A quantitative model for designing keyboard layout

This study analyzed the quantitative relationship between keytapping times and ergonomic principles in typewriting skills. Keytapping times and key-operating characteristics of a female subject typing on the Qwerty and Dvorak keyboards for six weeks each were collected and analyzed. The results showed that characteristics of the typed material and the movements of hands and fingers were significantly related to keytapping times. The most significant factors affecting keytapping times were association frequency between letters, consecutive use of the same hand or finger, and the finger used. A regression equation for relating keytapping times to ergonomic principles was fitted to the data. Finally, a protocol for design of computerized keyboard layout based on the regression equation was proposed.     

Individual differences in the hemispheric specialization of dual route variables

The dual route model suggests that reading of letter strings can occur through both a lexical and a nonlexical route. Hemispheric specialization of these routes has also been posited, suggesting that the left hemisphere has both lexical and nonlexical routes while the right hemisphere has only a lexical route. However, some recent data conflict with this hemispheric dual route model, suggesting that both hemispheres may have access to both routes. The purpose of the present study was to investigate individual differences in the hemispheric specialization of these routes and to determine whether these group differences in their specialization might explain conflicts in the literature. The effect of four individual difference factors was explored: handedness, biological sex, menstrual stage (i.e., fluctuations in estrogen), and self-rated degree of masculinity (i.e., sexual attribution). We looked at the interaction of these individual differences with the following dual route variables: (i) string length, (ii) word frequency, (iii) regularity of grapheme-phoneme correspondences of words, and (iv) the interaction of frequency and regularity using a bilateral lexical decision task. We observed that sex, menstrual stage, and masculinity each affected hemispheric specialization of the dual route variables, but did so in different ways. We posit that both hemispheres have orthographical (lexical) access as well as phonological (nonlexical) access to words. Further, we suggest that the presence of phonological processing in the right hemisphere depends on available resources and the strategies used, which are subject to individual differences.     

A passion of the soul: an introduction to pain for consciousness researchers

Pain is an important focus for consciousness research because it is an avenue for exploring somatic awareness, emotion, and the genesis of subjectivity. In principle, pain is awareness of tissue trauma, but pain can occur in the absence of identifiable injury, and sometimes substantive tissue injury produces no pain. The purpose of this paper is to help bridge pain research and consciousness studies. It reviews the basic sensory neurophysiology associated with tissue injury, including transduction, transmission, modulation, and central representation. In addition, it highlights the central mechanisms for the emotional aspects of pain, demonstrating the physiological link between tissue trauma and mechanisms of emotional arousal. Finally, we discuss several current issues in the field of pain research that bear on central issues in consciousness studies, such as sickness and sense of self.     

Mothers' adjustment to the birth of a second child: a longitudinal study on use of verbal and nonverbal behaviors toward two children

4 mothers' skillful use of verbal and nonverbal behaviors to their first and second children was examined while each mother was playing with them for about one year after the birth of the second child. Analysis showed that maternal verbal interactions with the firstborn were frequently accompanied by nonverbal interactions toward the secondborn, especially during the first few months postpartum. The concurrent use of verbal and nonverbal behaviors with the two children may be a behavioral strategy for the mother to adjust to the birth of the second child.     

Effect of practice in bilateral and unilateral reaction-time tasks

The effects of practice on bilateral and unilateral reaction times (RTs) for thumb flexion tasks were investigated. Four female and 23 male students were divided into 4 groups who practiced a task under a single condition: unilateral (with either the right or left hand), bilateral, or control. Unilateral and bilateral groups practiced 20 trials 3 days a week for 6 weeks. For the left hand, the RT shortened following practice in the Unilateral-left and Bilateral groups; however, the interaction of the practice group by task was not significant. For the right hand, the RT shortened following practice, but neither the interactions of the practice group by task nor the practice group by measurement time were significant. The changes in the bilateral RTs with practice were significantly correlated with the change of the unilateral-left RT but were not significantly correlated with the change of the unilateral-right RT. As a result, no significant change in bilateral deficit was found. There was no lateral specificity in the effect of practice on RT.     

Comprehension regularity in Broca's aphasia? There's more of it than you ever imagined.

We analyze the comprehension data in Broca's aphasia, pooled together by Berndt, Mitchum, and Haendinges (1996). We show that once analyzed properly, these data have statistical structure that is very similar to that revealed by the analysis in Grodzinsky, Pinango, Zurif, and Drai (1999). The suggestion that the latter authors doctored the data to obtain a desired outcome is as false as the claim that the data in Berndt et al. show no regularity. Comprehension scores in Broca's aphasia do have statistical structure, which correlates with syntactic structure. Thus, the role of Broca's area and its vicinity in language processing can be made more precise.     

Ethnic characteristics of mental disorders in five U.S. communities

The study examined the ethnic ratio of 16 DSM-III mental disorders among White, Black, Hispanic, and Asian Americans. A total of 18,126 residents from 5 sites and 2,939 residents from the Epidemiological Catchment Area's Los Angeles site were studied separately. Logistic regression analysis was performed. Results showed that Blacks were significantly less likely than Whites to have major depressive episode, major depression, dysthymia, obsessive-compulsive disorder, drug and alcohol abuse or dependence, antisocial personality, and anorexia nervosa, but they were significantly more likely than Whites to have phobia and somatization. Lifetime prevalence rates of schizophrenia, obsessive-compulsive disorder, panic, and drug abuse or dependence were significantly lower among Hispanics than among Whites. Asians also had significantly lower rates than Whites of schizophreniform, manic episode, bipolar disorder, panic, somatization, drug and alcohol abuse or dependence, and antisocial personality. Compared with the overall findings, ethnic differences at the Los Angeles site were lessened between Blacks and Whites, enhanced between Hispanics and Whites, and basically unchanged between Asians and Whites.     

Effects of attention on localization of stimuli in the visual field

Subjects localized a small letter that appeared inside one of three large circles that was either validly or invalidly cued. The results indicated that, although unattended stimuli were localized fairly accurately, attention still improved localization. Moreover, the results revealed a greater dispersion of localization responses along the horizontal axis and also showed that mislocalization of attended peripheral stimuli is biased toward the periphery.     

Sources of self-identity among Turkish adolescents

As part of the International Self-Identity Research Project, this study explored sources of identity among Turkish adolescents. The interview sample consisted of three male and three female high school students in Ankara, Turkey. The results indicated that social, familial, personal, physical, and moral-ethical dimensions contributed to adolescents' definitions of self, but to different degrees. Social and familial dimensions were very influential and were used as reference points for defining self in other areas. Physical and personal aspects of identity were also apparent, but were not as salient as social and familial dimensions. Patriotism and religion played a role in moral-ethical identity. Overall, self-identity influenced emotional state, cognitive and behavioral functioning, and social relations to a significant degree.