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.     

The long-term effect of high- and low-rate responding histories on fixed-interval responding in rats

Tell rats were given extended lever-press training on a fixed-interval (FI) 30-s food reinforcement schedule from the outset or following exposure to one or two previous reinforcement schedules. For 4 rats the previots schedule was either fixed-ratio 20, which generated high response rates, or differential-reinforcement-of-low-rate 20 s, which produced low response rates. For 4 additional rats the extended training on FI 30 s was preceded by experience with two schedules: fixed-ratio 20 followed by differential-reinforcement-of-low-rate 20 s; or the same two schedules in the reverse order. Fixed-interval response rates were initially affected by the immediately preceding schedule, but after 80 to 100 sessions, all traces of prior schedule history had disappeared. The results also showed no long-term effect of schedule history on the interfood-interval patterns of responding on the FI 30-s schedule. These results support one of the most central tenets of the experimental analysis of behavior: control by the immediate consequences of behavior.     

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.     

内隐与外显记忆重复学习效果的比较研究

实验采用重学—分离设计 ,分别用知觉辨认和再认测验作为内隐、外显测量的测验方法 ,比较重学—启动测验的结果与重学—再认的结果 ,发现 :重学和间接测量的结合能有效地揭示内隐记忆的叠加现象 ;一次重学能使知觉启动测验的成绩产生明显的叠加效应 ;高意识水平学习后 ,低意识水平的重复学习不能改变外显测验成绩持续下降的趋势。     

The role of the response-reinforcer relation in delay-of-reinforcement effects

The role of the response-reinforcer relation in maintaining operant behavior under conditions of delayed reinforcement was investigated by using a two-operandum (i.e., two-key) procedure with pigeons. Responding on one key was reinforced under a tandem variable-interval differential-reinforcement-of-other-behavior (tandem VI DRO) schedule. The schedule defined a resetting unsignaled delay-of-reinforcement procedure in that a response was required when the interfood interval of the VI schedule lapsed, but further responding during the DRO component on either key reset the time interval. This ensured a fixed delay duration between any response and reinforcement. Responding on another key, physically identical to the first one except for spatial location, otherwise was without consequence. The location of the key correlated with the delay-of-reinforcement procedure varied between sessions according to a semirandom sequence. Differences in response rates between the two keys were greater, with proportionally higher rates on the key correlated with the delay-of-reinforcement procedure, the longer the delay-of-reinforcement procedure remained correlated with the same key. Differences in responding on the two keys also increased within individual sessions. These results suggest that the response-reinforcer relation is the primary determinant of responding when responding is acquired and maintained with delayed reinforcement.     

Preference after training with differential changeover delays

Pigeons were trained on a multiple schedule in which each component consisted of concurrent variable-interval (VI) 30-s VI 60-s schedules. The two components of the multiple schedule differed only in terms of the changeover delays (COD): For one component short CODs were employed, and in the second component long CODs were used. After approximate matching was obtained in each component, probe tests involving new combinations of stimuli were presented (e.g., the VI 30-s schedule from each component) to determine how the different CODs affected preference. Despite shorter CODs producing higher changeover rates, the COD value had no systematic effect on preference on the probe trials. However, differences in reinforcement rate always produced preference for the schedule with the higher reinforcement rate. The results thus show that the the pattern of changeover behavior per se is not a critical determinant of choice in the probe-trial procedure.     

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.