@misc{WachsBilzFischeretal.2018, author = {Wachs, Sebastian and Bilz, Ludwig and Fischer, Saskia M. and Schubarth, Wilfried and Wright, Michelle F.}, title = {Students' Willingness to Intervene in Bullying}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {495}, issn = {1866-8364}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-421185}, pages = {11}, year = {2018}, abstract = {Although school climate and self-efficacy have received some attention in the literature, as correlates of students' willingness to intervene in bullying, to date, very little is known about the potential mediating role of self-efficacy in the relationship between classroom climate and students' willingness to intervene in bullying. To this end, the present study analyzes whether the relationship between classroom cohesion (as one facet of classroom climate) and students' willingness to intervene in bullying situations is mediated by self-efficacy in social conflicts. This study is based on a representative stratified random sample of two thousand and seventy-one students (51.3\% male), between the ages of twelve and seventeen, from twenty-four schools in Germany. Results showed that between 43\% and 48\% of students reported that they would not intervene in bullying. A mediation test using the structural equation modeling framework revealed that classroom cohesion and self-efficacy in social conflicts were directly associated with students' willingness to intervene in bullying situations. Furthermore, classroom cohesion was indirectly associated with higher levels of students' willingness to intervene in bullying situations, due to self-efficacy in social conflicts. We thus conclude that: (1) It is crucial to increase students' willingness to intervene in bullying; (2) efforts to increase students' willingness to intervene in bullying should promote students' confidence in dealing with social conflicts and interpersonal relationships; and (3) self-efficacy plays an important role in understanding the relationship between classroom cohesion and students' willingness to intervene in bullying. Recommendations are provided to help increase adolescents' willingness to intervene in bullying and for future research.}, language = {en} } @misc{StelzelBohleSchauenburgetal.2018, author = {Stelzel, Christine and Bohle, Hannah and Schauenburg, Gesche and Walter, Henrik and Granacher, Urs and Rapp, Michael Armin and Heinzel, Stephan}, title = {Contribution of the Lateral Prefrontal Cortex to Cognitive-Postural Multitasking}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {489}, issn = {1866-8364}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-421140}, pages = {12}, year = {2018}, abstract = {There is evidence for cortical contribution to the regulation of human postural control. Interference from concurrently performed cognitive tasks supports this notion, and the lateral prefrontal cortex (lPFC) has been suggested to play a prominent role in the processing of purely cognitive as well as cognitive-postural dual tasks. The degree of cognitive-motor interference varies greatly between individuals, but it is unresolved whether individual differences in the recruitment of specific lPFC regions during cognitive dual tasking are associated with individual differences in cognitive-motor interference. Here, we investigated inter-individual variability in a cognitive-postural multitasking situation in healthy young adults (n = 29) in order to relate these to inter-individual variability in lPFC recruitment during cognitive multitasking. For this purpose, a oneback working memory task was performed either as single task or as dual task in order to vary cognitive load. Participants performed these cognitive single and dual tasks either during upright stance on a balance pad that was placed on top of a force plate or during fMRI measurement with little to no postural demands. We hypothesized dual one-back task performance to be associated with lPFC recruitment when compared to single one-back task performance. In addition, we expected individual variability in lPFC recruitment to be associated with postural performance costs during concurrent dual one-back performance. As expected, behavioral performance costs in postural sway during dual-one back performance largely varied between individuals and so did lPFC recruitment during dual one-back performance. Most importantly, individuals who recruited the right mid-lPFC to a larger degree during dual one-back performance also showed greater postural sway as measured by larger performance costs in total center of pressure displacements. This effect was selective to the high-load dual one-back task and suggests a crucial role of the right lPFC in allocating resources during cognitivemotor interference. Our study provides further insight into the mechanisms underlying cognitive-motor multitasking and its impairments.