Connectionist models of neuropsychological disorders

Artificial neural networks ('connectionist models') embody aspects of real neuronal systems. But does studying the breakdown of performance in such models help us to understand cognitive impairments in humans following brain damage? Here we review recent attempts to capture different neuropsychological disorders using connectionist models with simulated lesions. We show how such lesion studies can be used to evaluate some of the standard assumptions made in neuropsychological research, concerning both double dissociations and associations between patterns of impairment. We also illustrate how lesioned models, like humans, can sometimes be more impaired on the easier of two tasks and demonstrate that connectionist models can incorporate forms of internal structure. Finally we discuss the utility of the models for understanding and predicting the effectiveness of different rehabilitation strategies. Future questions concern the role and possible development of internal structure within these models, whether the models can be generalized to larger-scale simulations, and whether they can accommodate higher-order linguistic disorders.     

The Preconditions and Consequences of Relative Deprivation: Two Field Studies1

Two field studies assessed the preconditions and behavioral consequences of relative deprivation. A sample of single mothers receiving government assistance participated in Study 1, and a sample of working women participated in Study 2. We found general support for a 2-factor model of the preconditions of relative deprivation, in which wanting the desired state and deserving the desired state were the best predictors of discontent. In both studies, discontent regarding the status of one's group (i.e., single mothers or working women) was specifically predictive of reports of group-directed protest behaviors. In Study 2, discontent regarding one's own status was specifically predictive of willingness to engage in self-improvement behaviors. Participants in both studies reported more group discontent than personal discontent. These findings provide support from naturalistic settings for the construct of relative deprivation.     

PREDICTORS OF RESPONSES TO UNWANTED SEXUAL ATTENTION

Data were collected from 4,011 male and female university students, faculty, and staff regarding responses to unwanted sexual attention. Women and undergraduate students reported the highest incidence of unwanted sexual attention; most harassers were peers. Ignoring the behavior was the most common response, followed by avoiding the harasser and talking to others about the harassment. Harassment severity was the strongest predictor of responses, with more direct responses being made to more severe harassment. Bivariate correlational analyses suggested that unwanted sexual attention was rated as more distressing by women than by men, by faculty/staff than by students, by individuals with less tolerant attitudes toward harassment, and when the harasser was in a position of authority or when the harassment was of longer duration. In path analyses, only the relations between attitudes and responses were mediated by differences in perceived severity. The gender and status (i.e., student vs. faculty/staff) of the harassee, the duration of the harassment, and whether the harasser was in a position of authority had direct effects on responses not attributable to perceived severity. Implications for policy and future research are discussed.     

The effects of sex-role taking on children's responses to aggressive conflict situations

The effects of sex-role taking on children's responses to aggressive conflict situations were investigated in the present study. Subjects were 40 boys and girls aged 8–9, who were asked to take the role of boy and girl story characters involved in the following kinds of aggressive situations: victim of a verbal attack, victim of a physical attack, and witness to an attack upon a friend. A significant interaction effect between type of conflict situation and sex of story character was obtained. Subjects expected boy characters to retaliate more strongly than girl characters when intervening in an attack upon a friend, and girl characters to retaliate more strongly than boy characters when being verbally or physically assaulted. These findings suggest the importance of situational factors in determining children's sex-stereotyped expectations for aggressive retaliation.     

Dyslexic and normal readers' eye movements

Dyslexic and normal readers' eye movements were compared while tracking a moving fixation point and in reading. Contrary to previous reports, the dyslexic and normal readers did not differ in their number of saccades, percentage of regressions, or stability of fixations in the tracking task. Thus, defective oculomotor control was not associated with or a causal factor in dyslexia, and the dyslexics' abnormal eye movements in reading must be related to differences in higher cognitive processes. However, individual differences in oculmotor efficiency, independent of reading ability, were found within both the dyslexic and normal groups, and these differences were correlated in reading and tracking tasks.     

The management of children''s distress in response to painful medical treatment for burn injuries

The purpose of the current study was to develop an initial assessment of the efficacy of astress-management program designed to reduce the behavioral distress of children undergoing highlypainful medical treatments for their burn injuries. The stress-management program was delivered to 4 male patients, ages 5–12 yr and its effects assessed in a combined multiple-baseline and reversal design. Results indicated that the program was moderately effective at reducing behavioral distress during the burntreatment procedures for 3 of the 4 patients and less effective with the fourth. However, the design also revealed that the presence of a therapist to coach the patient in the use of these techniques was essential and that distress levels rose substantially on days when there was no therapist present. Finally, speculations concerning the factors responsible for the effectiveness of the stress-management program as well as its reduced efficacy with 1 S were discussed.     

Repression-sensitization differences in responses to a decision

Repression-sensitization differences in postdecisional dissonance reduction were investigated. Repressors (who typically employ “avoidance” strategies for dealing with threatening stimuli) and sensitizers (who typically “approach” threatening stimuli) were allowed to choose and keep, as payment for participation in the experiment, one of two pairs of long-playing record albums. Control subjects indicated which pair of albums they preferred, but did not expect to keep the albums. Measures of postdecisional intellectualization (an “approach” strategy for dealing with dissonance, which involves separating affect from cognition) showed that experimental sensitizers intellectualized more than subjects in any other group. Measures of postdecisional attitude change, on the other hand, revealed no differences between any of the groups. The implications of these results for our understanding of repression-sensitization differences in responses to a decision were discussed.