A note on chaining and temporal discrimination

Four pigeons were exposed to a two-key DRL procedure. At the start of a trial, key A was illuminated. A response to the lighted key turned it off and simultaneously illuminated key B. Reinforcement was available for responses on key B which followed the initial key A response by more than 2 sec. In the course of exposure to these conditions, all birds acquired superstitious response chains on key A. The distribution of the number of responses on key A preceding a key B response and the distribution of intervals elapsing from the initial key A response to the key B response were of the same form. The suggestion is made that the superstitious responding on key A served to mediate the required delay interval. However, when intervals between successive key A responses were recorded for one subject, they were found to be regularly spaced in time. Thus, the problem remains of how this behavior is itself timed.     

Ideology,inquiry, and antiquity: a critical notice of Lloyd's The Ideals of Inquiry: An Ancient History

A discussion of Lloyd's Tarner Lectures at Trinity College. The importance of Lloyd's previous scholarship is characterized and these sweeping, erudite lectures are placed in the context of that scholarship. In the broadest terms, the lectures are a call to culturally and historically comparative study of human reasoning. At their heart is a comparative history of scientific theorizing from the ancients through to modern science. Lloyd rejects the positivist picture, and the view of modern and ancient science as discontinuous; he urges scholars to undertake comparative work on the ancient sciences in different traditions. This critical notice evaluates Lloyd's view and raises several questions for further reflection.     

Interest and liking: Further sequential effects

This study was designed to investigate subjects’ interest and liking preferences for stimuli varying in type and level of familiarity. Subjects were presented with stimulus material in the form of slides, and were asked to view the slides firstly without instruction, and then twice more in order to rate the material for interest and liking. Half the subjects were asked to rate liking before interest, and half rated interest before liking. Results showed that interest ratings were relatively unaffected by the rating sequence, whereas ratings of liking were affected: when ratings of likingpreceded interest ratings, familiar items were preferred to less familiar items, but when ratings of liking were madeafter interest ratings, ratings of liking for less familiar items were preferred to more familiar items. This study forms part of the work of the Leicester Aesthetics Research Group. The work was supported by a grant from the Research Board, University of Leicester.     

Components of dental fear in adults?

The functional relatedness between dental fear and multiple other fears was studied in a normative sample of 285 undergraduates. Rachman and Lopatka's work on the inter-dependence of multiple fears within individuals, as well as Lang's bioinformational theory of emotion, provided a theoretical background for this investigation. Fears about social contact, pain, mutilation (e.g. injury, blood, disfigurement), and being closed-in were assessed within the realm of verbal report; they were studied as possible components and/or concomitants of the dental fear construct. Multiple regression analyses with these variables utilized the Dental Fear Survey total score as a criterion variable. Fear of pain was found to be the most significant predictor of dental fear in both males and females. For females only, mutilation fear was the next strongest determinant. Fear of being closed-in was an additional significant dental fear predictor for both sexes. The possible role of social fears in the manifestation of dental fear was not confirmed and awaits further investigation. Results were consistent with the idea that there may often be a moderate degree of functional dependence between dental fear and the other fears identified here.     

Complexity and colour preferences in chicks of different ages

Five- and six-day old chicks were found to prefer a complex stimulus to a simple one, whilst 2-day old ones showed no such preference; but a red stimulus, whether simple or complex, tended to be preferred at both age levels when it was paired with a non-coloured complex stimulus. Preference for complexity may be usefully viewed in any species in the context of the behavioural development of the individual.     

Ratio reinforcement of matching behavior

Three pigeons, previously trained to a high level of accuracy on matching-to-sample procedures, were exposed to various schedules of ratio reinforcement for correct matches. Overall accuracy was lower on fixed ratio than on regular reinforcement. There was a high incidence of errors immediately after reinforcement on fixed ratio schedules with accuracy increasing as the ratio progressed. This increase was found to be inversely correlated with the latency of the observing response to the sample. By contrast, accuracy was high throughout the ratio on a variable ratio schedule.     

Interlocking schedules of reinforcement

Four male pigmented rats were exposed to a procedure designed to investigate the relation between several performance measures and a schedule continuum ranging from FR 36 to FI 2 through four intermediate interlocking schedules. On all schedules, each subject developed a stable performance that was generally break-and-run. Analysis of the cumulative records, post-S^R breaks, and running rates showed a continuum of performance related to the schedule continuum.