Attitudes toward posthumous organ donation and commitment to donate

The medical need for human organs suitable for use as transplants far exceed the supply, and is growing. More favorable attitudes about organ donation would increase people's willingness to sign posthumous donation pledges. But effective educational programs require information about the public's present views. Verbal attitude scales were constructed and administered to 110 adults, resulting in reliable measurement of two independent dimensions, prodonation and antidonation (r = .003). Cluster analysis of the instrument revealed that the positive dimension involves belief in the humanitarian benefits of organ donation and feelings of pride experienced by the donor. The negative dimension reflects fears of body mutilation and of receiving inadequate medical treatment when one's life is at risk. Pro and anti scores in combination predicted willingness to sign a donor card. A 2 X 2 analysis of variance (High-Low Positive X High-Low Negative) revealed significant main effects for both positive and negative attitude. Also, a significant interaction effect was obtained. Those subjects who had both strong positive attitudes and weak negative attitudes were especially willing to sign donor cards. Suggestions for designing educational campaigns to promote organ donation are offered.     

Cognitive, motivational, social, and environmental influences on children's food choices

This study tested the applicability of a cognitive-motivational model of health behavior to children's food choices. A sample of 107 elementary schoolchildren provided ratings of 15 foods in terms of possible choice criteria (e.g., how tasty or healthful specific foods were) and social or environmental influences (e.g., whether foods were eaten by friends or were easy to get). Several measures of food consumption were taken, and cognitive-developmental level was assessed. Within-person correlations were calculated between food choices and each choice criterion and social/environmental factor. These "correlational indices" of influences on food choice subsequently were used to identify five distinct subgroups in the sample. Children at the operational level of cognitive development tended to be in one of three groups characterized by health orientation in food choice, taste orientation, or multiple-motive orientation. Dietary quality was poorest in the taste-oriented group. Children at the preoperational level tended to have one of two undifferentiated patterns of values across the correlational indices. Results provide evidence of: the viability of cognitive-motivational models to explain children's food choices, the promise of within-person research methodology, and the potential for enhanced health behavior-change programs by use of population segmentation and tailored interventions.     

The effect of subject's gender on judgments of similarity and choice of a comparison other

This study examined the implications for social comparison theory of the proposition that women have lower self-confidence than men when there is a socially defined standard of performance. To this end, it was hypothesized that women would judge themselves to be similar to a lower ranked person, whereas men would judge themselves to be similar to a higher ranked person. Furthermore, it was hypothesized that women would choose to see a score lower than their own, whereas men would choose to see a score higher than their own. The results on the measure of similarity indicated that men did judge themselves to be similar to a higher ranked person, whereas women showed no consistent preferences in their judgments of similarity. The results on the choice of a comparison other were not as clear-cut.     

On neurotransmitter mechanisms of reinforcement and internal inhibition

Experiments reported in this study have been performed in order to investigate cholinergic and GABA-ergic neurotransmitter systems and substance P in the realization of internal inhibition and pain reinforcement. This was accomplished during the elaboration of inhibitory and defensive conditioned reflexes to light flashes in alert, nonimmobilized rabbits. Present results together with a review of past research indicate that the cholinergic system is directly involved in transmitting the effects of pain reinforcement to neocortical neurons. Substance P, a neuropeptide, reduces the background activity of neocortical and hippocampol neurons and the response of cortical neurons to pain and positive conditioned stimuli. The cholinergic system and substance P exert a modulating effect on the elaboration of internal inhibition. Phenybut, a GABA derivative capable of penetrating the blood-brain barrier, enhances inhibitory hyperpolarization in the cerebral cortex and improves discrimination between the inhibitory and reinforcing light flashes. It appears, therefore, that the GABA-ergic system plays a leading part in the elaboration of internal inhibition. Neuronal activity and slow potential changes in response to positive conditioned and pain stimuli occur in the same direction after administering the preparations, and the dynamics of these changes is different from that in responses to inhibitory stimuli. It may be supposed on these grounds that the neurotransmitter and neuromodulator systems studied possess a considerable degree of plasticity.     

Secobarbital and perceptual processing

An experiment which employed each of 18 subjects in four days of testing was used to examine acute secobarbital dose treatment effects on choice reaction time in a Cooper and Shepard (1973) character recognition task. Manipulations of visual stimulus degradation, character difficulty, 180 degree rotation, and mirror-image reversal were included in order to evaluate the hypothesis that the drug affects performance by disrupting early stimulus input processing. The results indicate significant increases in the effect of secobarbital on reaction time and errors under conditions of visual stimulus degradation. The effects of the drug, however, were not changed by 180 degree rotation of the target character or by the other task variables. The results were interpreted to indicate that secobarbital impairs performance primarily by placing selective stress on hypothetical early encoding activities and that later processing operations (associated with use of an internal representation of the target character) are not affected by the drug. Strengths and weaknesses of the two-stage model of visual stimulus processing are discussed and implications of the model for future drug research are indicated.     

Science as a justification for psychology as a social institution

Psychology seeks to justify its claims to privilege as a social institution largely on the basis of its scientific knowledge claims. These knowledge claims tend to be based on, and to reflect a particular view about the nature of science which is under increasing challenge. This situation is discussed and some of its implications examined.     

A word’s meaning affects the decision in lexical decision

The influence of an isolated word’s meaning on lexical decision reaction time (RT) was demonstrated through four experiments. Subjects in two experiments made lexical decision judgments, those in a third experiment pronounced the words used in the lexical decision task, and those in a fourth experiment quickly pronounced their first associative response to the words. Differences in lexical access time for the words were measured with the pronunciation task, and differences in meaning were assessed with the association task. Multiple regression analyses of lexical decision RT were conducted using associative RT, pronunciation RT, and other target word properties (printed frequency, length, instance dominance, and number of dictionary meanings) as predictor variables. These analyses revealed a relationship between lexical decision RT and associative RT after the effects of other variables had been partialed out. In addition, word frequency continued to have a significant relationship to lexical decision RT beyond that shared with pronunciation RT and the other variables. The results of these experiments indicate that at least some of the effect of word meaning and word frequency in lexical decision is attributable to a decision stage following lexical access.     

Postsurgical enrichment aids adult hemidecorticate rats on a spatial navigation task

The effect of environmental enrichment on normal rats, rats that received hemidecortication at birth, and rats that received hemidecortication when adult was studied in the Morris water task, which is a spatial navigation task requiring the use of distal cues for successful performance. Enrichment was achieved by housing the rats for 90 days in a large outdoor compound that was designed to model a natural environment. Adult hemidecorticated lab-raised rats were severely impaired in the acquisition of the task but neonatally hemidecorticated rats, although also impaired, showed significant sparing. Postsurgical, but not presurgical, enrichment of adult hemidecorticated rats significantly enhanced their recovery. Enrichment had little effect on neonatally decorticated rats or on normal rats. Although there were no gross anatomical changes associated with enrichment, the paradigm provides both a robust phenomena and a cortically dependent task that is ideal for investigating the processes in the remaining intact hemisphere that must support recovery.