The law and neuroscience

Some of the implications for law of recent discoveries in neuroscience are considered in a new program established by the MacArthur Foundation. A group of neuroscientists, lawyers, philosophers, and jurists are examining issues in criminal law and, in particular, problems in responsibility and prediction and problems in legal decision making.     

The neuroscience of grasping

People have always been fascinated by the exquisite precision and flexibility of the human hand. When hand meets object, we confront the overlapping worlds of sensorimotor and cognitive functions. We reach for objects, grasp and lift them, manipulate them and use them to act on other objects. This review examines one of these actions--grasping. Recent research in behavioural neuroscience, neuroimaging and electrophysiology has the potential to reveal where in the brain the process of grasping is organized, but has yet to address several questions about the sensorimotor transformations that relate to the control of the hands.     

The dream between neuroscience and psychoanalysis

The dream is tackled sometimes from the neurobiological viewpoint, sometimes from the neuropsychological angle, or from the positions of experimental and psychoanalytical psychology. Interest in dreams started with psychoanalysis in 1900, and 53 years later the discovery of REM sleep by Aserinski and Kleitman, and subsequent psychophysiological findings took the dream into the realm of biology. The dichotomous model of REM and non-REM sleep is described, as a basis for thought-like activity (non-REM sleep) and dreaming (REM sleep). This led to Hobson and McCarley's theory of activation-synthesis, suggesting that the mind while dreaming is simply the brain self-activated in REM sleep. Psychophysiological research has shown that people dream in all phases of sleep, from falling asleep to waking, but that the characteristics of the dreams may differ in the different phases. Bio-imaging studies indicate that during REM sleep there is activation of the pons, the amygdala bilaterally, and the anterior cingulate cortex, and disactivation of the posterior cingulate cortex and the prefrontal cortex. The images suggest there is a neuroanatomical frame within which dreams can be generated and then forgotten. Psychoanalysis studies the dream from a completely different angle. Freud believed it was the expression of hallucinatory satisfaction of repressed desires. Today it is interpreted as the expression of a representation of the transference in the hic et nunc of the session. At the same time it also has symbol-generating functions which provide an outlet by which affective experiences and fantasies and defences stored as parts of an unrepressed unconscious in the implicit memory can be represented in pictorial terms, then thought and rendered verbally. From the psychoanalytical point of view, the dream transcends neurobiological knowledge, and looks like a process of internal activation that is only apparently chaotic, but is actually rich in meanings, arising from the person's affective and emotional history.     

The neuroscience of remote memory

Recently, there has been renewed interest in the organization and neurobiology of remote memory, and the pace of work in this area has accelerated. Yet the recent literature does not suggest that a consensus is developing, and there is disagreement about both facts and their interpretation. This article undertakes a comprehensive review of the three kinds of evidence that have been most prominent in recent discussion: studies of retrograde amnesia in memory-impaired patients who have well-characterized lesions, neuroimaging of healthy volunteers, and work with experimental animals including lesion studies, imaging and mouse genetics. The available evidence tells a coherent story and leads to some straightforward conclusions about the neuroscience of remote memory.     

Genetic structure of the genera Psorophora (Diptera: Culicidae) in Columbian and North American populations using isoenzymes and ITS2 sequences

Two, a priori, Psorophora columbiae and one, a priori, Ps. toltecum populations from Colombia were studied by means of eleven isoenzyme loci. The levels of genetic diversity, Hardy-Weinberg equilibrium, gene flow estimates, isolation by distance and genetic relationships among these three populations were studied and the results were as follows: 1. The gene diversity levels were high as well as very similar among the three populations indicating no differences between them. 2. Within each population and from a hierarchical standpoint several loci were not in Hardy-Weinberg equilibrium simultaneously by excess and defect of heterozygous. This could reflect that several natural selection forces are acting upon these mosquito populations. 3. The gene flow estimate for these populations showed the existence of this event between them. This agrees quite well with the fact that the three populations really belong to a single species. In addition, maximum parsimony analyses with 16 isoenzyme for several individuals from four Colombian and two United States Psorophora populations showed that effectively only one species was present in the Colombian area surveyed, and that this species is Ps. columbiae, which hardly contrast with that previously suggested by other authors.     

