Mixed effects modeling of Morris water maze data: Advantages and cautionary notes

Morris water maze data are most commonly analyzed using repeated measures analysis of variance in which daily test sessions are analyzed as an unordered categorical variable. This approach, however, may lack power, relies heavily on post hoc tests of daily performance that can complicate interpretation, and does not target the nonlinear trends evidenced in learning data. The present project used Monte Carlo simulation to compare the relative strengths of the traditional approach with both linear and nonlinear mixed effects modeling that identifies the learning function for each animal and condition. Both trend-based mixed effects modeling approaches showed much greater sensitivity to identifying real effects, and the nonlinear approach provided uniformly better fits of learning trends. The common practice of removing a rat from the maze after 90 s, however, proved more problematic for the nonlinear approach and produced an underestimate of y-axis intercepts.     

Estimation of the Nonlinear Random Coefficient Model when Some Random Effects Are Separable

A method is presented for marginal maximum likelihood estimation of the nonlinear random coefficient model when the response function has some linear parameters. This is done by writing the marginal distribution of the repeated measures as a conditional distribution of the response given the nonlinear random effects. The resulting distribution then requires an integral equation that is of dimension equal to the number of nonlinear terms. For nonlinear functions that have linear coefficients, the improvement in computational speed and accuracy using the new algorithm can be dramatic. An illustration of the method with repeated measures data from a learning experiment is presented.     

Changing explicit and implicit attitudes: The case of self-esteem

Three experiments investigated predictions concerning asymmetrical patterns of implicit and explicit self-esteem change. Specifically, we investigated the influence of knowledge about the own self that is momentarily salient as well as the influence of affective valence associated with the self in memory on implicit and explicit self-esteem. The latter was induced by evaluative conditioning, the former by directed thinking about oneself. We found that while evaluative conditioning changed implicit but not explicit self-esteem (Experiment 1), thinking about the own self altered explicit but not implicit self-esteem (Experiment 2). Moreover, in a third experiment, it could be shown that the effect of evaluative conditioning can spill over to the explicit level when participants are asked to focus on their feelings prior to making their self-report judgements (Experiment 3). Implications of our results are discussed in terms of recent controversies regarding dual-process models of attitudes and associative versus propositional modes of information processing.     

BIS/BAS responses to emotional cues: Self report, autonomic measure and alpha band modulation

The study explored the effect of the subjective evaluation and of BIS/BAS (Behavioral Inhibition and Activation System) differences on psychophysiological and brain oscillation measures, in response to pleasant/unpleasant and high/low arousing stimuli. Skin conductance response, heart rate, and electromyography, and alpha frequency band, were registered, during viewing IAPS figures. Both BIS and BAS measures were significant in modulating behavioral, autonomic and brain responses, with a clear dichotomy BAS-appetitive/positive BIS-withdrawal/negative sensitivity. Withdrawal (BIS) and appetitive (BAS) behavior showed opposite patterns of responses by the subjects within the frontal cortical site more than other sites. In addition, a specific frontal lateralization effect was found as a function of BIS (more right-side activation for negative cues) and BAS (more left-side activation for positive cues). Moreover, autonomic variables and frequency band were found to be effected by arousal rating per se, with an increased response to high arousal in comparison with low arousal and neutral stimuli. The effects of subjective evaluation and individual differences were discussed in the light of the coping activity of emotion comprehension.     

Ways in which coherence is confirmation conducive

Recent works in epistemology show that the claim that coherence is truth conducive – in the sense that, given suitable ceteris paribus conditions, more coherent sets of statements are always more probable – is dubious and possibly false. From this, it does not follows that coherence is a useless notion in epistemology and philosophy of science. Dietrich and Moretti (Philosophy of science 72(3): 403–424, 2005) have proposed a formal of account of how coherence is confirmation conducive—that is, of how the coherence of a set of statements facilitates the confirmation of such statements. This account is grounded in two confirmation transmission properties that are satisfied by some of the measures of coherence recently proposed in the literature. These properties explicate everyday and scientific uses of coherence. In his paper, I review the main findings of Dietrich and Moretti (2005) and define two evidence-gathering properties that are satisfied by the same measures of coherence and constitute further ways in which coherence is confirmation conducive. At least one of these properties vindicates important applications of the notion of coherence in everyday life and in science.     

Between-measure consistency in social-skills assessment

The purpose of the present study was to assess the between-measure consistency of general and specific social-skills assessment strategies. Nineteen mentally retarded adults were assessed using both common and newly devised measures of social skills: (1) specific (molecular) behavior ratings from role-play assessments, (2) general (molar) ratings based on the role plays, staff (3) molar and (4) molecular predictions of client social skills use in the described role-play situations, (5) peer sociometric ratings, and molecular in vivoobservations conducted in (6) cafeteria and (7) party settings. For all molecular measures, the subjects were assessed on eye contact, response relevance, response latency, voice volume, and appropriate affect, which allowed for direct comparisons to be made between each of these assessment modalities. In addition, the role-play assessment was conducted under two distinct conditions to determine whether role-play performance varied between standard and reinforced administrations; however, multivariate analyses (MANOVA) revealed no differences between the two assessments. Correlations between the molar and the molecular measures suggested a substantial overlap between the measures, with staff ratings having the highest consistency with the other measures. Furthermore, MANOVAs calculated between role-play ratings and those of staff revealed little difference between the two. The limitations on and practical significance of these findings are discussed.     

Assessing the process of desensitization therapy: Five practical measures

Assessment of phobic behavior has included self-report, physiological, and in vivobehavioral measures. While self-report measures are convenient, they suffer from subject bias and a low predictive validity. Physiological and in vivobehavioral measures are often too cumbersome to implement in standard clinical practice. The current study investigated the validity of five convenient measures of phobic behavior during the process of desensitization therapy. Responses of 14 clinically phobic patients were compared on phobic and neutral scenes presented within the context of systematic desensitization therapy. Phobic scenes resulted in less clarity of scene visualization, a longer latency to clear scene visualization, higher subjective units of discomfort (SUDs) at clear visualization, a longer latency to relaxation, and higher SUDs at relaxation. The measures seemed to reflect accurately the process and stages of desensitization therapy and showed low to high intercorrelations. The pragmatic value of these measures is discussed, as well as suggestions for future validational research.     

Development and validation of adolescent-perceived microsystem scales: Social support,daily hassles,and involvement

Developed and validated instruments for urban and culturally diverse adolescents to assess their self-reported transactions with family, peer, school, and neighborhood microsystems for the constructs of social support, daily hassles, and involvement. The sample of 998 youth were from schools in three Eastern cities with high percentages of economically disadvantaged youth. Data were collected before and after the transition to junior high school or to senior high school. Blacks constituted 26%, whites 26%, and Latinos 37% of the sample. Factor analyses confirmed and enhanced the hypothesized four-factor microsystem factor structure for support, hassles, and involvement; internal consistency and stability coefficients were consistent with these structures. In general, the microsystem factors were common across gender, ethnicity, and age. However, when group differences did occur on these demographic variables, they tended to validate the salience of microsystem specificity. In contrast to the total scores, the microsystem-specific factors yielded more meaningful and differential information with regard to demographic differences and the mediating processes across a school transition.