Local and Global Sources of Control in Pigeon Delayed Matching-to-sample Performance

The present study employed a behavioural detection approach to investigate the combined effects of sample duration and sample presentation frequency on delayed matching accuracy of pigeons. Experiment 1 showed that when both samples were exposed at each of the two possible durations within a two-alternative, delayed matching session, discriminability was higher to the longer duration sample than to the short-duration sample, as found when sample duration is varied between sessions. Experiment 2's asymmetrical procedure increased bias toward the more frequent of the two samples but had no influence on discriminability. Initial discriminability was higher to samples exposed for longer durations, irrespective of stimulus presentation frequency. The results suggest qualitatively different effects of the two sources of stimulus control under consideration: Sample duration (a local or within-trial manipulation) exerted its effect on discrimination of the stimuli, whereas sample presentation frequence (a global factor) exerted its major effect on response bias. An interpretation of the data in terms of Blough's (1996) analysis of errors in matching tasks suggests that the amount of behaviour under control of the sample stimulus markedly changed with different sample durations. The analysis also showed that the biasing manipulation exerted most of its effect on the portion of behaviour outside of control by the critical stimulus. We argue that theoretical accounts of delayed matching performance need to consider both local and global factors as determinants of matching accuracy.     

Differences in alexithymia and emotional awareness in exhaustion syndrome and chronic fatigue syndrome

Symptoms of Exhaustion Syndrome (ES) and Chronic Fatigue Syndrome (CFS) are overlapping and create difficulties of differential diagnosis. Empirical studies comparing ES and CFS are scarce. This study aims to investigate if there are any emotional differences between ES and CFS. This cross‐sectional study compared self‐reported alexithymia and observer‐rated emotional awareness in patients with ES (n = 31), CFS (n = 38) and healthy controls (HC) (n = 30). Self‐reported alexithymia was measured with the Toronto Alexithymia Scale‐20 (TAS‐20) and emotional awareness with an observer‐rated performance test, the Level of Emotional Awareness Scale (LEAS). Additionally, depression and anxiety were scored by the Hospital Anxiety and Depression Scale (HADS). Results show that patients with ES expressed higher self‐reported alexithymia in the TAS‐20 compared to HC, but had similar emotional awareness capacity in the observer‐rated performance test, the LEAS. Patients with CFS expressed more difficulties in identifying emotions compared to HCs, and performed significantly worse in the LEAS‐total and spent more time completing the LEAS as compared to HC. Correlation and multiple regressions analyses revealed that depression and anxiety positively correlated with and explained part of the variances in alexithymia scores, while age and group explained the major part of the variance in LEAS. Findings of this study indicate that emotional status is different in patients with ES and CFS with respect to both self‐reported alexithymia and observer‐rated emotional awareness. Emotional parameters should be approached both in clinical investigation and psychotherapy for patients with ES and CFS.     

Hierarchical model of vulnerabilities for anxiety: replication and extension with a clinical sample

This study served to replicate and extend our previously obtained hierarchical model of the relationships among general anxiety vulnerabilities, specific anxiety vulnerabilities and specific anxiety manifestations including panic symptoms, health anxiety, obsessive-compulsive symptoms and worry. Questionnaires assessing these variables, as well as positive affectivity and depressiveness, were administered to 125 outpatients seeking treatment for panic disorder, social anxiety disorder, obsessive-compulsive disorder, generalized anxiety disorder or major depressive disorder. The results, using a clinical sample, were highly consistent with the hierarchical model obtained in the previous study using a student sample. A more elaborate model, based on published theoretical and empirical evidence, was identified and tested, and similar results were obtained. Negative affectivity had expected direct positive effects on all of the specific anxiety and depression manifestations, with the exception of health anxiety, which showed a negative relationship, and OCD symptoms, which showed no relationship. Positive affectivity was found to be a specific risk factor for depression, while intolerance of uncertainty was found to be a specific risk factor for worry and depression. Finally, anxiety sensitivity appears to be a significant risk factor for panic and health anxiety.