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Biomedical subjects

A E Wilson

Publications and source records attributed to A E Wilson.

At least 37 records · Page 2Linked to original sources

Lack of sex differences with the Baldwin illusion.

Responses of college students (16 men and 16 women) to the Baldwin illusion showed a significant effect for size of square but not for sex. Findings are consistent with those reported previously by Porac, Coren, Girgus, and Verde for adults and for the oldest group of children tested by Pressey and Wilson.

Adult↗

Examination of apparent extent as an explanation of the Poggendorff effect.

The explanation of apparent misalignment in the Poggendorff figure, based on underestimation of the intertransversal distance, was investigated in two experiments. In Experiment 1, subjects judged the intertransversal distance in the traditional Poggendorff figure and two of its variants. The size of the acute angle and the intertransversal distance were manipulated. Half of the subjects made the judgments with the method used by Wilson and Pressey (1976) and the other half made their judgments with the method used by Greist-Bousquet and Schiffman (1981). The results indicated that perceived intertransversal distance was greater with the former method. In Experiment 2, subjects adjusted the transversals to apparent collinearity in the same displays as were used in Experiment 1. The collinearity judgments were transformed to allow comparison with the results of Experiment 1. Comparison of the collinearity judgments with the distance judgments indicated that they did not follow similar trends. For each Poggendorff variant, proportional distance judgments increased as the size of the acute angle increased, and decreased as the intertransversal distance increased. Collinearity judgments did not vary as a function of intertransversal distance. As the size of the acute angle increased, collinearity judgments increased for two of the Poggendorff variants but decreased for the third. It was concluded that the findings did not support the explanation of apparent misalignment based on underestimation of the intertransversal distance.

Adult↗

Contrast and assimilation in the Baldwin illusion.

Four experiments were conducted to investigate the role of "large" squares on the occurrence of assimilation and contrast in the Baldwin illusion. In Exps. 1 and 2, in which subjects reproduced the length of the test line, large squares induced illusions of assimilation. In Exp. 3, reproduction of the entire length of the test line also resulted in illusions of assimilation but bisection of the test line and reproduction of one-half the length of the test line resulted in contrast. Exp. 4 replicated the findings involving judgments of one-half the length of the test line. Over-all, the results indicate that judgments of one-half the length of the test line result in contrast, whereas judgments of the entire extent result in assimilation.

Adult↗

Selected sleep disturbances in school children reported by parents: prevalence, interrelationships, behavioral correlates and parental attributions.

Epidemiological, behavioral and etiological variables related to sleep disturbances were investigated in a survey of 1695 children in Grades 1 to 12 from 11 randomly selected schools. Sleep-walking, nightmares and sleep-talking were strongly associated with each other as well as to a family history of sleep-walking. Enuresis, however, was not related to the other sleep variables. Socioeconomic status of father was weakly related to enuresis and sleep-talking but not to sleep-walking or nightmares. Gender was not related to any of the sleep disturbances. The behavioral variables, physical activity, attention, emotional excitability, and feelings easily hurt showed a small association with the sleep disturbances. Parents most frequently attributed causes of sleep-walking and nightmares to over-tiredness and over-excitement. As well, parents' comments indicated that they tend to associate specific events such as illness or more often, frightening TV content with nightmares, but not sleep-walking.

Adolescent↗

Transposition in backward masking. The case of the travelling gap.

The transfer of attributes from a test stimulus (TS) to a masking stimulus (MS) during backward masking was investigated. Results indicated that a gap inserted on a TS transferred to a MS and that the degree of transfer varied as an inverted U-shaped function of ISI. Two explanations of the findings were offered. One was based on preservation of distinctive features and the second was based on "filling in" theory and the decrease in masking which occurs with increased spatial separation. The suggestion was made that an explanation of the transposition effect should be consistent with theories of backward masking and apparent motion.

Female↗

Assessment of apparent length and angle explanations of the Poggendorff effect.

Explanations of the Poggendorff effect were assessed by comparing the degree of angular distortion induced by modified and traditional configurations. Assimilation theory predicted that the traditional effect would be reversed in modified configurations. Analysis showed that the effect, although reduced in magnitude, was not reversed. Comparison of the degree of the effect induced by modified and traditional configurations indicated that a substantial portion of the Poggendorff effect was due to processing of areas between the long vertical lines of the display. This finding is not consistent with theories based on subjective distortion of angles. It was concluded that a theory of the Poggendorff effect must include processing of internal areas of the configuration.

Adult↗

Evidence for the role of attentive fields in masking.

A masking task was employed to determine whether predictions derived from the attentive-field postulate of assimilation theory could be verified. The distance between masking and test lines was varied both towards and away from the center of the attentive field. As predicted, masking was greater when the mask was near the center of attention than when it was located at the periphery of the field. A variation of the mathematical formula developed previously to predict visual illusions was employed to fit the individual and group functions found in this study.

Attention↗

Plasma phencyclidine pharmacokinetics in dog and monkey using a gas chromatography selected ion monitoring assay.

Phencyclidine was determined by gas chromatography selected ion monitoring in six dogs and seven monkeys. Aliquots of venous blood were taken over 4 h in the monkey after 1.1 mg kg-1 and over 24 h in the dog after 1.0 mg kg-1 of phencyclidine i.v. Pentadeuterated phencyclidine was used as the internal standard. In the electron impact mode the most abundant fragments in the mass spectrum of phencyclidine were m/e 91 and 200, and 96 and 205 in the [2H5]phencyclidine spectrum. These fragments were used to quantitate the amount of phencyclidine present. In both species, a complex exponential decline of plasma phencyclidine was found in most animals that fit a two compartment open model. In monkeys, the mean half-life (beta phase) was 2.36 h and in the dog it was 2.86 h. Compared with the monkey, the dog considerable emergence delirium. The two species had rather different pharmacokinetics which may be relevant to the observed differences in degree of anesthesia and recovery.

Animals↗

Effects of urine acidification on plasma and urine phencyclidine levels in overdosage.

A gas chromatography--mass fragmentography--electron impact (GC-MS-EI) assay of phencyclidine (PCP) was adapted for human plasma and urine. This assay is specific for PCP and very sensitive (approximately 1 ng/ml). Patients with the putative diagnosis of PCP overdosage were studied to correlate plasma and urinary levels with clinical state. Urinary PCP levels were enhanced in an acid urine, which suggests that acidification of the urine is an adjunct in the therapy of PCP overdosage.

Chromatography, Gas↗

Brain acetylcholine in morphine pellet implanted rats given naloxone.

Adult male rats were implanted with intraventricular (ivt.) brain cannulae for injection of 5 mug of acetylseco-hemicholinium-3 (acetylseco HC-3) as a means of studying acetylcholine (ACh) utilization during morphine withdrawal. Animals were made dependent by implanting s.c. two 75 mg morphine base pellets 24 hrs apart. On the 4th day animals were given 10 mg/kg of naloxone i.p. and/or 5 mug acetylseco HC-3 ivt. and sacrificed by decapitation at various times. The brains were removed and assayed for ACH using a pyrolysis gas chromatographic procedure. Total brain ACh before or after acetylseco-HC-3 was not altered at 5, 30, 60 and 120 but was decreased at 10 min after naloxone. These results are in sharp contrast to our previous data of enhanced brain ACh utilization in withdrawn rats made dependent to morphine by several weeks of twice daily injections. It is apparent that short term morphine pellet administration does not produce the marked neurochemical and behavioral changes of long term morphine injections.

Acetylcholine↗