A tether system for psychophysiological studies in the dog

A system for monitoring blood pressure or other physiological variables in the unanesthetized and chronically instrumented dog is described. An indwelling catheter attaches to a pressure transducer affixed to the underside of a leather shield, which snaps onto a custom-fitted leather vest worn by the dog. The transducer cable ascends vertically through a hollow, flexible, stainless steel tether, which is attached at the lower end to the leather shield and at the upper end to a fluid and electrical swivel. The swivel is attached to an overhead counterbalanced boom assembly, which moves in concert with the dog, maintaining a constant minimal tension on the tether. The boom assembly is attached to a wall plate via a universal joint approximately 7 ft above floor level. Dogs can be maintained comfortably in this system 24 h/day over periods of months, with freedom of posture and movement, including rotational behavior. The system is economical to construct and provides versatile stimulation and record-ing capability and reliable long-term performance.     

The pursuit of the minor premise a commentary on normality

In this paper are explored the ethical implications of the answers to three questions: Whether or not a diseased state is discrete; the criteria by which that question is answered; and how the diseased state is to be identified. Examples are given showing that some states appear to be clearly discrete, and others equally clearly not discrete. The nature of the pertinent evidence will be affected accordingly. It is shown that a slavish and inappropriate concern with categories leads to anomalous ethics. Finally, it is suggested that many of these problems may be avoided by centering the ethics of medicine on optimizing the welfare of the patient rather than by thinking in terms of categorical disease.     

Conversion of a printing calculator to an inexpensive printing counter

A procedure is described for simple conversion of a printing calculator to an inexpensive printing counter. The unit is particularly useful for unattended data collection. A timing circuit controls printout of accumulated data at specified time intervals.     

Developing a laboratory course using PASCAL on the Apple II

Several resources are available to the person seeking to develop a laboratory course that utilizes microprocessors. Several roles for such equipment are envisioned, and some of the issues regarding types of equipment and programming languages are addressed.     

Salient features of color space

Recent research has demonstrated that focal regions of color space are cognitively more salient than nonfocal regions. Employing a linguistic hedge task, the experiment here sought mainly to verify the cognitive primacy of loci representing Berlin and Kay’s first four chromatic categories over foci representing the remainder. The experimental results failed to support the primacy hypothesis, an outcome that gives rise to a number of theoretical implications. Additional questions in the analysis concerned the relationship between the salience of a color and its lightness (Munsell value) and saturation (Munsell chroma). While the results permit no simple interpretation for lightness, a definite trend emerged in the case of saturation.     

Variations in apparent spatial frequency with stimulus orientation: IL Matching data collected under normal and interferometric viewing conditions

Using an adjustment procedure, human observers matched the apparent spatial frequencies of sinusoidal gratings presented in different orientations (0, 45, 90, and 135 deg). Matches were made between all possible pairwise orientation combinations. Significant match deviations indicated that the apparent frequency of a grating depends on its orientation. The most consistent deviations were found between horizontal and vertical gratings, with horizontal gratings appearing to be of a lower spatial frequency than vertical gratings. These effects were relatively independent of stimulus contrast and persisted when the optics of the eye were bypassed with laser interferometry. A neurophysiological explanation of these effects is proposed.     

The effects of binocular and motion-generated information on the perception of depth and height

The perception of distance and size in the presence of optical gradient information was investigated under four viewing conditions—binocular view with and without head motion, and monocular view with and without head motion. Subjects (60 adults) matched distance intervals (from 15 to 127 cm) and heights of a target triangle (from 5 to 15 cm) by adjusting the length of a metal tape. Both linear and power functions were fitted to each individual’s distance judgments, and the competing perceptual models were compared. For both models, it was found that binocular information was sufficient to specify relative, but not absolute, distance, that monocular information was sufficient to specify an orderly relation between target distance and judgment but not absolute distance, that average error was less in the binocular conditions, and that perceived distance was not affected in either condition by the addition of head motion. The analysis of size judgments revealed that monocular and binocular judgments did not differ, that matches made with and without head motion did not differ, and that, in all conditions, matches exceeded target heights by an average 30% to 40%. Judged size was also analyzed as a function of target distance. In all conditions but monocular view with head motion, the effect of distance was to increase size judgments. The distance judgments support the hypothesis (Purdy, 1958) that the binocular stimulus carries information that the monocular stimulus does not; they fail to support the hypothesis (Gibson, 1966) that observer motion adds information to the static stimulus. The size judgments support neither hypothesis but suggest an independence of perceived size from perceived distance.     

Arithmetic achievement as a function of introversion-extraversion and teacher-presented reward and punishment

Following Eysenck (1967), Gray (1973) and Wakefield (1979), it was hypothesized that the arithmetic achievement of extraverts would be better than introverts in those classrooms in which teacher-presented rewards predominated, and the arithmetic achievement of introverts would be better than extraverts in those classrooms in which teacher-presented punishment predominated. Five classrooms were rank-ordered according to their ratios of teacher-presented reward to teacher-presented punishment. A total of 101 fourth and fifth grade students from the five classrooms were then administered the Junior Eysenck Personality Questionnaire (JEPQ) and an arithmetic pretest. Subsequent to 40 school days, the students were administered the arithmetic posttest. Partialling out arithmetic pretest scores, lie scale scores from the JEPQ, and total arithmetic raw scores from the Comprehensive Test of Basic Skills (CTBS), regression analysis of arithmetic posttest scores with the interaction of extraversion scores from the JEPQ and classroom rank-order of the ratio of teacher-presented reward to teacher-presented punishment yielded significant results supporting the hypothesis. Additional analysis indicated the presence of non-hypothesized interactions of the Psychoticism and Neuroticism scales of the JEPQ with reward-punishment and extraversion.