Transfer to intermediate forms following concept discrimination by pigeons: chimeras and morphs

Two experiments examined pigeons' generalization to intermediate forms following training of concept discriminations. In Experiment 1, the training stimuli were sets of images of dogs and cats, and the transfer stimuli were head/body chimeras, which humans tend to categorize more readily in terms of the head part rather than the body part. In Experiment 2, the training stimuli were sets of images of heads of dogs and cats, and the intermediate stimuli were computer-generated morphs. In both experiments, pigeons learned the concept discrimination quickly and generalized with some decrement to novel instances of the categories. In both experiments, transfer tests were carried out with intermediate forms generated from both familiar and novel exemplars of the training sets. In Experiment 1, the pigeons' transfer performance, unlike that of human infants exposed to similar stimuli, was best predicted by the body part of the stimulus when the chimeras were formed from familiar exemplars. Spatial frequency analysis of the stimuli showed that the body parts were richer in high spatial frequencies than the head parts, so these data are consistent with the hypothesis that categorization is more dependent on local stimulus features in pigeons than in humans. There was no corresponding trend when the chimeras were formed from novel exemplars. In Experiment 2, when morphs of training stimuli were used, response rates declined smoothly as the proportion of the morph contributed by the positive stimulus fell, although results with morphs of novel stimuli were again less orderly.     

Refining the experimental analysis of academic skills deficits: part II. Use of brief experimental analysis to evaluate reading fluency treatments

The technology of brief experimental analysis is just beginning to be used for identification of effective treatments for individual students who experience difficulty with oral reading fluency. In this study, the effect of a reading fluency treatment package was examined on easy and hard passages, and generalization was assessed on passages with high content overlap. The results suggest that the treatment package increased reading fluency for all 3 students. Effects were moderated by difficulty level for all 3 students. Results are discussed in terms of future refinements to the procedures, validation of the methods, and potential applications in clinical and school settings.     

Equivalence relations, contextual control, and naming

This paper reports two experiments that investigated the role of verbal behavior in the emergence and generalization of contextually controlled equivalence classes. During both experiments, participants were trained with two different combinations of the same easily nameable, yet formally unrelated, pictorial stimuli. Match-to-sample baselines for eight four-member classes were established under the contextual control of two colors. In the presence of one color, conditional relations were established between stimuli whose normative names rhymed. In the presence of the other color, conditional relations were established between stimuli whose normative names did not rhyme. Although, during Experiment 1, all participants demonstrated equivalence classes involving rhyming stimuli, none demonstrated the formation of nonrhyme equivalence classes. To investigate this finding, Experiment 2 evaluated whether participants would demonstrate both rhyme and nonrhyme equivalence classes given more extensive exposure to the experimental contingencies. All participants demonstrated contextually controlled rhyme and nonrhyme equivalence classes, although rhyme classes were demonstrated with greater facility than nonrhyme classes. Results indicate that visual stimuli are named, that verbal bases for stimulus classification can affect the emergence of contextually controlled equivalence classes, and that untrained contextually controlled conditional discriminations involving novel stimuli can emerge on the basis of participants' verbal behavior.     

Generalization of delayed matching to sample following training at different delays

Four groups of pigeons were trained to perform a delayed matching-to-sample task with a single delay of 0, 2, 4, or 6 s from the outset of training. The longer the training delay, the more sessions were required for all birds to reach the same level of response accuracy. Following initial training, five test sessions that included nonreinforced trials with delay intervals of 0, 2, 4, 6, 8, and 10 s were interspersed between training sessions. Unlike typical forgetting functions in which accuracy decreases monotonically with increasing delay, the forgetting functions from test sessions resembled generalization gradients with the peak of the functions occurring at the training delay. Following additional training for all birds with a 0-s delay, forgetting functions decreased monotonically with increasing delay. The results suggested that remembering can be trained at a specific delay interval, and generalizes to similar delay intervals. Generalization along the temporal dimension of delay may contribute to typical forgetting functions in which accuracy decreases from 0-s delay.     

The nucleus basalis and memory codes: auditory cortical plasticity and the induction of specific, associative behavioral memory

Receptive field (RF) plasticity develops in the primary auditory cortex (ACx) when a tone conditioned stimulus (CS) becomes associated with an appetitive or aversive unconditioned stimulus (US). This prototypical stimulus-stimulus (S-S) association is accompanied by shifts of frequency tuning of neurons toward or to the frequency of the CS such that the area of best tuning of the CS frequency is increased in the tonotopic representation of the ACx. RF plasticity has all of the major characteristics of behavioral associative memory: it is highly specific, discriminative, rapidly induced, consolidates (becomes stronger and more specific over hours to days) and can be retained indefinitely (tested to two months). Substitution of nucleus basalis (NB) stimulation for a US induces the same associative RF plasticity, and this requires the engagement of muscarinic receptors in the ACx. Pairing a tone with NB stimulation actually induces specific, associative behavioral memory, as indexed by post-training frequency generalization gradients. The degree of acquired behavioral significance of sounds appears to be encoded by the number of neurons that become retuned in the ACx to that acoustic stimulus, the greater the importance, the greater the number of re-tuned cells. This memory code has recently been supported by direct neurobehavioral tests. In toto, these findings support the view that specific, learned auditory memory content is stored in the ACx, and further that this storage of information during learning and the instantiation of the memory code involves the engagement of the nucleus basalis and its release of acetylcholine into target structures, particularly the cerebral cortex.     

