Sleep deprivation impairs object recognition in mice

Many studies in animals and humans suggest that sleep facilitates learning, memory consolidation, and retrieval. Moreover, sleep deprivation (SD) incurred after learning, impaired memory in humans, mice, rats, and hamsters. We investigated the importance of sleep and its timing in an object recognition task in OF1 mice subjected to 6h SD either immediately after the acquisition phase (0-6 SD) or 6h later (7-12 SD), and in corresponding undisturbed controls. Motor activity was continuously recorded with infrared sensors. All groups explored two familiar, previously encountered objects to a similar extent, both at the end of the acquisition phase and 24h later during the test phase, indicating intact familiarity detection. During the test phase 0-6 SD mice failed to discriminate between the single novel and the two familiar objects. In contrast, the 7-12 SD group and the two control groups explored the novel object significantly longer than the two familiar objects. Plasma corticosterone levels determined after SD did not differ from time-matched undisturbed controls, but were significantly below the level measured after learning alone. ACTH did not differ between the groups. Therefore, it is unlikely that stress contributed to the memory impairment. We conclude that the loss of sleep and the activities the mice engaged in during the SD, impaired recognition memory retrieval, when they occurred immediately after acquisition. The delayed SD enabled memory consolidation during the 6h when the mice were allowed to sleep, and had no detrimental effect on memory. Neither SD schedule impaired object familiarity processing, suggesting that only specific cognitive abilities were sensitive to the intervention. Sleep may either actively promote memory formation, or alternatively, sleep may provide optimal conditions of non-interference for consolidation.     

The role of moral utility in decision making: An interdisciplinary framework

What decisions should we make? Moral values, rules, and virtues provide standards for morally acceptable decisions, without prescribing how we should reach them. However, moral theories do assume that we are, at least in principle, capable of making the right decisions. Consequently, an empirical investigation of the methods and resources we use for making moral decisions becomes relevant. We consider theoretical parallels of economic decision theory and moral utilitarianism and suggest that moral decision making may tap into mechanisms and processes that have originally evolved for nonmoral decision making. For example, the computation of reward value occurs through the combination of probability and magnitude; similar computation might also be used for determining utilitarian moral value. Both nonmoral and moral decisions may resort to intuitions and heuristics. Learning mechanisms implicated in the assignment of reward value to stimuli, actions, and outcomes may also enable us to determine moral value and assign it to stimuli, actions, and outcomes. In conclusion, we suggest that moral capabilities can employ and benefit from a variety of nonmoral decision-making and learning mechanisms.     

Preventing and reducing substance use among institutionalized adolescents

The Residential Student Assistance Program, serving high-risk, multiproblem, inner-city, primarily African-American and Latino youth, was evaluated for its ability to prevent and decrease alcohol and other drug use. Participants were drawn from several adolescent residential facilities: three foster care sites for abused, neglected, orphaned, or troubled adolescents, a nonsecure facility for adjudicated juvenile offenders, a treatment center for teens with severe psychiatric problems, and a locked county correctional facility. In addition, comparison groups were employed. A 5th-year outcome evaluation documented the program's effectiveness in both preventing and reducing substance use among participants, with impact related to program dosage. Qualitative process data clarified and strengthened confidence in the quantitative outcomes.     

Book reviews

A Reader on Classical Islam. F. E. Peters, 1994. Princeton, Princeton University Press. 420 pp., hb. £30.50, ISBN 0–691–03394–3; pb. £15.00, ISBN 0–691–00040–9.

The Physical Theory of Kalam: atoms, space and void in Basrian Mu'tazili cosmology. (Islamic Philosophy, Theology and Science, Vol. XIV). Alnoor Dhanani, 1994. Leiden, E. J. Brill. 209 pp., hb. n.p., ISBN 90–04–09831–3.

Empire to Commonwealth: consequences of monotheism in late antiquity. Garth Fowden, 1993. Princeton, Princeton University Press. 205 pp., hb. £12.95, ISBN 0–691–06989–1.

