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.     

Characteristics of Calls to Israeli Hotlines During the Gulf War

The current study presents results of a survey of 3,215 calls received at seven centers of telephone emergency services (TES) in Israel during the Gulf War, when citizens of Israel experienced severe stress resulting from SCUD missile attacks. Whereas former surveys have shown that characteristics of calls to TES in Israel are generally not affected by external stressogenic events, a remarkable change was recorded in both the quantity and quality of calls received in TES centers in Israel during the Gulf War. The relative frequencies of problem categories presented by callers during the Gulf War revealed a significant increase in environmental pressures, a category that reflected the stressful situation of the war, as opposed to intra- or interpersonal problems typical of peacetime calls. A comparison between this group of war calls and a control group of nonwar calls, revealed that the two groups represented populations of callers differing in sociodemographic characteristics, expectations, and benefits from the calls. Results are discussed in reference to the unique role of TES as a source of psychological first-aid in a community crisis situation.     

The effects of situational variations in role-play scenes on assertive behavior

The study was conducted to determine the extent to which variations in the situational parameters of role-play scenes affect subjects' levels of assertiveness. Thirty-six psychology undergraduate students were randomly assigned to one of three role-play conditions that differed in the situation-setting characteristics presented in the scenes: a Difficult condition, designed to inhibit assertive responding; an Easy condition, designed to facilitate assertive responding; and a Neutral condition. Subjects also completed a self-report assertion inventory. Videotapes of the role-played interactions were rated for a variety of component responses. Results indicate that subjects responded differently in the three conditions. Subjects in the Difficult and Neutral conditions were more compliant, and those in the Easy and Difficult conditions were more fluent. It is suggested that failure to specify the situational parameters of role-play scenes may affect the validity of this assessment procedure.This research was supported in part by NIMH Grant, MH28279 to the third author.     

Perceptions of current and ideal body shape of athletes and nonathletes

This study was done to examine the relationship between sex and perception of body image among athletes and nonathletes. A total of 211 men and women athletes and nonathletes completed a questionnaire which asked them to identify from a nine-figure body-silhouette scale their current image and the image that they thought was most ideal. t tests showed no significant differences for men based upon athletic participation and that both athletes and nonathletes were satisfied with their body image. However, when comparing current image and ideal image, significant differences were found for women athletes and nonathletes. These data support previous research documenting women's dissatisfaction with their body images and show athletic participation is not associated with this perception.     

Computer generation of textures

A method for displaying fixed or time-varying textured patterns under computer control is described. The luminance profiles of these patterns is fixed in one dimension (Y axis), but can be arbitrarily complex in the other dimension (X axis) since they are synthesized by software. An example of the use of the method in texture matching experiments is given.     

Unfamiliar Untrained Observers’ Ratings of Adolescent Safety Behaviors Within Social Interactions with Unfamiliar Peer Confederates

Adolescents experiencing social anxiety often engage in safety behaviors―covert avoidance strategies for managing distress (e.g., avoiding eye contact)―that factor into the development and maintenance of their concerns. Prior work supports the psychometric properties of the Subtle Avoidance Frequency Examination (SAFE), a self-report survey of safety behaviors. Yet, we need complementary methods for assessing these behaviors within contexts where adolescents often experience concerns, namely, interactions with unfamiliar peers. Recent work indicates that, based on short, direct social interactions with adolescents, individuals posing as unfamiliar peers (i.e., peer confederates) and without assessment training can capably report about adolescent social anxiety. We built on prior work by testing whether we could gather valid SAFE reports from unfamiliar untrained observers (UUOs), who observed adolescents within archived recordings of these short social interactions. A mixed clinical/community sample of 105 adolescents self-reported on their functioning and participated in a series of social interaction tasks with peer confederates, who also provided social anxiety reports about the adolescent. Based on video recordings of these tasks, trained independent observers rated adolescents’ observed social skills, and an additional set of UUOs completed SAFE reports of these same adolescents. Unfamiliar untrained observers’ SAFE reports (a) related to adolescents’ SAFE self-reports, (b) distinguished adolescents on clinically elevated social anxiety concerns, (c) related to trained independent observers’ ratings of adolescent social skills within interactions with peer confederates, and (d) related to adolescents’ self-reported arousal within these same interactions. Our findings support use of unfamiliar observers’ perspectives to understand socially anxious adolescents’ interpersonal functioning.     

Integrated-structure emergence and its mechanistic explanation

Synthese - This paper proposes an integrated-structure notion of interlevel (part-whole) emergence, from a dynamic relational ontological perspective. First, I will argue that only the...