Age-related EMG variables during maximum voluntary contraction

We studied the neuromuscular adaptation that occurs with aging by comparing changes in surface electromyography (EMG) variables from the tibialis anterior muscle in 12 young (21.4 +/- 1.7 yr. old) and 13 older subjects (70.8 +/- 3.1 yr. old). EMG variables such as the muscle fiber conduction velocity, median frequency, and averaged rectified value were calculated during maximum voluntary contraction for 5-sec. isometric contractions. The dorsiflexion force, muscle fiber conduction velocity, median frequency, and average rectified value during maximum voluntary contraction were significantly smaller in the older than in the younger group (p < .05). These results suggested that the neuromuscular system in older subjects is affected by the selective atrophy of fast twitch fibers and differences in motor unit firing statistics. Our results suggest the utility of applying the EMG observed during maximum voluntary contraction to the noninvasive evaluation of neuromuscular function in elderly persons.     

The Fascist Seduction of Narrative: Walter Benjamin’s Historical Materialism Beyond Counter-Narrative

This essay introduces Walter Benjamin’s historical materialism to illuminate how history teachers may invoke a critique of the past and present through democratizing the production of knowledge in the classroom. Historical materialism gives students access to the means of knowledge production and entrusts them with the task of generating a critique of politics though encounters with historical objects. The rise of the alt-right, alternative facts, and fake news sites necessitates social studies methods that intervene into the fascist seductions of narrative in history. A Benjaminian pedagogy emphasizes reading practices that acknowledge the political layers of history inscribed within the objects. This generates space for forms of pessimism and dialectic critiques of barbarism that students may experience with history beyond the teacher’s capacity for understanding. In the name of democracy over fascism, the article adds a political critique to students’ historical and critical thinking skills.     

Beyond the logic of Lemma: the oneness of life and its environment,the oneness of within and without

In this paper the ‘analyst as a citizen in the world’ is understood as the analyst interconnecting and harmonising with his or her environment, including not only society, but also nature and the universe. In this sense, Buddhism teaches the Oneness of Life and its Environment, and links are made between Mahayana Buddhism and Jung's understanding of the Self and individuation. The Logic of Lemma in the Flower Ornament Sutra indicates that all phenomena in the world can merge with each other without losing individuality; ten stages are described from the Lotus Sutra and links are made with the development in respect to the ego; Kenji Miyazawa and his work are given as examples to illustrate this. Causality and synchronicity are explored in terms of the interaction between the individual and the environment, and three examples are given where sometimes individual, egoic, causality is more of a feature and sometimes synchronicity has a greater prominence. The paper ends with an examination of tree drawings, made over a period of 50 years by junior high school students, which indicates the way that these individuals have portrayed themselves and their relation to their environment.     

Span of attention,backward masking,and reaction time

A test pattern consisting of 0 to 15 dots and a following random dot masking pattern were presented for 5 msec each with SOAs varying between 30 and 200 msec. The subject was asked to report the perceived number of dots in the test pattern as soon as possible and to assign a confidence rating to each report. The span of attention (upper limit for 50% correct numerosity judgments) increased from 2.4 to 9.5 as the SOA increased. Backward masking reduced the reported number of dots from the actual number in the test pattern, especially with small SOAs. Reaction time increased linearly at a low rate (approximately 40 msec/dot) up to 4 dots in the test pattern and then increased linearly at a high rate (approximately 370 msec/dot) as thereported, orperceived, number of dots increased. The two different branches of the reaction time curve were considered to represent two separate processes,subitizing andcounting, as suggested by Klahr (1973), who found similar dual increase rates as a function of the actual number of dots. These findings, as well as causal inference based on partial correlations and path analysis, indicated that the reported (perceived) number of dots and confidence rating were both determined by the number of stimulus dots and the SOA and that the reaction time was determined by the so-determined perceived number of dots and level of confidence. A multistage model is proposed.     

Relations among premorbid weight,referral weight,and psychological test scores for patients with anorexia nervosa

The purpose of this study was to test the hypothesis that, in anorexia nervosa, patients with a low premorbid weight are associated with a low weight at referral and that premorbid weight, referral weight, and weight loss are associated with mood states. The changes of Body Mass Index from premorbid to referral, the duration of illness, and the psychological scores on the Profile of Mood States and the Cornell Medical Index-Health Questionnaire were examined in 49 anorexia nervous patients. Body Mass Index at referral of patients with lower premorbid Body Mass Index was significantly lower than that of patients with higher premorbid level. For patients with a larger relative decrease, scores on depressive mood were lower. These findings suggested that in anorexia nervosa patients, lower premorbid Body Mass Index was associated with lower Body Mass Index at referral, and that the patients with higher relative decrease in Body Mass Index might be satisfied with their weight loss.     

Effects of voluntary activation on neuromuscular endurance analyzed by surface electromyography

The purpose was to examine the relation between voluntary muscle activation and neuromuscular endurance of individual subjects based on the pattern of surface electromyography (EMG). The voluntary muscle activation was estimated from the relation between voluntary force and tetanic force superimposed on the voluntary force (twitch interpolation technique). 14 male subjects (10 regular exercisers and 4 sedentary; 21-29 years old) were divided into a High Voluntary Activation group and a Low Voluntary Activation group. A significant positive correlation of .72 (p<.01) was found between maximum voluntary torque and voluntary activation. A fatigue test was conducted during isometric contractions of 60% and 20% maximum voluntary torque. The endurance time was significantly longer for the Low Voluntary Activation group than the High Voluntary Activation group. The mean power frequency of voluntary EMG obtained from the vastus lateralis muscle decreased consistently whereas the average rectified value increased. The final change of mean power frequency relative to the initial value was significantly greater in the 60% Fatigue task than in the 20% Fatigue task. For the 60% Fatigue task, the final change of mean power frequency and average rectified value relative to the initial value was significantly greater in the Low Voluntary Activation group than in the High Voluntary Activation group. These results suggest that the individual differences in voluntary activation determine the neuromuscular performance usually evaluated as maximum voluntary torque and endurance time and that the voluntary activation may depend on the daily exercise.     

Reading words with jumbled characters in Japanese

Rayner, et al. (2006) was replicated with 36 Japanese undergraduates who read Japanese sentences in which characters were transposed in one word at the beginning, middle, or end. The same pattern of reading delays in relation to transposition location was found but in smaller magnitude. Transposition of characters at the beginning of words caused the largest delay in reading.