Individual Pooling for Group-Based Modeling Under the Assumption of Ergodicity

Psychology principally utilizes nomothetic, interindividual approaches to model phenomena of interest. However, it is the case that these approaches do not always capture the processes for each individual in the sample. If the research is focused on individual processes, confining analysis to the idiographic level may be more appropriate. One way to overcome the nomothetic inability to capture idiographic processes is to identify those participants who meet the criteria of ergodicity and restrict analysis to the resulting sample. Under these conditions it is quantitatively justifiable to create a group model without concern that it may fail to represent each member's idiographic process. In this study we explore the utility of such a method by (a) applying an ergodic pooling test to a sample of dyads (N = 128) who provided daily (T = 50) self-reports of affect, (b) applying an ergodic pooling test to samples (N = 4) of simulated ergodic time series data (T = 50, 250, and 1,000), (c) modeling dyads and simulated subgroups identified as ergodic, and (d) comparing the results from a model specified at the group level with those from models specified at the individual level.     

Attachment Anxiety,Depressive Symptoms,and Adolescent Dating Violence Perpetration: A Longitudinal Mediation Analysis

Adolescent dating violence (ADV) is a prevalent public health issue that has been linked to many negative effects, including attachment anxiety and depressive symptoms. Previous literature suggests that the negative mental states characteristic of attachment anxiety could be associated with dating violence perpetration. Similarly, the negative mental states characteristic of depression have also been linked to perpetration, and might potentially increase an anxiously attached individual’s likelihood of engaging in dating violence perpetration. This study used a 10-month longitudinal design with a sample of 140 middle school and high school students from Southern California. Participants ranged in age from 13 to 18 years and were ethnically diverse. The study aimed at exploring depressive symptoms as a potential mediator for the relationship between attachment anxiety and ADV perpetration. Positive associations were found between attachment anxiety and perpetration (10 months after), attachment anxiety and depressive symptoms (10 months after), and between depressive symptoms and perpetration (both 10 months after). Furthermore, depressive symptoms partially mediated the relationship between attachment anxiety and ADV perpetration (10 months after). These findings have implications for the development of empirically driven school-based prevention and intervention programs.     

An Idiographic Approach to Estimating Models of Dyadic Interactions with Differential Equations

We present an idiographic approach to modeling dyadic interactions using differential equations. Using data representing daily affect ratings from romantic relationships, we examined several models conceptualizing different types of dyadic interactions. We fitted each model to each of the dyads and the resulting AICc values were used to classify the most likely configuration of interaction for each dyad. Additionally, the AICc from the different models were used in parameter averaging across models. Averaged parameters were used in models involving predictors of relationship dynamics, as indexed by these parameters, as well as models wherein the parameters predicted distal outcomes of the dyads such as relationship satisfaction and status. Results indicated that, within our sample, the most likely interaction style was that of independence, without evidence of emotional interrelations between the two individuals in the couple. Attachment-related avoidance and anxiety showed significant relations with model parameters, such that ideal levels of affect for males were negatively influenced by higher levels of avoidance from their partner while their own levels of anxiety had positive effects on their levels of dyadic coregulation. For females coregulation was negatively influenced by both time in the relationship and their partner’s level of avoidance. Analysis involving distal outcomes showed modest influences from the individual’s level of ideal affect.     

Effects of chronic cocaine administration on spatial learning and hippocampal spine density in two genetically different strains of rats

Lewis and Fischer-344 rats have been proposed as an addiction model because of their differences in addiction behaviour. It has been suggested that drug addiction is related to learning and memory processes and depends on individual genetic background. We have evaluated learning performance using the eight-arm radial maze (RAM) in Lewis and Fischer-344 adult rats undergoing a chronic treatment with cocaine. In order to study whether morphological alterations were involved in the possible changes in learning after chronic cocaine treatment, we counted the spine density in hippocampal CA1 neurons from animals after the RAM protocol. Our results showed that Fischer-344 rats significantly took more time to carry out test acquisition and made a greater number of errors than Lewis animals. Nevertheless, cocaine treatment did not induce changes in learning and memory processes in both strains of rats. These facts indicate that there are genetic differences in spatial learning and memory that are not modified by the chronic treatment with cocaine. Moreover, hippocampal spine density is cocaine-modulated in both strains of rats. In conclusion, cocaine induces similar changes in hippocampal neurons morphology that are not related to genetic differences in spatial learning in the RAM protocol used here.     

Individual characteristics and response to Contingency Management treatment for cocaine addiction

Voucher-based contingency management (CM) research has demonstrated efficacy for treating cocaine addiction, but few studies have examined associations between individual baseline characteristics and response to CM treatments. The aim of this study, involving 50 cocaine outpatients receiving CM for cocaine addiction, was to assess the impact of baseline characteristics on abstinence outcomes after six months of treatment. Patients who were abstinent after six months of treatment accounted for 58% of the sample. Patients with higher scores on the Alcohol area of the EuropASI and patients that were non-abstinent during the first month of treatment were less likely to achieve abstinence. These outcome predictors have implications both for treatment research and for clinical practice. Patients who do not respond early to treatment may need a more intensive intervention, and concomitant problematic alcohol use should be detected and treated. The remaining baseline variables examined were not statistically significant predictors of abstinence. This finding is important for the generalizability of CM across the range of individual characteristics of treatment-seeking cocaine abusers.     

Psychosocial predictors of relapse in cocaine-dependent patients in treatment

Relapses in cocaine abusers in treatment are an important problem. The majority of patients are incapable of sustaining abstinence over any length of time. To identify the factors associated to relapses risk in the cocaine use can be an optimal choice to improve the treatment strategies. The aim of this study was to analyze relapse-risk factors in cocaine-dependent patients on treatment. Participants were 102 patients who had begun outpatient treatment at a public health center in Spain. Some functional areas and cocaine use are evaluated for a period of six months. A structural equations model was used to identify possible predictive variables. The results show that social-family environment and economic-employment situation were associated with greater risk of relapse. Likewise, the social-family environment was related to severity of addiction. It is concluded that the incorporation of family intervention strategies and vocational/employment counseling may help to reduce relapse rates in cocaine addicts receiving treatment.     

Peter Harzem (1930–2008: Bonds and Remembrances in Mexico

The Psychological Record -     

A more complete task-set reconfiguration in random than in predictable task switch

Three experiments are presented that compare the cost found when switching from one task to another in two different conditions. In one of them, the tasks switch in predictable sequences. In the other condition, the tasks alternate at random. A smaller time cost is found in the random-switch condition when enough preparation time is allowed. Such an effect is due to the random-switch cost continuing to decrease with preparation time after the predictable-switch cost has reached an asymptote. Although the relationship between number of repetitions of one task and time cost is different in the random- and the predictable-switch conditions, only the latter shows the presence of an "exogenous" component of cost. The implications of this finding are discussed in relationship with the usual distinction between an endogenous component of switch cost that is affected by preparation time and another exogenous, residual component (e.g., Rogers & Monsell, 1995). It is proposed that a different kind of task-set preparation is at work when tasks alternate at random.