Processing capacity defined by relational complexity: implications for comparative, developmental, and cognitive psychology

Working memory limits are best defined in terms of the complexity of the relations that can be processed in parallel. Complexity is defined as the number of related dimensions or sources of variation. A binary relation has one argument and one source of variation; its argument can be instantiated in only one way at a time. A binary relation has two arguments, two sources of variation, and two instantiations, and so on. Dimensionality is related to the number of chunks, because both attributes on dimensions and chunks are independent units of information of arbitrary size. Studies of working memory limits suggest that there is a soft limit corresponding to the parallel processing of one quaternary relation. More complex concepts are processed by "segmentation" or "conceptual chunking." In segmentation, tasks are broken into components that do not exceed processing capacity and can be processed serially. In conceptual chunking, representations are "collapsed" to reduce their dimensionality and hence their processing load, but at the cost of making some relational information inaccessible. Neural net models of relational representations show that relations with more arguments have a higher computational cost that coincides with experimental findings on higher processing loads in humans. Relational complexity is related to processing load in reasoning and sentence comprehension and can distinguish between the capacities of higher species. The complexity of relations processed by children increases with age. Implications for neural net models and theories of cognition and cognitive development are discussed.     

Assessing Leadership Potential with a Biographical Measure of Personality Traits

The aim of this study was to demonstrate the feasibility of biographical inventories free of the limitations common to many current biographical measures by constructing and validating an inventory composed of homogeneous scales, with item content that is factual and fair, to assess personality traits predictive of leadership. The experimental inventory, with tentative scales for Dominance, Emotional Stability, Need for Achievement, Self-Confidence, and Sociability, was administered to incoming midshipmen at the US Naval Academy and item analyzed. The validity of the final scales was appraised against subsequent peer ratings of the traits and of leadership shortly after entering the Academy; military performance grades, and midshipman rank and leadership position at the Academy; and recommendations for promotion after graduating and serving as an officer. The Sociability, Dominance, and Need for Achievement scales demonstrated convergent and discriminant validity, and all of the scales except Self-Confidence correlated with the leadership criteria. The Sociability scale’s consistent correlations with several of the leadership criteria, including a nontrivial correlation (r = 0.28) with the leadership peer rating, implies that this measure may be useful in assessing leadership potential.     

Comorbidity of Hyperactivity-Impulsivity-Inattention and Conduct Problems: Risk Factors in Social, Affective, and Academic Domains

Children showing a comorbid behavior pattern of hyperactivity-impulsivity-inattention and conduct problems (HIA + CP) were contrasted to children having only an internalizing and externalizing behavior pattern (I + E) and matched controls. Children displaying the HIA + CP behavior pattern were at greater risk on a number of outcome measures in social and academic domains beginning in Grade 3 and continuing into Grade 4. The most marked differences among the three groups were found on peer measures of rejection and friendship and teacher ratings of social skills. On average, almost two-thirds of the HIA + CP group were rejected by their peers compared to one-third of the I + E group and only 12.5% controls. Over 70% of the HIA + CP group had no reciprocated friendships from Grade 3 to Grade 4 compared to less than half of the I + E group and approximately one-fourth of controls. Contrary to much theorizing in the literature, the HIA + CP and I + E groups showed average levels of academic self-concept and did not differ from controls in on measures of social self-concept and academic self-concept and general self-esteem. These findings were interpreted in light of positive illusory biases and the established link between aggressive behavior and egotism. The current article offers partial support for Lynam's (1996) notion of the fledgling psychopath.     

Measurement of the texture-coherence limit for bandpass arrays

Casual observation suggests that when the elements of a visual array are packed at a sufficiently high density they cohere to generate the percept of a texture. This 'texture-coherence limit' has been quantified by using arrays composed of Gabor functions, sixth Gaussian derivatives, or differences of Gaussians. In all cases the texture-coherence limit was a power-law function of the size of the elements as quantified by their space constants with an exponent averaging 0.7. Furthermore, the texture-coherence limit was independent of both element spatial frequency and contrast over a considerable range. A quantitative fit to the data is provided by a model in which the texture-coherence limit is determined by activation of complex cells, which pool a spatial range of subunit inputs, throughout the stimulus region. Possible extensions to two dimensions are considered.     

Group Performance Depends on the Majority Rule

Some group decisions require a two-thirds or three-quarters majority of the people voting; others require only a simple majority. Does the accuracy of a group's decision making depend on which majority rule is used? A signal detection theory analysis was used to answer this question. Each member of a group was presented with a noisy display of either a signal or a nonsignal, and then each member cast a yes or no vote for the existence of a signal. The group decision was determined by a majority rule of the members' votes. Normative groups and groups of 5 or 7 people exhibited the same behavior: Performance was best when the group used a simple-majority rule and decreased when the group used more stringent rules. The worst performance was produced by a unanimous rule. Some group members adopted more liberal response criteria when the majority rule was made more stringent.     

MULTICOMPONENT INTERVENTION FOR AGITATED BEHAVIOR IN A PERSON WITH ALZHEIMER'S DISEASE

We evaluated a multicomponent intervention for agitated behavior in a man with probable Alzheimer's disease. Hypotheses about variables controlling his agitated behavior guided intervention design. Based on staff interviews, direct observations, and brief experimental probes, intervention components were chosen to increase rate of reinforcement and decrease aversive aspects of his job. Intervention reduced agitated behavior without disrupting his work rate.     

Police-Public Interactions: The Impact of Conflict Resolution Tactics1

Following Hammock and Richardson (1992), it was hypothesized that a preference among some police officers for confrontational rather than conciliatory tactics when dealing with the public may serve to escalate a conflict and thereby explain the documented individual differences in reports of officer assaults. In order to test this possibility, preferred conflict tactics and officers' recent experiences of citizen compliance (and non-compliance) were measured for a sample of 115 English police and 48 Australian police. The results supported the hypothesized relationship by indicating a significant correlation between preferences for specific confrontational and coercive tactics and experiences of noncompliance from the public.     

Psychoeducation and managed care: Clinical issues for the 1990s

Managed care has challenged mental health professionals to develop more efficient ways of addressing patient care needs. Psychoeducational programs, for patients and their families, have emerged as a medium by which relevant education and mutual support can be provided to participants. A review of the literature, a comprehensive model of psychoeducation, and the advantages of such models within the managed care program are offered. Also addressed are issues and import, treatment and research considerations.     

Family-expressed emotion,childhood-onset depression,and childhood-onset schizophrenia spectrum disorders: Is expressed emotion a nonspecific correlate of child psychopathology or a specific risk factor for depression?

Expressed emotion (EE) was examined, using the brief Five Minute Speech Sample measure, in families of (1) children with depressive disorders, (2) children with schizophrenia spectrum disorders, and (3) normal controls screened for the absence of psychiatric disorder. Consistent with the hypothesis of some specificity in the association between EE and the form of child disorder, rates of EE were significantly higher among families of depressed children compared to families of normal controls and families of children with schizophrenia spectrum disorders. Within the depressed group, the presence of a comorbid disruptive behavior disorder was associated with high levels of critical EE, underscoring the need to attend to comorbid patterns and subtypes of EE in future research.This research was supported by a grant from the John D. and Catherine T. MacArthur Foundation as part of their Network on Risk and Protective Factors in the Major Mental Disorders. The authors wish to express their appreciation to Sybil Zaden and Ana Magana-Amato for their assistance coding the FMSS-EE data, to Gwen Gordon for her assistance with data analysis, and to the families participating in the project.