Children's spatial behavior is differentially affected after traumatic brain injury.

Spatial behavior in 20 children with severe traumatic brain injury (TBI) and 20 healthy controls was investigated using the Kiel Locomotor Maze. Children had to remember defined locations in an experimental chamber with completely controlled intra- and extra-maze cues until learning criterion was reached. In a second experiment, spatial orientation strategies were assessed. Children with TBI were shown to be impaired in spatial learning and spatial memory. Spatial orientation was found to be deficient even in cases where spatial learning and memory proved to be unimpaired, especially in tasks that demanded the use of relational place strategies. Children who suffered a TBI at an early age proved to be more severely impaired in spatial learning and orientation than older children.     

Effects of intraseptal zolpidem and chlordiazepoxide on spatial working memory and high-affinity choline uptake in the hippocampus

Injection of GABA(A)/benzodiazepine receptor ligands into the medial septum (MS) alters the activity of cholinergic neurons that innervate the hippocampus and can produce bidirectional modulation of spatial memory. Recent evidence suggests that two subtypes of the GABA(A) receptor are differentially localized to either GABAergic (alpha(1)/beta(2)/gamma(2)) or cholinergic (alpha(3)/beta(3)/gamma(2)) neurons within the MS. The present studies characterized the dose-related behavioral and neurochemical effects of intraseptal infusions of two benzodiazepine (BDZ) agonists that appear to exhibit different profiles of pharmacological specificity for these receptor subtypes. Male Sprague-Dawley rats were cannulated and then artificial CSF, chlordiazepoxide (CDP: 8 or 12 microg), or zolpidem (4, 8, or 12 microg) was injected into the MS. Spatial working memory was assessed in a delay radial-arm maze task and the activity of cholinergic neurons in the MS was evaluated by high-affinity choline uptake (HA-ChU) in the hippocampus. Intraseptal injection of either CDP or zolpidem produced dose-related impairments in spatial working memory and decreases in hippocampal HAChU. Both BDZ agonists were found to produce retrograde memory deficits and a decrease in HAChU following the highest dose tested (12 microg). However, intraseptal injection of 8 microg of zolpidem produced a behavioral deficit comparable to the high dose of CDP, but did not alter HAChU within the HPC. Although the cholinergic component of the septohippocampal pathway has been shown to be important in modulating hippocampal physiology and spatial memory processes, data from the present experiments suggest that the GABAergic component may also play an important role in the behavioral functions of the septohippocampal pathway.     

Switching binding states

Recently, we introduced two illusions: Feature inheritance and shine-through (Herzog & Koch, 2001). In both cases, a vernier precedes a grating for a short time. In feature inheritance the grating comprises a small number of elements to which properties of the foregoing vernier are bound. The vernier itself remains invisible. In shine-through, a grating comprising a larger number of elements follows the foregoing vernier. Surprisingly, the vernier becomes visible as an entity in its own right and does not bequeath its features to the grating. Two “objects” are perceived each preserving its properties. Therefore, each of the two illusions represents a different state of feature binding. Our results suggest that feature binding is based on an antecedent segmentation process that might be viewed as a binding process itself.     

religiosity and perceptions of crime seriousness by jewish and muslim respondents in israel

Most empirical research has attempted to demonstrate the relationship between religiosityandcriminal behavior principally onthebasis of self-reported measures of criminality. The present study analyzed the influence of individual religiosity on personal perceptions of the seriousness of a variety of criminal offenses. Findings obtained from a national sample of Israeli respondents with varyingdegrees of religiosity and belonging to two different religions--Judaism and Islam--support the existence of effects of religiosity on perceptions of crime seriousness. Moreover, in the case of the Jewish respondents, religiosity emerged as the variable exerting the most influenceon their perceptions of victimless offenses.     

An LCD tachistoscope with submillisecond precision

Tachistoscopes allow brief visual stimulation delivery, which is crucial for experiments in which subliminal presentation is required. Up to now, tachistoscopes have had shortcomings with respect to timing accuracy, reliability, and flexibility of use. Here, we present a new and inexpensive two-channel tachistoscope that allows for exposure durations in the submillisecond range with an extremely high timing accuracy. The tachistoscope consists of two standard liquid-crystal display (LCD) monitors of the light-emitting diode (LED) backlight type, a semipermeable mirror, a mounting rack, and an experimental personal computer (PC). The monitors have been modified to provide external access to the LED backlights, which are controlled by the PC via the standard parallel port. Photodiode measurements confirmed reliable operation of the tachistoscope and revealed switching times of 3?μs. Our method may also be of great advantage in single-monitor setups, in which it allows for manipulating the stimulus timing with submillisecond precision in many experimental situations. Where this is not applicable, the monitor can be operated in standard mode by disabling the external backlight control instantaneously.     

The concept of violence in the work of Hannah Arendt

Arendt claimed that violence is not part of the political because it is instrumental. Her position has generated a vast corpus of scholarship, most of which falls into the context of the realist-liberal divide. Taking these discussions as a starting point, this essay engages with violence in Arendt’s work from a different perspective. Its interest lies not in Arendt’s theory of violence in the world, but in the function that violence performed in her work, namely, in the constitutive role of violence in her thought. It argues that the concept of violence allowed Arendt to make important distinctions serving to catalyze the categories that constitute her political philosophy and, in particular, the categories of public and private. More specifically, it claims that the concept of violence in Arendt’s work is the a priori background against which both the public and private realms should be defined.     

Drug consumption and perception among Latin American immigrants

The aim of this study is to obtain information about drug consumption, leisure activities and knowledge of community services among Spanish-speaking immigrants to prevent drug abuse in this population. Quantitative methodology was used. The field work of this study has two phases: in the first stage (2003), a survey of social perception of drugs was administered to 147 subjects. During the second stage (2004), 610 surveys were administered. Data were analysed by bivariate analysis. Usual consumption of alcohol was 40.1%, usual consumption of tobacco was 31.3%, and usual consumption of cannabis was 3.4%. Drug users considered that the main reason for drug consumption was "to have fun" (p<.03). There is a relationship between leisure time and drug use. Family plays an important role in drug abuse prevention and preventive drug abuse programs must be adapted to this population.     

Fluency heuristic: a model of how the mind exploits a by-product of information retrieval

Boundedly rational heuristics for inference can be surprisingly accurate and frugal for several reasons. They can exploit environmental structures, co-opt complex capacities, and elude effortful search by exploiting information that automatically arrives on the mental stage. The fluency heuristic is a prime example of a heuristic that makes the most of an automatic by-product of retrieval from memory, namely, retrieval fluency. In 4 experiments, the authors show that retrieval fluency can be a proxy for real-world quantities, that people can discriminate between two objects' retrieval fluencies, and that people's inferences are in line with the fluency heuristic (in particular fast inferences) and with experimentally manipulated fluency. The authors conclude that the fluency heuristic may be one tool in the mind's repertoire of strategies that artfully probes memory for encapsulated frequency information that can veridically reflect statistical regularities in the world.