The effects of providing access to stimuli following choice making during vocal preference assessments

Two variations of a vocal paired-stimulus preference assessment were evaluated to determine whether the verbal reports of preference, given by individuals with developmental disabilities when no access to the activity was given, matched their verbal reports when access to the activity was given contingent on their choice. The results indicated different outcomes between the two methods for 6 of the 7 participants. Subsequent reinforcer assessments, conducted for 2 participants, showed that activities identified in the preference assessments that provided access contingent on selection resulted in more responding than did activities identified in the preference assessment that did not include access to items following their selection.     

Rapid acquisition in concurrent chains: evidence for a decision model

Pigeons' choice in concurrent chains can adapt to rapidly changing contingencies. Grace, Bragason, and McLean (2003) found that relative initial-link response rate was sensitive to the immediacy ratio in the current session when one of the terminal-link fixed-interval schedules was changed daily according to a pseudorandom binary sequence (e.g., Schofield & Davison, 1997). The present experiment tested whether the degree of variation in delays across sessions had any effect on acquisition rate in Grace et al.'s (2003) rapid-acquisition procedure. In one condition ("minimal variation"), the left terminal link was always fixed-interval 8 s and the right terminal link was either fixed-interval 4 s or fixed-interval 16 s. In the other condition ("maximal variation"), a unique pair of fixed-interval values was used in each session. Responding was sensitive to the current-session immediacy ratio in both conditions, but across subjects there was no systematic difference in sensitivity. These results challenge the view that initial-link responding in the rapid-acquisition procedure is determined by changes in the learned value of the terminal-link stimuli, and suggests instead that a process resembling categorical discrimination may control performance. A decision model based on the assumption that delays are categorized as short or long relative to the history of delays provided a good account of the data and shows promise in being able to explain other choice phenomena.     

Cognitive-behaviour therapy for depersonalisation disorder: an open study

Depersonalisation (DP) and derealisation (DR) are subjective experiences of unreality in, respectively, one's sense of self and the outside world. These experiences occur on a continuum from transient episodes that are frequently reported in healthy individuals to a chronic psychiatric disorder that causes considerable distress (depersonalisation disorder: DPD). Despite the relatively high rates of reporting these symptoms, little research has been conducted into psychological treatments for this disorder. We report on an open study where 21 patients with DPD were treated individually with cognitive behavioural therapy (CBT). The therapy involved helping the patients re-interpret their symptoms in a non-threatening way as well as reducing avoidances, safety behaviours and symptom monitoring. Significant improvements in patient-defined measures of DP/DR severity as well as standardised measures of dissociation, depression, anxiety and general functioning were found at post-treatment and six-months follow-up. Moreover, there were significant reductions in clinician ratings on the Present State Examination (Wing, Cooper & Sartorius, 1974), and 29% of participants no longer met criteria for DPD at the end of therapy. These initial results suggest that a CBT approach to DPD may be effective, but further trials with larger sample sizes and more rigorous research methodology are needed to determine the specificity of this approach.     

The effects of methylphenidate on a functional analysis of disruptive behavior: a replication and extension

In the present investigation, a functional analysis of the disruptive behavior of a 18-year-old man who had been diagnosed with attention deficit hyperactivity disorder and moderate mental retardation was conducted, both when he was taking methylphenidate and when he was not taking the medication. The results of this functional analysis demonstrated that the participant's disruptive behaviors were reinforced by access to attention only when he was not taking methylphenidate.     

Embedding leader characteristics: an examination of homogeneity of personality and values in organizations

The authors (a) investigated trait homogeneity in organizations by examining within-organization similarity among members' personality traits and personal values and (b) tested the relationship between the top leaders' personal characteristics and organizational profiles of personality and values. Results replicate and extend B. Schneider, D. B. Smith, S. Taylor, and J. Fleenor's (1998) hypothesis of the homogeneity of personality in organizations. Using data from CEOs and 467 employee participants from 32 organizations, the authors found evidence of within-organization homogeneity of both personality and values. Results also suggest initial empirical support for assumptions presented by E. Schein (1992) and B. Schneider (1987) about leader-follower congruence. Some implications regarding leadership and organizational behavior are discussed.     

