Concurrent schedules: Spatial separation of response alternatives

Four pigeons were exposed to independent concurrent variable-interval 20-second variable-interval 60-second schedules of reinforcement. A transparent partition was inserted midway between the two response keys. The length of the partition was systematically manipulated. Increasing partition length produced a decrease in changeover rate in Experiment 1. Over-matching was observed with a partition length of 20 centimeters. In Experiment 2 a four-second limited hold was added to the schedules. Increasing partition length produced a decrease in changeover rate that exceeded the decrease observed in Experiment 1. This manipulation produced nearly exclusive choice of the variable-interval 20-second component. The present results, together with results obtained in related research, suggest that deviation from matching is a function of procedural variables that determine the consequences of a changeover response.     

Screening for intellectual disability in Dutch police suspects

The screener for mild intellectual disability (SCIL) was developed to screen for mild intellectual disability (IQ below 85). The aims of this study were (a) to examine the predictive validity of the SCIL in screening for intellectual disability among police suspects and (b) to explore the prevalence of cognitive intellectual disability among suspects in police custody in the Netherlands. An unselected sample of police suspects (N = 178) charged with a variety of offences was assessed with the SCIL, a Wechsler Adult Intelligence Scale (WAIS)‐III‐NL short form, and a malingering measure. The SCIL screened 50.0% of the sample as having mild intellectual disabilities, whereas the short WAIS classified 84.3% of the sample with an IQ below 85. A principal component analysis of the SCIL showed ambiguous results. Furthermore, the short WAIS classified 55.6% of our sample with a borderline IQ (IQ = 70–84), 84.3% with an IQ below 85 and 28.7% with an IQ below 70. The prevalence of intellectual disability in this sample of Dutch (police) suspects appears to be higher than prevalence rates found in previous international studies. More exhaustive research is needed to examine the prevalence of intellectual disabilities in police suspects, and the utility of the SCIL to screen for these disabilities.     

A test of symmetry and transitivity in the conditional discrimination performances of pigeons

In a matching-to-sample context, pigeons were taught two conditional discriminations according to one of three equivalence paradigms: train if A, then select B and if B, then select C; train if B, then A and if B, then C; or train if A, then B and if C, then B. Test trials without reinforcement revealed that the conditional relations did not satisfy the symmetrical and transitive properties of an equivalence relation. Apparently, only specific if... then relations were learned. Contrary to Kendall's (1983) findings, and probably as a consequence of procedural differences, none of the pigeons in the present experiment were observed to emit mediating behavior during the transitivity probe trials. The absence of symmetry and transitivity may be related to the individual stimuli not being reflexive. Behavioral techniques other than the commonly used matching-to-sample technique might better succeed in avoiding unintended stimulus control in the study of the formation of stimulus classes.     

Concurrent schedules: Transient-state changeover behaviour

Ten pigeons responded in a two-alternative continuous-choice situation. Rein-forcers were programmed by a single variable-interval 30-sec schedule. The proportion of reinforcers assigned to one alternative was either 0.67 or 0.50 in different conditions. The changes in local changeover rates following changes of conditions were adequately described by an exponential function. This result can be explained by a model of changeover behaviour proposed by Myerson and Miezin (1980), if a simplifying assumption is made about reinforcement rates as controlling variables. A modification of the Myerson and Miezin model that accounts for the exponential function but does not make assumptions about reinforcement rates as controlling variables is presented.     

Affect and Affect Regulation Strategies Reciprocally Influence Each Other in Daily Life: The Case of Positive Reappraisal,Problem-Focused Coping,Appreciation and Rumination

Feelings of positive or negative affect are not restricted to temporary states. They can also determine future affective experiences, by influencing the building of an individual’s personal resources. The present study was designed to understand the daily fluctuations in positive and negative affect more fully. To this end, we examined the involvement of a variety of affect regulation strategies in these fluctuations. The affect regulation strategies we explored included positive reappraisal, problem-focused coping, appreciation and rumination. We adopted an experience sampling method, consisting of five daily assessments over a 2-week period. As expected, within a few hours of experiencing more positive affect, participants engaged in greater positive reappraisal, problem-focused coping and appreciation. In turn, greater use of each of these three strategies was followed by more intense experiences of positive affect. We observed analogous reciprocal influences between rumination and the experience of negative affect, within the same time interval. Changes in affective experience over several hours were also directly influenced by concurrent use of these strategies. More specifically, greater positive reappraisal, problem-focused coping and appreciation accelerated the rise in positive affect that follows low feelings of positive affect, and slowed the decline in positive affect that follows high feelings. Rumination had an analogous influence on change in negative affect. The clinical implications of these findings are discussed.     

