Does the philosophy of medicine exist? A commentary on Caplan

Caplan has argued that the philosophy of medicine does not exist. Although I will not deny the points he makes, I will argue that the philosophy of medicine has characteristics of a developing field with the potential to meet all of Caplan's criteria. The argument is based on Dewey's established views on logical development for a field of inquiry, as well as pointing out how other criteria Caplan imposes can be fulfilled.The U.S. Government right to retain a non-exclusive, royalty free licence in and to any copyright is acknowledged.     

VISUAL SCREENING: AN ALTERNATIVE METHOD FOR REDUCING STEREOTYPIC BEHAVIORS

Visual screening, a mildly aversive response suppression procedure, was evaluated across two studies for its effectiveness in reducing topographically similar and dissimilar stereotypic behaviors of four developmentally disabled children. In the first study, a multiple baseline design across subjects and behaviors was used to assess the effectiveness of the procedure as a treatment for reducing the visual and auditory self-stimulatory responses of two 9-yr-old mentally retarded and behaviorally disturbed children. A multiple baseline design across subjects was used in the second study to evaluate the effectiveness of visual screening as a treatment for reducing stereotypic fabric pulling and self-mutilative ear bending, respectively, of two 13-yr-old mentally retarded, autisticlike adolescents. Long-term follow-up data for both studies were reported. The results suggested that visual screening was an easily administered, effective, and exceptionally durable treatment procedure for controlling a variety of stereotypic behaviors commonly associated with the developmentally disabled.     

Stimulus control of schedule-induced activity in pigeons during multiple schedules

Stimulus control of schedule-induced general activity was demonstrated with pigeons using multiple schedules of response-independent food delivery. In Experiment 1, the introduction of food during a multiple variable-time 30-second variable-time 30-second schedule produced a tenfold increase in activity above the no-food baseline. Each pigeon developed stable differential activity rates during the components (correlated with red and green lights) of a multiple variable-time 30-second extinction schedule. Lengthening the extinction component from 1 to 7 minutes increased the rate differences and produced a reliable pattern of responding during S− (the stimulus correlated with extinction): Activity rate was high immediately following the change from S+ (the stimulus correlated with variable-time 30-second) to S−, then decreased abruptly and remained low throughout the middle of the interval, and subsequently showed a positively accelerated increase until the stimulus changed to S+. In Experiment 2, three pigeons were exposed to a mixed variable-time extinction schedule prior to a multiple variable-time extinction schedule. Auditory rather than visual stimuli were used to determine the generality of Experiment 1 results. The multiple- versus mixed-schedule results indicated that stimulus control of activity occurred for two of the birds, but rate differences between S+ and S− were much less than those demonstrated with visual stimuli. A direct comparison of visual and auditory stimulus control in Experiment 3 supported this conclusion. These parallels between the stimulus control of reinforced responding and that of schedule-induced activity suggest that the stimulus control of induced activity may be a factor in operant stimulus control.     

Useful Field of View and Other Neurocognitive Indicators of Crash Risk in Older Adults

Older adults represent a rapidly growing segment of the driving population. Although most older drivers are safe, research has shown that this group has more crashes per mile driven than most other age groups. The purpose of the present investigation was to examine the utility of a set of commonly used neuropsychological/cognitive tests in comparison to a newer measure of visual attention (Useful Field of View; UFOV®) in predicting state-recorded, at-fault crashes over the previous five years in a group of older adult drivers. Participants (N = 239) completed tests of mental status, visual attention, memory, and UFOV®. Results show that among all cognitive tests administered, UFOV® was most strongly related to crash involvement, with high levels of sensitivity (86.3%) and specificity (84.3%) at the standard cutoff score of 40% reduction. Practical implications for the assessment of crash risk are discussed.     

Negotiating the Reality of Visual Impairment: Hope, Coping, and Functional Ability

A consecutive sample of 63 adventitiously blinded American military veterans in a interdisciplinary inpatient rehabilitation program participated in this study examining the relation of hope to self-reported functional ability level. Scores from a modified oral administration of the Hope Scale and the Millon Behavioral Health Inventory basic coping styles were used as predictor variables to test regression-based models of mediation and moderation relations to functional ability level. Results support a mediating role for hope in the relation between a proactive sociable style and perceived level of functional ability.     

