Successive, simultaneous, and anticipatory contrast in the consumption of saccharin solutions

Contrast effects were obtained in rats in the consumption of saccharin solutions in three different paradigms. Degree of negative contrast varied as a function of concentration disparity, but not equally in the three procedures. Successive negative contrast occurred following shifts from 0.15% to either 0.075% or 0.05% saccharin but did not occur following shifts to 0.10% or 0.125% saccharin. Some degree of simultaneous contrast was obtained with all four concentration disparities. Anticipatory contrast, where the intake of the first substance is suppressed by a more preferred second substance, occurred only in the case of the 0.05%-0.15% difference in concentrations. It was suggested that the several contrast paradigms engage somewhat different psychological processes differentially involving emotional, sensory, and associative mechanisms, but all lead to behavior based on relative value. A modification of Toates's (1981) incentive model of ingestive behavior was suggested to incorporate relativity effects based on both associative and nonassociative factors in the consumption of both nutritive and nonnutritive substances.     

Moving the debate forward in small steps: A reply to Morrison

Morrison (1996) criticised the authors' 1995 evaluation on three main grounds: that it was too narrow, that it was circular, and that the model evaluated was contradictory. It is argued that the narrow focus was deliberate, that the methodology was standard and logical, and that the framework evaluated was coherent. Although the authors agree with Morrison in some respects, e.g. on the value of variety of methodology, there seems to be a basic difference in view on scientific method. The authors see research as (mainly) small steps which are erratic but generally cumulative; Morrison appears to favour grand-scale, multi-purpose research.     

Ethics education in science and engineering: The case of animal research

Conclusion The past one hundred fifty years of debate over the use of animals in research and testing has been characterized mainly byad hominem attacks and on uncritical rejection of the other sides’ arguments. In the classroom, it is important to avoid repeating exercises in public relations and to demand sound scholarship. This paper is a modification of material originally included in the handbook which accompanied the American Association for the Advancement of Science (AAAS) Seminar “Teaching Ethics in Science and Engineering”, 10–11 February 1993.     

THE VISUAL SYSTEM'S MEASUREMENT OF INVARIANTS NEED NOT ITSELF BE INVARIANT

Abstract— When two shapes that differ in orientation or size have to be compared or objects have to be recognized from different viewpoints, the response time and error rate art systematically affected by the size of the geometric difference. In this report, we argue that these effects are not necessarily solid evidence for the use of mental transformations and against the use of invariants by the visual system. We report an experiment in which observers were asked to give affine-invariant coordinates of a point located in an affine frame defined by three other points. The angle subtended by the coordinate axes and the ratio of the lengths of their unit vectors systematically affected the measurement errors. This finding demonstrates that the visual system's measurement of invariants need not itself be invariant.     

Poisson signal-detection theory: Link between threshold models and the Gaussian assumption

The Gaussian model of signal detection cannot fit asymmetric data as long as the variances of the distributions are kept equal. It is therefore common practice to assume unequal variances in order to fit these data. But this assumption leads to the well-known crossover problem. The present paper provides new arguments for the abandonment of the Gaussian model with unequal variances. In its stead, this paper reevaluates multiple-parallel-threshold models. In particular, the Poisson model turns out to be very useful: it can handle data with any degree of asymmetry, giving a reasonable interpretation of the two parameters of the receiver-operating characteristic. The three-state-threshold model (Krantz, 1969) is given a new interpretation in light of the Poisson model. The slope of Poisson double-probability plots turns out to be much closer to unity than is predicted by the Gaussian approximation.     

Differential effects of person in the dog and in the human

People have marked effects on dog’s heart rate, with great individual variations for different persons. Apparently people to which the dog is attached have the greatest effect upon heart rate. Replications of the animal experiments using the psychotherapist and two other people revealed no effects upon the heart rate of a schizophrenic human. In the human the effects of people are probably best demonstrated in connection with verbal communication.     

The 'open circle' in counsellor education and training: Rationale and criticisms

The apparently simple open circle is described and five elements of a rationale are discussed: that it acts as a 'buffer'; contributes efficiently towards developing trust; highlights aspects of self-disclosure; enhances awareness of emotions, biases etc; and, most subtly, provides practice of feeling sympathetic but not 'rescuing'. In the final section, four criticisms of the open circle are countered: that it is pointless; artificial; taxing; and insensitive.