Human foraging behavior in a virtual environment

We have developed an experimental platform that allows a large number of human participants to interact in real time within a common virtual world. Within this environment, human participants foraged for resources distributed in two spatially separated pools. In addition to varying the relative replenishment rate for the two pools (50-50, 65-35, or 80-20), we manipulated whether the participants could see each other and the entire resource distribution or had their vision restricted to resources at their own location. Two empirical deviations from an optimal distribution of the participants were found. First, the participants were more scattered within a resource pool than the resources were themselves. Second, there was systematic underutilization of the richer pool. For example, the participants distributed themselves 73% and 27% to resource pools that had replenishment rates of 80% and 20%, respectively. In addition, there were oscillations in the harvesting rate of the pools across time, revealed by a Fourier analysis with prominent power near 50 sec per cycle. The suboptimalities and oscillations were more apparent when the locations of the participants and the food were not visible. Individual participant knowledge thus affects the efficiency with which a population of participants harvests resources.     

Enhanced occipital and anterior cingulate activation in men but not in women during exposure to angry and fearful male faces

Blood-oxygenation-level-dependent signal was measured with functional magnetic resonance imaging in 24 healthy young subjects (12 men and 12 women) during viewing of angry, fearful, and neutral male and female face pictures. Exposure to angry male as opposed to angry female faces activated the visual cortex and the anterior cingulate gyrus significantly more in men than in women. A similar sex-differential brain activation pattern was present during exposure to fearful but not neutral faces. Previous behavioral studies indicate enhanced physiological arousal in men but not in women during exposure to angry male as opposed to female faces, and brain imaging studies have shown that the occipital cortex and the anterior cingulate gyrus are influenced by activity in the autonomic nervous system as well as by visual attention. Hence, we suggest that the elevated occipital and anterior cingulate activation in men during confrontation with other angry and fearful males may reflect enhanced vigilance in a potentially dangerous situation.     

Touchscreen-enhanced visual learning in rats

The efficiency of traditional levers and of modern touchscreen technology for training rats on a computerized visual discrimination was studied in a series of observations. When compared with a lever-based discrimination procedure, the use of touchscreens supported the faster development of signal tracking behavior and acquisition of a two-stimulus simultaneous visual discrimination. It did not affect the final level of accuracy. Factors related to spatial proximity of the responses with the stimuli, sign-tracking, and increased ease of touchscreen motor responses were suggested as possible reasons for the touchscreen training advantage. This increased efficiency allows large numbers of animals to be tested quickly, a necessary requirement for studies involving genetic and physiological interventions.     

Is the asymmetry in young infants’ categorization of humans versus nonhuman animals based on head,body, or global gestalt information?

Quinn and Eimas (1998) reported an asymmetry in the exclusivity of the category representations that young infants form for humans and nonhuman animals: category representations for nonhuman animal species were found to exclude humans, whereas a category representation for humans was found to include nonhuman animal species (i.e., cats, horses). The present experiment utilized the familiarization/novelty-preference procedure with 3- and 4-month-olds to determine the perceptual cues (i.e., whole stimulus, head alone, body alone) that provided the basis for this asymmetry. The data revealed the asymmetry to be observable only with the whole animal stimuli and not when infants were provided with information from just the head or the body of the exemplars. The results indicate that the incorporation of nonhuman animal species into a category representation for humans is based on holistic information.     

Reading long words embedded in sentences: informativeness of word halves affects eye movements

The possibility was explored that the informativeness of a specific region within a word can influence eye movements during reading. In Experiment 1, words containing identifying information either toward the beginning or toward the end were displayed asymmetrically around the point of fixation so that the reader was initially presented with either the informative or noninformative zone. Words were read with shorter summed initial fixation time when the reading was started from the informative zone. In Experiments 2 and 3, the target words were presented in sentences that were to be comprehended. More attention was given to the informative endings of words than to redundant endings. The latter were also skipped more often. The duration of the first fixation was not affected by information distribution within the word, whereas the second fixation duration was. The results of these experiments lend good support to the hypothesis of immediate lexical control over fixation behavior and to the notion of a convenient viewing position.     