Religions in the UK: a multi‐faith directory. Paul Weller (Ed.), 1993. Derby, University of Derby in association with the Interfaith Network for the United Kingdom. 630 pp. plus indices, pb. £21.50, ISBN 0–901437–06–9.

Islamic Britain: religion, politics and identity among British Muslims: Bradford in the 1990s. Philip Lewis, 1994. London, I. B. Tauris. 250 pp., pb. £9.95, ISBN 1–85043–861–7.

Bosnia and Hercegovina: a tradition betrayed. Robert J. Donia and John V. A. Fine, Jr., 1994. London, Hurst and Company. 280 pp., hb. £9.50, ISBN 1–85065–211–2.

French and Algerian Identities from Colonial Times to the Present: a century of interaction. Alec G. Hargreaves and Michael J. Heffernan (Eds), 1993. Lampeter, The Edwin Mellen Press. 253 pp., hb. £39.95, ISBN 0–7734–9233‐X.

The Course of Islam in Africa. (Islamic Surveys 15). Mervyn Hiskett, 1994. Edinburgh, Edinburgh University Press. 218 pp., hb. £35.00, ISBN 0–7486–0464–2; pb. £16.95, ISBN 0–7486–0461–8.

The Writings of Eastern Sudanic Africa to c. 1900. R. S. O'Fahey (comp.) 1994. Leiden, E. J. Brill. 434 pp., hb. n.p., ISBN 90–04–09450–4.     

Obstacles to Personal Creativity between Brazilian and Mexican University Students: A Comparative Study

The study focused on personal obstacles to creativity between 385 Brazilian and 305 Mexican university students. The Obstacles to Personal Creativity Inventory, designed and validated by Alencar (1999b), was administered to these students. The results indicated that Lack of Time/Opportunity was the most frequent obstacle. Significant differences were observed between Brazilian and Mexican students in the cluster of obstacles named Lack of Motivation, and between male and female students in the cluster of obstacles named Inhibition/Shyness. The results point to several obstacles to personal creativity which are common among university students. These obstacles should be known by those involved in education in order for them to help students to be less susceptible to obstacles that hinder their creativity.     

Conceptual representations in goal-directed decision making

Emerging evidence suggests that the long-established distinction between habit-based and goal-directed decision-making mechanisms can also be sustained in humans. Although the habit-based system has been extensively studied in humans, the goal-directed system is less well characterized. This review brings to that task the distinction between conceptual and nonconceptual representational mechanisms. Conceptual representations are structured out of semantic constituents (concepts)—the use of which requires an ability to perform some language-like syntactic processing. Decision making—as investigated by neuroscience and psychology—is normally studied in isolation from questions about concepts as studied in philosophy and cognitive psychology. We ask what role concepts play in the “goal-directed” decision-making system. We argue that one fruitful way of studying this system in humans is to investigate the extent to which it deploys conceptual representations.     

The cognitive and neural basis of option generation and subsequent choice

Decision-making research has thoroughly investigated how people choose from a set of externally provided options. However, in ill-structured real-world environments, possible options for action are not defined by the situation but have to be generated by the agent. Here, we apply behavioral analysis (Study 1) and functional magnetic resonance imaging (Study 2) to investigate option generation and subsequent choice. For this purpose, we employ a new experimental task that requires participants to generate options for simple real-world scenarios and to subsequently decide among the generated options. Correlational analysis with a cognitive test battery suggests that retrieval of options from long-term memory is a relevant process during option generation. The results of the fMRI study demonstrate that option generation in simple real-world scenarios recruits the anterior prefrontal cortex. Furthermore, we show that choice behavior and its neural correlates differ between self-generated and externally provided options. Specifically, choice between self-generated options is associated with stronger recruitment of the dorsal anterior cingulate cortex. This impact of option generation on subsequent choice underlines the need for an expanded model of decision making to accommodate choice between self-generated options.