}, language = {en} } @misc{SlimaniParavlicGranacher2018, author = {Slimani, Maamer and Paravlic, Armin and Granacher, Urs}, title = {A Meta-Analysis to Determine Strength Training Related Dose-Response Relationships for Lower-Limb Muscle Power Development in Young Athletes}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {472}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-417738}, pages = {14}, year = {2018}, abstract = {It is well-documented that strength training (ST) improves measures of muscle strength in young athletes. Less is known on transfer effects of ST on proxies of muscle power and the underlying dose-response relationships. The objectives of this meta-analysis were to quantify the effects of ST on lower limb muscle power in young athletes and to provide dose-response relationships for ST modalities such as frequency, intensity, and volume. A systematic literature search of electronic databases identified 895 records. Studies were eligible for inclusion if (i) healthy trained children (girls aged 6-11 y, boys aged 6-13 y) or adolescents (girls aged 12-18 y, boys aged 14-18 y) were examined, (ii) ST was compared with an active control, and (iii) at least one proxy of muscle power [squat jump (SJ) and countermovement jump height (CMJ)] was reported. Weighted mean standardized mean differences (SMDwm) between subjects were calculated. Based on the findings from 15 statistically aggregated studies, ST produced significant but small effects on CMJ height (SMDwm = 0.65; 95\% CI 0.34-0.96) and moderate effects on SJ height (SMDwm = 0.80; 95\% CI 0.23-1.37). The sub-analyses revealed that the moderating variable expertise level (CMJ height: p = 0.06; SJ height: N/A) did not significantly influence ST-related effects on proxies of muscle power. "Age" and "sex" moderated ST effects on SJ (p = 0.005) and CMJ height (p = 0.03), respectively. With regard to the dose-response relationships, findings from the meta-regression showed that none of the included training modalities predicted ST effects on CMJ height. For SJ height, the meta-regression indicated that the training modality "training duration" significantly predicted the observed gains (p = 0.02), with longer training durations (>8 weeks) showing larger improvements. This meta-analysis clearly proved the general effectiveness of ST on lower-limb muscle power in young athletes, irrespective of the moderating variables. Dose-response analyses revealed that longer training durations (>8 weeks) are more effective to improve SJ height. No such training modalities were found for CMJ height. Thus, there appear to be other training modalities besides the ones that were included in our analyses that may have an effect on SJ and particularly CMJ height. ST monitoring through rating of perceived exertion, movement velocity or force-velocity profile could be promising monitoring tools for lower-limb muscle power development in young athletes.}, language = {en} } @misc{SchaeferBittmann2018, author = {Schaefer, Laura and Bittmann, Frank}, title = {Muscular Pre-Activation Can Boost the Maximal Explosive Eccentric Adaptive Force}, series = {Postprints der Universit{\"a}t Potsdam Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam Humanwissenschaftliche Reihe}, number = {582}, issn = {1866-8364}, doi = {10.25932/publishup-43918}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-439189}, pages = {14}, year = {2018}, abstract = {The improvement of power is an objective in training of athletes. In order to detect effective methods of exercise, basic research is required regarding the mechanisms of muscular activity. The purpose of this study is to investigate whether or not a muscular pre-activation prior to an external impulse-like force impact has an effect on the maximal explosive eccentric Adaptive Force (xpAFeccmax). This power capability combines different probable power enhancing mechanisms. To measure the xpAFeccmax an innovative pneumatic device was used. During measuring, the subject tries to hold an isometric position as long as possible. In the moment in which the subjects' maximal isometric holding strength is exceeded, it merges into eccentric muscle action. This process is very close to motions in sports, where an adaptation of the neuromuscular system is required, e.g., force impacts caused by uneven surfaces during skiing. For investigating the effect of pre-activation on the xpAFeccmax of the quadriceps femoris muscle, n = 20 subjects had to pass three different pre-activation levels in a randomized order (level 1: 0.4 bar, level 2: 0.8 bar, level 3: 1.2 bar). After adjusting the standardized pre-pressure by pushing against the interface, an impulse-like load impacted on