Cognitive sequelae of repeated head injury in a population of intravenous drug users

The relationship between closed head injury and performance on neuropsychological (NP) tests was investigated in a group of intravenous drug users (IVDUs). Subjects with repeated head traumas involving loss of consciousness (LOC) performed worse than both a control group without LOC and reference group with only a single episode of LOC. There were no significant differences between the last two groups. Performance on tests of memory, attention, and motor performance was significantly worse in the group with repeated head injury. The average time since the last episode of LOC was more than 11 years. We conclude from these findings that a single episode of LOC does not result in significant cognitive impairment in this population. Two or more episodes, however, are more likely to produce chronic cognitive impairment.     

Dark-adaptation of the human rod system: A new hypothesis

Following a long, full bleach, rod dark-adaptation curves from two normal trichromats were obtained with test fields of various size, exposure time and retinal eccentricity. The results show that there is a substantial region of threshold recovery with an approximately constant, linear slope of about 0.27 log per minute of dark-adaptation, which is independent of the test variables. It is suggested that the increase in sensitivity during this constant, linear slope is completely determined by changes in the concentration of bleached rhodopsin. The relationship between change of relative threshold (T) and fraction of bleached rhodopsin ( B ) is given by T=B ^3,7. This exponential law is well described by the displacement of the equilibrium between the active and inactive states of an allosteric enzyme built as a tetrarner.     

The psychobiology of parenting in mammals

Parental behavior denotes a vareity of genetically programmed activities in which parents help their young to survive to maturity. A highly successful research has been devoted to the psychoneuroendocrine bases of parenting in two species, rat and sheep. As a result empirical data along with conceptual formulations have been obtained which provide a model for generating hypothesis for the study of other species. This review was written to draw the attention to this research because of its enormous potential significance for problems pertaining to human infant care. It discusses the current status of research on the physiological bases of parental behavior,     

Explicatio and Complicatio: On the Understanding of the Relationship between God and the World in the Work of Nicholas Cusanus

Cusanus understands the relationship between God and the world through the concept of participation, which he explores through the twin concepts of explicatio (unfolding) and complicatio (enfolding). In Cusanus' view, the dialectics of explicatio and complicatio even apply concerning the relationship between God and humanity. This is explored concerning the relation between divine providence and human freedom, concerning the problem of worship and idolatry, and concerning the understanding of Christ as unfolded divinity and enfolded humanity. It is argued that this allows for an understanding of salvation through grace without reducing the importance of human involvement.     

Differentiating between ADHD sub-types on CCPT measures of sustained attention and vigilance

The aim of the study was to test whether sustained attention and vigilance, often considered as the same phenomenon, dissociate on the Conners' Continuous Performance Test, and whether subjects with ADHD-Inattentive type and ADHD-Combined type differ with regard to these measures. Sixty-five healthy controls and 67 subjects with ADHD between 9 and 16 years of age participated in the study. The ADHD-I group performed below control children on Hit Reaction Time Block Change, considered to measure sustained attention and the ADHD-C group scored below controls on Hit Reaction Time Inter-Stimulus-Interval, considered to measure vigilance. Comparing the two clinical groups showed a test by group interaction, with ADHD-I subjects performing below ADHD-C subjects with regard to sustained attention and above ADHD-C subjects with regard to vigilance. Sustained attention on the CCPT correlated specifically with parent and teacher ratings of inattention, but not with ratings of hyperactivity-impulsivity, while vigilance correlated with all symptom ratings.     

Self-stimulation and mating behavior in the male rat

Abstract.— A presumed relationship between selfstimulation of the brain and sexual behavior was studied in two experiments. In the first experiment the male rat was allowed self-stimulation during a period of 5 minutes and thereafter transferred to a mating cage with a female. No effects of the self-stimulation were recorded in the mating behavior. In the second experiment the male was allowed one intromission and thereafter presented with a lever for self-stimulation, still having access to the female. The sexual responses were completely inhibited, and selfstimulation at normal rate resumed. It was concluded that there is no necessary link between self-stimulation of the brain and sexual behavior.     

Assessing therapeutic problem solving skills: Empirical analysis of a measuring operation

Employment of caregivers as trainers is an imperative in the training and treatment of mentally retarded persons. Besides being taught specific behavior modification skills, these paraprofessional trainers have to obtain a set of general skills in order to adjust their specific skills to new clients, situations, and behaviors across time. Empirical research on the characteristics of therapeutic problem-solving skills are scarce. This may be due to a reluctance of behavior researchers against including cognitive factors in the analysis of behavior influence. However, the development of basic knowledge on the existence of therapeutic problem-solving skills should be one of the primary research goals. This article describes the development and application of four scales assumed to be representative of an important set of general skills—therapeutic problem-solving skills. By means of these four scales 21 caregivers were evaluated before and after extensive training. A multifaceted measuring operation is employed with the main objective of empirically testing the dimensionality of problem-solving skills. Rater consistency and individual differences in change from pre- to post-training level are also uncovered. It is concluded that the four scales of therapeutic skills, largely reflect the same underlying concept of a rather general therapeutic problem-solving skill. Discussion of the findings also pointed to future research.