Tolerance to effects of cocaine on behavior under a response-initiated fixed-interval schedule

Tolerance to effects of cocaine can be modulated by schedules of reinforcement. With multiple ratio schedules, research has shown an inverse relationship between ratio requirement and amount of tolerance that resulted from daily administration of the drug. In contrast, tolerance to the effects of cocaine on behavior under multiple interval schedules generally has developed regardless of interval value. Under interval schedules reinforcement depends on the animal making one response following a time interval. Thus, as time to respond increases, the time to reinforcement decreases. On the other hand, fixed ratio schedules require a specified number of responses to be made prior to reinforcement. Therefore, delaying the initiation of responding does not coincide with a significant decrease in the time to reinforcement. In the current experiment, 6 pigeons were trained to respond under a three-component multiple schedule, with a different tandem fixed-ratio 1 fixed-interval schedule in each component. The multiple schedule required one response, which was followed by one of three fixed-interval values (5, 15, or 60 s). Thus, the multiple schedule was interval-like because after the fixed-ratio 1, only one more response was required for reinforcement, but it was also ratio-like because the length of the pause at the beginning of each interreinforcer interval affected the time until the next reinforcer. Acute administration of cocaine generally resulted in dose-dependent decreases in responding. Chronic (i.e., daily) administration of a rate-decreasing dose resulted in tolerance patterns similar to those usually obtained with multiple ratio schedules. That is, the magnitude of tolerance was related inversely to schedule size. These results suggest that delay to reinforcement from the initial response may play a role in the development of schedule-parameter-related tolerance.     

Accurate reaching after active but not passive movements of the hand: evidence for forward modeling

Converging behavioral findings support recent models of motor control suggesting that estimates of the future positions of a limb as well as the expected sensory consequences of a planned movement may be derived, in part, from efference copies of motor commands. These estimates are referred to as forward models. However, relatively little behavioral evidence has been obtained for proposed forward models that provide on-line estimates of current position. We report data from a patient (JD) who reached accurately to visualized targets with and without vision of her hand despite substantial proprioceptive loss. Additionally, we administered a double-start reaching test to examine the possibility that efference copy information could be used to estimate current limb position. JD reached accurately, without vision, to a final target after actively reaching to a landmark, but exhibited severely impaired reaching after passive movements to the landmark. This finding suggests that forward modeling of efference copy signals may provide relatively accurate estimates of current limb position for the purpose of motor planning. The possibility that such estimates may also contribute to the awareness of body position and to self-recognition is discussed.     

The Role of Small and Medium-Sized African-American Churches in Promoting Healthy Life Styles

The issues of poor health care, poverty, crime, and HIV infection make it more difficult for minority communities to combat substance abuse and other diseases that are prevalent in the African-American community. Faith communities in general, and African-American churches in particular, are a largely untapped, but potent, resource to reduce the toll of substance abuse and other health issues. Information about ministers' knowledge, attitudes, and behaviors regarding leading health indicators, the frequency with which they discuss these issues from the pulpit, and organizational readiness to develop and implement interventions can be the foundation of clergy training and health intervention efforts.     

Work‐place bullying: A group processes framework

Work‐place bullying is primarily conceptualized in the literature from an individual or interpersonal perspective with a focus on the victim. The impact of the broader organizational context on bullying has also been considered to a lesser extent. Only a small amount of research exists, however, regarding the group‐level processes that impact on the incidence and maintenance of bullying behaviour. We adopt a group level perspective to theoretically discuss and explain the processes involved in the occurrence and maintenance of work‐place bullying behaviours. Using Social Identity Theory ( Tajfel & Turner, 1986 ) and Social Rules Theory ( Argyle, Henderson, & Furnham, 1985 ), two conceptual frameworks are presented that consider work‐place bullying at the intra‐group and inter‐group levels. Several propositions are put forward regarding the likelihood of bullying in work groups. Suggested directions for empirical research are addressed and practical implications are also discussed.     

The identity status of African Americans in middle adolescence: a replication and extension of Forbes and Ashton (1998)

This study is a replication and extension of the work of Forbes and Ashton (1998). Seventy-seven African American high school students completed the revised version of the Extended Objective Measure of Ego Identity Status. Most of the students were found to be in uncommitted identity statuses. Similar results were found in both the ideological and interpersonal domains.     

Mental time travel into the episodic future,episodic past,and episodic counterfactual past in everyday life

To date, studies exploring the relationship of counterfactual thoughts with episodic memories and episodic future thoughts have focused mainly on voluntary mental time travel. We explore mental time travel in everyday life and find that episodic counterfactual thinking occurs to a much lesser extent than thinking about the past or the future (12%, 22%, and 54%, respectively), is used mainly for mood regulation purposes, and the temporal distribution decreases as a function of time. We observe similarities in phenomenological detail: memories and counterfactual thoughts sharing similar ratings of sensory detail, memories and future thoughts sharing similar ratings of positivity, and counterfactual and future thoughts sharing similar ratings of mental time travel. We discuss the implications of episodic counterfactual thinking in everyday life.     

Lessons worth repeating: Sidman's Tactics of Scientific Research

Murray Sidman's (1960) Tactics of Scientific Research: Evaluating Experimental Data in Psychology just celebrated its sixtieth anniversary. It is without doubt one of the most influential books in the history of Behavior Analysis. This review outlines the rationales for, and details of, methods for the investigation of the behavior of individual subjects that Sidman presented. Many of his observations and recommendations are as timely as ever, maybe even more so, given the “reproducibility crisis” and one of its major origins.     

Connecting in the Twitterverse: Using Twitter to satisfy unmet belonging needs

The current study explored how social media can satisfy unmet needs for belonging. We predicted that, of those who experience chronic ostracism (feeling excluded and ignored frequently), people high in need to belong would utilize Twitter to satisfy their unmet belonging needs more than those low in need to belong. Specifically, individuals high in need to belong and chronic ostracism should use Twitter to form and maintain parasocial relationships (one-sided relationships with media figures). Participants (n = 315) completed a survey assessing their chronic ostracism experiences, dispositional need to belong, and Twitter behavior, particularly regarding potential parasocial relationship targets (n = 229). As expected, when participants reported experiencing high rates of chronic ostracism, participants high in need to belong used Twitter more than those low in need to belong, particularly following more parasocial relationship targets. Thus, maintaining parasocial relationships on Twitter may be an effective way to satisfy unmet belonging needs.