Journal of the experimental analysis of behavior最新文献

This study investigates the mechanisms that underlie pigeons' performance in the number-left task. After producing x light flashes, pigeons had to choose between a standard option that delivered reinforcement after a fixed number of additional flashes, S = 4, and a number-left option that delivered reinforcement after a variable number of additional flashes, L = 8 − x. In Experiment 1, pigeons were trained with forced and choice trials with 1 ≤ x ≤ 7. During testing, the number of choice trials was simply increased. In Experiment 2, pigeons were trained only with the anchor numerosities x = 1 and x = 7 and during testing unreinforced probe trials introduced the intermediate numerosities, x = 2, 3, 4, 5, and 6. Performance was similar in both experiments and consistent with a computational mechanism. To test whether performance in the previous experiments was due to the substantial overlap in the induced generalization gradients around the anchor numerosities, in Experiments 3a and 3b, we selected anchor numerosities that were farther apart (x = 5 and x = 50, with S = 12 and L = 53 − x). Yet, pigeons' performance remained similar. We discuss the implications of these findings for the mechanisms that underlie numerosity discrimination.

Two experiments examined pigeons' discounting of probabilistic food reinforcers using a concurrent-chains procedure within sessions combined with an adjusting-amount procedure across sessions. The study is the first to evaluate probability discounting functions in nonhuman animals in which the obtained probability equaled that programmed in each session. In Experiment 1, pigeons chose between a smaller, certain and a larger, but probabilistic food reinforcer. In Experiment 2, the probabilities of receiving both reinforcement options were reduced by a common factor, creating a choice situation in which both options were probabilistic: a smaller, more probable reinforcer and a larger, but less probable reinforcer. Results revealed that regardless of whether choices involved a certain versus a probabilistic reinforcer or they involved two probabilistic reinforcers, subjective value decreased systematically as a function of the odds against receipt of the reinforcer and that the data were well described by the hyperboloid discounting function. In addition, no significant effect of reinforcer amount on degree of probability discounting was observed, consistent with results from studies of the discounting of delayed reinforcers by nonhuman animals.

As a data-driven science, the field of behavior analysis necessitates accumulating evidence for research and theory development and clinical intervention. The most comprehensive evidence will come from systematic review and meta-analysis of a given topic. Systematic reviews comprise an established set of methods for collecting and synthesizing a body of research to identify trends, examining the strength of evidence and potential sources of bias, and identifying areas in need of further investigation. Despite their utility and widespread use in other disciplines, systematic reviews are underused in many behavior analysis domains. This technical report is part of a series on research synthesis methods in behavior analysis, with Part 1 focusing on systematic reviews and Part 2 focusing on meta-analysis. In Part 1, we provide a step-by-step guide to conducting systematic reviews using current best practices and adhering to international guidelines. Examples of tables and figures commonly included in these types of reviews are also provided. We conclude by emphasizing the importance of these reviews for behavior analysis research, practice, and theory and calling for increased numbers of published systematic reviews in behavior analysis. Finally, we provide annotated references to additional in-depth methodology resources for the interested behavior analyst.

Discounting is a pervasive phenomenon in human decision making and has been extensively studied across disciplines. This article focuses on area under the curve (AUC) as a popular measure of discounting. We provide a comprehensive review of AUC in relation to discounting, focusing on its atheoretical underpinnings and methods to calculate the measure. Additionally, we delve into the limitations of traditional AUC measures and limitations of more recent modifications of AUC (i.e., ordinal and logarithmic AUC). First, authors using AUC do not routinely report whether and how they impute an indifference point at the y-intercept, which is critically important when using the ordinal or logarithmic versions. Additionally, the ordinal version of AUC requires removing the x-axis information (e.g., delay, odds against, social distance, etc.) and replacing them with ordinal values. The logarithmic version of AUC often introduces nonintuitive values on the x-axis that lead to a high likelihood of miscalculations. We propose that authors always impute an indifference point at the y-intercept—when such data were not collected—and propose a novel method to shift indifference points that leads to a more intuitive logarithmic AUC calculation. An R package and Excel workbook to help calculate AUC are also provided and discussed.

