Circadian factors during sustained performance: Background and methodology

Cornell University Medical College, Westchester Division, The New York Hospital, White Plains, New York It is well established that there is a complex timekeeping mechanism in the human brain. This mechanism is associated with a variety of physiological and psychological rhythms having a period of about a day, and thus referred to as circadian rhythms. The circadian system has recently been modeled in terms of two underlying oscillators, one much more resistant to changes in routine than the other. These oscillators are considered to be endogenous, that is, internal to the organism, and not reliant for their existence upon changes in the person’s environment or general behavior. They thus continue to run even when the sleep/wake cycle is suspended, as in sustained operations. Thus, by their very nature, sustained operations require the individual to override the inputs that are coming from his or her circadian system (especially the indication that sleep is required). The aim of this paper is to provide a background to the area of circadian rhythms research, including a section on the methodology, so that the impact of the circadian system on sustained operations can be better understood.     

Effects of implementing (APA) ethical principles in collecting classroom data

The study examined the effects of providing six levels of research information to 270 classroom subjects on the data obtained from three different cognitive tasks. The effects of the three tasks on the subjects' academic self-concepts were also investigated. No significant differences were found among the six levels of information for each of the three tasks. On the logical task a significant linear relationship was found supporting previous research which indicates that the more information that is given to research subjects, the more negative the results. There were no significant differences on self-concept scores across the three tasks used. Overall, the implementation of ethical principles had little effect on data collected in classroom settings, indicating support for implementation. This data did indicate, however, that providing more information than required under the ethical principles can result in data bias on a specific task.     

Depth of processing: When the principle of congruity fails

Two factors, level of processing (Craik & Lockhart, 1972) and congruity (Schulman, 1974), known to have large effects on the recall of experimenter-provided responses to questions, were examined in a series of five incidental learning experiments using subject-generated responses. The data show that manipulation of level of processing has the same effect on recall of subjectgenerated responses as it does on experimenter-provided responses. However, the effect of congruity is reversed for subject-generated responses. The data suggest that the difficulty of generating unrelated responses (“incongruous“ items) may account, at least in part, for the failure of the “principle of congruity“ with subject-generated responses.     

Meaning,amount of processing,and memory for words

Two experiments were carried out in order to try to resolve the controversy about whether the semantic processing of a word necessarily involves all the elements of its meaning. In the first experiment, subjects categorized a list of auditorially presented words according to whether or not they were natural consumable solids (e.g., “apple“). They were then given an unexpected test of their ability to recall the whole list, which contained equal numbers of words with none, one, two, or all three of the target components. The results confirmed the prediction that the greater the number of components a word has in common with a target category, the better it will be recalled. The second experiment used a visual presentation of a list of words, which subjects scanned for members of a particular target category. There were four different target categories assigned to independent groups of subjects. The results again confirmed the prediction. On the assumption that memorability in such tasks is determined by amount of processing, we conclude that some elements of the meaning of a word can be processed without having to process all of them.     

Matrix derivatives with chain rule and rules for simple,Hadamard, and Kronecker products

The differential calculus for scalars is used to develop theorems for a calculus of functions of matrices. No appeal to scalar notation is necessary in the resulting calculus, so that the given chain and matrix product rules have wide applicability to matrix theory and models. The chain and product rules of scalar calculus become a special case of the matrix rules. The methods are illustrated by application to a generalized stochastic process model potentially relevant to long- and short-term memory.     

Personality differences between established and less-established male and female creative artists

Past research on personality constructs of creative individuals has focused on men rather than women and has neglected the essentially social aspect of being considered creative. Therefore, personality variables of 60 male and 60 female creative artists were described using the California Psychological Inventory (CPI). Male and female groups were further divided equally into two subgroups reflecting a difference in degree of social acceptance of their work. Relationships between the four groups were explored by multiple discriminant analysis. The major conclusion noted was that creative females tend to be more like their creative male counterparts, in terms of CPI scale variation, than are males and females in general.