Aristotelian syllogisms and generalized quantifiers

The paper elaborates two points: i) There is no principal opposition between predicate logic and adherence to subject-predicate form, ii) Aristotle's treatment of quantifiers fits well into a modern study of generalized quantifiers.To the memory of Jerzy Supecki     

A flavor paired with lithium chloride blocks the formation of a pentobarbital-lithium chloride association

Thirsty rats were used in order to determine whether a vinegar solution, which had been paired with an injection of lithium chloride, could block the formation of an association between a pentobarbital- and a lithium chloride-induced state. During phase 1 the rats in the blocking group had a 2.0% vinegar solution paired with an injection of 240 mg/kg of lithium chloride, during phase 2 these rats were reexposed to the vinegar prior to each injection of 20 mg/kg of pentobarbital and 240 mg/kg of lithium chloride, and during phase 3 these rats were given access to a novel 0.75% saccharin solution and were injected with pentobarbital after saccharin removal. Animals with this history did not form an association between the pentobarbital- and lithium chloride-induced states during phase 2 as evidenced by their refusal to consume the saccharin solution over repeated pairings of saccharin with pentobarbital during phase 3. Control groups that received forward pairings of pentobarbital and lithium chloride, in the absence of a previously conditioned vinegar solution during phase 2, formed an association between pentobarbital and lithium chloride. These findings indicate that drug states and flavors can interfere with each others' capacity to predict the occurrence of lithium chloride.     

Visual perception of surface curvature: psychophysics of curvature detection induced by motion parallax

The continuous approach to optic-flow processing shows that the curvature of a moving surface is related to a second spatial derivative of the velocity field, the spin variation (Droulez & Cornilleau-Pérès, 1989). With this approach as a theoretical framework, visual sensitivity to the curvature of a cylinder in motion was measured using a task of discrimination between cylindrical and planar patches. The results confirm the predictions suggested by the theory: (1) Sensitivity to curvature was always greater when the cylinder axis and the frontal translation were parallel than when they were orthogonal. The ratio of curvature detection thresholds in the two cases was between 1.3 and 2.5; the value predicted from the spin variation theory is about 2. (2) Sensitivity to curvature increased strongly with the velocity of the motion but was only weakly affected by its amplitude and the duration of viewing for the range of values used in our experiments.     

HyperCard administration of a block-design task

HyperCard (Atkinson, 1987) is a new development environment for the Macintosh that shows promise for use in psychological research and testing. In this paper, we discuss the development of HyperCard stackware with which a block-design task similar to that of the Wechsler Adult Intelligence Scale-Revised (WAIS-R) can be administered. The reliability and validity of the computerized block-design task was evaluated by administering both the computerized task and the WAIS-R subtest to college undergraduates. Results indicated that the computerized task’s reliability compared favorably with that of the WAIS-R subtest. Validity coefficients were equivocal; although an elapsed-time measure showed moderate correlation between the tasks, the numbers of designs correctly completed in each condition were not significantly correlated.     

Cerebral laterality and depression: differences in perceptual asymmetry among diagnostic subtypes

Examined the influence of diagnostic subtype of depression on perceptual asymmetry for dichotic listening and visual tachistoscopic tasks. A total of 65 unmedicated patients with major depressive disorders and 30 normal controls were tested on a verbal and nonverbal task in each modality. Patients diagnosed according to the DSM-III with melancholia had abnormal perceptual asymmetry for dichotic nonsense syllable and complex tone tasks. In contrast, patients having a nonmelancholic "atypical depression" (reactivity of mood with preserved pleasure capacity and associated features) did not differ from normal controls on these tasks, but had an increased incidence of left handedness. Bipolar depression (history of hypomania) differed from unipolar depression in showing abnormal perceptual asymmetry for a tachistoscopic dot enumeration task. Alterations of perceptual asymmetry in melancholia and bipolar depression were consistent with hypothesized right hemisphere dysfunction.     

Residential density and psychological health: the mediating effects of social support

People report excessive, unwanted social interactions, insufficient privacy, and are observed to be more socially withdrawn under crowded living conditions. If people socially withdraw from one another as a way to cope with crowding, this could lead to an unintended side effect of breakdowns in socially supportive relationships. A breakdown in socially supportive relationships could, in turn, account for some of the pathological consequences of chronic, high density living conditions. An empirical study of 175 male heads of household among inner city residents in India suggests that the adverse effects of residential crowding on psychological health are mediated by a breakdown of social support systems. The study also points to the value of examining social support as an endogenous variable in the stress and health process.     

ASSESSMENT OF STIMULUS PREFERENCE AND REINFORCER VALUE WITH PROFOUNDLY RETARDED INDIVIDUALS

We evaluated a procedure for identifying potential reinforcers with profoundly retarded individuals. In Experiment 1, six persons were repeatedly exposed to 16 stimuli, and approach behaviors to each stimulus were used to identify preferred and nonpreferred stimuli. In Experiment 2, we examined the reinforcing properties of preferred and nonpreferred stimuli by delivering them contingently on the occurrence of arbitrarily selected responses. Results revealed that the preferred stimulus conditions typically produced higher rates of responding than did either the baseline or the nonpreferred stimulus conditions, suggesting that the procedure can be used to assess reinforcer value for individuals with limited behavioral repertoires.     

School psychology in Australia

The status of school psychology in Australia is reviewed. Information is presented on the education system, the role of the school psychologist, historical development, special problems, contributions, and future trends in Australian school psychology.