Effect of reaction time condition on EMG activities of the biceps brachii muscle in elbow flexion and forearm supination

Under simple- and choice-RT conditions, the biceps brachii muscle was examined in 8 healthy male subjects to determine how the temporal and spatial characteristics of elbow flexion and forearm supination differed at the initial phase of EMG activity and whether preparation or the presence of response uncertainty influenced the EMG outputs of the two movements. In the simple-RT condition, RT of supination was significantly faster than that of flexion but EMG activity of supination was less than that of flexion. In contrast, in the choice-RT condition, RT of flexion was significantly faster than that of supination but EMG activity of flexion was significantly reduced compared to supination. These findings indicate that advanced preparation or motor set facilitates the differentiation of RTs and EMG activities of the response movements and that response uncertainty causes a significant change in the temporal and spatial specificity of both elbow flexion and forearm supination.     

Structural connectivity between the hippocampus and cortical/subcortical area relates to cognitive impairment in schizophrenia but not in mood disorders

Cognitive impairment in schizophrenia and other psychiatric disorders is a challenge to be overcome in order to maintain patients' quality of life and social function. The neurological pathogenesis of cognitive impairment requires further elucidation. In general, the hippocampus interacts between the cortical and subcortical areas for information processing and consolidation and has an important role in memory. We examined the relationship between structural connectivity of the hippocampus and cortical/subcortical areas and cognitive impairment in schizophrenia, major depressive disorder and bipolar disorder. Subjects comprised 21 healthy controls, 19 patients with schizophrenia, 20 patients with bipolar disorder and 18 patients with major depressive disorder. Diffusion-weighted tensor images data were processed using ProbtrackX2 to calculate the structural connectivity between the hippocampus and cortical/subcortical areas. Cognitive function was assessed using the Brief Assessment of Cognition in schizophrenia composite score. Hippocampal structural connectivity index was significantly correlated with composite score in the schizophrenia group but not in the healthy control, major depressive disorder or bipolar disorder groups. There were no statistically significant differences in hippocampal structural connectivity index between the four groups. Structural connectivity between the hippocampus and cortical/subcortical areas is suggested to be a pathophysiological mechanism of comprehensive cognitive impairment in schizophrenia.     

Visual information for categorizing facial expression of emotions

Two experiments were conducted to reveal the visual information from the face utilized for the categorization of its expression of emotions. In Experiment 1 the subjects produced six schematic faces expressing six basic emotions by using a computer graphics system. By a series of factor analyses on the variables of displacements of feature points for deforming a neutral schematic face to produce the six expressional ones, two factors of ‘curvedness/openness’ and ‘slantedness’ of facial elements were obtained. In Experiment 2 another group of subjects made category judgements of emotions for 72 of the total 216 schematic faces produced in Experiment 1. The relationship between the displacements of feature points in Experiment 1 and subjects' categorical responses in Experiment 2 were examined by canonical discriminant analysis. It was found that the categorical judgements were well explained by two canonical variables whose structures were quite similar to those of factors obtained in Experiment 1. These results indicated that we extract the information of changes in curvedness/openness and slantedness of facial elements among other information on the face for categorizing its expressions of emotions. Lastly, the relationship between the dimensions of visual information obtained here and those of semantic affective meanings found in earlier research was discussed.     

Accreditation Standards for University and College Counseling Centers

The accreditation standards outlined in the article are used by the International Association of Counseling Services, Inc., as the basis for the formal accreditation of college and university counseling programs throughout the United States and Canada. They reflect the program elements and practice standards that are deemed essential in a counseling center that provides high-quality services to students.     

The discrimination learning of the liquids /r/ and /l/ by Japanese speakers

The discrimination learning of the /r/ and /l/ sounds in a single 1-h session by Japanese college students who had received little or no English conversation training was examined. About half of the subjects exhibited significant improvement after this brief amount of training. A three-state Markov model with the unconditioned, intermediate, and conditioned states was applied as a first approximation of the learning of the liquid pairs, learning which is characterized as two-stage all-or-none conditioning. Also found in the study was a significant correlation between the ability to perceive the liquids and the ability to read English as assessed by a cloze procedure. This correlation is interreted in light of general theory on phoneme awareness.     

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.     

Instruction in reliability and magnitude of evaluation parameters at each phase of a sit-to-stand movement

The sit-to-stand movement strategy of each subject is different depending on whether the subjects perform voluntary movements or have concrete instructions (i.e., stand quickly), which is strongly reflected in the performance of each sit-to-stand movement phase. Thirty young-adult male subjects participated in this study (M age=20.7 yr; SD=2.6). Subjects performed the two movements from a chair height adjusted to the subject's lower thigh length. In the self-administered (SA) condition, subjects voluntarily stood up from the chair without instruction, and in the assigned-ordered (AO) condition subjects stood up from the chair as fast as possible. Vertical floor reaction force and electromyograms of the rectus femoris and tibialis anterior muscles were measured, and 15 parameters were selected. The parameters in the phase between the peak value of the floor reaction force and completion of the movement was highly reliable regardless of instruction. However, other parameters had different reliabilities between the instruction conditions. In particular, the parameters in the phase between starting the movement and the peak value of the floor reaction force under the assigned-order were higher than those of the self-administered condition. Moreover, the sit-to-stand movement was conducted faster in the assigned-order condition during the phase between starting the movement and buttocks-syneresis, and the peak value of the floor reaction force and completion of the movement. From the above, in the assigned-order condition "as fast as possible," the anteflexion bending movement and extension of knee and trunk joints were faster, and anteflexion movement was repeated more similarly under a concrete instruction such as moving as fast as possible.     

Involvement of BDNF receptor TrkB in spatial memory formation

The N-methyl-D-aspartate (NMDA) receptors are involved in long-term potentiation (LTP), and are phosphorylated by several tyrosine kinases including a Src-family tyrosine kinase Fyn. Brain-derived neurotrophic factor (BDNF) is a neurotrophin, which also enhances hippocampal synaptic transmission and efficacy by increasing NMDA receptor activity. Here, we show that Fyn is a key molecule linking the BDNF receptor TrkB with NMDA receptors, which play an important role in spatial memory formation in a radial arm maze. Spatial learning induced phosphorylation of TrkB, Fyn, and NR2B, but not NR2A, in the hippocampus. Fyn was coimmunoprecipitated with TrkB and NR2B, and this association was increased in well-trained rats compared with control animals. Continuous intracerebroventricular infusion of PP2, a tyrosine kinase inhibitor, in rats delayed memory acquisition in the radial arm maze, but PP2-treated animals reached the same level of learning as the controls. The phosphorylation of Fyn and NR2B, but not TrkB, was diminished by PP2 treatment. Our findings suggest the importance of interaction between BDNF/TrkB signaling and NMDA receptors for spatial memory in the hippocampus.     

The left superior longitudinal fasciculus within the primary sensory area of inferior parietal lobe plays a role in dysgraphia of kana omission within sentences

Functional neurological changes after surgery combined with diffusion tensor imaging (DTI) tractography can directly provide evidence of anatomical localization of brain function. Using these techniques, a patient with dysgraphia before surgery was analyzed at our hospital in 2011. The patient showed omission of kana within sentences before surgery, which improved after surgery. The brain tumor was relatively small and was located within the primary sensory area (S1) of the inferior parietal lobe (IPL). DTI tractography before surgery revealed compression of the branch of the superior longitudinal fasciculus (SLF) by the brain tumor. These results suggest that the left SLF within the S1 of IPL plays a role in the development of dysgraphia of kana omission within sentences.