the distal tibia of the subject. During this, the xpAFeccmax was detected. The maximal voluntary isometric contraction (MVIC) was also measured. The torque values of the xpAFeccmax were compared with regard to the pre-activation levels. The results show a significant positive relation between the pre-activation of the quadriceps femoris muscle and the xpAFeccmax (male: p = 0.000, η2= 0.683; female: p = 0.000, η2= 0.907). The average percentage increase of torque amounted +28.15 ± 25.4\% between MVIC and xpAFeccmax with pre-pressure level 1, +12.09 ± 7.9\% for the xpAFeccmax comparing pre-pressure levels 1 vs. 2 and +2.98 ± 4.2\% comparing levels 2 and 3. A higher but not maximal muscular activation prior to a fast impacting eccentric load seems to produce an immediate increase of force outcome. Different possible physiological explanatory approaches and the use as a potential training method are discussed.}, language = {en} } @misc{SchaeferBittmann2018, author = {Schaefer, Laura and Bittmann, Frank}, title = {Coherent behavior of neuromuscular oscillations between isometrically interacting subjects}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {480}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-419864}, pages = {10}, year = {2018}, abstract = {Previous research has shown that electrical muscle activity is able to synchronize between muscles of one subject. The ability to synchronize the mechanical muscle oscillations measured by Mechanomyography (MMG) is not described sufficiently. Likewise, the behavior of myofascial oscillations was not considered yet during muscular interaction of two human subjects. The purpose of this study is to investigate the myofascial oscillations intra- and interpersonally. For this the mechanical muscle oscillations of the triceps and the abdominal external oblique muscles were measured by MMG and the triceps tendon was measured by mechanotendography (MTG) during isometric interaction of two subjects (n = 20) performed at 80\% of the MVC using their arm extensors. The coherence of MMG/MTG-signals was analyzed with coherence wavelet transform and was compared with randomly matched signal pairs. Each signal pairing shows significant coherent behavior. Averagely, the coherent phases of n = 485 real pairings last over 82 ± 39 \% of the total duration time of the isometric interaction. Coherent phases of randomly matched signal pairs take 21 ± 12 \% of the total duration time (n = 39). The difference between real vs. randomly matched pairs is significant (U = 113.0, p = 0.000, r = 0.73). The results show that the neuromuscular system seems to be able to synchronize to another neuromuscular system during muscular interaction and generate a coherent behavior of the mechanical muscular oscillations. Potential explanatory approaches are discussed.}, language = {en} } @misc{RubertusNoiray2018, author = {Rubertus, Elina and Noiray, Aude}, title = {On the development of gestural organization}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {478}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-419753}, pages = {21}, year = {2018}, abstract = {In the first years of life, children differ greatly from adults in the temporal organization of their speech gestures in fluent language production. However, dissent remains as to the maturational direction of such organization. The present study sheds new light on this process by tracking the development of anticipatory vowel-to-vowel coarticulation in a cross-sectional investigation of 62 German children (from 3.5 to 7 years of age) and 13 adults. It focuses on gestures of the tongue, a complex organ whose spatiotemporal control is indispensable for speech production. The goal of the study was threefold: 1) investigate whether children as well as adults initiate the articulation for a target vowel in advance of its acoustic onset, 2) test if the identity of the intervocalic consonant matters and finally, 3) describe age-related developments of these lingual coarticulatory patterns. To achieve this goal, ultrasound tongue imaging was used to record lingual movements and quantify changes in coarticulation degree as a function of consonantal context and age. Results from linear mixed effects models indicate that like adults, children initiate vowels' lingual gestures well ahead of their acoustic onset. Second, while the identity of the intervocalic consonant affects the degree of vocalic anticipation in adults, it does not in children at any age. Finally, the degree of vowelto-vowel coarticulation is significantly higher in all cohorts of children than in adults. However, among children, a developmental decrease of vocalic coarticulation is only found for sequences including the alveolar stop /d/ which requires finer spatiotemporal coordination of the tongue's subparts compared to labial and velar stops. Altogether, results suggest greater gestural overlap in child than in adult speech and support the view of a non-uniform and protracted maturation of lingual coarticulation calling for thorough considerations of the articulatory intricacies from which subtle developmental differences may originate.