Midsession reversal examines behavioral flexibility by requiring animals to reverse a discrimination midway within a session. This reversal behavior is controlled by changing temporal factors over the session. We tested behavioral flexibility in pigeons by reversing the contingencies within a session from a visual matching-to-sample (MTS) task to a non-matching-to-sample (NMTS) task. To examine how visual context influenced the reversal, the stimuli were assigned according to two different mapping conditions. In the bounded mapping condition, different stimuli exclusively appeared in either the MTS or NMTS for half of the session, and in the unbounded condition, the stimuli appeared across both the MTS and NMTS halves of a session. In the unbounded condition, pigeons showed a modest switching function, from matching to non-matching, at the reversal boundary. In contrast, in the bounded condition, the pigeons learned the contingences faster and to a higher accuracy and exhibited a more precise switching function at the reversal. The latter outcome suggests there was little or no temporal interference, as the different visual contexts allowed the MTS and NMTS tasks to be segregated within a session. These contrasting results show that reversal interference in the midsession reversal task is influenced by context and temporal factors, with corresponding implications for behavioral flexibility.

Rats are a social species, often used as a research model to study social behavior. However, isolating the factors (i.e., environmental stimuli, experiences with social interactions, novelty, etc.) that influence rats' social behavior can be difficult in many existing social choice assessments. A procedure that may help researchers investigate these variables more systematically is the olfactory choice procedure. The present set of experiments used a free-operant olfactory choice procedure to assess individually housed female rats' preference for social and nonsocial scents. In Experiment 1, rats ran daily sessions in which a response to a nose-poke port produced either a social or nonsocial scent. A response to a second nose-poke port produced a control scent. In Experiment 2, the same female rats could respond in one nose-poke port to produce a social scent and in a second port to produce a nonsocial scent. The results from Experiment 1 indicate that rats prefer social and nonsocial scents over a control scent and that this preference persists across a location reversal and 100+ daily sessions. Although there were individual differences, group results from Experiment 2 suggest that rats prefer social and nonsocial scents relatively equally.

Antecedent stimulus prevalence can affect detectability. Two contrasting effects have been reported in humans. The low-prevalence effect is when participants are less likely to report the presence of the target stimulus when it occurs with low prevalence. Recently, an opposite effect has been discovered in which participants are more likely to report the presence of low-prevalence stimuli. There is little if any research on stimulus prevalence with nonhuman animals; therefore, the present study investigated prevalence effects in rats to extend species generality, determine which effect would occur, and identify controlling variables. Rats were trained to press left and right levers conditional on the flash rate of the sample stimulus (1 or 5 Hz). A between-group, within-subject comparison in which the two flash rates were not always equally prevalent was employed. Low-prevalence stimuli were underreported, systematically replicating the low-prevalence effect. Rats initially trained under the unequal-prevalence condition failed to acquire or took longer to acquire high accuracy with the low-prevalence stimulus but quickly achieved high accuracy with the high-prevalence stimulus. Subsequent training under equal-prevalence conditions remediated these effects, and prior training under equal prevalence seemed to offer a protective effect from later decreases in stimulus prevalence.

The amount of time that organisms spend on a variable-interval schedule of a concurrent pair before departing to the other one (i.e., the dwell time on the schedule) follows an exponential distribution, meaning that the probability of switching to the other schedule does not increase or decrease throughout the visit. This appears to reflect an innate behavioral pattern and implies that concurrent-schedule performance can be modeled using continuous-time Markov chains. In the two-alternative case, the behavior of a Markov chain is completely determined by the leaving rates from each alternative (i.e., the number of departures per unit of time), so finding expressions for these leaving rates should suffice to completely characterize changeover behavior in concurrent schedules. Such expressions can be derived from the matching law in combination with either the mathematical principles of reinforcement or Baum's laws of allocation, induction, and covariance. The resulting equations are assessed in the particular case of concurrent variable-interval schedules using a large data set from a published study that systematically manipulated both the relative and the overall rates of reinforcement, resulting in excellent fits. The performance of the model is also assessed against that of competing models, proving to be superior in most cases.

Concepts can be taught by presenting examples and nonexamples and giving the learner feedback on whether they accurately identify the examples, but it is not clear how to select examples and nonexamples. Specifically, the degree to which examples and nonexamples should differ is unknown. Six experiments were conducted to compare conceptual learning for four stimulus sets (three sets of arbitrary stimuli and one set of biological stimuli) across up to three practice conditions: (a) nonexamples that were relatively similar to the examples, (b) nonexamples that were relatively dissimilar to the examples, and (c) examples only. Conceptual learning was measured before and after practice using tests with examples and nonexamples that were not used during practice. Including nonexamples in practice increased the likelihood of conceptual learning relative to including only examples. Using nonexamples that were more similar to the examples resulted in the most robust conceptual learning. Adding new but conceptually irrelevant features to the testing stimuli disrupted conceptual learning but less so when the practice included nonexamples that were more similar to the examples. The efficacy and efficiency of instruction for conceptual learning were affected by features of the stimuli used to practice and test conceptual learning.