Fixed-time schedule effects as a function of baseline reinforcement rate

Using an arbitrary response, we evaluated fixed-time (FT) schedules that were either similar or dissimilar to a baseline (response-dependent) reinforcement schedule and extinction. Results suggested that both FT schedules and extinction resulted in decreased responding. However, FT schedules were more effective in reducing response rates if the FT reinforcer rate was dissimilar to baseline reinforcer rates. Possible reasons for this difference were evaluated with data analysis methods designed to identify adventitious response-reinforcer relations.     

Second-order schedules of token reinforcement with pigeons: effects of fixed- and variable-ratio exchange schedules

Pigeons' key pecks produced food under second-order schedules of token reinforcement, with light-emitting diodes serving as token reinforcers. In Experiment 1, tokens were earned according to a fixed-ratio 50 schedule and were exchanged for food according to either fixed-ratio or variable-ratio exchange schedules, with schedule type varied across conditions. In Experiment 2, schedule type was varied within sessions using a multiple schedule. In one component, tokens were earned according to a fixed-ratio 50 schedule and exchanged according to a variable-ratio schedule. In the other component, tokens were earned according to a variable-ratio 50 schedule and exchanged according to a fixed-ratio schedule. In both experiments, the number of responses per exchange was varied parametrically across conditions, ranging from 50 to 400 responses. Response rates decreased systematically with increases in the fixed-ratio exchange schedules, but were much less affected by changes in the variable-ratio exchange schedules. Response rates were consistently higher under variable-ratio exchange schedules than tinder comparable fixed-ratio exchange schedules, especially at higher exchange ratios. These response-rate differences were due both to greater pre-ratio pausing and to lower local rates tinder the fixed-ratio exchange schedules. Local response rates increased with proximity to food under the higher fixed-ratio exchange schedules, indicative of discriminative control by the tokens.     

Behavioral and pharmacological variables affecting risky choice in rats.

The effects of manipulations of response requirement, intertrial interval (ITI), and psychoactive drugs (ethanol, phencyclidine, and d-amphetamine) on lever choice under concurrent fixed-ratio schedules were investigated in rats. Responding on the "certain' lever produced three 45-mg pellets, whereas responding on the "risky" lever produced either 15 pellets (p = .33) or no pellets (p .67). Rats earned all food during the session, which ended after 12 forced trials and 93 choice trials or 90 min, whichever occurred first. When the response requirement was increased from 1 to 16 and the ITI was 20 s, percentage of risky choice was inversely related to fixed-ratio value. When only a single response was required but the ITI was manipulated between 20 and 120 s (with maximum session duration held constant), percentage of risky choice was directly related to length of the ITI. The effects of the drugs were investigated first at an ITI of 20 s, when risky choice was low for most rats, and then at an ITI of 80 s, when risky choice was higher for most rats. Ethanol usually decreased risky choice. Phencyclidine did not usually affect risky choice when the ITI was 20 s but decreased it in half the rats when the ITI was 80 s. For d-amphetamine, the effects appeared to he related to baseline probability of risky choice; that is, low probabilities were increased and high probabilities were decreased. Although increase in risky choice as a function of the ITI is at variance with previous ITI data, it is consistent with foraging data showing that risk aversion decreases as food availability decreases. The pharmacological manipulations showed that drug effects on risky choice may be influenced by the baseline probability of risky choice, just as drug effects can be a function of baseline response rate.     

论中西医结合的过程与层次

中西医结合是一个长期困扰人们的难题。中医理论研究人体外部现象的变化规律,以古代哲学思想为指导,具有整体联系、动态把握的合理内核。而目前现代医学对人体结构和功能的认识,并不能完全揭示生命现象本质,因而也不能完全解释中医现象。这种认识有一个不断发展和深化的过程,自然辩证法观点认为层次越低、结合越紧密。分子导次是具有生物意义的最低层次。人类“基因组”计划的实现可能在一个新的高度阐明人体本质,也使中医现象     

Exploring Decision Making Around Therapist Self‐Disclosure in Cognitive Behavioural Therapy

Background

Therapist self‐disclosure (TSD) usage varies greatly among different psychotherapy orientations. Anecdotal evidence seems to suggest that there are reasons for its judicious use, and a small number of researchers have proposed guidelines for how TSD should be used to help therapists across psychotherapy models make decisions around disclosure. However, there is almost no literature specifically exploring how cognitive behaviour therapy (CBT) practitioners make decisions around employing TSD within the CBT framework.

Objective

This study aimed to explore how experienced CBT practitioners make decisions around TSD.

Method

In‐depth qualitative interviews were conducted with six clinical psychologists who were trained and experienced in CBT, and the interviews were analysed thematically.

Results

There were two overarching themes in terms of how they made decisions to self‐disclose: (A) the rules for TSD use, which included sub‐themes (a) it must have a clear purpose, (b) it must fit, (c) the therapist must maintain boundaries, and (d) the therapist must always reflect on his/her use of TSD; and (B) how they use TSD, which included subthemes of (a) using it as a tool for change and (b) using it to manage the therapeutic relationship.

Conclusion

Participants’ decisions on whether or not to self‐disclose were strongly influenced by the CBT model, and this process went beyond what is suggested in the transtheoretical literature. Understanding this process may lead to the development of CBT‐specific guidelines for making TSD‐related decisions.     

A Systematic Review: Non‐Suicidal Self‐injury in Australia and New Zealand's Indigenous Populations

Objective

To undertake a systematic review of non‐suicidal self‐injury (NSSI) prevalence, patterns, functions, and behavioural correlates for the Indigenous populations of Australia (Aboriginal and Torres Strait Islanders) and New Zealand (NZ; Maori).

Method

We searched the following electronic databases: PubMed, MedLine, Scopus, Web of Science, ScienceDirect, PsycInfo, and PsycArticles, CINAHL, and the Informit Health and Indigenous Peoples collections. Studies were included for review if they were published within the last 25 years and reported on NSSI in Australia and NZ's Indigenous populations.

Results

Seven studies were included, six of which came from Australia. The prevalence of NSSI in Australia ranged from 0.9% up to 22.50%; statistics varied by the different samples, types of prevalence, and relationship to alcohol. Several studies found that Aboriginal and Torres Strait Islander peoples had higher rates of NSSI than other Australians, but that this was not significantly higher. Two studies indicated that NSSI was linked to alcohol use, incarceration, and a younger age. The one NZ study was of injury and not specifically NSSI.

Conclusions

Findings are limited due to a small pool of literature. Cultural variations in NSSI presentation should be considered when working with Indigenous populations. Further research is required to help determine what cultural variations may exist.