The effects of hand and direction parameter preknowledge on choice reaction times

The two studies undertaken investigated how reaction times are affected by preknowledge concerning hand and direction parameters, and the order in which these data are disclosed. In the first experiment, preknowledge was manipulated by selecting 2-CRT pairs which had either a common hand or direction component. Reaction signal information content (as defined by the number of unknown response parameters) was controlled, but no parameter differences emerged. When parameter order was manipulated by sequential precuing, the ‘hand then direction’ order conferred a significant advantage. Motor preparation and response selection explanations for this effect are considered. Various difficulties with the paradigms used are discussed, including those of distinguishing between response selection and motor programming contributions, controlling and inferring the strategies adopted by subjects, and defining task difficulty. The prospects for independently fostering either response identification or motor preparation by means of an appropriate selection of precues are also discussed.     

The component awareness and accuracy of dual- and single-jointed actions

The accuracy with which people execute wrist and elbow movements were measured using three main conditions: (i) single-jointed (wrist or elbow) movements to targets, (ii) dual-jointed (wrist and elbow) movements to targets, and (iii) components of dual-jointed movements to targets, when the task for the subject was to perform the elbow or wrist constituent of the action in isolation, without displacing the second joint. Elbow precision was significantly worse under component than dual conditions, which is compatible with the notion that wrist and elbow activity are conjugately, rather than independently, programmed when a dual-jointed action is performed. The pattern of wrist accuracy was divergent, but possible reasons for this were discussed. In all cases, error was measured in terms of deviation from perfect posture; using this index, the hypothesis that incorporating more moving joints into an action serves to increase movement complexity and jeopardise precision was tested, but the results were ambiguous. Discussion also centered on the problems of using performance data to infer changes in motor programming, and the need for rigorous conceptualisation and research in this area.     

Is preparation of responses precluded by choice reaction time testing?

Choice reaction times for short (Dit) and long (Dah) Morse key presses were measured using a number of different left hand/right hand Dit/Dah 2-response combinations. When Dit and Dah responses were made with the same hand, Dits were initiated significantly faster, which confirms the finding of Klapp et al. (1974). The absolute sizes of Dit and Dah CRT's, however, varied significantly from one test situation to another; and the Dit:Dah difference was shown to be intransitive. Such context effects cast doubt on the extrapolative power of CRT findings, and on the usefulness of CRT as a measure of movement complexity. Latencies were reduced when subjects knew in advance which hand would be used; but the usefulness of response duration pre-knowledge was not unambiguously demonstrated. Preparation of responses is, therefore, not precluded by CRT testing; and possible explanations for these savings in terms of response selection and motor preprogramming were discussed. On balance, the hypothesis that the longer reaction times of Dah responses are due to their greater movement complexity (Klapp et al. 1974) was rejected, in favour of the explanation that subjects adopt a strategy of preferentially preparing Dit responses.     

The choice reaction times of single and dual jointed actions

The choice reaction times of dual (elbow and wrist) and single (elbow) jointed movements were measured using ‘mixed’ (dual and single) and ‘matched’ (both dual or both single) response pairings. Although subjects found it more difficult to execute dual jointed actions (as shown by error rate), there was no concomitant prolongation of latencies for acceptable responses. In the light of these findings, the utility of CRT as an index of motor programming complexity, and the claim that pre-programming of responses is precluded with CRT testing, were discussed.     

论流行病学与医学创新

流行病学随医学的发展而发展,同时,它的发展对整个医学学科的发展也产生了重大的影响。从流行病学对医学思维、医学研究方法、医学模式及医学目的的实现等几个方面讨论了该学科在现代医学发展中的作用和地位。     

Training interpersonal skills among mentally retarded and socially dysfunctional children

Two moderately retarded boys, ages 11 and 12 yr, who resided in an inpatient unit for emotionally disturbed children, were treated for deficits in social skills. The deficits included physical gestures, facial mannerisms, eye contact, words spoken, and intonation and content of speech. The treatment package consisted of instructions, performance feedback, social reinforcement, modeling, and role-playing. The effects of the treatment in developing appropriate social performance were evaluated in separate multiple-baseline designs across behaviors for each child. The training improved social skills and brought children up to or beyond the level of normal control subjects who were the same age and gender.     

生存·发展·创新——对20世纪中医学发展道路的反思

为了中医学的生存和发展,中医药研究人员苦苦思索着中医学的本质,探索着中医学的现代化道路。目前中医学在研究思路和方法上仍存在一些问题,因此回顾和总结现代中医学及中西医结合医学的发展状况,有利于我们认清中医学的发展形势,发现其中存在的问题,寻求解决问题的方法。     

王吉民、伍连德的《中国医史》及其中译本

王吉民、伍连德撰写英文版<中国医史>的起因与美国医史学家嘉里逊的<医学史>一书有关.伍连德的信可能使嘉里逊对中国医学的看法有了改变.<中国医史>有未正式公开出版的中文译本,其翻译初衷是为了批判所用.     

