Stereospatial masking and aftereffect with normal and transformed random-dot patterns

Masking and aftereffect in the perception of binocular depth were studied using random-dot sterograms as adaptation and target stimuli. Detection of the target was impaired by prior adaptation only when the two stimuli differed in disparity by less than 2 minarc. The masking function was unaffected by uniocular enlargement and blurring within the adaptation stimulus, but masking was no longer selective to disparity when the elements seen by the two eyes were reversed in brightness. The stereoscopic depth aftereffect was also insensitive to uniocular enlargement and blurring, and could not be generated when there was brightness complementation within the adaptation stimulus. Both the masking and aftereffect data are interpreted as evidence that stereospatial detectors in human vision are insensitive to transforms that maintain luminance-spatial correlations in binocular input.     

The ethics of enforced medical treatment: the balance model

ABSTRACT When is it right to enforce medical treatment on a patient who is refusing that treatment? English law recognises two ethical principles as of paramount importance: the autonomy of the patient; and the consequences of not treating compared with treating. The law, by and large, operates these principles in succession. Thus, in the case of a patient refusing treatment, the law asks first, is the patient competent? Only if the answer is no, are the consequences considered. We criticise the position taken by English law and argue, first, that competence is a graded and not a binary concept, and secondly, that the two ethical principles should be applied not sequentially but at the same time. These two ideas form what we have called the balance model. This model could be used for an empirical study of individuals’ ethical beliefs, and in particular to test the hypothesis that the ethical beliefs of most individuals conform to the balance model rather than to the position taken by English law.     

Non-Informative Effects of Stimuli Functioning as Cues

The category of a first stimulus (S₁) serving as a cue may allow a subject to predict the category of a second stimulus (S₂). However, a cue may have effects on RT to S₂ that are independent of those derived from its intended role as a predictor. These non-informative effects of a cue may add to or subtract from the benefits associated with its predictive function. Two experiments demonstrate that when S₁ is in the same category as S₂ (as is frequently the case for valid cues in cueing experiments) but provides no information about S₂, RT is slower than when S₁ is in a different category from S₂. It is suggested that this category relation effect arises because inhibition of a response to S₁ is still present when S₂ arrives and that, in some cueing experiments, it may subtract from the RT benefits derived from the cue as a predictor of S₂. Also, RT to a visual but not to an auditory S₂ was faster after an auditory S₁ than after a visual S₁. It is argued that this modality combination effect is consistent with the view that auditory signals are more alerting than visual ones and that this is another factor to be taken into account in the design of cueing and other experiments.     

A device for concurrent bilateral measurement of outer eyelid closures in the rabbit

This paper describes a transducer that allows for the concurrent recording of outer eyelid closure on both the left and the right eyes of a rabbit. The device makes use of voltage induced across a current-carrying conductor when the conductor is exposed to a magnetic field perpendicular to its axis (the Hall effect). The transducer is relatively compact, inexpensive, and allows the animal to be loosely restrained.     

A Comparative Study of Knowledge of Changing Demographic Trends and the Importance of HRM Practices in Three European Countries

Recent changes in the demographic structures of industrialized nations pose a potentially serious threat to work organizations in terms of their ability to attract and retain high calibre personnel. Specifically, the number of young people in their late teens and early-to-mid twenties is on the decline at the present time, coupled with a long-term recession, thus posing a dilemma for organizations concerned to develop and maintain a viable workforce. This article reports the findings of a three-country comparative study, conducted in The Netherlands, France and the United Kingdom, designed to investigate the extent to which graduate employers are aware of current demographic trends in the labour market and what HRM policies they are instituting, given this context. The findings reveal considerable levels of ignorance across all three countries, suggesting that attempts by various Government bodies, employers' organizations, professional associations and academics to draw attention to the potentially serious consquences of inadequate planning and future skill provision have largely failed. The results indicate that many organizations are engaging in human resource strategies which are not well suited to meeting the challenges of the 1990s.     

An investigation of the gate control theory of pain using the experimental pain stimulus of potassium iontophoresis

This study investigated a prediction derived from gate control theory—that there would be a pulse of pain as a pain stimulus was being ramped off due to the rapidly transmitting, inhibitory large fiber activity falling away sooner at the spinal level than the excitatory activity of the slow-transmitting, small nociceptive afferents. A further prediction was that the more distant the peripheral stimulus was from the spine, the greater the pain pulse would be. Fourteen subjects had the pain stimulus of iontophoretically applied potassium ions (K⁺) applied to an upper and a lower site on the dominant arm. In a threshold detection task using the double random staircase method, subjects were asked to indicate whether they could detect a pulse of additional pain during this ramp-off phase. The average rate of stimulus ramp-off in order to detect a pain pulse was statistically greater for the upper-arm site (14.3 μg K⁺/sec) than for the lower-arm site (9.4 μg K⁺/sec). These results were consistent with gate control theory. Alternative explanations, including intrinsic differences in nociceptive responding for different dermatomes and anode break, were considered. It was concluded that the detection of a pain pulse during the ramping off of a peripheral pain stimulus potentially provides a quantitative measure of the spinal modulation of pain.     

Complementarity in relationships of couples affected by HIV

Psychological interventions with patients with HIV infection may affect the stability of the patient's relationship with others. Two clinical cases are described to illustrate this. Both the impact of AIDS on patients and their relationships, and the impact of psychological interventions on the index patient and others, should always be considered when HIV-infected patients are referred to psychiatrists and other mental health care workers.     

Sentential synonymity judgment

Despite the acknowledged theoretical importance of sentential synonymity, there has been little interest in the psychological mechanisms responsible for recognizing it. Here an attempt is made to explore ways in which specific models originally devised for other particular psycholinguistic tasks (e.g., sentence-picture verification, three-term series problems, syllogistic reasoning) can be generalized to synonymity judgment and ways in which recent psychosemantic theories can be made more specific to deal with this same paradigm. Differential predictions from these models are derived for a set of spatiotemporal bidimensional comparative synonym pairs (e.g., High before Low, First above Second), and an experiment to test these predictions is reported. It is argued that, although the results are consonant with predictions from one type of model, they do not favor it definitively. This is because models of this type do not detail how bidimensional comparatives can be parsed into the same propositional representation and because other models can be subjected to further post hoc modifications to account for the data. Finally, general problems arising from attempts to adapt existing models to new tasks are discussed.     

Can the Discretionary Nature of Certain Criteria Lead to Differential Prediction Across Cultural Groups?

We examined the conjecture that relations between constructs across cultures may be susceptible to cultural moderation where the performance of the criterion construct is discretionary. This hypothesis was investigated using the relationship between personality and three performance constructs, with samples from the United States and New Zealand, two ideologically distinct cultures with respect to achievement orientation. All hypotheses were supported by results of hierarchical moderated regression analyses using bias free measures, suggesting that considering whether construct behaviors are discretionary is important when considering the merit of generalizing research findings across cultures.