Motion perception and aging.

The authors used a correlated motion paradigm to investigate the effects of aging and gender on motion sensitivity. In 2 experiments with a total of 50 elderly and 50 young subjects, motion thresholds were significantly higher for elderly women. The correlated motion signal, which was embedded in random motion, may have been coherent to subjects in much the same way a form is in Witkin's Embedded Figures Test (EFT). In Experiment 2, EFT scores were obtained. A significant positive relationship between motion thresholds and EFT performance was found within each age group. Although gender-related perceptual style differences may contribute to motion perception effects, the authors argue that a common neural factor contributes to performance on both the EFT and the correlated motion task.     

A comparative analysis of global and local processing of hierarchical visual stimuli in young children (Homo sapiens) and monkeys (Cebus apella)

Results obtained with preschool children (Homo sapiens) were compared with results previously obtained from capuchin monkeys (Cebus apella) in matching-to-sample tasks featuring hierarchical visual stimuli. In Experiment 1, monkeys, in contrast with children, showed an advantage in matching the stimuli on the basis of their local features. These results were replicated in a 2nd experiment in which control trials enabled the authors to rule out that children used spurious cues to solve the matching task. In a 3rd experiment featuring conditions in which the density of the stimuli was manipulated, monkeys' accuracy in the processing of the global shape of the stimuli was negatively affected by the separation of the local elements, whereas children's performance was robust across testing conditions. Children's response latencies revealed a global precedence in the 2nd and 3rd experiments. These results show differences in the processing of hierarchical stimuli by humans and monkeys that emerge early during childhood.     

Enhanced retention in the passive-avoidance task by 5-HT(1A) receptor blockade is not associated with increased activity of the central nucleus of the amygdala

The effect of blockade of 5-HT1A receptors was investigated on (1). retention in a mildly aversive passive-avoidance task, and (2). spontaneous single-unit activity of central nucleus of the amygdala (CeA) neurons, a brain site implicated in modulation of retention. Systemic administration of the selective 5-HT1A antagonist NAN-190 immediately after training markedly-and dose-dependently-facilitated retention in the passive-avoidance task; enhanced retention was time-dependent and was not attributable to variations in wattages of shock received by animals. Systemic administration of NAN-190 had mixed effects on spontaneous single-unit activity of CeA neurons recorded extracellularly in vivo; microiontophoretic application of 5-HT, in contrast, consistently and potently suppressed CeA activity. The present findings-that 5-HT1A receptor blockade by NAN-190 (1). enhances retention in the passive-avoidance task, and (2). does not consistently increase spontaneous neuronal activity of the CeA-provide evidence that a serotonergic system tonically inhibits modulation of retention in the passive-avoidance task through activation of the 5-HT1A receptor subtype at brain sites located outside the CeA.     

Building the Better Mental Training Mousetrap: Is Periodization a More Systematic Approach to Promoting Performance Excellence?

Over the past two decades, mental skills training (MST) has experienced a tremendous surge in popularity, yet MST is not without its critics, including some athletes and coaches. Additionally, a number of concerns have arisen about mental training effectiveness, and its ability to maximize athlete development, performance, and peaking. Periodization is a systematic program development and implementation strategy that holds promise for enhancing mental training effectiveness and combating some of the problems currently limiting MST interventions. Thus, the purpose of this conceptual paper was threefold. First, periodization concepts are introduced by demonstrating how they are utilized to systematically guide physical training. Second, strategies to adapt periodization concepts to enhance mental training programs are examined, along with techniques to integrate physical and mental training, including: mental training tool and skill periodization plans and mental training drill menus. Finally, a case study is presented to illustrate how an integrated approach to periodized training that targets both physical and mental skill development can enhance the effectiveness of MST while minimizing implementation problems.     

Humean dispositionalism

Humean metaphysics is characterized by a rejection of necessary connections between distinct existences. Dispositionalists claim that there are basic causal powers. The existence of such properties is widely held to be incompatible with the Humean rejection of necessary connections. In this paper I present a novel theory of causal powers that vindicates the dispositionalist claim that causal powers are basic, without embracing brute necessary connections. The key assumptions of the theory are that there are natural types of causal processes, and that manifestations of powers are identified with certain kinds of causal processes. From these assumptions, the modal features of powers are explained in terms of internal relations between powers themselves and the process-types in which powers are manifested.     

Intimate partner violence: A narrative review of the biological and psychological explanations for its causation

Intimate partner violence (IPV) is a major social and public health problem that affects men and women across the globe regardless of their culture, religion and other demographic characteristics. During the last 100 years many different theories have been proposed to explain the phenomenon of IPV. Much research is been conducted using these theories as a guiding or underlying framework. However, it is difficult to find a single account that provides a succinct and up-to-date overview of these theories. As a result considerable effort is required to identify and retrieve relevant papers to understand the various theories which attempt to explain IPV. This article attempts to provide a succinct and up-to-date integrative review of the biological and psychological explanations of IPV. Both perspectives have been critically evaluated in the light of the available literature and an attempt has been made to discuss the strengths and limitations of each perspective in shedding light on the causation of IPV.     

Is the donut in front of the car? An electrophysiological study examining spatial reference frame processing.

The process of describing an object's location relative to another object results in ambiguity. How do people handle this ambiguity? The present studies examined spatial language processing when use of different reference frames results in ambiguity. We investigated whether electrophysiological (ERP) measures of cognitive processing may elucidate underlying reference frame processing; in particular, we were interested in semantic integration. ERP results showed a larger N400, peaking between 300 and 375 ms, when the intrinsic frame was not used. Behavioural results mirrored this finding, indicating a reduced cognitive processing requirement for the intrinsic reference frame. Previous work has not definitively tied spatial reference frame processing to specific ERP components and their associated cognitive processes. Although the N400 peak seen in this data is early, additional work supports the N400 interpretation, thereby linking spatial frame processing to semantic integration. Results are discussed within the larger context of spatial reference frame processing.     

Generating multiple samples of multivariate data with arbitrary population parameters

A method of generating any number of score and correlation matrices with arbitrary population parameters is described. EitherZ scores or stanines are sampled from a normal population to represent factor scores by an IBM 1620 program. These are converted to variates from a population with an a priori factor structure. The effectiveness of the method is illustrated from research data. Some further modifications and uses of the method are discussed.