Masculinity-femininity perceptions of job requirements and their relationship to job-sex stereotypes

Perceived sex appropriateness of the work situation is believed to constrain work opportunities, particularly for women. However, sex appropriateness may be defined either with respect to the entire job or with respect to the tasks which comprise the job. In this study sex appropriateness of job tasks was examined by obtaining subjective estimates of the masculinity-femininity of the job requirement dimensions defined by the Dictionary of Occupational Titles (DOT). Results indicate that interacting with things is perceived as masculine, interacting with people is perceived as feminine, and interacting with data is perceived as falling between the other two. There is less agreement on the masculinity-femininity of specific types of interactions with data, people, and things. Sex appropriateness of specific requirements was found to be only moderately associated with the DOT's assessment of the complexity of those requirements. Further, sex appropriateness of job requirements was not highly related to the job sextypes established by Shinar (Shinar, E. H. Journal of Vocational Behavior, 1975, 7, 99–110) and Krefting et al. (Krefting, L. A., Berger, P. K., and Wallace, M. J. Jr. Journal of Vocational Behavior, 1978, 13, 181–191). This suggests that sex appropriateness of a job and sex appropriateness of the tasks which comprise the job are distinct, separate concepts.     

Regional cerebral blood flow response during rest and memory activation in a patient with global amnesia

A college professor with a classical amnesic syndrome is described. He has a WAIS IQ of 130, but dramatic memory loss for episodes ranging from a few seconds ago all the way back to portions of his childhood. The amnesia was of sudden onset, 2 years prior to the current memory tests and regional cerebral blood flow measurements. The etiology is believed, though not conclusively proven, to be medial thalamic infarction. rCBF measurements were taken on six separate occasions, four resting baseline, one memory activation, using the previous procedure of Wood, Taylor, et al., and one carbon dioxide activation. The resting baseline showed extremely low flows throughout the cortex, with some hyperfrontal response on the first baseline. With CO₂ activation, however, there was brisk, uniform reactivity, with all sites showing increased flow. This suggested that there were no prominent areas of impaired vasomotor control or probable ischemic damage in the cortical surface. During memory activation, there was also a generalized increase in flow, especially in the frontal areas. This was in sharp contrast to the pattern for normals, described by Wood, Taylor, et al., which shows a slight overall decrease in flow from baseline to memory activation. The results are interpreted in light of Talland's proposal that the amnesic syndrome reflects an arousal failure, with premature closure and shutdown of memory processing, especially at retrieval. Here the arousal failure is interpreted as an inadequate restriction or focusing of cortical activation, with resulting pathologically diffuse flow increases.     

A sensory basis for the lateral difference in the newborn infant's response to somesthetic stimulation

To determine whether lateral differences in the newborn infant's response to somesthetic stimulation are a consequence of lateral differences in sensitivity or whether they are the result of lateral differences in motor tendencies, cardiac response to stimulation of the left and right perioral region was examined. Cardiac acceleration occurred significantly more frequently to stimulation of the right than to stimulation of the left. Ipsilateral head turning also occurred more reliably to stimulation of the infant's right side than to stimulation of his left side. Evidence of reliable lateral differences in cardiac acceleration responses even under conditions in which the effects of lateral differences in head turning were removed suggested that the laterally differentiated cardiac responsiveness was not merely a function of increased motor activity consequent upon stimulation of the infant's right side but reflected a difference in sensitivity at the infant's two sides as well.     

Gestural impairment and gestural ability in aphasia: A review

Studies of gestural ability in aphasic subjects have found impairment of gestural expression and comprehension, with a close relationship between severity of aphasia and degree of gestural impairment. A few investigators have correlated gestural ability with specific language functions or subcategories of aphasia. Reading appears to correlate better with gestural recognition than does auditory comprehension. Despite the general findings of gestural impairment in aphasia, successes have been reported with gestural training including artificial language techniques, pantomime, Amerind, and American Sign Language. Future studies of gestural therapy in aphasia should examine specific language deficits in order to identify those aphasic individuals who can benefit from gestural training.     

Stuttering onset after laryngectomy

Two cases of onset of stuttering subsequent to laryngectomy are reported. These patients demonstrate that the existence of a larynx is not necessary for the generation of stuttering. The findings support the hypothesis that neuromotor control of sound source (laryngeal or alaryngeal) plays a critical role in the generation of stuttering-type dysfluencies and, perhaps, even in the onset of stuttering. They also suggest that dramatic alteration in sound source has the potential for dramatically altering fluency.     

Effects of erotic stimuli on sexually functional and dysfunctional women: Multiple measures before and after sex therapy

A group of 11 women entering sex therapy for treatment of low arousal, and a comparison group of 11 women experiencing no arousal deficit, viewed an erotic film, listened to an erotic audiotape, and engaged in sexual fantasy during two experimental sessions. Session I occurred pre-treatment for the low arousal group. Session II occurred post-treatment. The adequate arousal group was tested at comparable points in time. Sexual arousal was measured subjectively by self-rating and physiologically by a vaginal photoplethysmograph. Contrary to expectation, the two groups showed equivalent significant increases in physiological response during the erotic stimuli in both sessions. However, the adequate arousal group rated subjective arousal significantly higher than the low arousal group in Session I, while no difference was found between the groups in Session II. Significant correlations were present between physiological response and ratings of several affective reactions to the audiotape, though few significant correlations were found between physiological and subjective sexual arousal measures. These data indicate a discrepancy between genital responses and ratings of sexual arousal for which several interpretations are offered.