Punishment by noise in an alternative response situation

Operant responses of human subjects were conditioned according to a variable-interval schedule of positive reinforcement. A brief noise was delivered as punishment for each of the responses. The noise suppressed the punished responses more when an alternative unpunished response was concurrently available than when only a single punished response was available. This finding extends the generality of a previous study that had used a period of extinction rather than the brief noise as the punishing stimulus.     

Bottlenosed dolphin and human recognition of veridical and degraded video displays of an artificial gestural language

2 bottlenosed dolphins proficient in interpreting gesture language signs viewed veridical and degraded gestures via TV without explicit training. In Exp. 1, dolphins immediately understood most gestures: Performance was high throughout degradations successively obscuring the head, torso, arms, and fingers, though deficits occurred for gestures degraded to a point-light display (PLD) of the signer's hands. In Exp. 2, humans of varying gestural fluency saw the PLD and veridical gestures from Exp. 1. Again, performance declined in the PLD condition. Though the dolphin recognized gestures as accurately as fluent humans, effects of the gesture's formational properties were not identical for humans and dolphin. Results suggest that the dolphin uses a network of semantic and gestural representations, that bottom-up processing predominates when the dolphin's short-term memory is taxed, and that recognition is affected by variables germane to grammatical category, short-term memory, and visual perception.     

Recruitment Strategies for a Home-Based Physical Activity Intervention for Breast Cancer Patients

Recruiting cancer patients for randomized trials investigating psychosocial interventions presents several unique challenges. This paper describes the challenges and yields for different recruitment methods used in Moving Forward, a randomized trial of a home-based moderate-intensity physical activity program for early-stage breast cancer survivors. Recruitment methods included letters sent to patients by their oncologists, direct referrals from oncologists, in-person recruitment in oncology clinics, referrals from nurses and medical assistants, passive recruitment, other mailings, and community outreach strategies. Of the 424 screenings completed, 86 (20.3%) participants were randomized. Physician letters yielded the greatest number of initial screenings (147; 34.7%) and participants randomized (28; 32.5%). In-person recruitment also proved to be a productive recruitment strategy; 14 (16.3%) of the participants were recruited via this strategy. Community outreach efforts did not provide as great a yield and were labor intensive. We discuss suggestions for recruitment of cancer patients in future trials.     

The effects of aging and dual task demands on language production

A digital pursuit rotor task was used to measure dual task costs of language production by young and older adults. After training on the pursuit rotor, participants were asked to track the moving target while providing a language sample. When simultaneously engaged, young adults experienced greater dual task costs to tracking, fluency, and grammatical complexity than older adults. Older adults were able to preserve their tracking performance by speaking more slowly. Individual differences in working memory, processing speed, and Stroop interference affected vulnerability to dual task costs. These results demonstrate the utility of using a digital pursuit rotor to study the effects of aging and dual task demands on language production and confirm prior findings that young and older adults use different strategies to accommodate to dual task demands.     

Effects of Resolving to Change One's Own Behavior: Expectations vs. Experience

The “false-hope syndrome” suggests that unrealistic expectations are responsible for the cycle of repeated failure and renewed efforts at self-change characterizing many self-changers. Our hypotheses were that: (1) committing to a particular self-change task would inflate initial expectations, (2) participants would be unsuccessful relative to their expectations, and (3) more elevated expectations would lead to more negative outcomes. Participants were randomly assigned to either increase their physical activity or reduce their stress through meditating or were assigned to a no-change control group. In accordance with Hypotheses 1 and 2, exercise participants had more positive expectations about their resolutions immediately after committing to them, and both exercise and meditation participants were unsuccessful relative to their expectations. With respect to Hypothesis 3, however, having more positive expectations about one's resolution did not predict a worse outcome.     

The onset and mastery of spatial language in children acquiring British Sign Language

In the course of language development children must solve arbitrary form-to-meaning mappings, in which semantic components are encoded onto linguistic labels. Because sign languages describe motion and location of entities through iconic movements and placement of the hands in space, child signers may find spatial semantics-to-language mapping easier to learn than child speakers. This hypothesis was tested in two studies: a longitudinal analysis of a native signing child's use of British Sign Language to describe motion and location events between the ages 1–10 and 3–0, and performance of 18 native signing children between the ages of 3–0 and 4–11 on a motion and location sentence comprehension task. The results from both studies argue against a developmental advantage for sign language learners for the acquisition of motion and location forms. Early forms point towards gesture and embodied actions followed by protracted mastery of the use of signs in representational space. The understanding of relative spatial relations continues to be difficult, despite the iconicity of these forms in the language, beyond 5 years of age.