Variability of response location on fixed-ratio and fixed-interval schedules of reinforcement

Variability of response location was studied in monkeys performing in a six-lever chamber. Fixed-ratio schedules, ranging from FR 1 to FR 300, generated a high degree of stereotypy of response location. In contrast, fixed-interval schedules of comparable reinforcement frequencies (0.06 to 4 minutes) generated much greater variability. These results failed to confirm any simple relationship between response variability and intermittence of reinforcement. Rather, variability seems to be determined by the particular characteristics of the reinforcement schedule.     

Psychiatric hospitalization after deliberate self-poisoning

The decision for psychiatric hospitalization after deliberate self-poisoning (DSP) is not well understood. This study, a longitudinal cohort study of 3,148 consecutive DSP patients found 920 (29.2%) subjects were referred for psychiatric hospitalization, 576 (18.3%) on involuntary basis. A logistic regression analysis showed increased risk for: age 25 or older, homelessness, unemployment, previous self-harm, psychiatric inpatient treatment within 12 months, earlier psychiatric inpatient treatment, suicidal ideation or plan, mood or psychotic disorders, and lower clinician experience; and lower risk for being married/defacto, and after hours presentation. Recommendation for psychiatric hospitalization was based on complex decision making. These findings have implications for clinical practice guidelines, service costs, and service organization.     

Ambiguity and explanation

This paper presents evidence that ‘because’ is importantly ambiguous between two closely related senses covering what are usually called causal explanations, on the one hand, and grounding or metaphysical explanations, on the other hand. To this end, it introduces the lexical categories of monosemy, polysemy and homonymy; describes a test for polysemy; and discusses the results of the test when applied to ‘because’. It also shows how to understand so-called hybrid explanations in light of the semantic facts established by the analysis.     

The Influence of a Manager's Own Performance Appraisal on the Evaluation of Others

This study examined the possibility that the performance appraisal process is affected by a pervasive and inherent effect that has heretofore been unidentified. This effect derives from the results of the performance appraisal most recently performed on the manager who subsequently conducts appraisals of others. The nature of this effect was examined in four studies. In a case study, the ratings received by two area coordinators in a university academic department affected their subsequent ratings of faculty. In a simulation, 30 managers received hypothetical feedback regarding their own job performance. The managers subsequently evaluated an employee on videotape. Managers who received positive feedback about their performance subsequently rated the employee significantly higher than managers who received negative feedback regarding their own performance. This occurred despite the fact that the managers knew the evaluation of them was bogus. The results of two follow‐up field studies involving 74 manager–employee dyads in a manufacturing company in Canada and 39 manager–subordinate dyads in a retail organization in Turkey are consistent with the view that one's own performance appraisal is related to the subsequent appraisal of one's subordinates. Both anchoring with insufficient adjustment and a mood induction may explain this effect, but the results are more consistent with the former explanation than the latter.     

Time for a unified approach to medical ethics

A code of ethics is used by individuals to justify their actions within an environment. Medical professionals require a keen understanding of specific ethical codes due to the potential consequences of their actions. Over the past thirty years there has been an increase in the scope and depth of ethics instruction in the medical profession; however the teaching of these codes is still highly variable. This inconsistency in implementation is problematic both for the medical practitioner and for the patient; without standardized training, neither party can be assured of the practitioner's overall depth of knowledge. Within the field of ethics certain principles have reached a consensus of importance. Incorporation of these concepts in meaningful ways via a consistent curriculum would provide students with an appropriate skill set for navigating their ethical environment. Moreover, this curriculum should also be extended to residents and professionals who may have missed formal ethical training. This would provide a consistent framework of knowledge for practitioners, creating a basis for clear judgment of complex issues.     

An assessment of response, direction and place learning by rats in a water T-maze

Behavioral data suggest that distinguishable orientations may be necessary for place learning even when distal cues define different start points in the room and a unique goal location. We examined whether changes in orientation are also important in place learning and navigation in a water T-maze. In Experiment 1, rats were trained to locate a hidden platform and given a no-platform probe trial after 16 and 64 trials with the maze moved to a new position. Direction and response strategies were more prevalent than a place strategy. In Experiment 2, acquisition of place, response and direction strategies was assessed in a water T-maze that was moved between two locations during training. Rats were impaired on the place task when the maze was translated (moved to the L or R) but were successful when the maze was rotated across trials. These data are consistent with findings from appetitive tasks.     

The psycho‐physical laws of intentionality

Intentional mental states have causes and effects. Davidson has shown that this fact alone does not entail the existence of psycho‐physical laws, but his anomalism makes the connection between the content and causation of intentional states utterly mysterious. By defining intentional states in terms of their causes and effects, functionalism promises to explain this connection. If intentional states have their causes and effects in virtue of their contents, then there must be intrinsic states (of the people who have them) which are ‘local causal surrogates’ for the propositions believed, desired, or whatever. We can define these intrinsic states in terms of the laws that govern them, but these laws alone are not sufficient to account for intentional content. To do that we need to invoke laws which link these intrinsic states with their contents. Such a ‘wide’ functional account is sketched; it combines a suggestion of Ramsey's about truth conditions with a ‘feedback’ account of the content of desires.