New lower and upper bounds for communality in factor analysis

We derive several relationships between communalities and the eigenvalues for ap ×p correlation matrix under the usual factor analysis model. For suitable choices ofj, _j (), where _j () is thej-th largest eigenvalue of , provides either a lower or an upper bound to the communalities for some of the variables. We show that for at least one variable, 1 - _p () improves on the use of squared mulitiple correlation coefficient as a lower bound.This research was done while the second author was at Tokyo Institute of Technology.     

A field study of step-up exercises with touch for elderly people

This study assessed step-up exercises appropriate for elderly persons (M age=70.7 yr., SD=7.0). The group did several exercises in 7 sessions per month (average participants per session was 14, SD=3). A 30-sec. chair-stand test (sit-to-stand), questionnaires on activities of daily living, and impressions of the exercises were examined. Activities of daily living were expected to differ on cluster analysis before and after exercise sessions. Each cluster was classified by basic and instrumental activities. The 30-sec. chair-stand test did not significantly improve. Subjects enjoyed doing exercises with touch. Appropriate exercises for elderly persons should promote activities of daily living. Functional movements with touch seem appropriate for maintaining physical fitness and social interaction.     

Relationship between vection and motion perception in depth

This study examined the effects of cues to motion in depth – namely, stereoscopic (i.e., changing-disparity cues and interocular velocity differences) and changing-size cues on forward and backward vection. We conducted four experiments in which participants viewed expanding or contracting optical flows with the addition of either or both cues. In Experiment 1, participants reported vection by pressing a button whenever they felt it. After each trial, they also rated the magnitude of the vection (from 0 to 100). In Experiments 2 and 3, the participants rated the perceived velocity and motion-in-depth impression of the flows relative to standard stimuli, respectively. In Experiment 4, the participants rated the perceived depth and distance of the display. We observed enhancements in vection, motion-in-depth impression, and perceived depth and distance when either or both types of cues indicated motion-in-depth, as compared to those when the cues did not (Experiments 1, 3, and 4). The perceived velocity changed with cue conditions only for the high velocity condition (Experiment 2). Correlational analyses showed that the vection can be best explained by the motion-in-depth impression. This was partially supported by the multiple regression analyses. These results indicate that the enhancement of vection caused by cues is related to the impression of motion-in-depth rather than the perceived velocity and perceived three-dimensionality.     

Slow movement execution in event-related potentials (P300)

We examined whether slow movement execution has an effect on cognitive and information processing by measuring the P300 component. 8 subjects performed a continuous slow forearm rotational movement using 2 task speeds. Slow (a 30-50% decrease from the subject's Preferred speed) and Very Slow (a 60-80% decrease). The mean coefficient of variation for rotation speed under Very Slow was higher than that under Slow, showing that the subjects found it difficult to perform the Very Slow task smoothly. The EEG score of alpha-1 (8-10 Hz) under Slow Condition was increased significantly more than under the Preferred Condition; however, the increase under Very Slow was small when compared with Preferred. After performing the task. P300 latency under Very Slow increased significantly as compared to that at pretask. Further, P300 amplitude decreased tinder both speed conditions when compared to that at pretask, and a significant decrease was seen under the Slow Condition at Fz, whereas the decrease under the Very Slow Condition was small. These differences indicated that a more complicated neural composition and an increase in subjects' attention might have been involved when the task was performed under the Very Slow Condition. We concluded that slow movement execution may have an influence on cognitive function and may depend on the percentage of decrease from the Preferred speed of the individual.     

Cross-cultural comparison of ADHD symptoms among Japanese and US university students

Problems related to attention, hyperactivity, and impulsiveness are known to impact social, academic, and vocational success. When the problems begin in childhood and lead to impaired functioning, the syndrome is identified as attention-deficit/hyperactivity disorder (ADHD). Symptoms of the syndrome persist into adolescence and adulthood for many individuals, but less is known about characteristics of adults compared to children, especially adults attending university. Furthermore, there is little cross-national and cross-cultural research. This study compared DSM-IV-TR ADHD symptoms of US university students (N=271) to Japanese peers (N=712). Comparison of group means on a DSM-IV-TR-based checklist indicated that Japanese students reported more problems with inattention (and overall ADHD symptoms) but not hyperactive-impulsive symptoms. Although differences were statistically significant, effect sizes were small, indicating that for practical purposes, the students reported similar levels of symptoms. Japanese students reported higher rates of meeting or exceeding symptom counts that comprise diagnostic criteria for ADHD, but differences were quite small. Using DSM-IV-TR thresholds, 5.70% of US students and 6.27% of Japanese students reported enough symptoms to meet the cut-off for inattentive, hyperactive/impulsive, or combined type during childhood. With regard to recent problems, 2.66% of US students and 4.52% of Japanese students reported enough symptoms to meet the cut-off for one of the three subtypes. Comparisons using other methods of calculating rates are also provided. This research adds to the limited knowledge of ADHD symptoms in university students across countries and it supports the view that ADHD is not merely a cultural construct. This study is among the first to identify potential attention problems in Japanese university students.     

