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.     

ASSESSING FOOD PREFERENCES AMONG PERSONS WITH PROFOUND MENTAL RETARDATION: PROVIDING OPPORTUNITIES TO MAKE CHOICES

Increased attention has been directed recently to assisting persons with severe handicaps to express preferences concerning events in their lives. We evaluated a program for assessing choice-making skills to provide opportunities for persons with profound mental retardation to express food and drink preferences. In Experiment 1, the assessment procedure involving repeated, paired-item presentations resulted in active choice making and the identification of preferences for all 5 participants. Results also indicated that caregiver opinion was not predictive of participant food and drink preferences. A survey of service providers supported the importance of meal-related choices in this population. In Experiment 2, the practicality of the assessment procedure was supported by demonstrating that (a) routine caregivers could apply the procedure with appropriate supervision to provide choice opportunities, and (b) results of the procedure were predictive of participant choices when a less structured and more normal opportunity to express a preference was provided during regular mealtimes. Results are discussed in terms of extending the developing technology of preference and reinforcer identification to other important areas for persons with severe disabilities.     

EFFECTS OF CHOSEN VERSUS ASSIGNED JOBS ON THE WORK PERFORMANCE OF PERSONS WITH SEVERE HANDICAPS

We evaluated the effects of several choice-related variables on the work performance of adults with severe handicaps. After assessing client work preferences, three choice-related situations were presented: (a) providing clients with the opportunity to choose a work task, (b) assigning a preferred task, and (c) assigning a nonpreferred task. Results indicated that clients attended to work tasks almost twice as much when they chose their tasks and when assigned to work on preferred tasks versus when assigned to work on nonpreferred tasks. Results are discussed regarding the need to assess systematically the effects of choice-related variables.     

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.