Response interference in compatibility tasks

Affective priming (AP) is a well-established phenomenon in which performance to a valenced target is typically better when it is preceded by an affectively congruent prime than when it is preceded by an incongruent prime. Several studies have emphasized a strong similarity between AP and Stroop suggesting that both are driven by response interference. The present study investigated this hypothesis by testing whether a general prediction of the response interference model was verified in the two tasks. This prediction refers to target strength and states that the size of compatibility effects should increase as the strength of the relevant information decreases. In four experiments, we show that this general prediction of the response interference model was verified in AP and Stroop when the strength of the relevant information was manipulated at the perceptual level (Experiments 1 and 2), while the opposite pattern was observed when this variable was manipulated at the semantic level (Experiments 3 and 4). While the results do not undermine the hypothesis that AP and Stroop effects are governed by response interference, they suggest that the model should be refined in order to account for differential effects of target strength in compatibility tasks.     

Influence des caractéristiques affectives et sémantiques des exemplaires d’un IAT Jeunes-Vieux sur les mesures d’attitudes résultantes

The IAT is supposed to be a method of indirect measure of the associative strengths between two target concepts (e.g., Young people versus Old) and two attribute concepts (e.g., Good versus Bad). But the stimuli used to represent these concepts can have an influence on IAT effects. We systematically manipulated the affective and semantic features of the stimuli used in a Young-Old IAT. The appearance of target exemplars (photos) and attribute exemplars (words) were perfectly differentiated. Three hundred and twenty subjects participated in the experiment and the results show that IAT effects are both influenced by the stimuli used and by the associative strengths between concepts. Practical and theoretical implications are discussed.     

Concurrent schedules: Maximization versus reinforcement of changeover behaviour

Pigeons responded on concurrent variable-interval 180-sec variable-interval 36-sec schedules during Conditions 1 and 3 of Experiment 1. Condition 2 arranged variable-interval 60-sec schedules for both response alternatives. The schedule assigned to the alternative that was associated with the variable-interval 36-sec schedule in Conditions 1 and 3 operated only when the subject responded on that alternative. The proportion of time spent responding on the alternative with the conventional variable-interval 60-sec schedule increased during Condition 2, but exclusive choice of that alternative did not develop. This result is inconsistent with maximization of the overall reinforcement rate and with maximization of the momentary probability of reinforcement (momentary maximizing). Increasing time proportions were also found in Experiment 2, which arranged similar conditions, except that reinforcement was provided on a variable-time basis. The time proportions were close to the momentary maximizing prediction in Experiment 2. The results of both experiments can be explained if it is assumed that time allocation is controlled by delayed reinforcement of changeovers between alternatives.     

Neurocognitive functioning in patients with conversion disorder/functional neurological disorder

Neurocognitive symptoms are common in individuals with somatic symptom and related disorders (SSRD), but little is known about the specific impairments in neurocognitive domains in patients with conversion disorder (CD)/functional neurological disorder (FND). This study examines neurocognitive functioning in patients with CD/FND compared to patients with other SSRD. The sample consisted of 318 patients. Twenty-nine patients were diagnosed with CD/FND, mean age 42.4, standard deviation (SD) = 13.8 years, 79.3% women, and 289 patients had other SSRD (mean age 42.1, SD = 13.3, 60.2% women). Patients completed a neuropsychological test battery that addressed a broad range of neurocognitive domains, including information processing speed, attention and executive functioning. Patients with CD/FND had clinically significant neurocognitive deficits in all neurocognitive domains based on normative data comparison. Patients with CD/FND also performed significantly worse than patients with other SSRD on information processing speed (Digit Symbol Substitution Test (V = .115, p = .035), Stroop Color–Word Test (SCWT) card 1 (V = .190, p = .006), and SCWT card 2 (V = .244, p < .001). No CD/FND vs. other SSRD differences were observed in other neurocognitive domains. These findings indicate the patients with CD/FND perform worse on information processing speed tests compared to patients with other SSRD.