Generalized instruction following with pictorial prompts

The benefits of permanent pictorial prompts in enhancing maintenance and generalization are likely dependent on their degree of stimulus control and the extent to which their use is generalized. Although several studies on the use of pictorial prompts have demonstrated their efficacy (e.g., Pierce & Schreibman, 1994; Wacker & Berg, 1983; Wacker, Berg, Berrie, & Swatta, 1985), there is still some question regarding what ultimately controlled responding. The present study allowed an explicit examination of stimulus control by pictorial prompts. Three 4-year-old children with developmental disabilities were taught to complete 4 instructional sets (5 steps each) using pictorial prompts such that the prompts would control responding. All 3 participants showed generalization to the final set after training with 3 sets. These results suggest that training a single task sequence may not be sufficient for acquisition of generalized pictorial instruction following. However, establishing stimulus control by the pictorial prompts rather than teaching behavioral chains may facilitate acquisition of a generalized repertoire.     

Does Generalized (Dis)Trust Travel? Examining the Impact of Cultural Heritage and Destination‐Country Environment on Trust of Immigrants

At least two contrasting perspectives on the roots of generalized trust exist: The cultural perspective emphasizing how trust is a stable trait passed on from one generation to the next through parental socialization, and the experiential perspective, which stresses that trust is subject to change with what we experience in the environment in which we live. Analyzing trust of immigrants is an effective way to contrast the two perspectives, as the cultural perspective predicts that immigrants' level of trust will continue to reflect the level of trust of their home country, whereas the experiential perspective predicts that trust of immigrants will change according to the environment of the destination country. This article examines how first‐generation immigrants from three low‐trust countries of origin (Turkey, Poland, and Italy) are affected by migrating to high‐trust countries in Northern Europe, which hold qualities conducive to trust. In contrast to earlier studies examining trust of immigrants, I build on one data set containing data on both migrants and nonmigrants from the same country of origin as well as on a wide range of relevant covariates of trust. Using the method of matching, the results of the analysis lend most support to the experiential perspective on trust as the destination‐country context has a massive impact on trust of immigrants, who display significantly higher levels of trust than comparable respondents in their country of origin. The results are robust to limiting the destination‐country context to only one country (Germany) and comparing migrants and nonmigrants responding in the same language.     

Relaxation of electrons following trapping in the space-charge-limited conduction regime of n + -i-n + hydrogenated amorphous silicon structures

The relaxation of a space charge due to trapped electrons in an n + -i-n + hydrogenated amorphous silicon structure has been modelled by Solomon. Here we extend the model by obtaining analytical expressions for the current at the beginning of the relaxation as well as for long times when retrapping of electrons is taken into account. Our expression for the current at long times differs considerably from that given previously. Consequences for the derived values of the capture cross-sections of the gap states near the Fermi level are examined and discussed.     

Performance and Learning of Generalized Motor Programs: Relative (GMP) and Absolute (Parameter) Errors

The effects of practice (Experiment 1) and parameter variability (Experiment 2) on the learning of generalized motor programs (GMPs) and movement parameterization were investigated In each experiment, 2 tasks with different relative force-time structures were tested. Participants (N = 32, Experiment (N = 40, Experiment 2) attempted to exert a pattern of force that resembled in force and time a waveform that was displayed on a computer monitor. In both experiments, the analysis suggested that the GMP, although refined over practice, was relatively stable (i.e., resistant to decay and interference), even early in practice (after 20 trials). In addition, the results indicated that constant and variable parameter practice did not differentially affect GMP learning but did degrade the learning of the parameter that was not varied. The data provided additional evidence for the dissociation of the GMP and the parameterization processes proposed in GMP theory. Contrary to schema theory, the present data suggest an interdependence between the force and the time parameters: The manipulation of 1 of the parameters has a negative effect on the learning of the other parameter.     

Effect of Practice on Effector Independence

The authors' primary purpose in the present experiment was to determine if practice changes the extent to which simple motor sequences are effector independent. Contralateral and ipsilateral effector transfers were assessed in 24 participants after 1 (200 trials) and 4 (800 trials) days of practice. The response sequence became increasingly effector dependent; the response structure and the scaling of force on the effector transfer tests were no better after 4 days of practice than after only 1 day, even though retention performance improved substantially. Those results are consistent with the notion that participants refine their movements over extended practice by exploiting the unique characteristics of the effectors. The additional practice results in a more effective movement when the same effectors are used but is of little value when different effectors are required.     

Cognitive Behavioural Therapy and Applied Relaxation for Generalized Anxiety Disorder: A Time Series Analysis of Change in Worry and Somatic Anxiety

The present study examined symptom change profiles in patients with generalized anxiety disorder (GAD) receiving either cognitive behavioural therapy (CBT) or applied relaxation (AR). It was hypothesized that (a) changes in worry would uniquely predict changes in somatic anxiety for most participants receiving CBT and (b) changes in somatic anxiety would uniquely predict changes in worry for most participants in the AR condition. Twenty participants (CBT n = 10; AR n = 10) completed daily ratings of worry and somatic anxiety during therapy, and multivariate time series analysis was used to assess the causal impact of each variable on the other. The hypotheses were not supported because we found no evidence of a match between individual symptom change profiles and treatment condition. Rather, a bidirectional relationship between worry and somatic anxiety was observed in 80% of participants receiving CBT and 70% of participants receiving AR. When only treatment responders were considered, 83% of participants receiving CBT and 86% of those receiving AR had such a bidirectional effect. The findings are discussed in terms of models of psychopathology that posit dynamic interactions between symptom clusters and in terms of the value of examining treatment mechanisms at the individual level.     