}, language = {en} } @misc{RonasiFischerZimmermann2018, author = {Ronasi, Golnoush and Fischer, Martin H. and Zimmermann, Malte}, title = {Language and Arithmetic}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {469}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-417278}, pages = {12}, year = {2018}, abstract = {We examined cross-domain semantic priming effects between arithmetic and language. We paired subtractions with their linguistic equivalent, exception phrases (EPs) with positive quantifiers (e.g., "everybody except John") while pairing additions with their own linguistic equivalent, EPs with negative quantifiers (e.g., "nobody except John"; Moltmann, 1995). We hypothesized that EPs with positive quantifiers prime subtractions and inhibit additions while EPs with negative quantifiers prime additions and inhibit subtractions. Furthermore, we expected similar priming and inhibition effects from arithmetic into semantics. Our design allowed for a bidirectional analysis by using one trial's target as the prime for the next trial. Two experiments failed to show significant priming effects in either direction. Implications and possible shortcomings are explored in the general discussion.}, language = {en} } @misc{RohlfHollKirschetal.2018, author = {Rohlf, Helena L. and Holl, Anna K. and Kirsch, Fabian and Krah{\´e}, Barbara and Elsner, Birgit}, title = {Longitudinal Links between Executive Function, Anger, and Aggression in Middle Childhood}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {382}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-409471}, pages = {14}, year = {2018}, abstract = {Previous research has indicated that executive function (EF) is negatively associated with aggressive behavior in childhood. However, there is a lack of longitudinal studies that have examined the effect of deficits in EF on aggression over time and taken into account different forms and functions of aggression at the same time. Furthermore, only few studies have analyzed the role of underlying variables that may explain the association between EF and aggression. The present study examined the prospective paths between EF and different forms (physical and relational) and functions (reactive and proactive) of aggression. The habitual experience of anger was examined as a potential underlying mechanism of the link between EF and aggression, because the tendency to get angry easily has been found to be both a consequence of deficits in EF and a predictor of aggression. The study included 1,652 children (between 6 and 11 years old at the first time point), who were followed over three time points (T1, T2, and T3) covering 3 years. At T1, a latent factor of EF comprised measures of planning, rated via teacher reports, as well as inhibition, set shifting, and working-memory updating, assessed experimentally. Habitual anger experience was assessed via parent reports at T1 and T2. The forms and functions of aggression were measured via teacher reports at all three time points. Structural equation modeling revealed that EF at T1 predicted physical, relational, and reactive aggression at T3, but was unrelated to proactive aggression at T3. Furthermore, EF at T1 was indirectly linked to physical aggression at T3, mediated through habitual anger experience at T2. The results indicate that deficits in EF influence the later occurrence of aggression in middle childhood, and the tendency to get angry easily mediates this relation.}, language = {en} } @misc{RamirezCampilloGarciaPinillosGarciaRamosetal.2018, author = {Ramirez-Campillo, Rodrigo and Garc{\´i}a-Pinillos, Felipe and Garc{\´i}a-Ramos, Amador and Yanci, Javier and Gentil, Paulo and Chaabene, Helmi and Granacher, Urs}, title = {Effects of Different Plyometric Training Frequencies on Components of Physical Fitness in Amateur Female Soccer Players}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {474}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-419377}, pages = {11}, year = {2018}, abstract = {Plyometric jump training (PJT) is a frequently used and effective means to improve amateur and elite soccer players' physical fitness. However, it is unresolved how different PJT frequencies per week with equal overall training volume may affect training-induced adaptations. Therefore, the aim of this study was to compare the effects of an in-season 8 week PJT with one session vs. two sessions per week and equal training volume on components of