Medial preoptic area/anterior hypothalamus and sexual motivation

The medial preoptic area/anterior hypothalamus (MPOA/AH) is a brain site derived from proliferative zones from the diencephalon and telencephalon. It is probably this characteristic that makes this brain region participate in different physiological and behavioral functions. The present review addresses the role of the MPOA/AH in the control of male sexual behavior. It is clear that the MPOA/AH is a crucial site in the control of sexual behavior in males of all species studied to date. But although many different publications have followed the contribution of Heimer and Larsson there is no agreement as to what is specifically the role of the MPOA/AH in sexual behavior. At least three hypotheses have been presented. The first one suggests that this brain region is involved in the consummatory aspects (execution) of sexual behavior. The second indicates that the MPOA/AH is involved in the appetitive components (motivation) of masculine sexual behavior. The third hypothesis considers that MPOA/AH neurons are involved in the regulation of consummatory and appetitive aspects of sexual behavior. From the literature reviewed, it will become evident that the evidence supporting a role of the MPOA/AH in the execution of sexual behavior is based on a number of limited studies not easy to interpret. On the other hand, several lines of evidence using a variety of methodologies support the notion that the MPOA/AH is involved in the motivational aspects of male sexual behavior.     

Letter visibility and the viewing position effect in visual word recognition

The ease with which printed words are recognized depends on the position at which the eyes initially fixate the word. In this study, we examined to what extent recognition performance for each fixation position depends on the average visibility of the word's constituent letters. Experiment 1 measured recognition performance to single letters embedded in strings of Xs (lengths of 5 and 7) for all combinations of letter position and initial fixation position in the string. In Experiment 2, recognition performance was measured for five-letter and seven-letter words as a function of initial fixation position in the word. Whereas average letter visibility showed a symmetric function in Experiment 1, the word recognition data of Experiment 2 showed the typical asymmetric curve. Combining the letter visibility data with measures of lexical constraint using absolute letter-in-string positions failed to capture the pattern in the word data. An alternative measure of constraint based on relative position coding of letters generated more accurate predictions.     

Functional Equations in Binocular Space Perception

A general theory of the relationship of binocular visual space to physical space is formulated within a conjoint measurement framework. Psychophysically motivated invariance relations induce various functional equations. Another class of functional equations arises if we additionally assume the validity of a different psychophysical theory that is based on a formula suggested by A. A. Blank. We solve and interpret most of these equations and point out an unsolved problem. The obtained results lead to a measurement-theoretic foundation of the psychophysical assumptions underlying the Luneburg theory of binocular vision. They also contribute to clarifying the relationship between the presented general theory and Blank's approach. Copyright 1999 Academic Press.     

Fairness Evaluations of Encounters With Police Officers and Correctional Officers1

The fairness of treatment can be inferred from 2 aspects of the relationship between authority and other party: the person-related aspect and the role-related aspect. One hundred seventy-five American detainees were interviewed about their encounters with police officers and correctional officers. The role-related aspect affected procedural fairness judgments most when first-time incarcerated detainees evaluated the encounter with police officers. The person-related aspect affected procedural fairness judgments most when first-time detainees and repeatedly incarcerated detainees evaluated encounters with correctional officers. Consequences for the group value model of procedural fairness as well as for the legal practice are discussed.     

Hand-movement profiles in a tactual—tactual matching task: Effects of spatial factors and laterality

We examined the effect of spatial factors and hemispheric lateralization upon hand-scanning strategies in 14 right-handed men tested in a tactual—tactual matching task. The experiment involved comparisons (judgments of same or different) between two objects sequentially touched by the fingertips of the left or right hand. Stimuli were made of smoothly joined cubes whose junctions were not haptically discernible. Exploratory strategies were inferred from the durations and locations of hand contacts with any of the cubes composing the stimuli. Accuracy was greater when the same stimulus was touched twice by the same hand than when different hands were used to feel it. With regard to strategies, both hands touched the upper parts of the object longer than the lower parts. Subjects also inspected more portions of the objects ipsilateral to the hand used. Overall differences in time spent touching cubes were greater for the right hand than for the left hand, showing that touch times were less evenly distributed on object parts for the former than for the latter. In this study, the process of information gathering by touch appears to be determined by the intertwining integration of contextual factors (e.g., stimulus position in space), biomechanical constraints on hand movements, and such cognitive factors as hemispheric differences on the ability to encode spatial pattern information.     

Composantes culturelles du développement du raisonnement technique chez les enfants d'âge préscolaire lors de substitutions instrumentales

Cette recherche vise à définir le rôle du milieu culturel dans la substitution d'un outil par un autre instrument dans trois tâches techniques quotidiennes: découpage, dévissage, clouage. Trois catégories de sujets (n = 180) d'âge préscolaire (milieu: gitan, technicien, “favorisé”) ont été testées dans deux conditions expérimentales de substitution: (1) les sujets ont à choisir un instrument adéquat parmi les substituts (11 objets proposés) socialement marqués par leur usage courant; (2) les sujets sont invités à remplacer l'outil manquant par un objet non investi de significations sociales particulières. Les résultats montrent une supériorité générale du milieu gitan dans les deux conditions expérimentales; surtout dans la mesure où le substitut proposé ne se trouve pas investi par les valeurs culturelles propres au mode de vie du groupe social.     

ROTATION OF MENTAL IMAGES IN BABOONS WHEN THE VISUAL INPUT IS DIRECTED TO THE LEFT CEREBRAL HEMISPHERE

Abstract— The mental rotation phenomenon was examined in baboons and humans using a video-formatted matching-to-sample task. Sample stimuli were presented either centrally or in the right or left visual half-field. Immediately afterward, subjects had to distinguish the previously presented sample Stimulus from its mirror image after both had been rotated to the same angular deviation. A mental rotation phenomenon was found in baboons and humans, but in baboons this effect wax limited to conditions in which visual input was directed to the right visual half-field. These data represent the first evidence of mental rotation in a nonhuman species.     

In search of a measure to investigate mental performance among children: Development of the mental speed test

Processing speed is a component of general intelligence and an indicator of learning potential. There is a need for robust measures of mental speed based on contemporary theoretical developments. The current study addressed this need by proposing a mental speed test for children aged 60 to 96 months (5 to 8 years) and examining its psychometric properties. The test included indicators of perceptual speed, memory speed, reasoning speed, and fluency-flexibility speed presented through nonverbal items administered individually using touchscreen tablets. After establishing gender non-bias and concurrent validity with a contemporary intelligence test (i.e., ASIS, r = .59) with 107 children, the next administration included 373 children. Exploratory factor analysis (EFA) with subtest scores revealed a single-factor structure accounting for 45% of the total variance. Additional data from 212 children were used to assess structural validity and gender bias, which showed acceptable goodness of fit, providing evidence of the validity and reliability of the new measure for further use.