontrol. We used a full-factorial experiment excluding birds, bats, and ants to assess their effects on (a) the abundance of multiple arthropod groups; (b) predation pressure on arthropods evaluated through artificial sentinel caterpillars; and (c) cacao yield over 1 year in shaded agroforestry systems of native cacao varieties in Peru. Birds and bats increased cacao yield by 118%, which translates in smallholder benefits of ca. US $959 ha-1 year-1 . Birds and bats decreased predation by ants and other arthropods, but contributed to the control of phytophagous taxa such as aphids and mealybugs. By contrast, ant presence increased the abundance of these sap-sucking insects, with negative impacts for cacao yield. Notably, high abundances of the dominant ant Nylanderia sp., known to attend sap-sucking insects, were associated with lower cacao yield along a distance gradient from the closest forest edge. According to these results, arthropod predation by birds and bats, rather than mesopredation by arthropods, was most responsible for increases in cacao yield. Moving forward, detailed research about their trophic interactions will be necessary to identify the cause of such benefits. Retaining and restoring the large benefits of birds and bats as well as minimizing disservices by other taxa in cacao agroforests can benefit from management schemes that prioritize preservation of shade trees and adjacent forests within agroforestry landscapes.

Quantifying services and disservices provided by insects and vertebrates in cacao agroforestry landscapes.

Animals provide services such as pollination and pest control in cacao agroforestry systems, but also disservices. Yet, their combined contributions to crop yield and fruit loss are mostly unclear. In a full-factorial field experiment in northwestern Peru, we excluded flying insects, ants, birds and bats from cacao trees and assessed several productivity indicators. We quantified the contribution of each group to fruit set, fruit loss and marketable yield and evaluated how forest distance and canopy closure affected productivity. Fruit set dropped (from 1.7% to 0.3%) when flying insects were excluded and tripled at intermediate (40%) compared to high (greater than 80%) canopy cover in the non-exclusion treatment. Fruit set also dropped with bird and bat exclusion, potentially due to increased abundances of arthropods preying on pollinators or flower herbivores. Overall, cacao yields more than doubled when birds and bats had access to trees. Ants were generally associated with fruit loss, but also with yield increases in agroforests close to forest. We also evidenced disservices generated by squirrels, leading to significant fruit losses. Our findings show that several functional groups contribute to high cacao yield, while trade-offs between services and disservices need to be integrated in local and landscape-scale sustainable cacao agroforestry management.

Influences of Neck and/or Wrist Pain on Hand Grip Strength of Industrial Quality Proofing Workers.

BACKGROUND: The aim of this study was to analyze the interaction between neck and/or wrist pain and hand grip strength (HGS) and to investigate factors (age, sex, neck disorders, and carpal tunnel syndrome) influencing the HGS of industrial quality proofing workers (N = 145). METHODS: Standardized questionnaires [Neck Disability Index (NDI), Boston Carpal Tunnel Questionnaire] were used to evaluate existing neck and/or wrist pain. HGS measurements were performed in different wrist positions. RESULTS: Significant differences between participants with and without neck pain were found in different wrist positions, in neutral wrist position right [without neck pain (n = 48) 46.34 (43.39 - 49.30); with neck pain (n = 97) 38.46 (36.20 - 40.72), F (1,144)  = 16.82, p < 0.001, ŋ p 2 = 0.11] and left [without neck pain 44.06 (41.19 - 46.94); with neck pain 37.36 (35.13 - 39.58), F (1,144)  = 12.70, p < 0.001, ŋ p 2 = 0.08]. A significant difference between participants with and without wrist pain was found for neutral wrist position right [without wrist pain (n = 105) 42.53 (40.37 - 44.70); with wrist pain (n = 40) 37.24 (33.56 - 40.91), F (1,144)  = 6.41, p = 0.01, ŋ p 2 = 0.04]. Regression analysis showed significant results especially for steps two (age and weight, NDI) and three (age and weight, NDI, Boston Carpal Tunnel Questionnaire) for neutral position right (R2 = 0.355, R2 = 0.357, respectively). CONCLUSION: Neck pain has an impact on HGS but should be evaluated in consideration of age and sex.

