Recall of rapidly presented random chess positions is a function of skill

A widely cited result asserts that experts’ superiority over novices in recalling meaningful material from their domain of expertise vanishes when they are confronted with random material. A review of recent chess experiments in which random positions served as control material (presentation time between 3 and 10 sec) shows, however, that strong players generally maintain some superiority over weak players even with random positions, although the relative difference between skill levels is much smaller than with game positions. The implications of this finding for expertise in chess are discussed and the question of the recall of random material in other domains is raised.     

REM motivation induced by brief REM deprivation: the influence of cognition, gender, and personality.

Prominence of the brain's right-hemisphere information processing and intensity of dream experience are two theoretically related constructs that have been proposed as important psychological aspects of REM sleep. Either view is consistent with the prediction that the effect of REM deprivation will depend in part on the nature of cognitive activity that is initiated at the onset of each REM period and that "substitutes" for the interrupted REM process. In the present study, the effect of REM deprivation was more striking for female subjects given a digits task than for female subjects given a fantasy-reporting task during awakening used to induce REM deprivation for the first 6 hours of the night. High neuroticism appeared to exaggerate the effect. No corresponding pattern was observed for the male subjects. These preliminary finding may be exaggerated by cognitive activity that is functionally incongruent with those processes. The results also raise interesting questions about individual differences.     

The contribution of music vs instructions in the Musical Mood Induction Procedure

The relative contribution of the instructions and the music to the effects of the Musical Mood Induction Procedure (MMIP) were investigated. Using an experimental procedure which minimised covert experimenter bias, subjects performed under both elation and depression mood inductions in one of four conditions: music present or absent by mood change instructions present or absent, using a crossover design. Results indicated that instructions were both necessary and sufficient to produce change on mood sensitive measures. Mood change effects were reduced by controlling for the effect of subjects who responded so as not to ‘louse-up’ the experiment. The MMIP seems to be much less musical than the name implies. Further research is needed to determine which aspects of the instructions contribute most to the changes on mood sensitive measures.     

Modeling semantic memory: Effects of presenting semantic information in different modalities

How is semantic information from different modalities integrated and stored? If related ideas are encountered in French and English, or in pictures and sentences, is the result a single representation in memory, or two modality-dependent ones? Subjects were presented with items in different modalities, then were asked whether or not subsequently presented items were identical with the former ones. Subjects frequently accepted translations and items semantically consistent with those presented earlier as identical, although not as often as they accepted items actually seen previously. The same pattern of results was found when the items were French and English sentences, and when they were pictures and sentences. The results can be explained by the hypothesis that subjects integrate information across modalities into a single underlying semantic representation. A computer model, embodying this hypothesis, made predictions in close agreement with the data.     

Probabilistic inference in human semantic memory

The idea of viewing human cognition as a rational solution to computational problems posed by the environment has influenced several recent theories of human memory. The first rational models of memory demonstrated that human memory seems to be remarkably well adapted to environmental statistics but made only minimal assumptions about the form of the environmental information represented in memory. Recently, several probabilistic methods for representing the latent semantic structure of language have been developed, drawing on research in computer science, statistics and computational linguistics. These methods provide a means of extending rational models of memory retrieval to linguistic stimuli, and a way to explore the influence of the statistics of language on human memory.