Evaluating and developing a multidimensional, dispositional measure of appraisal

Although theories of stress have emphasized the critical role of the appraisal process, the use of dispositional measures of appraisal have not been readily investigated. Using a large multiethnic sample, we examined the factorial validity and dimensionality of a dispositional version of the Stress Appraisal Measure (SAM; Peacock & Wong, 1990). Both exploratory and confirmatory factor analyses resulted in a 4-factor representation of dispositional appraisal fitting better than its originally proposed 6-factor representation. This 4-factor model was invariant across gender groups. Although the 6-factor model purported to measure 3 dimensions of primary appraisal and 3 dimensions of secondary appraisal, these factors were found to be highly unstable and had questionable internal consistency. In contrast, the more parsimonious 4-factor solution identified 4 relative distinct and reliable scales of appraisal: 3 primary (Challenge, Threat, and Centrality) and 1 secondary (Resources). These findings suggest that meaningful dispositional dimensions of appraisal can be derived and incorporated into trait-state models of the stress process.     

Resilience to loss in bereaved spouses, bereaved parents, and bereaved gay men

Recent research has indicated that many people faced with highly aversive events suffer only minor, transient disruptions in functioning and retain a capacity for positive affect and experiences. This article reports 2 studies that replicate and extend these findings among bereaved parents, spouses, and caregivers of a chronically ill life partner using a range of self-report and objective measures of adjustment. Resilience was evidenced in half of each bereaved sample when compared with matched, nonbereaved counterparts and 36% of the caregiver sample in a more conservative, repeated-measures ipsative comparison. Resilient individuals were not distinguished by the quality of their relationship with spouse/partner or caregiver burden but were rated more positively and as better adjusted by close friends.     

A reminder about procedures needed to reliably produce perfect timesharing: comment on Lien, McCann, Ruthruff, and Proctor (2005)

M.-C. Lien, R. S. McCann, E. Ruthruff, and R. W. Proctor (2005) argued that simultaneous ideomotor-compatible choice tasks cannot be perfectly timeshared. Their conclusion is limited in generalizability for 2 reasons: (a) Their experiments did not include procedures that previous research has shown to be necessary for obtaining perfect timesharing (motivating subjects to perform the 2 tasks rapidly and simultaneously; homogeneous blocks of simultaneous stimuli for the 2 tasks), and (b) their experiments included a procedure that previous research has shown to interfere with perfect timesharing of simultaneous tasks (within-block variation of task interstimulus intervals). Also discussed here are problems in M.-C. Lien et al.'s (2005) analysis of slopes relating Task 2 latency to Task 1 latency and their advocacy of a central bottleneck theory that may not be disconfirmable.     

Fluent versus nonfluent primary progressive aphasia: a comparison of clinical and functional neuroimaging features

To better characterize fluent and nonfluent variants of primary progressive aphasia (PPA). Although investigators have recognized both fluent and nonfluent patients with PPA, the clinical and neuroimaging features of these variants have not been fully defined. We present clinical and neuropsychological data on 47 PPA patients comparing the fluent (n=21) and nonfluent (n=26) subjects. We further compared language features with PET/SPECT data available on 39 of these patients. Compared to the nonfluent PPA patients, those with fluent PPA had greater impairment of confrontational naming and loss of single word comprehension. They also exhibited semantic paraphasic errors and loss of single word comprehension. Patients with nonfluent PPA were more likely to be female, were more often dysarthric, and exhibited phonological speech errors in the absence of semantic errors. No significant differences were seen with regard to left hemisphere abnormalities, suggesting that both variants result from mechanisms that overlap frontal, temporal, and parietal regions. Of the language measures, only semantic paraphasias were strongly localized, in this case to the left temporal lobe. Fluent and nonfluent forms of PPA are clinically distinguishable by letter fluency, single word comprehension, object naming, and types of paraphasic errors. Nevertheless, there is a large amount of overlap between dysfunctional anatomic regions associated with these syndromes.