Stimulus generalization of behavioral history

Undergraduates responded under a variable-ratio 30 schedule in the presence of a 25-mm long line and on a differential-reinforcement-of-low-rate 6-s schedule when a 13-mm long line was present. Following this, a line-length continuum generalization test was administered under a fixed-interval 6-s schedule (Experiment 1) or extinction (Experiment 2). In both experiments, obtained generalization gradients conformed to typical postdiscrimination gradients. Responses were frequent under stimuli physically similar to the 25-mm line and infrequent under stimuli physically similar to the 13-mm line. The generalization gradients were generally asymmetric with peak response rates occurring at line lengths greater than 25 mm.     

Effects consistent with behavioral contrast during a multiple schedule for discrimination training on mands for attention

This study used a multiple schedule to assess the effects of an S+ or S- in the absence of rules on excessive mand rates with three school-aged children with disabilities and assessed possible contrast effects occurring in conjunction with the intervention. Each of the three participants was exposed to the presence or absence of an S- (black baseball cap). When it was worn, mand approach rates decreased for all three participants; conversely, mand rates increased to twice the baseline rates when the experimenter was not wearing the black baseball cap. Generalization probes conducted for one of the three caregivers showed similar changes when the caregiver wore the cap. Results suggest that effects consistent with positive behavioral contrast occurred with all participants.     

Using self-monitoring to increase on-task behaviors of students with attention deficit hyperactivity disorders (ADHD) in inclusive classrooms in Turkey (Türkiye)

Self-monitoring interventions have been found to be effective in improving the on-task behaviors of students with a wide range of disabilities. However, there are ongoing limitations in the literature, including the (a) lack of planning in generalization and maintenance, (b) interventions are predominantly conducted in segregated settings, and (c) inadequate number of data points collected in each condition. In the current study, self-monitoring was used to improve the on-task behavior of three elementary school students with ADHD in inclusive classrooms in Turkey. A concurrent multiple-baseline across-participants design was used. Generalization and maintenance were programmed via sequential modification, partial withdrawal, and continuous data collection. Additionally, classroom teachers rated the students' overall classroom behaviors in each data collection session. Based on the visual and the effect size analyses (i.e., performance criteria-based effect size [PCES]), the intervention was effective in improving the students' on-task behaviors. The self-monitoring intervention had 1.18 (high effect), 1.06 (effective) in generalization, and 1.14 (effective) in the first maintenance set and 1.03 (effective) in the second maintenance data set. The teacher ratings aligned with the increased on-task behaviors of the students. Implications for practice are discussed.     

Greeting skills: A systematic review of the literature

Individuals with disabilities often demonstrate difficulty in social communication skills such as greetings. Studies have shown that deficits in greetings may negatively affect social interactions and vocational opportunities. Therefore, previous research has evaluated a variety of teaching procedures to increase greetings for individuals with disabilities with varying efficacy. This review of the literature provides an overview of studies to date in which greetings were taught to individuals with intellectual disabilities. A variety of teaching procedures were identified, and implications of those procedures are discussed. Results suggest that multiple teaching procedures may be effective; however, component analyses, further replication, and modified generalization procedures are necessary. Implications for future researchers include identifying a technological definition of greetings and evaluating effective teaching procedures and generalization strategies. Implications for practitioners include teaching one greeting type at a time, limiting the number of social skills taught simultaneously, identification of effective teaching procedures and generalization considerations.     

ROLE REVERSALS: AN ANALYSIS OF THERAPEUTIC EFFECTS ACHIEVED WITH DISRUPTIVE BOYS DURING THEIR APPOINTMENTS AS PEER MONITORS

Three 7-year-old boys with histories of negative interactions were appointed to monitor individual classmates during daily noon recess. As monitors, the boys awarded points to their classmates for playing appropriately and, on rare occasions, withdrew a point for negative interactions. The three boys immediately decreased their own rates of negative interactions during the sessions in which they were appointed as monitors. Two of the boys concomitantly increased their rates of positive interactions. Their reductions in negative interactions were not maintained during reversals and did not clearly generalize to the morning or afternoon recess periods. Subsequent appointment of the boys as peer monitors during the morning recess produced similar improvements in their behavior. Results suggest that appointment to the role of peer monitor may itself function as an intervention.