The recognition of threatening facial stimuli

Two studies examined the information that defines a threatening facial display. The first study identified those facial characteristics that distinguish between representations of threatening and nonthreatening facial displays. Masks that presented either threatening or nonthreatening facial displays were obtained from a number of non-Western cultures and scored for the presence of those facial features that discriminated between such displays in the drawings of two American samples. Threatening masks contained a significantly higher number of these characteristics across all cultures examined. The second study determined whether the information provided by the facial display might be more primary nonrepresentational visual patterns than facial features with obvious denotative meaning (e.g., diagonal lines rather than downturned eyebrows). The subjective response to sets of diagonal, angular, and curvilinear visual stimuli revealed that the nonrepresentational features of angularity and diagonality in the visual stimulus appeared to have the ability to evoke the subjective responses that convey the meaning of threat.     

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.     

Rater bias in the EASI temperament scales: a twin study

Under trait theory, ratings may be modeled as a function of the temperament of the child and the bias of the rater. Two linear structural equation models are described, one for mutual self- and partner ratings, and one for multiple ratings of related individuals. Application of the first model to EASI temperament data collected from spouses rating each other shows moderate agreement between raters and little rating bias. Spouse pairs agree moderately when rating their twin children, but there is significantly rater bias, with greater bias for monozygotic than for dizygotic twins. MLE's of heritability are approximately .5 for all temperament scales with no common environmental variance. Results are discussed with reference to trait validity, the person-situation debate, halo effects, and stereotyping. Questionnaire development using ratings on family members permits increased rater agreement and reduced rater bias.