Hemispheric asymmetries in the identification of band-pass filtered letters

Processing of band-pass filtered letters in the left versus right cerebral hemispheres (LH vs. RH) was examined. The present experiments constituted a partial replication of a study in which Peterzell, Harvey, and Hardyck (1989) found no hemispheric differences in accuracy or reaction time (RT) as a function of spatial frequency. However, methodological limitations of their study (e.g., the possibility that subjects were engaged in a detection, not identification, task) may have obscured possible hemispheric differences. We addressed these problems in the present study, obtaining significant hemisphere × spatial frequency interactions for RT andd', with RH advantages at low frequencies and LH advantages at high frequencies; however, these effects were not large in magnitude and were often restricted to particular dependent variables, stimulus sizes, and so forth. Hemispheric differences in response bias were also found.     

Questions of criteria: Reply to Peterzell (1997)

In a reply to our report on hemispheric differences in processing band-pass filtered letters (Christman, Kitterle, & Niebauer, 1997), Peterzell (1997) argues that our results are not attributable to hemispheric asymmetries in spatial frequency processing. Rather, Peterzell argues that factors such as response criteria and stimulus visibility can account for our results. We argue that our results are attributable (at least in part) to hemispheric asymmetries in spatial frequency processing, while at the same time we acknowledge the potential influence of other factors in the determination of hemispheric differences.     

Correlation,partial correlation,and causation

Philosophers and scientists have maintained that causation, correlation, and “partial correlation” are essentially related. These views give rise to various rules of causal inference. This essay considers the claims of several philosophers and social scientists for causal systems with dichotomous variables. In section 2 important commonalities and differences are explicated among four major conceptions of correlation. In section 3 it is argued that whether correlation can serve as a measure of A's causal influence on B depends upon the conception of causation being used and upon certain background assumptions. In section 4 five major kinds of “partial correlation” are explicated, and some of the important relations are established among two conceptions of “partial correlation”, the conception of “screening off”, the conception of “partitioning”, and the measures of causal influence which have been suggested by advocates of path analysis or structural equation methods. In section 5 it is argued that whether any of these five conceptions of “partial correlation” can serve as a measure of causal influence depends upon the conception of causation being used and upon certain background assumptions. The important conclusion is that each of the approaches (considered here) to causal inference for causal systems with dichotomous variables stands in need of important qualifications and revisions if they are to be justified.     

Anhedonia and perceptual aberration in first-episode psychotic patients and their relatives

One hundred eighteen psychiatric patients, each experiencing his or her first lifetime episode of psychosis, 125 of their first-degree relatives, and 155 normal subjects were assessed using the physical anhedonia, social anhedonia, and perceptual aberration scales of Chapman et al. (1976, 1978). We hypothesized that psychotic subjects would obtain higher scores on these scales than their relatives and the controls, and we expected the group of relatives to score more deviantly than the normal controls. The physical anhedonia and social anhedonia scales successfully differentiated the psychiatric patients from the relatives and the latter from the normal subjects. These findings testify to the construct validity of the scales and suggest that they tap a predisposition to psychosis. Unexpectedly, the relatives scored lower on the perceptual aberration scale than did the normal controls, perhaps because the relatives adopted a defensive response set.     

THE REBIRTH OF MEANING: A HUMAN PROBLEM

Abstract. With the rise of the social sciences, it was expected they would replace philosophy in solving practical problems and improving the human condition. Ernest Becker's The Birth and Death of Meaning describes this project to cure humankind, but also points out the failures along the way. Nonetheless, a new psychology, based on a final science of humanity, still can accomplish this task. While Becker admits an incurable religious tendency in human nature, he counts on its being satisfied through a "new heroism." However, in light of past failures, it is worthwhile taking another look at religion as a source for "the rebirth of meaning."     

Self-focused attention and reactions to conflicting standards

A fundamental postulate of self-awareness theory that has received considerable empirical support is that self-focused attention increases behavioral consistency with “standards of correctness.” This appears to be true whether the standards are internal (such as attitudes or values) or external (e.g., norms). There is some question, however, as to what happens in situations in which an important personal standard conflicts with a salient external standard. Research by E. Diener and T. K. Srull (Journal of Personality and Social Psychology, 1979, 37, 413–423) has suggested that under such circumstances the social standard is likely to predominate. However, there is reason to believe that the standards employed in their study may not have been very salient nor very important to the subjects. In the present experiment, subjects with either conservative or liberal sexual attitudes were exposed to information suggesting a prevailing norm of sexual liberalism. They were then asked to respond to a number of sexual and nonsexual attitude measures while their attention was or was not self-directed by means of a mirror. Primary results indicated that self-awareness enhanced conformity to the social standard (as in Diener & Srull, 1979) for the conservative subjects; however, correlational analyses within the self-focused and non-self-focused conditions indicated that self-aware subjects did not “abandon” their personal standards when responding to the conformity pressure. Instead, their responses tended to be more in line with their previously expressed attitudes than did the responses of the non-self-focused group. Results are discussed in terms of the effects of self-awareness on reactions to potent, but conflicting behavioral standards.