Varying reinforcement magnitude on interval schedules

In Experiment 1, rats were trained on either a random-interval or a variable-interval 60-sec schedule of reinforcement, and reinforcement magnitude was varied across conditions between one and four pellets. Although the two schedules maintained different patterns of behaviour, patterns and rates of responding were not systematically affected by the variation in reinforcement magnitude. In Experiment 2, a regulated probability interval schedule that generated similar rates of reinforcement to those of the schedules of Experiment 1 was used, with the pattern of behaviour generated resembling that typical of a random-interval schedule. Changing reinforcement magnitude again produced few systematic changes in behaviour. In Experiment 3, a variable-ratio schedule was used within a procedure that otherwise resembled that of Experiments 1 and 2. Increasing the reinforcement magnitude now decreased the rates of responding, and examination of the patterns of responding showed that this came about because rates of responding were higher early in the interreinforcer interval in the one-pellet condition. These experiments demonstrate the insensitivity of behaviour under interval schedules to changes in reinforcement magnitude and suggest the operation of mechanisms different from those engaged by ratio schedules and discretetrial learning procedures.     

If We Build It … Will They Come? – Establishing a Cancer Genetics Services Clinic for an Underserved Predominantly Latina Cohort

Background: Cancer genetic counseling and testing is a standard of care option for appropriate families and can identify individuals at increased risk prior to diagnosis, when prevention or detection strategies are most effective. Despite documented efficacy of cancer risk reduction in high-risk individuals, underserved and minority individuals have a disproportionate cancer burden and limited access to genetic counseling. Methods: A needs assessment survey documented gaps in knowledge and interest in prevention. Satellite clinics were established at two indigent healthcare systems. Cancer genetics CME lectures were conducted and referral guidelines disseminated to clinicians who referred patients for counseling. Results: An increase in clinician knowledge was demonstrated post-CME and reflected by quality referrals. Eighty-eight percent of patients kept their appointments. In the predominantly Latina⁶ (n=77) clinic population, 71.4% were affected with cancer, and 17 mutation positive families were identified. Preliminary data shows a positive impact on patients' motivation and behavior. The majority has expressed satisfaction and reduction in anxiety. Conclusions: This study demonstrates feasibility and acceptability of cancer genetics services in this population, suggesting the potential to reduce cancer morbidity in underserved, high-risk families.“Latino” is the most common census term for individuals of Spanish, Mexican, Central and South American, Cuban, or Puerto Rican descent, referring to ethnicity, and is generally considered a more ethnically/culturally based term for individuals of the aforementioned groups. As this cohort is female the feminine noun “Latina” is used