中国早期放射科的建制化初探——以北大医院放射科为例

基于文献回溯与口述访谈,勾勒了北京大学第一医院放射科从1922年建科到1980年中期的发展历程.通过回顾该科室人事变迁、设备更新、科研及学术活动各方面的演进,展现了人-机依赖型临床医学科室的建制化路径及放射学技术的发展特色,反映了科室的技术价值积淀.     

An evaluation of the effects of supplemental “fluency” training during maintenance

The voice onset time (VOT) of two groups of treated stutterers and a normal-speaking group was assessed by spectrographic analysis. Both groups of stutterers had significantly slower VOT than the normal speakers. The experimental group of stutterers was given 8 wk of “fluency” training designed to remediate characteristics of speech identified as related to “tenuous” fluency. The control group of stutterers received ongoing maintenance therapy. Posttreatment VOT was assessed. The experimental stuttering group had significantly decreased their VOT in the direction of the normal-speaking group, whereas the control group of stutterers had a greater VOT between pre- and posttreatment. The implication of these results for the maintenance of fluency are discussed.     

Lexical knowledge in anterior and posterior aphasics

A semantic categorization task was used to assess the structure of lexical knowledge in anterior and posterior aphasics. In general responses were faster for typical category members than for atypical ones and slower for semantically related nonmembers than for unrelated ones. Both groups performed at a high level of accuracy when classifying typical category members and semantically unrelated nonmembers. Their performance diverged at the category boundary. Anterior aphasics maintained relatively high levels of accuracy when classifying atypical category members and semantically related nonmembers while posterior aphasics did not. These results point to differences in the status of lexical knowledge for anterior and posterior aphasics.     

Effects of induced elation-depression on the accessibility of memories of happy and unhappy experiences

Elated and depressed moods were induced in student volunteers on separate occasions. On each occasion they retrieved past real-life experiences associated to stimulus words presented. Subjects subsequently rated the experiences for happiness-unhappiness and pleasantness-unpleasantness on a third occasion in a neutral mood state. Extremely unhappy memories were significantly more likely to be retrieved in the depressed mood than in the elated mood. Extremely happy memories were significantly more likely to be retrieved in the elated mood than in the depressed mood. Measures of latency of retrieval showed a significant interaction between mood state and type of memory. The results confirm the generality of previous findings in suggesting an effect of mood state on the accessibility of different types of cognition. The results are considered in relation to mood as a context in contextual-specific encoding and retrieval, and in relation to models and treatment of clinical conditions.     

Visual problem solving in the absence of lexical semantics: Evidence from dementia

A case of dissociation between visual and praxic skills and linguistic, referential, and semantic skills is described in a case of dementia. Testing revealed that her visual processing was intact and that she was capable of a wide range of visually based tasks. These included copying geometric figures and block designs; matching items on the basis of number, color, or relative size, matching upper and lower case letters, sequencing numerals, orienting pictures, coins, and letters appropriately, and solving problems based on the identification of geometric patterns or on the identification of logical sequences based on pattern alternation, number, and size increases. In contrast, she was completely incapable of matching pictures on the basis of their semantic or referential meaning; similarly she had lost all comprehension of language. It was argued that this case demonstrates the capacities of a visual system cut off from all symbolic and semantic processes. When examined with other case studies this case provides information about the nature of and interaction between modality-specific perceptual processing and semantic processing, and information about the various cognitive factors involved in visual gnosis. The CT scan indicated frontal atrophy and marked anterior temporal atrophy, a pattern that is consistent with Pick's disease. The case was discussed in terms of the correlation between the pattern of observed strengths and deficits and the neurological pattern of atrophy.     

Probability learning and coping in dysphoria and obsessive-compulsive tendencies

The processing of stress-relevant categorical events and their contributions to subsequent probability judgments were examined among subjects who were psychometrically categorized as dysphoric, obsessive-compulsive, or “control.” stress-relevant symptomatology of depression was considered to be characterized by a deficit of active counterstress coping activity and obsessive-compulsiveness by ritualistic efforts which have little or no direct effect on stress occurrence. Subjects were presented with a sequence of stressful (loud white noise) and benign (illumination of a green light) events in association with a series of discrete stimuli (alphabetic letters) in three conditions of counterstress activity. Results generally supported the predicted tendency to learn probability information primarily in conditions which reflected the subjects' characteristic ways of responding to stress. Obsessive-compulsives acquired the information primarily in a “ritualistic” context, controls in an active coping context, and dysphorics in both a coping deficit context and unexpectedly in an active coping context. The role of enhanced stressor predicability in maintaining typical stress response patterns of the three groups was discussed.     

Effects of eye movements on the recognition and localization of dichotic stimuli

Three experiments examined the effect of gaze shifts on overall performance and ear differences in dichotic listening. In the first two experiments, lights were switched on and off so as to induce rightward, leftward, or upward gaze during dichotic stimulation. The dichotic material consisted of musical passages in Experiment 1 and two kinds of verbal material in Experiment 2. Vertical eye movements enhanced the accuracy of identification of music but not verbal material. The lateral direction of eye movements affected subjects' ability to localize targets in Experiment 1: localization was more accurate in the direction toward which subjects were looking. In the third experiment it was found that optokinetic nystagmus (OKN) influenced the asymmetry of performance on a dichotic consonant-vowel (CV) test. The right-ear advantage was greatest when the OKN drum rotated from left to right and least when it rotated from right to left. The effect was due to corresponding variation in left-ear scores. Possible mechanisms through which shifts of gaze affect auditory identification and localization are proposed.