Schultz, Wolfram. Predictive reward signal of dopamine neurons. J. Neurophysiol. 80: 1–27, 1998. The effects of lesions, receptor blocking, electrical self-stimulation, and drugs of abuse suggest t...

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Predictive Reward Signal of Dopamine Neurons

http://www.columbia.edu/itc/gsas/g9600/2003/JavitchReadings/Schultz(Sulzer).pdf

Getting Formal with Dopamine and Reward

Fluid intelligence (Gf) refers to the ability to reason and to solve new problems independently of previously acquired knowledge. Gf is critical for a wide variety of cognitive tasks, and it is considered one of the most important factors in learning. Moreover, Gf is closely related to professional and educational success, especially in complex and demanding environments. Although performance on tests of Gf can be improved through direct practice on the tests themselves, there is no evidence that training on any other regimen yields increased Gf in adults. Furthermore, there is a long history of research into cognitive training showing that, although performance on trained tasks can increase dramatically, transfer of this learning to other tasks remains poor. Here, we present evidence for transfer from training on a demanding working memory task to measures of Gf. This transfer results even though the trained task is entirely different from the intelligence test itself. Furthermore, we demonstrate that the extent of gain in intelligence critically depends on the amount of training: the more training, the more improvement in Gf. That is, the training effect is dosage-dependent. Thus, in contrast to many previous studies, we conclude that it is possible to improve Gf without practicing the testing tasks themselves, opening a wide range of applications.

/pdf/improving-fluid-intelligence-with-training-on-working-memory-1lofpgaegw.pdf

Improving fluid intelligence with training on working memory

The biological existence of human beings has become political in novel ways. The object, target and stake of this new 'vital' politics are human life itself. The contemporary state does not 'nationalize' the corporeality of its subjects into a body politic on which it works en masse, in relation to the body politics of other states competing in similar terms. Biopolitics addresses human existence at the molecular level: it is waged about molecules, amongst molecules, and where the molecules themselves are at stake. Human beings in contemporary Western culture are increasingly coming to understand themselves in somatic terms – corporeality has become of the most important sites for ethical judgements and techniques. Biopolitics was inextricably bound up with the rise of the life sciences, the human sciences, clinical medicine. It has given birth to techniques, technologies, experts and apparatuses for the care and administration of the life of each and all, from town planning to health services.

/pdf/the-politics-of-life-itself-4278mv6s8b.pdf

The Politics of Life Itself

Inverted-U-shaped dopamine actions on human working memory and cognitive control.

Previous studies of the effects of the psychomotor stimulant, methylphenidate, have concentrated on vigilance and reaction time tasks. In this study, the effects of methylphenidate on more complex aspects of cognition were studied using tasks from the CANTAB battery and related tests which have been shown to be sensitive to frontal lobe dysfunction. Twenty-eight young healthy men participated in a counterbalanced, double-blind, placebo-controlled study of the effects of methylphenidate. Cognitive assessment included tests of spatial working memory, planning, verbal fluency, attentional set-shifting and sustained attention. Methylphenidate had significant effects on performance of the tests of spatial working memory and planning but not on the attentional and fluency tests. When the drug was taken on the first test session, performance on the spatial tests was enhanced by the drug compared to placebo. However, when the drug was taken second, performance accuracy was impaired whereas response latencies were decreased. These results are consistent with a hypothesis that methylphenidate influences performance in two conflicting ways; enhancing executive aspects of spatial function on novel tasks but impairing previously established performance. This pattern of effects is discussed within the framework of dual, interacting arousal mechanisms.

A. Bannerjea

Papers

Effects of methylphenidate on spatial working memory and planning in healthy young adults