Some tests of response membership in acquired equivalence classes

Pigeons were trained on many-to-one matching in which pairs of samples, each consisting of a visual stimulus and a distinctive pattern of center-key responding, occasioned the same reinforced comparison choice. Acquired equivalence between the visual and response samples then was evaluated by reinforcing new comparison choices to one set of samples, and examining generalization of these choices to the other samples. Three separate experiments found no evidence of such generalization, as indexed by performance on class-consistent versus class-inconsistent tests. Other tests showed that the pigeons' center-key response patterns during training had indeed served as a conditional cue for choice. These results do not support the hypothesis that different defined responses can become members of acquired equivalence classes.     

Treatment of obsessive-compulsive disorder: cognitive behavior therapy vs. exposure and response prevention

The efficacy of contemporary cognitive therapy for obsessive–compulsive disorder (OCD) has only recently been investigated. The current study compares exposure and response prevention (ERP) and cognitive behavior therapy (CBT) delivered in an individual format. Participants were randomly assigned to the 12 consecutive-week CBT or ERP treatment. Based on 59 treatment completers, there was no significant difference in YBOCS scores between CBT and ERP at post-treatment or at 3-month follow-up. A higher percentage of CBT participants obtained recovered status at post-treatment (67%) and at follow-up (76%), compared to ERP participants (59% and 58%, respectively), but the difference was not significant. Effect sizes (ESs) were used to compare the results of the current study with a previous study conducted at our center that utilized group CBT and ERP treatments, as well as other controlled trials that have compared CBT and ERP. The significance of these results is discussed and a comparison is made with the existing literature.     

The effects of a seatbelt-gearshift delay prompt on the seatbelt use of motorists who do not regularly wear seatbelts

A seatbelt-gearshift delay was evaluated in two U.S. and three Canadian vehicles using a reversal design. The seatbelt-gearshift delay required unbelted drivers either to buckle their seatbelts or to wait a specified time before they could put the vehicle in gear. After collecting behavioral prebaseline data, a data logger was installed in all five vehicles to collect automated data on seatbelt use. Next the seatbelt-gearshift delay was introduced. The results showed that the delay increased all 5 drivers' seatbelt use, and that the duration of the delay that produced relatively consistent seatbelt use varied across drivers from 5 to 20 s. When the device was deactivated in four of the five vehicles, behavior returned to baseline levels.     

Impaired verbal short-term memory in Down syndrome reflects a capacity limitation rather than atypically rapid forgetting

Individuals with Down syndrome suffer from relatively poor verbal short-term memory. Recent work has indicated that this deficit is not caused by problems of audition, speech, or articulatory rehearsal within the phonological loop component of Baddeley and Hitch's working memory model. Given this, two experiments were conducted to investigate whether abnormally rapid decay underlies the deficit. In a first experiment, we attempted to vary the time available for decay using a modified serial recall procedure that had both verbal and visuospatial conditions. No evidence was found to suggest that forgetting is abnormally rapid in phonological memory in Down syndrome, but a selective phonological memory deficit was indicated. A second experiment further investigated possible problems of decay in phonological memory, restricted to item information. The results indicated that individuals with Down syndrome do not show atypically rapid item forgetting from phonological memory but may have a limited-capacity verbal short-term memory system.     

The sensitivity of response rate to the rate of variable-interval reinforcement for pigeons and rats: a review

The relation between the rate of a response (B) and the rate of its reinforcement (R) is well known to be approximately hyperbolic: B = kR/(R + Ro), where k represents the maximum response rate, and Ro indicates the rate of reinforcers that will engender a response rate equal to half its maximum value. A review of data reported in 17 published papers revealed that, under variable-interval schedules of reinforcement, Ro was usually lower when pigeons were the subjects than when rats were the subjects. The value of k, in contrast, did not differ consistently between pigeons and rats. Some accounts interpret Ro as the rate of alternative, unscheduled reinforcers in the situation, expressed in units of the scheduled reinforcer. So interpreted, the difference in Ro implies that less alternative reinforcement (relative to the scheduled reinforcement) typically is available to pigeons in their operant conditioning chambers than it is to rats in theirs. Whether or not that interpretation of Ro is valid, the pigeon-rat difference in Ro ensures that for reinforcer rates above about 10 per hour, response rate will be noticeably less sensitive to changes in reinforcer rate (and presumably to changes in other incentive and motivational operations) with pigeons than with rats as subjects, at least with the experimental conditions typically employed.     

The novelty effect: support for the Novelty-Encoding Hypothesis

In two experiments, we examined the "Novelty-Encoding Hypothesis" proposed by Tulving and Kroll (1995), suggesting that the encoding of online information into long-term memory is influenced by its novelty and that novelty increases recognition performance. In Phase 1 (familiarization phase), subjects participated in a standard memory experiment in which different types of materials (verbs and nouns) were studied under different encoding conditions (enactment and non-enactment) and were tested by an expected recognition test. In Phase 2 (critical phase), subjects evaluated the materials (both familiar materials which were encoded earlier in Phase 1, and novel materials which were not presented earlier in Phase 1) in a frequency judgment task and were given an unexpected recognition test. The results of both experiments showed that novel items were recognized better than familiar items. This result held true for both hit rates - false alarms and hit rates. The novelty effect was observed for different subjects (Swedish and Japanese), different materials (verbs and nouns; high frequency and low frequency), and different types of encoding in Phase 1 (enactment and non-enactment). These findings provide support for the "Novelty-Encoding Hypothesis" stating that the effect is based on the encoding of target items at the time of the critical study (Phase 2). A comparison between the present experiments and the Tulving and Kroll (1995), Dobbins, Kroll, Yonelinas & Liu (1998) and Greene (1999) studies suggests that the novelty effect is more pronounced under incidental encoding than under intentional encoding.     

