Cigarette smoking and cognitive task performance: Experimental effects of very-low nicotine-content cigarettes.

Reductions in the nicotine content of cigarettes decrease smoking rate and dependence severity, but effects on cognition are less well established. The potential impacts of very-low nicotine-content (VLNC) cigarettes on cognitive task performance must be evaluated, especially in vulnerable populations. The aim of the present study is to experimentally examine the effects of VLNC cigarettes on cognitive performance. Adults who smoked daily (n = 775) from three vulnerable populations (socioeconomically disadvantaged reproductive-age women, individuals with opioid use disorder, affective disorders) were examined. Participants were randomly assigned to normal nicotine content (NNC; 15.8 mg nicotine/g tobacco) or VLNC (2.4 mg/g or 0.4 mg/g) cigarettes for 12 weeks. Response inhibition (stop-signal task), working memory (n-back task; n of 2-n of 0), and cognitive interference (nicotine Stroop task) were assessed at baseline, 2, 6, and 12 weeks. Results were analyzed using mixed-model repeated-measures analyses of variance. Extended exposure to VLNC cigarettes produced no significant changes in any measure of cognitive performance compared to NNC cigarettes. Over weeks, response times on the n-back task decreased across doses. No significant effects were observed on the stop-signal or nicotine Stroop tasks. All three vulnerable populations performed comparably on all three cognitive tasks. Extended exposure to VLNC cigarettes produced no impairments in cognitive performance on any of the assessed tasks compared to NNC cigarettes. These findings are consistent with the larger literature detailing other consequences following exposure to VLNC cigarettes and are encouraging for the adoption of a nicotine-reduction policy. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Examining Associations Between Baseline Health-Related Quality of Life and Depression and Physical Functioning Improvement Following Pulmonary Rehabilitation.

PURPOSE: This study examined whether health-related quality of life (HRQL) and depression assessed prior to pulmonary rehabilitation (PR) participation (ie, at baseline) predicted change in 6-min walk distance (6MWD) from baseline to end of PR. METHODS: Patients with pulmonary disease were consecutively referred/enrolled in a PR program from 2009-2022 (N = 503). Baseline 6MWD was assessed along with self-report measures of HRQL (St George's Respiratory Questionnaire [SGRQ]) and depression (Geriatric Depression Scale [GDS]). The SGRQ total score was used to assess overall HRQL, and SGRQ subscales assessed pulmonary symptoms, activity limitations, and psychosocial impacts of pulmonary disease. Multiple linear regression was used to examine whether baseline SGRQ scores and depression predicted Δ6MWD. RESULTS: Baseline SGRQ total score ( F(1,389) = 8.4, P = .004) and activity limitations ( F(1,388) = 4.8, P = .03) predicted Δ6MWD. Patients with an SGRQ activity limitation score ≤ 25th percentile showed the most 6MWD improvement (mean = 79.7 m, SE = 6.7), and significantly more improvement than participants scoring between the 50-75th percentiles (mean = 54.4 m, SE = 6.0) or >75th percentile (mean = 48.7 m, SE = 7.5). Patients scoring between the 25-50th percentiles (mean = 70.2 m, SE = 6.1) did not differ significantly from other groups. The SGRQ symptoms and impacts subscales were unrelated to Δ6MWD ( F(1,388) = 1.2-1.9, P > .05), as was depression ( F(1,311) = 0.0, P  > .85). CONCLUSIONS: Patients with greater HRQL at baseline may experience greater physical functioning improvement following PR. Additional support for patients with lower HRQL (eg, adjunctive self-management interventions) may enhance PR outcomes, particularly for patients who report greater activity limitations. Alternatively, early referral to PR (ie, when less symptomatic) may also benefit physical function outcomes.

An analysis of coordinated responding of pigeons.

Experimental analyses of coordinated responding (i.e., cooperation) have been derived from a procedure described by Skinner (1962) in which reinforcers were delivered to a pair of subjects (a dyad) if both responded within a short interval, thus satisfying a coordination contingency. Although it has been suggested that this contingency enhances rates of temporally coordinated responding, limitations of past experiments have raised questions concerning this conclusion. The present experiments addressed some of these limitations by holding the schedule of reinforcement (Experiment 1: fixed ratio 1; Experiment 2; variable interval 20 s) constant across phases and between dyad members and by varying, in different conditions, the number of response keys (one to three) across which coordination could occur. Greater percentages of coordinated responding occurred under the coordinated-reinforcement phases than under independent-reinforcement phases in most conditions. The one exception during the one-key condition of Experiment 1 appeared to be a consequence of variability introduced by the independent-reinforcement phase procedure. Furthermore, coordination percentages decreased with increasing response options under both schedules. These results confirm and extend the finding that coordination contingencies control higher rates of temporally coordinated responding than independent-reinforcement contingencies do.

