A distributive method to increase the analogic output (D/A) resolution of a microcomputer

This paper describes a simple and efficient method to increase the D/A output resolution of an 8-bit microcomputer, as exemplified on the Apple II. The “distributive method” can increase the final output resolution up to 32K with two 8-bit analogic channels. A simple interface based on balanced sets of resistors and driver software are described. Some applications are also reported.     

Monocular and binocular vision in the control of goal-directed movement

In the present research the authors examined the time course of binocular integration in goal-directed aiming and grasping. With liquid-crystal goggles, the authors manipulated vision independently to the right and left eyes of 10 students during movement preparation and movement execution. Contrary to earlier findings reported in catching experiments (I. Olivier, D. J. Weeks, K. L. Ricker, J. Lyons, & D. Elliott, 1998), neither a temporal nor a spatial binocular advantage was obtained in 1 grasping and 2 aiming studies. That result suggests that, at least in some circumstances, monocular vision is sufficient for the precise control of limb movements. In a final aiming experiment involving 3-dimensional spatial variability and no trial-to-trial visual feedback about performance, binocular vision was associated with greater spatial accuracy. Binocular superiority appeared to be most pronounced when participants were unable to adjust their limb control strategy or procedure on the basis of terminal feedback about performance.     

Emotional intelligence: impact on post-secondary academic achievement

This research examined the simultaneous influences of emotional intelligence, adjustment to university, authoritative versus other parenting style, and high school average on first year university students’ grade point average (GPA) via structural equation modeling. The participants were 299 first year students from the social science faculty at Laurentian University, Canada. The sample was comprised of 86 males (28.7 %) and 213 females (71 %); most students (96.7 %) were between the ages of 17 and 23. The results showed that high school average had a direct influence on first year university GPA. Emotional Intelligence was not directly associated with first year university GPA, but it was significantly associated with adjustment to university which in turn was significantly associated with the first year GPA. This tends to suggest that the influence of emotional intelligence on academic achievement may be mediated by adjustment to university. Furthermore, parenting style (authoritative versus other) had a significant influence on adjustment to university but not on emotional intelligence and university GPA. Students who came from families with authoritative parenting styles tended to be better adjusted than students who came from families with other parenting styles (authoritarian and permissive). Problem behaviors such as alcohol use, academic dishonesty and academic procrastination were found to have a negative influence on university GPA and adjustment to university. In conclusion, emotional intelligence and an authoritative parenting style are influential in enhancing adjustment to university which in turns affects academic achievement in university.     

Age differences in the prevalence of physical aggression among 5-11-year-old Canadian boys and girls

It has been proven extremely difficult in the past to estimate the prevalence of physical aggression in children for two main reasons: (a) a heterogeneous sampling of behaviors (i.e., mix between physically aggressive and non-physically aggressive antisocial behaviors), and (b) a lack of a "gold standard" to identify children who exhibit physically aggressive behaviors on a frequent basis. The goal of this study was to test for age differences in the prevalence of physical aggression in the Canadian population of school-aged boys and girls, using cross-sectional data from the National Longitudinal Survey of Children and Youth (NLSCY). The first wave of the NLSCY included a representative sample of 12,292 Canadian children aged 5-11 years. We used latent class analysis to identify children whose propensity to exhibit physically aggressive behaviors was much higher than that of other children of the same age and sex in the population. The prevalence of physical aggression was estimated at 3.7% in 5-11-year-old boys and ranged from .5% to 2.3% in 11 and 5-year-old girls, respectively. Hence, the results show a decreasing trend in the prevalence of physical aggression with age for girls, but not for boys. These findings suggest the importance of considering the developmental pathways of physical aggression for boys and girls separately.     

Rats take correct novel routes and shortcuts in an enclosed maze

In 3 experiments, rats were allowed to travel selected routes along the internal alleys of a cross-maze that led from one distinctive end box to another. The maze and procedures used were designed to control the rats' ability to use intrinsic and extrinsic cues to their location in the maze; thus, only the internal geometry of the maze could be learned and used to travel between one end box and another. After an initial exploration phase, rats were given novel routes and shortcut tests that involved peripheral alleys not before traveled. Rats chose the correct novel path or shortcut significantly above chance on some tests in Experiments 1 and 2 and significantly better than a control group in Experiment 3. The findings suggest that rats were able to compute novel routes and shortcuts within the maze on the basis of limited experience with the internal geometry of the maze.     

Reproducibility of distance and direction errors associated with forward, backward, and sideway walking in the context of blind navigation

The ability to navigate without vision towards a previously seen target has been extensively studied, but its reliability over time has yet to be established. Our aims were to determine distance and direction errors made during blind navigation across four different directions involving three different gait patterns (stepping forward, stepping sideway, and stepping backward), and to establish the test-retest reproducibility of these errors. Twenty young healthy adults participated in two testing sessions separated by 7 days. They were shown targets located, respectively, 8 m ahead, 8 m behind, and 8 m to their right and left. With vision occluded by opaque goggles, they walked forward (target ahead), backward (target behind), and sideway (right and left targets) until they perceived to be on the target. Subjects were not provided with feedback about their performance. Walked distance, angular deviation, and body rotation were measured. The mean estimated distance error was similar across the four walking directions and ranged from 16 to 80 cm with respect to the 8 m target. In contrast, direction errors were significantly larger during sideway navigation (walking in the frontal plane: leftward, 10 degrees +/- 15 degrees deviation; rightward, 18 degrees +/- 13 degrees) than during forward and backward navigation (walking in the sagittal plane). In general, distance and direction errors were only moderately reproducible between the two sessions [intraclass correlation coefficients (ICCs) ranging from 0.682 to 0.705]. Among the four directions, rightward navigation showed the best reproducibility with ICCs ranging from 0.607 to 0.726, and backward navigation had the worst reliability with ICCs ranging from 0.094 to 0.554. These findings indicate that errors associated with blind navigation across different walking directions and involving different gait patterns are only moderately to poorly reproducible on repeated testing, especially for walking backward. The biomechanical constraints and increased cognitive loading imposed by changing the walking pattern to backward stepping may underlie the poor performance in this direction.     

The contribution of “cool” and “hot” components of decision-making in adolescence: Implications for developmental psychopathology

Impairments in either “cool” or “hot” processes may represent two pathways to deficient decision-making. Whereas cool processes are associated with cognitive and rational decisions, hot processes are associated with emotional, affective, and visceral processes. In this study, 168 boys were administered a card-playing task at ages 13 and 14 years to assess response perseveration. This task was designed to initially reward playing and gradually associate playing with punishment. Measures of subjective ordering (cool processes) and neuroticism (hot processes) at age 13 years were used to examine how these individual characteristics relate to perseveration over time. A decrease in perseveration from age 13 to 14 was associated with cool processes whereas hot processes were associated with response perseveration only over time. A complementary but simultaneous assessment of cool and hot processes, such as neuropsychological and personality tests, could facilitate treatment planning of children with behavioral problems.