A generalized method of image analysis from an intercorrelation matrix which may be singular

Following the works of Guttman (1953) and Kaiser (1976), we show that the image and anti-image covariance matrices can be derived from a singular correlation matrix, by making use of the orthogonal projector and a weaker generalized inverse matrix.     

Retrograde amnesia in patients with hippocampal, medial temporal, temporal lobe, or frontal pathology

There is considerable controversy concerning the theoretical basis of retrograde amnesia (R.A.). In the present paper, we compare medial temporal, medial plus lateral temporal, and frontal lesion patients on a new autobiographical memory task and measures of the more semantic aspects of memory (famous faces and news events). Only those patients with damage extending beyond the medial temporal cortex into the lateral temporal regions showed severe impairment on free recall remote memory tasks, and this held for both the autobiographical and the more semantic memory tests. However, on t-test analysis, the medial temporal group was impaired in retrieving recent autobiographical memories. Within the medial temporal group, those patients who had combined hippocampal and parahippocampal atrophy (H+) on quantified MRI performed somewhat worse on the semantic tasks than those with atrophy confined to the hippocampi (H-), but scores were very similar on autobiographical episodic recall. Correlational analyses with regional MRI volumes showed that lateral temporal volume was correlated significantly with performance on all three retrograde amnesia tests. The findings are discussed in terms of consolidation, reconsolidation, and multiple trace theory: We suggest that a widely distributed network of regions underlies the retrieval of past memories, and that the extent of lateral temporal damage appears to be critical to the emergence of a severe remote memory impairment.     

Human figure drawing size and body image in preschool children from a self-physique perspective

To learn about the relationship between size of human figure drawings and the physiques of children, we investigated body image characteristics in childhood by using the Human Figure Drawing test. Height, weight, Kaup Index (a body mass index for children) and Human Figure Drawing traits (vertical height, horizontal width, waist size, surface area of head, surface area of the self-drawing) were measured for drawings of 122 4- to 6-yr.-old children (62 boys, 60 girls). Analysis showed that boys, who are physically larger than girls, produced self-drawings with somewhat larger surface areas. For vertical height of self-drawings of boys, 4-yr.-olds characteristically made taller self-drawings than 5-yr.-olds. While we hypothesized that taller children would make vertically taller self-drawings, we observed a negative relationship between children's physical height and the vertical height of the self-drawings. 4-yr.-old boys showed the most interest in their own physical height, making taller drawings and in doing so gave a clue to an early childhood feature of body image.     

Effect of slow movement execution on cognitive function

We investigated the effect of slow paced movement on cognitive function. The task movement was a dual-task performance composed of a continuous forearm rotation for the right hand and a simple reaction task for the left hand. Exp. 1 was designed to compare reaction time during performance at a slow pace to that at medium pace by 14 female undergraduate students. The mean reaction time for the left hand under the Slow Pace was significantly longer than that under the Middle Pace condition (p < .05), which showed that the subjects were required to give more attention to right-hand performance at the slow pace as it was difficult. Exp. 2 examined changes in reaction time when using the left hand that were associated with the learning of a slow paced task while using the right hand. Twenty-three female undergraduate students participated and repeated the task 6 times. The 3 sec. prior to and the 3 sec. after each auditory stimulus were used to establish rotation speed and mean coefficients of variation. The mean coefficients of variation, evaluated as within-subject variability, showed a significantly positive correlation with reaction time at Trials 1 and 6 for prestimulus and Trials 5 and 6 for poststimulus. Over successive trials participants continued performing the primary forearm task at a constant slow pace before and after receiving auditory stimuli, and this progress was related to a decrease in reaction time. Further, the sense of concentration evaluated by the subjects poststimulus was significantly higher than that prestimulus (p < .01). Performance at a constant speed, which was much slower than the ordinary or preferred speed of each subject, may have had a strong effect on their ability to remain conscious of movement execution.