Forms of memory failure in schizophrenia.

Effortful and automatic memory task performances were examined in 36 schizophrenic patients and 18 normal control Ss. Tasks included free recall, recognition, and frequency estimation. Patients demonstrated impairment in recall, in recognition, in semantic encoding, and in frequency estimation. Deficits were observed across tasks despite differences in attentional demands. The results suggest a basic compromise of memory function, which is consistent with recent neuroimaging evidence of structural or physiological abnormalities in frontal and temporal lobe structures in schizophrenia.     

Parallel distributed processing and neuropsychology: A neural network model of Wisconsin card sorting and verbal fluency

Neural networks can be used as a tool in the explanation of neuropsychological data. Using the Hebbian Learning Rule and other such principles as competition and modifiable interlevel feedback, researchers have successfully modeled a widely used neuropsychological test, the Wisconsin Card Sorting Test. One of these models is reviewed here and extended to a qualitative analysis of how verbal fluency might be modeled, which demonstrates the importance of accounting for the attentional components of both tests. Difficulties remain in programming sequential cognitive processes within a parallel distributed processing (PDP) framework and integrating exceedingly complex neuropsychological tests such as Proverbs. PDP neural network methodology offers neuropsychologists co-validation procedures within narrowly defined areas of reliability and validity.     

Reference and comprehension: A topic-comment analysis of sentence-picture verification

A sentence often contains two components: a topic, which refers to a nonlinguistic object whose existence is presupposed; and a comment, which asserts some thought about this object. In addition, a sentence will often repeat (or refer back to) information that was expressed earlier in a text or conversation. The purpose of this article is to propose a single theoretical framework to describe the mechanisms that relate a sentence to its nonlinguistic environment as well as those that relate a sentence to its linguistic context. The theory developed in this article suggests that sentences can strongly influence the representation of visible nonlinguistic events and that this representation is sensitive to the distinction between presupposed and asserted information. To evaluate this theory, a sentence-picture verification priming task was developed. In this task, subjects were presented with pairs of sentence-picture displays, and were asked to verify whether or not the sentence in each display correctly applied to an accompanying picture. The relationship between pairs of sentence-picture displays was varied systematically. Across five experiments, three hypotheses were supported: (a) The processes which evaluate presupposed information and the processes which evaluate asserted information are differentially affected by nonlinguistic factors, (b) only those aspects of the picture which are referred to by the sentence are encoded for future use, and (c) coherence between successive sentences is in part a function of the referential continuity of the presupposed information.     

Belief in afterlife as a moderator of fear of death?

Investigating the notion that belief in afrerlife (BA) serves the function of helping the individual to deal with fear of death, a study was designed to explore the effect of public commitment to religion, repression-sensitization, and anticipatory concern with death and dying on BA, and examine the relationship between BA and state anxiety. Fifty students of theology and fifty students of various other subjects responded to a German version of Byrne's R-S scale, and then were randomly assigned to two conditions: they either worked through Thanatos-Questionnaire, and thereby were confronted with death and dying for about 15 to 20 minutes, or filled out a questionnaire unrelated to the topic. Thereupon, a BA scale was administered, and at last, subjects responded to a scale measuring state anxiety. The findings of Osarchuk and Tatz (1973) that religiously committed persons are strengthening BA after being confronted with death and dying could not be replicated. However, among subjects with no public commitment, those concerned with death and dying scored significantly lower on BA than those not concerned. This effect was especially observed among students classified as sensitizers. Because changes of BA did not correspond with changes of within cell correlations between BA and state anxiety, an alternative explanation of the findings in terms of dissonance theory is put forward.     

Factors limiting the generality of the risky-shift phenomenon

While a considerable amount of research has centered on explaining the risky shift (enhancement of risk acceptance through group discussion; see, for example, Dion, Baron, and Miller, 1970), few studies have investigated the generality of the phenomenon. Three of several ways in which the laboratory context is usually lacking of reality are: (a) The decision consequences are imaginary, as in the ‘Choice-Dilemma’ situations used in most of the risky-shift research; (b) the decision consequences - even if they are real (e.g. money) - are slight; and (c) the decisions are made for oneself (whereas in real life many decisions involve agents acting on behalf of others). The present study was designed to investigate the effects of the above three factors - type of incentive, magnitude of stake and decision target - using a betting task as the decision situation.