Self-Reported Executive Function in Hospitalized Cardiac Patients and Associations With Patient Characteristics and Cardiac Rehabilitation Attendance.

PURPOSE: Executive function (ExF), the ability to do complex cognitive tasks like planning and refraining from impulsive behavior, is associated with compliance with medical recommendations. The present study identified associations between self-reported ExF and demographics of patients with cardiac disease as well as with cardiac rehabilitation (CR) attendance. METHODS: Self-reported ExF impairment was measured using the Behavior Rating Inventory of Executive Function (BRIEF) on 316 individuals hospitalized for CR-qualifying cardiac events. Scores were calculated for a global measure (Global Executive Composite [GEC]) and the two BRIEF indices: Behavioral Regulation Index and Metacognition Index (MCI). Participants were followed up post-discharge to determine CR attendance. Univariate logistic regressions between ExF measures and demographic variables were conducted, as were multiple logistic regressions to identify significant, independent predictors. Analyses were conducted using clinical (T scores ≥ 65) and subclinical (T scores ≥ 60) criteria for significant ExF impairment as outcomes. One-way analyses of variance were performed between ExF impairment and CR attendance. RESULTS: Self-reported ExF deficits were relatively rare; 8.9% had at least subclinical scores on the GEC. Using the subclinical criterion for the MCI, having diabetes mellitus (DM) and being male were significant, independent predictors of MCI impairment. No significant relationship was found between ExF and CR attendance. CONCLUSION: Using the subclinical criterion only, individuals with DM and males were significantly more likely to have MCI impairment. No significant effect of ExF impairment on CR attendance was found, suggesting that self-reported ExF measured in the hospital may not be an appropriate measure for predicting behavioral outcomes.

What is an extinction burst?: A case study in the analysis of transitional behavior.

Among the tactics of experimental science discussed by Sidman (1960) were those used to study transitional behavior. Drawing from his insights, this review considers an often cited but infrequently analyzed aspect of the transition from reinforcement to extinction: the extinction burst. In particular, the review seeks to answer the question posed in its title. The generic definition of an extinction burst as an increase in response rate following the onset of extinction is found to be wanting, raising more questions than it answers. Because questions of definition in science usually come down to those of measurement, the answer to the title's question is suggested to be found in how behavior prior to extinction is maintained and measured, when and how extinction is introduced, and where in time and how behavior early in extinction is measured. This analysis suggests that a single, uniform, and precise definition of the extinction burst is misguided. Examining how each of these facets contributes to what has been described generically as the extinction burst is a small, but important, part of Sidman's methodological legacy to the experimental analysis of behavior.

A critical examination of best dose analysis for determining cognitive-enhancing potential of drugs: studies with rhesus monkeys and computer simulations.

RATIONALE: Best dose analysis involves identifying the dose associated with the greatest improvement in performance for each subject and comparing performances associated with these individually determined best doses to control performances. OBJECTIVES: The current experiments were conducted to examine whether significant best dose effects might result from the selective analysis of data rather than an actual drug effect. METHODS: Experiment 1 examined the effects of nicotine and methylphenidate on delayed matching-to-sample (DMTS) and self-ordered spatial search (SOSS) performances in rhesus monkeys (DMTS: n = 7; SOSS: n = 6) to determine the validity and reliability of best dose effects. Experiment 2 used Monte Carlo computer simulations to estimate the likelihood of obtaining a significant outcome when the best dose method was applied to randomly generated data sets for which no difference existed. RESULTS: Significant effects were obtained when the best dose analysis was applied to performances from nondrug sessions, and best dose performances were not significantly different from the best nondrug performances. The doses identified as best doses from two nicotine dose-response curve determinations were unrelated, and the improvement associated with the best dose observed during the first dose-response curve determination was not reliable when the dose was administered repeatedly. Finally, there was a high likelihood of obtaining a statistically significant difference when no real difference existed. CONCLUSIONS: Best dose analysis for the identification of potential therapeutic agents should be replaced by single-subject designs.