Chimpanzee gaze following in an object-choice task

Many primate species reliably track and follow the visual gaze of conspecifics and humans, even to locations above and behind the subject. However, it is not clear whether primates follow a human’s gaze to find hidden food under one of two containers in an object-choice task. In a series of experiments six adult female chimpanzees followed a human’s gaze (head and eye direction) to a distal location in space above and behind them, and checked back to the human’s face when they did not find anything interesting or unusual. This study also assessed whether these same subjects would also use the human’s gaze in an object-choice task with three types of occluders: barriers, tubes, and bowls. Barriers and tubes permitted the experimenter to see their contents (i.e., food) whereas bowls did not. Chimpanzees used the human’s gaze direction to choose the tube or barrier containing food but they did not use the human’s gaze to decide between bowls. Our findings allowed us to discard both simple orientation and understanding seeing-knowing in others as the explanations for gaze following in chimpanzees. However, they did not allow us to conclusively choose between orientation combined with foraging tendencies and understanding seeing in others. One interesting possibility raised by these results is that studies in which the human cannot see the reward at the time of subject choice may potentially be underestimating chimpanzees’ social knowledge. Received: 16 February 1998 / Accepted after revision: 5 July 1998     

学生的认知风格与教师的教学策略之间关系的研究

本研究对２５５名初二学生认知风格测验与教师教学策略调查结果表明,初中学生存在着认知风格差异,属场依存性学生多于场独立性学生,认知风格与性别差异之间并不存在显著差异,表明初中学生在认知风格方面是总体上的平衡性与发展上的不平衡性的统一,教师的教学策略与教学方法对学生信知风梧的形成和发展具有一定的影响教学上应采取与初中学生认知风各相适应的教学方式,以促进学习能力的提高。     

Reduced visual acuity is mirrored in low vision imagery

Research has examined the nature of visual imagery in normally sighted and blind subjects, but not in those with low vision. Findings with normally sighted subjects suggest that imagery involves primary visual areas of the brain. Since the plasticity of visual cortex appears to be limited in adulthood, we might expect imagery of those with adult-onset low vision to be relatively unaffected by these losses. But if visual imagery is based on recent and current experience, we would expect images of those with low vision to share some properties of impaired visual perception. We examined key parameters of mental images reported by normally sighted subjects, compared to those with early- and late-onset low vision, and with a group of subjects with restricted visual fields using an imagery questionnaire. We found evidence that those with reduced visual acuity report the imagery distances of objects to be closer than those with normal acuity and also depict objects in imagery with lower resolution than those with normal visual acuity. We also found that all low vision groups, like the normally sighted, image objects at a substantially greater distance than when asked to place them at a distance that ‘just fits’ their imagery field (overflow distance). All low vision groups, like the normally sighted, showed evidence of a limited visual field for imagery, but our group with restricted visual fields did not differ from the other groups in this respect. We conclude that imagery of those with low vision is similar to that of those with normal vision in being dependent on the size of objects or features being imaged, but that it also reflects their reduced visual acuity. We found no evidence for a dependence on imagery of age of onset or number of years of vision impairment.     

Categorization in infancy based on novelty and co-occurrence

Abstract categories (i.e., groups of objects that do not share perceptual features, such as food) abound in everyday situations. The present looking time study investigated whether infants are able to distinguish between two abstract categories (food and toys), and how this ability may extend beyond perceived information by manipulating object familiarity in several ways. Test trials displayed 1) the exact familiarized objects paired as they were during familiarization, 2) a cross-pairing of these same familiar objects, 3) novel objects in the same category as the familiarized items, or 4) novel objects in a different category. Compared to the most familiar test trial (i.e., Familiar Category, Familiar Objects, Familiar Pairings), infants looked longer to all other test trials. Although there was a linear increase in looking time with increased novelty of the test trials (i.e., Novel Category as the most novel test trial), the looking times did not differ significantly between the Novel Category and Familiar Category, Unfamiliar Objects trials. This study contributes to our understanding of how infants form object categories based on object familiarity, object co-occurrence, and information abstraction.