Genetic structure of the genera Psorophora (Diptera: Culicidae) in Columbian and north American populations using isoenzymes and ITS2 sequences

Two a priori Psorophora columbiae and one a priori Ps. toltecum populations from Colombia were studied by means of eleven isoenzyme loci. The levels of genetic diversity, Hardy-Weinberg equilibrium, gene flow estimates, isolation by distance and genetic relationships among these three populations were studied and the results were as follows: (1) The gene diversity levels were high as well as very similar among the three populations indicating no differences between them. (2) Within each population and from a hierarchical standpoint several loci were not in Hardy-Weinberg equilibrium simultaneously by excess and defect of heterozygous. This could reflect that several natural selection forces are acting upon these mosquito populations. (3) The gene flow estimate for these populations showed the existence of this event between them. This agrees quite well with the fact that the three populations really belong to a single species. In addition, maximum parsimony analyses with 16 isoenzyme for several individuals from four Colombian and two United States Psorophora populations showed that effectively only one species was present in the Colombian area surveyed, and that this species is Ps. columbiae, which hardly contrast with that previously suggested by other authors. The text was submitted by the authors in English.     

Ectoparasites and fitness of female Columbian ground squirrels

Parasites play an important role in the evolution of host traits via natural selection, coevolution and sexually selected ornaments used in mate choice. These evolutionary scenarios assume fitness costs for hosts. To test this assumption, we conducted an ectoparasite removal experiment in free-living Columbian ground squirrels (Urocittelus columbianus) in four populations over three years. Adult females were randomly chosen to be either experimentally treated with anti-parasite treatments (spot-on solution and flea powder, N = 61) or a sham treatment (control, N = 44). We expected that experimental females would show better body condition, increased reproductive success and enhanced survival. Contrary to our expectations, body mass was not significantly different between treatments at mating, birth of litter or weaning of young. Further, neither number nor size of young at weaning differed significantly between the two treatments. Survival to the next spring for adult females and juveniles was not significantly different between experimental and control treatments. Finally, annual fitness was not affected by the treatments. We concluded that females and their offspring were able compensate for the presence of ectoparasites, suggesting little or no fitness costs of parasites for females in the different colonies and during the years of our experiments.     

The emergence of consequential thought: evidence from neuroscience

The ability to think counterfactually about the consequence of one's actions represents one of the hallmarks of the development of complex reasoning skills. The legal system places a great emphasis on this type of reasoning ability as it directly relates to the degree to which individuals may be judged liable for their actions. In the present paper, we review both behavioural and neuroscientific data exploring the role that counterfactual thinking plays in reasoning about the consequences of one's actions, especially as it pertains to the developing mind of the adolescent. On the basis of assimilation of both behavioural and neuroscientific data, we propose a brain-based model that provides a theoretical framework for understanding the emergence of counterfactual reasoning ability in the developing mind.     

Early contributions of Russian stress and exercise physiologists.

In Russia, the free development of scientific ideas was suppressed in 1950 as a result of the actions of the Joint Session of the Academy of Sciences and the Academy of Medical Sciences of the USSR. Hans Selye's theory on the general adaptation syndrome was considered unscientific. From 1956 to 1958, Pjotr Anokhin and Pjotr Gorizontov presented definitive arguments for having the theory accepted by scientists while the significance of hormones in adaptation became a topic of endocrine studies (Boris Aleshin, Igor Eskin, Vassily Komissarenko, Samuel Leites, and Michael Kolpakov). Later, Felius Meerson made essential contributions to the adaptive significance of protein synthesis and stress-limiting systems. The area of exercise physiology dealing with acute and chronic adaptation to strong physiological stressors was founded by Leon Orbeli and developed by Aleksei Krestovnikov. Significant contributors to this area were Vladimir Farfel, Nikolai Yakovlev, and Nikolai Zimkin. Although the majority of their publications have remained unknown outside of Russia, it is interesting that many of their results have been "rediscovered" by others. Yakovlev also deserves recognition because he was among the founders of contemporary exercise biochemistry and because his research has provided the foundation for current investigations. Several generations of young scientists have been inspired by the above-mentioned Russian scientists. Today, however, the research activities of scientists are no longer limited by political pressures but by financial resources instead.     

Cognitive neuroscience: numerate neurons

Whether the neuronal encoding of number is linear or logarithmic divides cognitive neuroscientists working on mathematical cognition. Recordings from the prefrontal cortex of the monkey support the logarithmic hypothesis. Similarities between number and the coding of other quantities are also beginning to become apparent.