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.     

Study for now,but judge for later: Delayed judgments of learning promote long‐term retention

Larsson Sundqvist, M., Todorov, I., Kubik, V. & Jönsson, F.U. (2012) Study for now, but judge for later: Delayed judgments of learning promote long‐term retention. Scandinavian Journal of Psychology 53, 450–454. Delayed judgments of learning (JOL) are assumed to be based on covert retrieval attempts. A common finding is that testing memory during learning improves later retention (i.e., the testing effect), and even more so than an equivalent amount of study, but only after a longer retention interval. To test the assertion that also delayed JOLs improve memory, the participants either studied Swahili‐Swedish word pairs four times, or they both studied (two times) and performed delayed JOLs (two times) alternately. Final cued recall test were given after either five minutes or one week. Results showed a reliable learning‐group by retention‐interval interaction, with less forgetting in the group that alternated between studying and making JOLs. The results are discussed in relation to the self‐fulfilling prophecy account of Spellman and Bjork (1992) , and in terms of study advice, the results further underscore the importance of delaying JOLs when studying and evaluating one’s ongoing learning.     

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.     

Memory dysfunction in mild aphasics

The effect of mild aphasia ( n = 9), as a result of subarachnoid haemorrhage (SAH), was evaluated against one matched (sex, age, and education) control group suffering from SAH of unknown origin without aphasia, and against one matched healthy control group. According to aphasia testing (Reinvang & Engvik, 1980), criteria for a classical diagnosis were not met. Therefore, the patients were characterized as mild aphasics: They generally displayed intact audo-verbal comprehension and repetition abilities, and they demonstrated a fluent, spontaneous speech. However, they showed phonemic and semantic paraphasias, with self-corrections; a few patients displayed alexia and agraphia. Memory performance of these three groups was evaluated by a neuropsychological test battery, designed to tap various components of verbal memory function. From the results it was concluded that: (a) Short-term memory is impaired, as regards the phonological loop and the central executive in working memory, whereas maintenance rehearsal is unaffected, given that the demands on phonological coding is minimized, (b) long-term memory is also generally impaired, whereas long-term learning and forgetting by means of subject-performed tasks proceeds within a normal range. Impairments were hypothesized to reflect less efficient central executive functions of working memory, involving generation of less appropriate semantic codes and phonological representations, (c) mildy aphasic patients are not subjectively aware of their own memory deficits, and (d) aphasia classification by means of standard procedures do not sufficiently characterize the nature of a mildy aphasic patient's memory problems.     

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.     

Outline and description of an electronic system for lateralization of visual stumuli in studies of hemispheric asymmetry

An automatic electronic systenm for lateralization of visual stimuli research on hemispheric asymmetry is described. The system consists of three different units: 1) A stimulas projection- unit; 2)an electronic control-unit; and 3)a programming-unit. Necessary characteristics of apparatus for studies using lateralized visual stimuli are described in the paper. Among the listed requirements are: range of stimulus-duration, rise- and fall-time for onset and offset to full intensity of the stimulus, stimulus-eccentricity, and eye-fixation control. The system described in the paper has been in use in our laboratory for the last two years. It is concluded that the system meets the requirements for apparatus used in studies with laterlized visual input. A block-diagram of the electronics and a schematic outline according to scale of the stimulus projection-unit are enclosed with the paper.     

Some aspects on behavioral teratology research

A compelling question in teratology research is whether the experimental model used allows for extrapolation from laboratory animals to man. Our thesis is that behaviors that are biologically relevant for the animal are more likely to reveal the relationship between the behavior and its substrate than are non-specific behaviors. Applying this reasoning to the study of the ontogenesis of the behavior, we plead for including the use of species-typical behaviors in testing for teratogenic effects. Our further discussion is focussed upon the different levels at which an analysis of teratogenic effects may be carried out. At one level, the analysis is directed towards the behavioral effects of a given treatment; at another level to specify the function that is impaired by the treatment.     

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.