Distress and Avoidance in Generalized Anxiety Disorder: Exploring the Relationships with Intolerance of Uncertainty and Worry

Theory and research suggest that treatments targeting experiential avoidance may enhance outcomes for patients with generalized anxiety disorder (GAD). The present study examined the role of experiential avoidance and distress about emotions in a treatment-seeking sample with a principal diagnosis of GAD compared with demographically matched nonanxious controls and sought to explore their shared relationship with two putative psychopathological processes in GAD: intolerance of uncertainty and worry. Patients with GAD reported significantly higher levels of experiential avoidance and distress about emotions compared with nonclinical controls while controlling for depressive symptoms, and measures of these constructs significantly predicted GAD status. Additionally, experiential avoidance and distress about anxious, positive, and angry emotions shared unique variance with intolerance of uncertainty when negative affect was partialed out, whereas only experiential avoidance and distress about anxious emotions shared unique variance with worry. Discussion focuses on implications for treatment as well as future directions for research.     

Emergent identity matching after successive matching training, I: reflexivity or generalized identity

This research investigated the source of an ostensible reflexivity effect in pigeons reported by Sweeney and Urcuioli (2010). In Experiment 1, pigeons learned two symmetrically reinforced symbolic successive matching tasks (hue-form and form-hue) using red-green and triangle-horizontal line stimuli. They differed in their third concurrently trained baseline task: form-form matching with stimuli appearing in the symbolic tasks (triangle and horizontal) for one group versus hue-hue matching with stimuli not appearing in the symbolic tasks (blue and white) for the other. During subsequent nonreinforced probe tests, all pigeons in the former group and most pigeons in the latter group responded more to the comparisons on matching than on nonmatching red-green probes. In Experiment 2, the latter group was tested on nonreinforced form-form probes. One of the 4 pigeons responded significantly more to the comparisons on matching than on nonmatching triangle-horizontal probes. These data are consistent with generalized identity and at least one other interpretation of the reflexivity results and question the functional stimulus assumption of Urcuioli's (2008) stimulus-class theory.     

Analyzing temporal patterns of infant sleep and negative affective behavior: a comparison between different statistical models

Objective

Variability in infant sleep and negative affective behavior (NAB) is a developmental phenomenon that has long been of interest to researchers and clinicians. However, analyses and delineation of such temporal patterns were often limited to basic statistical approaches, which may prevent adequate identification of meaningful variation within these patterns. Modern statistical procedures such as additive models may detect specific patterns of temporal variation in infant behavior more effectively.

Method

Hundred and twenty-one mothers were asked to record different behaviors of their 4–44 weeks old healthy infants by diaries for three days consecutively. Circadian patterns as well as individual trajectories and day-to-day variability of infant sleep and NAB were modeled with generalized linear models (GLMs) including a linear and quadratic polynomial for time, a GLM with a polynomial of the 8th order, a GLM with a harmonic function, a generalized linear mixed model (GLMM) with a polynomial of the 8th order, a generalized additive model, and a generalized additive mixed model (GAMM).

Results

The semi-parametric model GAMM was found to fit the data of infant sleep better than any other parametric model used. GLMM with a polynomial of the 8th order and GAMM modeled temporal patterns of infant NAB equally well, although the GLMM exhibited a slightly better model fit while GAMM was easier to interpret. Besides the well-known evening clustering in infant NAB we found a significant second peak in NAB around midday that was not affected by the constant decline in the amounts of NAB across the 3-day study period.

Conclusion

Using advanced statistical procedures (GAMM and GLMM) even small variations and phenomena in infant behavior can be reliably detected. Future studies investigating variability and temporal patterns in infant variables may benefit from these statistical approaches.     

Substitution effects in a generalized token economy with pigeons

Pigeons made repeated choices between earning and exchanging reinforcer‐specific tokens (green tokens exchangeable for food, red tokens exchangeable for water) and reinforcer‐general tokens (white tokens exchangeable for food or water) in a closed token economy. Food and green food tokens could be earned on one panel; water and red water tokens could be earned on a second panel; white generalized tokens could be earned on either panel. Responses on one key produced tokens according to a fixed‐ratio schedule, whereas responses on a second key produced exchange periods, during which all previously earned tokens could be exchanged for the appropriate commodity. Most conditions were conducted in a closed economy, and pigeons distributed their token allocation in ways that permitted food and water consumption. When the price of all tokens was equal and low, most pigeons preferred the generalized tokens. When token‐production prices were manipulated, pigeons reduced production of the tokens that increased in price while increasing production of the generalized tokens that remained at a fixed price. The latter is consistent with a substitution effect: Generalized tokens increased and were exchanged for the more expensive reinforcer. When food and water were made freely available outside the session, token production and exchange was sharply reduced but was not eliminated, even in conditions when it no longer produced tokens. The results join with other recent data in showing sustained generalized functions of token reinforcers, and demonstrate the utility of token‐economic methods for assessing demand for and substitution among multiple commodities in a laboratory context.