physical fitness in amateur female soccer players. A single-blind randomized controlled trial was conducted. Participants (N = 23; age, 21.4 ± 3.2 years) were randomly assigned to a one session PJT per-week (PJT-1, n = 8), two sessions PJT per-week (PJT-2, n = 8) or an active control group (CON, n = 7). Before and after training, participants performed countermovement jumps (CMJ), drop-jumps from a 20-cm drop-height (DJ20), a maximal kicking velocity test (MKV), the 15-m linear sprint-time test, the Meylan test for the assessment of change of direction ability (CoDA), and the Yo-Yo intermittent recovery endurance test (Yo-YoIR1). Results revealed significant main effects of time for the CMJ, DJ20, MKV, 15-m sprint, CoDA, and the Yo-YoIR1 (all p < 0.001; d = 0.57-0.83). Significant group × time interactions were observed for the CMJ, DJ20, MKV, 15-m sprint, CoDA, and the Yo-YoIR1 (all p < 0.05; d = 0.36-0.51). Post-hoc analyses showed similar improvements for PJT-1 and PJT-2 groups in CMJ (Δ10.6\%, d = 0.37; and Δ10.1\%, d = 0.51, respectively), DJ20 (Δ12.9\%, d = 0.47; and Δ13.1\%, d = 0.54, respectively), MKV (Δ8.6\%, d = 0.52; and Δ9.1\%, d = 0.47, respectively), 15-m sprint (Δ8.3\%, d = 2.25; and Δ9.5\%, d = 2.67, respectively), CoDA (Δ7.5\%, d = 1.68; and Δ7.4\%, d = 1.16, respectively), and YoYoIR1 (Δ10.3\%, d = 0.22; and Δ9.9\%, d = 0.26, respectively). No significant pre-post changes were found for CON (all p > 0.05; Δ0.5-4.2\%, d = 0.03-0.2). In conclusion, higher PJT exposure in terms of session frequency has no extra effects on female soccer players' physical fitness development when jump volume is equated during a short-term (i.e., 8 weeks) training program. From this, it follows that one PJT session per week combined with regular soccer-specific training appears to be sufficient to induce physical fitness improvements in amateur female soccer players.}, language = {en} } @misc{PrieskeKruegerAehleetal.2018, author = {Prieske, Olaf and Kr{\"u}ger, Tom and Aehle, Markus and Bauer, Erik and Granacher, Urs}, title = {Effects of Resisted Sprint Training and Traditional Power Training on Sprint, Jump, and Balance Performance in Healthy Young Adults}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {383}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-409645}, pages = {10}, year = {2018}, abstract = {Power training programs have proved to be effective in improving components of physical fitness such as speed. According to the concept of training specificity, it was postulated that exercises must attempt to closely mimic the demands of the respective activity. When transferring this idea to speed development, the purpose of the present study was to examine the effects of resisted sprint (RST) vs. traditional power training (TPT) on physical fitness in healthy young adults. Thirty-five healthy, physically active adults were randomly assigned to a RST (n = 10, 23 ± 3 years), a TPT (n = 9, 23 ± 3 years), or a passive control group (n = 16, 23 ± 2 years). RST and TPT exercised for 6 weeks with three training sessions/week each lasting 45-60 min. RST comprised frontal and lateral sprint exercises using an expander system with increasing levels of resistance that was attached to a treadmill (h/p/cosmos). TPT included ballistic strength training at 40\% of the one-repetition-maximum for the lower limbs (e.g., leg press, knee extensions). Before and after training, sprint (20-m sprint), change-of-direction speed (T-agility test), jump (drop, countermovement jump), and balance performances (Y balance test) were assessed. ANCOVA statistics revealed large main effects of group for 20-m sprint velocity and ground contact time (0.81 ≤ d ≤ 1.00). Post-hoc tests showed higher sprint velocity following RST and TPT (0.69 ≤ d ≤ 0.82) when compared to the control group, but no difference between RST and TPT. Pre-to-post changes amounted to 4.5\% for RST [90\%CI: (-1.1\%;10.1\%), d = 1.23] and 2.6\% for TPT [90\%CI: (0.4\%;4.8\%), d = 1.59]. Additionally, ground contact times during sprinting were shorter following RST and TPT (0.68 ≤ d ≤ 1.09) compared to the control group, but no difference between RST and TPT. Pre-to-post changes amounted to -6.3\% for RST [90\%CI: (-11.4\%;-1.1\%), d = 1.45) and -2.7\% for TPT [90\%CI: (-4.2\%;-1.2\%), d = 2.36]. Finally, effects for change-of-direction speed, jump, and balance performance varied from small-to-large. The present findings indicate that 6 weeks of RST and TPT produced similar effects on 20-m sprint performance compared with a passive control in healthy and physically active, young adults. However, no training-related effects were found for change-of-direction speed, jump and balance performance. We conclude that both training regimes can be applied for speed development.}, language = {en} }