Dependence of Finger Flexion Force on the Posture of the Nonperforming Fingers During Key Pressing Tasks

In visuomotor tasks that involve accuracy demands, small directional changes in the trajectories have been taken as evidence of feedback-based error corrections. In the present study variability, or intermittency, in visuomanual tracking of sinusoidal targets was investigated. Two lines of analyses were pursued: First, the hypothesis that humans fundamentally act as intermittent servo-controllers was re-examined, probing the question of whether discontinuities in the movement trajectory directly imply intermittent control. Second, an alternative hypothesis was evaluated: that rhythmic tracking movements are generated by entrainment between the oscillations of the target and the actor, such that intermittency expresses the degree of stability. In 2 experiments, participants (N = 6 in each experiment) swung 1 of 2 different hand-held pendulums, tracking a rhythmic target that oscillated at different frequencies with a constant amplitude. In 1 line of analyses, the authors tested the intermittency hypothesis by using the typical kinematic error measures and spectral analysis. In a 2nd line, they examined relative phase and its variability, following analyses of rhythmic interlimb coordination. The results showed that visually guided corrective processes play a role, especially for slow movements. Intermittency, assessed as frequency and power components of the movement trajectory, was found to change as a function of both target frequency and the manipulandum's inertia. Support for entrainment was found in conditions in which task frequency was identical to or higher than the effector's eigenfrequency. The results suggest that it is the symmetry between task and effector that determines which behavioral regime is dominant.     

Book Reviews

Dan Olweus. Prediction of Aggression (On the Basis of a Projective Test). Stockholm: Scandinavian Test Corporation, 1969. Reviewed by A. I. Rabin

F. D. Naylor. Personality and Educational Achievement. New York: Wiley, 1972, 162 pages, $6.95. Reviewed by Frank H. Farley

Hendrik M. Ruitenbeek (Ed.) The Analytic Situation: How Patient and Therapist Communicate. Chicago: Aldine, 1973, 222 pages, $8.50. Reviewed by Emanuel Berman     

Building a Bridge of Trust: Collaborative Assessment With a Person With Serious Mental Illness

Collaborative assessment utilizes psychological testing to help people make positive changes in their lives. Limited research has evaluated the utility of collaborative assessment for persons with serious mental illness. This case example uses the Personality Assessment Inventory to illustrate the usefulness of collaborative assessment with a person with serious mental illness. This approach informed not only diagnostic considerations but also revealed the client's current level of distress, contributed to enhanced therapeutic alliance, and directly pointed to psychiatric rehabilitation strategies.     

The factor structure and composite reliability of the Rosenberg Self-Esteem Scale among ex-prisoners

The aim of this study was to examine the factor structure and composite reliability of the Rosenberg Self-Esteem Scale (RSES) using a sample of 669 ex-prisoners identified in the National Survey of American Life. Six distinct factor models, with uncorrelated measurement error terms, were specified and tested using confirmatory factor analysis (CFA). Results indicated that the two-factor model consisting of positive and negative latent variables provided a better fit to the data than the alternative models. Moreover, only positive self-esteem was a significant predictor of recidivism. Composite reliability indicated that the two factors were measured with very good reliability. The results consequently provide additional support for a two-dimensional model of the RSES within offender populations.     

The Chinese Version of the Self-Report Family Inventory: Reliability and Validity

The reliability and validity of the Chinese Self-Report Family Inventory (C-SFI) were examined in three studies. In Study 1, data based on 361 adolescents showed that the C-SFI was temporally stable and internally consistent and there was support for its concurrent and construct validities. In Study 2, data analyzed from a clinical group and a nonclinical group (N = 281 and 451, respectively) showed that the C-SFI scores were able to discriminate these two groups. With data pertaining to 3649 secondary school students, Study 3 gives support for the internal consistency, concurrent validity, and construct validity of the C-SFI in different adolescent samples. These studies strongly suggest that the C-SFI possesses good psychometric properties in different Chinese adolescent samples.     

