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.     

Monocular without stereopsis with and head movement

Random dots moving with various velocity gradients were presented to observers; the motion was yoked to head movement in one condition and to no head movement in another. In Experiment 1, 12 observers were shown motion gradients with sine, triangle, sawtooth, and square waveforms with amplitudes (equivalent disparities) of 12′ and 1° 53′. In Experiment 2, 48 observers were shown only the sinewave or square-wave gradient of 1° 53′ disparity either with or without head movement so that the observers’ expectation to see depth in one condition did not transfer to another. The main findings were: (1) with 12′ disparity, the head-movement condition produced perceived depth but almost no perceived motion, whereas the no-head-movement condition produced both perceived depth and perceived motion; (2) with 1° 53′ disparity, both conditions produced perceived depth and perceived motion; and (3) when the expectation to see depth was removed, the no-head-movement condition with the square-wave gradient produced no perceived depth, only motion. We suggest that monocular stereopsis with head movement can be achieved without perception of motion but monocular stereopsis without head movement requires perception of motion.     

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.     

A marginalization model for the multidimensional unfolding analysis of ranking data

A marginalization model for the multidimensional unfolding analysis of ranking data is presented. A subject samples one of a number of random points that are multivariate normally distributed. The subject perceives the distances from the point to all the stimulus points fixed in the same multidimensional space. The distances are error perturbed in this perception process. He/she produces a ranking dependent on these error-perturbed distances. The marginal probability of a ranking is obtained according to this ranking model and by integrating out the subject (ideal point) parameters, assuming the above distribution. One advantage of the model is that the individual differences are captured using the posterior probabilities of subject points. Three sets of ranking data are analyzed by the model.     

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.     

Fixation disengagement and eye-movement latency

We examined eye-movement latencies to a target that appeared during visual fixation of a stationary stimulus, a moving stimulus, or an extrafoveal stimulus. The stimulus at fixation was turned off either before target onset (gap condition) or after target onset (overlap condition). Consistent with previous research, saccadic latencies were shorter in gap conditions than they were in overlap conditions (the gap effect). In Experiment 1, a gap effect was observed for vergence eye movements. In Experiment 2, a gap effect was observed for saccades directed at a target that appeared during visual pursuit of a moving stimulus. In Experiment 3, a gap effect was observed for saccades directed at a target that appeared during extrafoveal fixation. The present results extend reports of the gap effect for saccadic shifts during visual fixation to (a) vergence shifts during visual fixation, (b) saccadic shifts during smooth visual pursuit, and (c) saccadic shifts during extrafoveal fixation. The present findings are discussed with respect to the incompatible goals of fixation-locking and fixation-shifting oculomotor responses.     

Effectiveness of word order and grammatical marker as syntactic indicators of semantic relations

The effectiveness of word order and grammatical markers as syntactic indicators of semantic relations was explored using an artificial linguistic system. The results showed: (1) semantic interpretation of novel sentences was possible not only for Ss given fixed word order sentences with or without the markers, but also for Ss given the markers in random word order sentences; (2) Ss given neither indicator showed chance performance; (3) word order tended to be more efficient than grammatical markers as clues to semantic relations. The results suggest that the critical condition for language acquisition is the constant covariation of linguistic structure with semantic contexts. A process approach is discussed in accounting for the findings.Half of the data of the present experiment (FP and FA) were collected by Miss Norie Wake for her BA thesis, Okayama University (1978). The other half (RP and RA) were collected by the three juniors for their advanced course of experimental psychology, Okayama University (1979).     

Temporal course of activation of the antecedent by the reflexive in syntactically ambiguous sentences in Japanese

Three experiments examined the temporal course of the activation of an antecedent triggered by a reflexive,jibun, in syntactically ambiguous sentences in Japanese. Twenty-two students in Experiment 1 were tested for sentences where a subject word occupied the first position and an indirect object word the second, with the probe given for each word either immediately after the reflexive or at the end of the sentence. Reaction times (RTs) were faster when the probe was for subject (S-probe) than when it was for indirect object (IO-probe) irrespective of the probe position. Experiment 2 tested 22 students to determine the effect of order of mention of participant on the probe recognition time. RTs were faster for the S-probe than for the IO-probe, although the difference between the two probes was smaller when the probe was given immediately after the reflexive. Experiment 3 tested 22 students to examine the effect of context on an activation pattern. RTs were lower for the S-probe than for the IO-probe, though no difference was found between them for the probe given at the end of the sentence. Findings were interpreted as supporting the single-interpretation model for on-line analysis of syntactically ambiguous sentences and also the immediate-activation model in an assignment of the reflexive to its antecedent.     

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.