A Mirror Drawing Apparatus for the Instructional Laboratory

Eighteen pairs of parents of children with Down's syndrome were tested on self-concept items prior to and immediately following genetic counseling. There was significant improvement on five of 20 self-concept items, with mothers improving on four items, and fathers on two items. Only one item demonstrated improvement by both mothers and fathers. Genetic counseling was found to be of value in improving self-concepts of parents of children afflicted with at least one type of heritable disease.     

A runway for the fish

A runway and a training procedure arc described. Acquisition and extinction curves for a sample of 12 goldfish trained in spaced trials are plotted in terms of three measures.     

A simple,inexpensive, liquid-tight swivel connection for use in chronic infusion systems

This note describes the fabrication of a simple, inexpensive, liquid-tight swivel joint for twist-free coupling of small, freely moving animals to infusion systems. The device uses a disposable hypodermic needle and syringe as the main components, and fabrication requires only readily available hand tools and minimal mechanical expertise.     

A simple stereo television system with application to the measurement of three-dimensional coordinates of fish in schools

Stereo television is achieved through a rapid switch circuit that alternately selects fields from a pair of matched television cameras. Images are recorded with conventional VCRs. After image positions are digitized, stereo coordinates are estimated relative to a calibration grid, which may be removed during an experiment. Necessary geometry, including calibration and iteration procedures, is detailed. The method is flexible and accurate enough to allow the use of zoom, pan, and tilt on both cameras when a calibration grid is retained in view. Examples of the system’s application are given for the measurement of three-dimensional coordinates of fish in schools, both for glass-fronted aquarium tanks and in the natural environment using underwater television in sea cages.     

A Cathode Ray Oscillograph Apparatus for the Psychological Laboratory

A computer simulation which generated various sample distributions was performed. The equal interval assumption and degree of skewness were systematically manipulated to examine the sensitivity of the t and Mann-Whitney tests to varying degrees of violations of these t test assumptions. Results show that of the 348 sets (2436 t tests), 94 (27%) contained shifts from significant to nonsignificant t test values under mild violations of the equal-interval and normality assumption and would have led to decision errors. Of these, 55% would have been Type I and 45% would have been Type II. The implications of these results are discussed relative to Types I and II errors, to the use of parametric and nonparametric statistics, and to the likelihood of encountering such problems in sampled distributions.     

A simple method using a single video camera to determine the three-dimensional position of a fish

In the present paper, we describe a method for recording the coordinates of a fish in an aquarium in a three-dimensional space, using a single video camera and a mirror. We use photogrammetic equations for this, considering the image obtained in the mirror as a virtual image obtained by a second camera. A transformation of the coordinate system is required to express the obtained coordinates in anx,y,z system defined by the edges of the aquarium. The accuracy of the proposed method was estimated, and errors in extreme conditions were found to be 0.8% to 1.2 %, compared with the dimensions of the aquarium used in the test.     

A simple method for evaluation of Rorschach Imagery Reactivity.

A general scoring system, previously developed for the analysis of pictorial associations within the paradigm of Visual Imagery Sequences, was applied in the evaluation of visual associations to memory images of Rorschach inkblots (Imagery condition) in a comparison with standard Rorschach responses (Conventional condition). The participants, 80 consecutively selected psychiatric outpatients, were divided into Clinical Reactor and Nonreactor groups, according to how productive they were of psychodynamically revealing material during insight-oriented therapy using imagery. For this simple scoring method (which does not include the customary Rorschach scores), conclusions concerning Imagery Reactivity in the Rorschach agreed with those of previous studies using a scoring system more unique to the Rorschach. The inferences drawn from statistical analysis by groups and conditions also contribute additional refinements to the understanding of the subtle interplay between defensiveness and sensitivity to imagery in determining the patterns of scorable components within the response complex. This general scoring method correctly identified 95.6% of Imagery Reactors and 100% of Imagery Nonreactors, an improvement over the 87% efficiency of the previously described, Rorschach-based method for assessing Imagery Reactivity in the Rorschach.     

A technique for measuring thermoregulatory behavior in the fish

Apparatus and procedure are described for studying thermoregulatory behavior in fish. Results obtained with rainbow trout suggest that the described apparatus has several advantages over previously utilized devices.     

A simple epidural cannula for the rat

A simple epidural cannula for use with small animals is described.     

A simple model for the utility of gambling

A model of the utility of gambling is presented in a modified von Neumann-Morgenstern format. Axioms imply a utility function that preserves preferences between sure things and between gambles. The addition of a utility of gambling term to the expected utility of a gamble preserves preference comparisons between gambles and sure things. Aspects of the utility of gambling are noted, and comparisons are made to standard concepts of risk attitudes.The author is indebted to Joseph Sani for valuable discussions on the topic of this paper.