Components of working memory predict symptoms of distress

Working memory (WM) is a cognitive system that allows us to select, organise, and integrate perceptual information with memories and current goal-directed intentions. As such, this system is central to day-to-day functioning and would be expected to be especially important in decision making and problem solving. We hypothesised that to the extent that individuals differ in WM capacity they would also be differentially vulnerable to the experience of depression and anxiety. Undergraduate students completed a computerised change detection task in which storage capacity and filtering efficiency measures were obtained. It was found that low WM storage and poor filtering efficiency interacted to predict higher levels of emotional distress as measured by self-reported depressive symptoms, ruminative coping, and state anxiety. It was suggested that low capacity and a poor ability to ignore task-irrelevant information may lead to poorer problem solving, more extreme judgements of oneself and circumstances, increased rumination, and poorer emotional regulation.     

Factors Affecting the Adequacy and Preferability of Semiparametric Groups-Based Approximations of Continuous Growth Trajectories

Psychologists have long been interested in characterizing individual differences in change over time. It is often plausible to assume that the distribution of these individual differences is continuous in nature, yet theory is seldom so specific as to designate its parametric form (e.g., normal). Semiparametric groups-based trajectory models (SPGMs) were thus developed to provide a discrete approximation for continuously distributed growth of unknown form. Previous research has demonstrated the adequacy of the approximation provided by SPGM but only under relatively narrow, theoretically optimal conditions. Under alternative conditions, which may be more common in practice (e.g., higher dimension random effects, smaller sample sizes), this study shows that approximation adequacy can suffer. Furthermore, this study also evaluates whether SPGM's discrete approximation is preferable to a parametric trajectory model that assumes normally distributed random effects when in fact the distribution is modestly nonnormal. The answer is shown to depend on distributional characteristics of both repeated measures (binary or continuous) and random effects (bimodal or skewed). Implications for practice are discussed in light of empirical examples on externalizing behavior.     

Holism about value: some help for invariabilists

G.E. Moore’s principle of organic unity holds that the intrinsic value of a whole may differ from the sum of the intrinsic values of its parts. Moore combined this principle with invariabilism about intrinsic value: An item’s intrinsic value depends solely on its bearer’s intrinsic properties, not on which wholes it has membership of. It is often said that invariabilism ought to be rejected in favour of what might be called ‘conditionalism’ about intrinsic value. This paper is an attempt to show how invariabilism might be filled out in ways that allow its proponents to answer their conditionalist opponents. The main point consists in identifying how some amount of extrinsic part-value may contribute to whole-value that is nevertheless intrinsic. This enables an invariabilist to explain how the intrinsic value of a whole may differ from the sum of its intrinsic part-values, without abandoning the Moorean doctrine that intrinsic value supervenes on intrinsic properties (the proposal is nevertheless consistent with the view that invariabilist and conditionalist accounts might exist side by side). I finish with a brief explanation of how the main proposal could help construct invariabilist accounts of particular organic unities, looking beyond the more general argument they have with conditionalists.     

Learning time-varying categories

Many kinds of objects and events in our world have a strongly time-dependent quality. However, most theories about concepts and categories either are insensitive to variation over time or treat it as a nuisance factor that produces irrational order effects during learning. In this article, we present two category learning experiments in which we explored peoples’ ability to learn categories whose structure is strongly time-dependent. We suggest that order effects in categorization may in part reflect a sensitivity to changing environments, and that understanding dynamically changing concepts is an important part of developing a full account of human categorization.     

Anxiety, Sensory Over-Responsivity, and Gastrointestinal Problems in Children with Autism Spectrum Disorders

Children with autism spectrum disorders (ASD) experience high rates of anxiety, sensory processing problems, and gastrointestinal (GI) problems; however, the associations among these symptoms in children with ASD have not been previously examined. The current study examined bivariate and multivariate relations among anxiety, sensory over-responsivity, and chronic GI problems in a sample of 2,973 children with ASD enrolled in the Autism Treatment Network (ages 2–17 years, 81.6 % male). Twenty-four percent of the sample experienced at least one type of chronic GI problem (constipation, abdominal pain, bloating, diarrhea, and/or nausea lasting three or more months). Children with each type of GI problem had significantly higher rates of both anxiety and sensory over-responsivity. Sensory over-responsivity and anxiety were highly associated, and each provided unique contributions to the prediction of chronic GI problems in logistic regression analyses. The results indicate that anxiety, sensory over-responsivity and GI problems are possibly interrelated phenomenon for children with ASD, and may have common underlying mechanisms.