Pavlovian contingencies and temporal information

The effects of altering the contingency between the conditioned stimulus (CS) and the unconditioned stimulus (US) on the acquisition of autoshaped responding was investigated by changing the frequency of unsignaled USs during the intertrial interval. The addition of the unsignaled USs had an effect on acquisition speed comparable with that of massing trials. The effects of these manipulations can be understood in terms of their effect on the amount of information (number of bits) that the average CS conveys to the subject about the timing of the next US. The number of reinforced CSs prior to acquisition is inversely related to the information content of the CS.     

Psychological management and body image issues in facial transplantation

Facial transplantation, although controversial, is proposed as a major advance in facial reconstructive surgery, with the first partial transplant having taken place in France in November 2005. Although the psychological impact of facial transplantation will not be understood until several procedures have been carried out, this article examines the psychological issues likely to arise with particular reference to body image. A detailed framework for anticipation and management of psychological change is proposed. Pre-operative preparation must include thorough psychological preparation for the patient and their family. The immediate post-operative period is likely to be challenging, and a detailed management plan is proposed emphasising early return to function; subsequent psychological issues including altered body image, anxiety, shame, depression, communication and behavioural avoidance are discussed and a management strategy based on cognitive behavioural principles is proposed for the first post-operative year. Previous discussion frames psychological outcome in terms of complication and risk, tending to downplay the potential advantages of a successful procedure; the focus of this paper is on ensuring psychological adjustment as an inevitable consequence of change.     

The role of awareness in delay and trace fear conditioning in humans

Expression of conditional fear without awareness has been previously demonstrated during delay conditioning, a procedure in which the conditioned stimulus (CS) and unconditioned stimulus (UCS) overlap. However, less is known about the role of awareness in trace fear conditioning, where an interval of time separates the CS and UCS. The present study assessed skin conductance response (SCR) and UCS expectancy during delay and trace conditioning. UCS predictability was varied on a trial-bytrial basis by presenting perithreshold auditory CSs. Differential UCS expectancies were demonstrated only on perceived delay and trace trials. Learning-related SCRs were observed during both perceived and unperceived delay CSs. In contrast, differential SCRs were demonstrated only for perceived trace CSs. These data suggest that awareness is necessary for conditional responding during trace, but not delay, fear conditioning.     

The Moral Judgment of Juvenile Delinquents: A Meta-Analysis

A meta-analysis of 50 studies was conducted to investigate whether juvenile delinquents use lower levels of moral judgment than their nondelinquent age-mates and, if so, what factors may influence or moderate the developmental delay. The results show a lower stage of moral judgment for juvenile delinquents (d=.76). Effect sizes were large for comparisons involving male offenders, late adolescents, delinquents with low intelligence, and incarcerated delinquents. The largest effect sizes were found for period of incarceration and comparisons involving juvenile delinquents with psychopathic disorder. Production instead of recognition measures, dilemma-free assessment methods, and non-blind scoring procedures yielded relatively large effect sizes, whereas effect sizes were medium for comparisons involving delinquents with average intelligence, non-incarcerated delinquents, female offenders, as well as early and middle adolescents. Psychopathic disorder and institutionalization were identified as unique moderators of the link between moral judgment and juvenile delinquency. It is concluded that developmentally delayed moral judgment is strongly associated with juvenile delinquency, even after controlling for socioeconomic status, gender, age and intelligence.This article stems from a paper presented at the meeting of the Association for Moral Education, July 2006, Fribourg, Switzerland.     

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.     

Effects of the timing and identity of retrieval cues in individual recall: an attempt to mimic cross-cueing in collaborative recall

Inhibitory effects in collaborative recall have been attributed to cross-cueing among partners, in the same way that part-set cues are known to impair recall in individuals. However, studies of part-set cueing in individuals typically involve presenting cues visually at the start of recall, whereas cross-cueing in collaboration is likely to be spoken and distributed over time. In an attempt to bridge this gap, three experiments investigated effects of presenting spoken part-set or extra-list cues at different times during individual recall. Cues had an inhibitory effect on recollection in the early part of the recall period, especially when presented in immediate succession at the start of recall. There was no difference between the effects of part-set and extra-list cues under these presentation conditions. However, more inhibition was generated by part-set than extra-list cues when cue presentation was distributed throughout recall. These results are interpreted as suggesting that cues presented during recall disrupt memory in two ways, corresponding to either blocking or modifying retrieval processes. Implications for explaining and possibly ameliorating inhibitory effects in collaborative recall are discussed.