On-Field Perceptual-Cognitive Training Improves Peripheral Reaction in Soccer: A Controlled Trial.

Abilities such as peripheral reaction are of special importance in soccer. Whether these abilities can be improved by sport-specific on-field interventions remains unclear. The aim of the present controlled trial was to investigate the effect of a soccer-specific perceptual-cognitive on-field training on peripheral reaction of highly talented soccer players aged 12-13 years. N = 38 male elite athletes from young talent centers were allocated to an intervention (n = 19) and a control group (CG) (n = 19). Computer-based peripheral perception tests were conducted before and after intervention. Combining a sport-specific and a juggling task, the intervention was performed once a week (8 weeks, 20 min per week) in addition to team training. The CG exclusively underwent usual team training. Analyses show significant differences between the two groups for peripheral reaction time (PRT), with significant improvements for the intervention group and none for the CG. Furthermore, results indicate that improvements in peripheral reaction might be due to changes in the reaction time of right-footed players. Future studies should be conducted to clarify the effect of sport-specific on-field training approaches on PRT. These analyses should consider the influence of lateralization on effectivity of perceptual-cognitive on-field training approaches.

Peripheral Vision Tests in Sports: Training Effects and Reliability of Peripheral Perception Test.

Various studies suggest the importance of peripheral vision (PV) in sports. Computer-based test systems provide objective methods to measure PV. Nevertheless, the reliability and training effects are not clarified in detail. The purpose of this investigation was to present a short narrative non-systematic review on computer-based PV tests and to determine the reliability and the training effects of peripheral perception sub-test (PP) of the Vienna test system (VTS) in a test-retest design. N = 21 male athletes aged between 20 and 30 years (M = 26.15; SD = 3.1) were included. The main outcome parameters were peripheral reaction (PR), PR left (PRL), PR right (PRR), field of vision (FOV), visual angle left (VAL), and visual angle right (VAR). Reliability was assessed using intraclass correlation coefficient (ICC) and Bland-Altman plots. Training effects were determined by students t-test. Good reliability was observed in PR, PRL, and PRR. Moderate reliability was found in FOV, VAL, and VAR. Significant improvements between T0 and T1 were found in PRL with a mean difference of 0.04 s (95% CI [0.00-0.07]) and in PR with a mean difference of 0.02 s (95% CI [0.00-0.05]). For PRR, FOV, VAL, VAR, no significant differences were detected. These results indicate that PP can be applied to asses PV abilities in sports. Future research is needed to clarify the influence of test repetitions on visuomotor learning in PP. Moreover, PV tests should be cross-validated with sport-specific measurements (e.g., on-field and/or 'virtual reality' approaches).

General perceptual-cognitive abilities: Age and position in soccer.

Various studies suggest the importance of sport-specific cognitive and perceptual abilities in soccer. However, the role of general perceptual-cognitive abilities and the relation of age respective to position have not been clarified for soccer in detail. Therefore, it was the objective of the present study to determine the relation of age and position to general perceptual-cognitive abilities. 178 highly talented male soccer players (mean age 16.2, age range 10 to 33 years) were involved. The participants performed computer-based sustained attention and anticipation (using Vienna Test System) tests. 139 subjects (mean age 16.6) took part in visual and acoustic reaction tests (using Talent Diagnostic System). The soccer players, subdivided into age and position groups, were recruited from a youth academy of a professional soccer club and played at the highest and 2nd highest national soccer competition for their age. Group differences were tested using analysis of variance. Correlations were analyzed for age and abilities. Significant correlations and group differences were found for age and sustained attention tasks. Significant differences for position groups were observed with regard to acoustic reaction time (ART). Further, we found statistical tendencies for group differences regarding the visual reaction time (VRT), indicating that midfielders outperform defenders and strikers in simple reaction tasks. Improved skills in sustained attention tasks resulted for defenders, who worked faster and more precisely in figural tasks. Regarding general anticipation tasks differences were not found. No group differences were found in basic anticipation tasks. Our study indicates that additional research is needed to further clarify the development of general perceptual-cognitive abilities and position-specific differences in the above abilities of highly talented soccer players.