Deficient Behavioral Inhibition and Anomalous Selective Attention in a Community Sample of Adolescents with Psychopathic Traits and Low-Anxiety Traits

Socialization is the important process by which individuals learn and then effectively apply the rules of appropriate societal behavior. Response modulation is a psychobiological process theorized to aid in socialization by allowing individuals to utilize contextual information to modify ongoing behavior appropriately. Using Hare’s (1991) Psychopathy Checklist and the Welsh (1956) anxiety scale, researchers have identified a relatively specific form of a response modulation deficit in low-anxious, Caucasian psychopaths. Preliminary evidence suggests that the Antisocial Process Screening Device (APSD; Frick & Hare, 2001) may be used to identify children with a similar vulnerability. Using a representative community sample of 308 16-year-olds from the Child Development Project (Dodge, Bates, & Pettit, 1990), we tested and corroborated the hypotheses that participants with relatively low anxiety and high APSD scores would display poorer passive avoidance learning and less interference on a spatially separated, picture-word Stroop task than controls. Consistent with hypotheses, the expected group differences in picture-word Stroop interference were found with male and female participants, whereas predicted differences in passive avoidance were specific to male participants. To the extent that response modulation deficits contributing to poor socialization among psychopathic adult offenders also characterize a subgroup of adolescents with mild conduct problems, clarification of the developmental processes that moderate the expression of this vulnerability could inform early interventions.     

Developing Transdiagnostic Internalizing Disorder Prognostic Indices for Outpatient Cognitive Behavioral Therapy

A growing literature is devoted to understanding and predicting heterogeneity in response to cognitive behavioral therapy (CBT), including using supervised machine learning to develop prognostic models that could be used to inform treatment planning. The current study developed CBT prognostic models using data from a broad dimensionally oriented pretreatment assessment (324 predictors) of 1,210 outpatients with internalizing psychopathology. Super learning was implemented to develop prognostic indices for three outcomes assessed at 12-month follow-up: principal diagnosis improvement (attained by 65.8% of patients), principal diagnosis remission (56.8%), and transdiagnostic full remission (14.3%). The models for principal diagnosis remission and transdiagnostic remission performed best (AUROCs = 0.71–0.73). Calibration was modest for all three models. Three-quarters (77.3%) of patients in the top tertile of the predicted probability distribution achieved principal diagnosis remission, compared to 35.0% in the bottom tertile. One-third (35.3%) of patients in the top two deciles of predicted probabilities for transdiagnostic complete remission achieved this outcome, compared to 2.7% in the bottom tertile. Key predictors included principal diagnosis severity, social anxiety diagnosis/severity, hopelessness, temperament, and global impairment. While additional work is needed to improve performance, integration of CBT prognostic models ultimately could lead to more effective and efficient treatment of patients with internalizing psychopathology.     

Two efficient selection methods for high-dimensional CD-CAT utilizing max-marginals factor from MAP query and ensemble learning approach

Computerized adaptive testing for cognitive diagnosis (CD-CAT) needs to be efficient and responsive in real time to meet practical applications' requirements. For high-dimensional data, the number of categories to be recognized in a test grows exponentially as the number of attributes increases, which can easily cause system reaction time to be too long such that it adversely affects the examinees and thus seriously impacts the measurement efficiency. More importantly, the long-time CPU operations and memory usage of item selection in CD-CAT due to intensive computation are impractical and cannot wholly meet practice needs. This paper proposed two new efficient selection strategies (HIA and CEL) for high-dimensional CD-CAT to address this issue by incorporating the max-marginals from the maximum a posteriori query and integrating the ensemble learning approach into the previous efficient selection methods, respectively. The performance of the proposed selection method was compared with the conventional selection method using simulated and real item pools. The results showed that the proposed methods could significantly improve the measurement efficiency with about 1/2–1/200 of the conventional methods' computation time while retaining similar measurement accuracy. With increasing number of attributes and size of the item pool, the computation time advantage of the proposed methods becomes more significant.     

Response effort and resurgence

This study provides an initial translational examination of response effort and resurgence. Eleven typically developing adults and five adolescents with autism served as participants across two experiments. Participants received points for touching moving stimuli on a computer screen. The resurgence evaluation consisted of three phases: establishment wherein R1 was reinforced, elimination wherein R1 was placed on extinction while R2 was reinforced, and extinction wherein R1 and R2 no longer resulted in reinforcement. Rate of R1 during extinction was compared across three conditions: intermediate, easy, and difficult. Disparity in effort was created by manipulations of the size and speed of objects that moved about on a computer screen. In Experiment 2, control stimuli were added to the experimental arrangement. Across the two experiments, the magnitude of resurgence was greater when R1 was easy. In Experiment 2, both R1 and control responding were greater in the extinction phase than in the elimination phase in all conditions with all participants. The present study supports the hypothesis that response effort affects resurgence and that less effortful responses are likely to recur with greater magnitude under conditions that produce resurgence than are their more effortful counterparts.