Evaluating Arguments Based on Toulmin’s Scheme

Toulmin’s scheme for the layout of arguments (1958, The Uses of Argument, Cambridge University Press, Cambridge) represents an influential tool for the analysis of arguments. The scheme enriches the traditional premises-conclusion model of arguments by distinguishing additional elements, like warrant, backing and rebuttal. The present paper contains a formal elaboration of Toulmin’s scheme, and extends it with a treatment of the formal evaluation of Toulmin-style arguments, which Toulmin did not discuss at all. Arguments are evaluated in terms of a so-called dialectical interpretation of their assumptions. In such an interpretation, an argument’s assumptions can be evaluated as defeated, e.g., when there is a defeating reason against the assumption. The present work builds on recent research on defeasible argumentation (cf. e.g. the work of Pollock, Reiter, Loui, Vreeswijk, Prakken, Hage and Dung). More specifically, the author’s work on the dialectical logic DEFLOG and the argumentation tool ARGUMED serve as starting points.     

Surgeons and the Spirit: A Study on the Relationship of Religiosity to Clinical Practice

This study aimed to identify the religious practices and beliefs of surgeons and the relationship between surgeons locus of control and religiosity. Thirty-five surgeons completed a survey that included items from the Duke University Religion Index, the Salesian Center Intrinsic Religiosity Scale for Clinicians, and Rotters Locus of Control Scale. Over 68% of sampled surgeons affirmed that their religious beliefs play a part in their practice, 47% attend religious services at least weekly, and 44% pray daily. There was no correlation between locus of control and religiosity. These results challenge the myth of the egocentric, agnostic surgeon.     

John Dewey,The Other Face of the Brazilian New School

This paper intents to analyze the influence of John Dewey’s ideas in the movement that defended the educationl renovation in Brazil (named New School) at the end of the 1920s and in the 1930s. For this, it explains two trends of that movement: the first is described by the metaphor of industrial or mechanical efficiency, whose emphasis was in the power derived from the disciplinary idea of progress, which was embedded in the process of rationalization of the social relations submitted by a factory model; the second, developed by influence of Dewey, is characterized by a project of democratization of society and school that prevented the individual massification and the adoption of the rationalizing model inspired by the factory without any criticism. When Dewey was put in the center of the debate on political, pedagogical and social goals of the Brazilian New School, he was called to introduce a series of concepts that helped to find the balance between the respect for individuality and the observation of the social needs. This paper has some of the conclusions of a major research project, “Philosophy and Science in the New Educational Discourse (Brazil: l930–1960),” sponsored by CNPq.     

Free Choice Permission is Strong Permission

Free choice permission, a crucial test case concerning the semantics/ pragmatics boundary, usually receives a pragmatic treatment. But its pragmatic features follow from its semantics. We observe that free choice inferences are defeasible, and defend a semantics of free choice permission as strong permission expressed in terms of a modal conditional in a nonmonotonic logic.     

Emotion Socialization in Families of Children With an Anxiety Disorder

Compared emotion socialization in 26 children with anxiety disorders ages 8–12 years and their mothers to 26 nonclinical counterparts without psychopathology. Children and their mothers participated in an emotion interaction task in which they discussed occasions when the child felt worry, sadness, and anger. Responses were coded for length of discussion, proportion of words spoken by child vs. mother, frequency of positive and negative emotion words, explanatory discussion of emotion, and maternal facilitation of emotion discussion. Children and their mothers also completed the Expressiveness and Control scales of the Family Environment Scale. Results indicated that mothers of children with an anxiety disorder spoke less frequently than their child, used significantly fewer positive emotion words, and discouraged their childrens emotion discussions more than did mothers of nonclinical children. Nonclinical children and their mothers indicated significantly more emotional expressiveness in their families than did children with an anxiety disorder and their mothers. These results highlight the potential role of truncated family emotional expressivity in the emotional development and functioning of children with an anxiety disorder.