Acquisition of discrimination learning of patterns identical in configuration in macaques (Macaca mulatta and M. fuscata)

The acquisition of discrimination of five pairs of pattern cues in a Wisconsin General Testing Apparatus by 223 naive macaque monkeys was compared. The pairs of discriminanda were identical in configuration but varied slightly in either the size of the cue or the size of the background plaque; thus, the degree of separation of the cue from the fringe of the plaque, the response site, was slightly different for each pair of discriminanda. These small differences in cue-response separation had marked effects on the rate of acquisition of the discriminations. Even an increment of separation as small as 0.5 cm resulted in a remarkable retardation of the acquisition. This retardation was due entirely to prolonged performance at the chance level, and not to a slow rate of improvement from the chance to a criterion level. The finding indicates that the difficulty in the acquisition learning on pattern tasks depends largely on the difficulty of attending to the pattern cues at small cue-response separations.     

A Breast Cancer Experience Re-narrated: The Undying: Pain,Vulnerability, Mortality,Medicine, Art,Time, Dreams,Data, Exhaustion,Cancer, and Care by Anne Boyer,New York: Farrar,Straus and Giroux, 2019

Journal of Medical Humanities -     

Effect of small cue-response separation on pattern discrimination in macaques (Macaca fuscata and M. mulatta)

In order to elucidate the nature of the effect of small cue-response separations on pattern discriminations by monkeys, three studies were performed. When training on a pattern discrimination with a cue-response separation was discontinued during performance at the chance level, there was no saving on the rate of learning a second task (with identical cues but a different cue-response separation) relative to the performance of naive control animals. By contrast, when training was discontinued at a performance level a little better than chance, there was significant saving on learning a second task. After learning the second task, a third task with new pattern cues was learned, with marked saving on the duration of performance at the chance level. The results indicate that during the initial stage of performance at the chance level, monkeys do not attend to cues if there is even a small separation between the cue and the response site.     

Open-field behavior in two models of genetic hypertension and the behavioral effects of salt excess

In order to assess the relationship of behavior to blood pressure and salt intake, open-field behavior was studied in 123 rats of the spontaneously hypertensive (SHR), Wistar-Kyoto (WKY), Sprague-Dawley (SD), and Dahl resistant (DR) and sensitive (DS) strains. DS rats become hypertensive upon exposure to either high dietary salt or psychogenic stress, while DR rats remain normotensive. A circular photobeam open field was used under full room illumination. Three 5-min trials were given on consecutive days. Rats were tested with or without 5 days of an 8% NaCl diet. We found that DS rats were less active than DR rats, regardless of diet. In contrast, SHR rats were more active than WKY rats. However, DS and SHR rats were equally active. Thus, behavioral differences between these two models of hypertension are expressed by the normotensive control strains. The relative ranking of activity levels between strains was DR = SD greater than SHR = DS greater than WKY. High-salt-enhanced intertrial habituation, defined as the decrease in activity across trials (DS, 100%; SD, 82%; SHR, 90%; WKY, 1350%; but DR, -50%) as well as intratrial habituation, defined as the decrease from the first to the second half of the trial (14%, all subjects). Defecation was increased with high salt (DS, 975%; SD, 59%; SHR, 267%; WKY, 89%; but DR, 40%). These effects of high salt may reflect an increase in an emotionality factor. DR rats were largely resistant to the behavioral effects of salt. Total activity was positively correlated with blood pressure in hypertensive rats, r(42) = 0.33, p less than .01, but negatively correlated in normotensive rats, r(81) = -0.34, p less than .01. The proportion of total activity occurring in the first half of the trial for the initial test day was correlated with blood pressure in normotensive rats r(81) = 0.44, p less than .01. Dietary salt excess has behavioral as well as cardiovascular consequences.     

Studies on the balancing,the minimal balancing,and the minimum balancing processes for social groups with planar and nonplanar graph structures

Balancing processes of social groups which transform an unbalanced group to a balanced one by changing the interpersonal relations in the group are characterized in terms of signed graphs. The graphs are given by categorizing the (interpersonal) relations within groups as positive or negative. A balanced state of a group is defined as one in which all the circuits of the graph have a positive sign, and the other cases are called unbalanced states. First, we show that a balancing process for a signed graph (changing the signs of its lines) is decomposed into that for each of the block components of the graph. Second, we classify signed graphs as planar and nonplanar. For the planar cases, we define the dual graph of a planar signed graph, and the balancing processes are characterized by specified sets of lines of the graph. According to the characterization, effective algorithms to derive the minimal and the minimum balancing processes are proposed. For the nonplanar cases, the balancing processes are characterized in terms of adjacency matrices of nonplanar signed graphs by introducing the notion of sign vectors. The characterization results in effective algorithms to derive the minimal and the minimum balancing processes. These discussions are also extended to the case where interpersonal relations have their own directions.     

Alexithymia and sociocultural factors in a Japanese sample: a study with the Rorschach

We reexamined the Japanese version of the 20-item Toronto Alexithymia Scale, a self-report sc ale for measuring alexithymic characteristics, by comparing the scores on three factors and the total scores with variables of the Rorschach in a sample of 40 (originally 48) Japanese college students. Based on prior studies, our aims were to further validate the 20-item Toronto Alexithymia Scale by comparing its scores with those on a projective technique. We also investigated whether sociocultural factors, such as repression of hostility. are associated with scores on the 20-item Toronto Alexithymia Scale (especially Factor 3). None of the seven Rorschach Alexithymia Variables were significantly related to the factors and total scores of the 20-item Toronto Alexithymia Scale. However, scores for Factor 1 (difficulty identifying feelings) of the 20-item Toronto Alexithymia Scale correlated positively with scores on Sum C' (reserved responses to emotional stimuli) and Adj es (stimulus demand), suggesting that individuals who score high for Factor 1 experience gloomy, depressive feelings but in constricted ways. Scores for Factor 3 (externally oriented thinking) correlated positively with the D scores (stress tolerance) and negatively with m (situational stress) responses, suggesting that Factor 3 may reflect a psychological defense that enhances stress tolerance. There was a nonsignificant negative correlation between Factor 1 and Factor 3 scores, but, unlike our hypothesis. Factor 3 was neither related to AG (aggression) nor S (space responses reflecting oppositional tendency), indices of aggression or hostility in the Rorschach Comprehensive System. It may be that the 20-item Toronto Alexithymia Scale and the Rorschach measure quite different aspects of personality, but further research is necessary.     

Construction of a conditional probability learning model and information theoretical evaluation of its efficiency

A learning model is introduced based on the simple idea that a learning subject has two hypotheses about the results (the outputs of the environment) caused by his actions and calculates the a posteriori probabilities of the hypotheses. Introducing a randomized decision rule of actions related to the probabilities, it is shown that the model is equivalent to Luce's beta model, while these models are derived from completely different considerations. Introducing an information theoretic measure and martingale theory, the asymptotic behavior of the model is examined. Using the information theoretic measure, the effect of memory function on the learning behavior is evaluated. Finally, the model is extended in such a way that the learning subject has more than two hypotheses or a continuum of hypotheses. The learning behaviors of the extended models are discussed.