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The present experiment investigated the effects of 1) repeated exposures to escalating punishment intensities and 2) repeated exposure to punishment after periods of vacation on response allocation between punished and unpunished responding in three groups of rats. The first group (intensity + vacation) experienced repeated exposures to escalating punishment intensities after a period of vacation (i.e., return to baseline) from punishment. The second group (intensity‐only) experienced repeated exposures to escalating punishment intensities without vacation from punishment. The third group (vacation‐only) experienced repeated exposures to a constant punishment intensity after a period of vacation from punishment. Results showed that superimposition of punishment on one of two concurrently available responses decreased allocation toward the punished response and increased allocation toward the unpunished response. Furthermore, greater changes in allocation were observed with the introduction of a moderate constant intensity than with the introduction of a low intensity that increased across sessions. Reexposure to punishment had different effects between the groups. Although there was evidence that high shock intensities can enhance the efficacy of lower intensities to shift allocation away from the punished response and toward the unpunished response, there was little evidence of changes in response allocation with reintroduction of punishment after a period of vacation.

Effects of delays of reinforcement on zebrafish behavior were examined following training with immediate reinforcement. The delay was either signaled by an exteroceptive stimulus present for the entire delay period (fully signaled), signaled briefly only at delay onset (partial signal), or without a stimulus (unsignaled). Unsignaled delays consistently resulted in low response rates. Fully signaled delays resulted in higher response rates than unsignaled delays when the delay was 3 s, but this difference in response rates disappeared at 6‐s delays. Partially signaled delays were less effective in maintaining responding than fully signaled delays, but more effective than unsignaled delays, although these results were only suggestive. These results indicate that stimulus changes that occur during delays to reinforcement have similar effects with zebrafish as with other species, but also that responding of zebrafish has a relatively low tolerance to the delay duration. A vast majority of experiments examining zebrafish behavior suggests that the fish have potential to serve as an interface between biological and behavioral science, but this may not be the case in some research areas involving delays, such as delay discounting.

Due to the prevalence of words that cannot be read phonetically in the English language, sight word instruction is required to supplement phonics instruction. In this study, we manipulated stimulus disparity in sight word sets by comparing the effects of sets of sight words with the same initial letter (3 words per set, 3 total sets) versus distributing words with the same initial letter across sets when assessing acquisition of the combined set (9 words) for 5 children who ranged from 4–6 years of age using a combined adapted alternating treatments design and pre‐posttest design. All participants mastered the 3‐word sets in both teaching conditions but did not master the control sets. In general, participants required more teaching sessions when the words in sets began with the same letter. These findings are consistent with stimulus disparity research demonstrating that discrimination training is generally less efficient when comparison stimuli are similar.

The dopamine‐depleting agent tetrabenazine alters effort‐based choice, suppressing food‐reinforced behaviors with high response requirements, while increasing selection of low‐cost options. In the present experiments, rats were tested on a concurrent fixed ratio 5/chow feeding choice task, in which high‐carbohydrate Bio‐serv pellets reinforced lever pressing and lab chow was concurrently available. Detailed timing of lever pressing was monitored with an event recording system, and the temporal characteristics of operant behavior seen after 1.0 mg/kg tetrabenazine or vehicle injections were analyzed. Tetrabenazine shifted choice, decreasing lever pressing but increasing chow intake. There was a small effect on the interresponse‐time distribution within ratios, but marked increases in the total duration of pauses in responding. The postreinforcement‐pause (PRP) distribution was bimodal, but tetrabenazine did not increase the duration of PRPs. Tetrabenazine increased time feeding and duration and number of feeding bouts, but did not affect feeding rate or total time spent lever pressing for pellets and consuming chow. Thus, TBZ appears to predominantly affect the relative allocation of lever pressing versus chow, with little alteration in consummatory motor acts involved in chow intake. Tetrabenazine is used to model motivational symptoms in psychopathology, and these effects in rats could have implications for psychiatric research.

The present study investigated the effects of variability requirements on learning difficult target sequences in humans. Twenty university students emitted five‐response sequences. For the experimental groups, 30 nontarget sequences were reinforced according to the Lag‐10 variation criterion or the Lag‐3 repetition criterion across conditions. For the control groups, the probability of reinforcers for nontarget sequences was yoked to that obtained by the experimental groups. In addition, for both groups, two difficult target sequences were continuously reinforced. U values were higher with the Lag‐10 variation criterion than with the Lag‐3 repetition criterion for the experimental groups and were unsystematic for the control groups. Higher U values ​​were accompanied by a random pattern in the emission of nontarget sequences for all groups. Higher levels of variability, regardless of whether they were directly produced by reinforcement or were contingency induced, facilitated learning of difficult target sequences.

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This study examined if listener behavior and responding by exclusion would emerge after training 3 participants with autism to tact stimuli. Tacts for 2 of 3 stimuli were directly trained using discrete trial training methodology and were followed by an auditory–visual discrimination probe in which auditory–visual discrimination by naming (i.e., bidirectional naming of trained tacts) and auditory–visual discrimination by exclusion were assessed; in subsequent sessions, tacting by exclusion probes were conducted in which tacts for the exclusion target (i.e., stimulus not trained as a tact) were assessed. All 3 participants demonstrated auditory–visual discrimination by naming, auditory–visual discrimination by exclusion, and tacting by exclusion across all comparisons. Results suggest that programming for learning by exclusion can provide an efficient way to enhance skill acquisition.

AbstractWe evaluated whether intraverbal and reverse intraverbal behavior emerged following listener training in children with autism spectrum disorder (ASD). Six participants were each taught three sets of three “when?” questions in listener training. A multiple baseline design across behaviors (stimulus sets) was used to assess the effects of listener training. Results showed that intraverbal behavior emerged following listener training for five out of six participants. One participant received additional listener training and intraverbal training before intraverbal behavior emerged. Furthermore, reverse intraverbal responding occurred across all three sets of questions for three of the six participants. Establishing listener behavior may be a pathway for emergent intraverbal and reverse intraverbal responding in children with ASD. Future research could examine what skill repertoire may facilitate such transfer.