Evaluation of a dynamical model of speech perception

Previous work (Tuller, Case, Ding, & Kelso, 1994) has revealed signature properties of nonlinear dynamical systems in how people categorize speech sounds. The data were modeled by using a twowell potential function that deformed with stimulus properties and was sensitive to context. Here we evaluate one prediction of the model—namely, that the rate of change of the potential’s slope should increase when the category is repeatedly perceived. Judged goodness of category membership was used as an index of the slope of the potential. Stimuli from a “say”-“stay” continuum were presented with gap duration changing sequentially throughout the range from 0 to 76 to 0 msec, or from 76 to 0 to 76 msec. Subjects identified each token as either “say” or “stay” and rated how good an exemplar it was of the identified category. As predicted, the same physical stimulus presented at the end of a sequence was judged a better exemplar of the category than was the identical stimulus presented at the beginning of the sequence. In contrast, stimuli presented twice near the middle of a sequence with few (or no) stimuli between them, as well as stimuli presented with an intervening random set, showed no such differences. These results confirm the hypothesis of a context-sensitive dynamical representation underlying speech.     

Pigeons' preference for variable-interval water reinforcement under widely varied water budgets.

Water budget of pigeons was varied to assess the dependence of risk-sensitive preferences upon economic context such as has been reported for energy-budget manipulations with small animals in behavioral ecology research. Fixed- and variable-interval terminal-link water schedules reinforced choice between equal variable-interval initial-link schedules arranged on two pecking keys. While keeping a severely restrictive budget the same across three phases of the experiment, a contrasting distinct ample budget was arranged in each. To mimic typical methods in behavioral ecology studies, in each ample budget a more than three-fold increase in amount of water per reinforcer presentation was instituted simultaneously with significantly increased overall access to water. Total choice response rates plummeted in the ample budgets, and body weights either increased significantly or remained unchanged in different phases as expected by the nature of the different manipulations. Clear preferences for the variable-interval schedule were found throughout the experiment, except for rare instances of key bias. The results agree with similar operant food-reinforcement studies and extend conditions under which risk preference apparently does not depend upon economic context.     

Action observation produces motor resonance in Parkinson's disease

Observation of movement activates the observer's own motor system, influencing the performance of actions and facilitating social interaction. This motor resonance is demonstrated behaviourally through visuomotor priming, whereby response latencies are influenced by the compatibility between an intended action and an observed (task‐irrelevant) action. The impact of movement disorders such as Parkinson's disease (PD) on motor resonance is unclear, as previous studies of visuomotor priming have not separated imitative compatibility (specific to human movement) from general stimulus‐response compatibility effects. We examined visuomotor priming in 23 participants with mild‐to‐moderate PD and 24 healthy older adults, using a task that pitted imitative compatibility against general stimulus‐response compatibility. Participants made a key press after observing a task‐irrelevant moving human finger or rectangle that was either compatible or incompatible with their response. Imitative compatibility effects, rather than general stimulus‐response compatibility effects, were found specifically for the human finger. Moreover, imitative compatibility effects did not differ between groups, indicating intact motor resonance in the PD group. These findings constitute the first unambiguous demonstration of imitative priming in both PD and healthy ageing, and have implications for therapeutic techniques to facilitate action, as well as the understanding of social cognition in PD.     

Should They Be Recruited? Fan Perceptions of Deviant Student-Athletes

The purpose of this study was to examine fan opinion toward the active recruitment of prospective student-athletes with deviant pasts. College football fans were surveyed to determine to what extent the deviant behavior of a prospective student-athlete impacted how much they would support their favorite team recruiting that athlete. There were three primary findings: (a) deviant behavior negatively impacts a prospective student-athlete’s fan support score, (b) assault of a female student is the most severe deviant behavior in which an athlete could engage, and (c) White recruits were judged more harshly for using illegal drugs when compared to Black recruits.     

A Meta-analysis of Wilderness Therapy Outcomes for Private Pay Clients

Wilderness therapy is becoming a more widely used intervention for adolescents, but there have not been any meta-analyses focused solely on its clinical effectiveness for private pay clients. This study’s objective was to conduct outcome-based meta-analyses of private-pay wilderness therapy programs, benchmark primary features of this approach, and educate the clinical community as to its effectiveness. The authors conducted a review of all available databases, as well as manual searches. Searches resulted in a meta-analysis based on 36 studies, totaling 2399 participants receiving wilderness therapy. Our meta-analyses found medium effect sizes for all six constructs assessed: self-esteem (g = 0.49), locus of control (g = 0.55), behavioral observations (g = 0.75), personal effectiveness (g = 0.46), clinical measures (g = 0.50) and interpersonal measures (g = 0.54). Subgroup analyses included age of participants, duration of program, open or closed model, presence of a mental health practitioner, and publication year.     

Qualitative Investigation of Student Reflections on a Spiritual/Religious Diversity Experience

Twenty‐six master's‐level counselor education students participated in a spiritual and religious diversity assignment, which involved participation in a spiritual or religious activity for 5 weeks. Participants then discussed these experiences in reflection papers. After analysis of the student papers, the authors identified the following themes: (a) discomfort related to the experience, (b) initial assumptions regarding spirituality and religion, (c) movement toward appreciation of spiritual and religious diversity, (d) increases in self‐understanding, (e) the value of experiential learning, and (f) motivation for additional learning. The authors provide suggestions for counselor training on spirituality and religion.     

Computation of cone contrasts for color vision research

Cone-contrast coordinates have proved useful for representing transient test stimuli used in color vision experiments. These representations automatically take into account the spectral absorption of cones and any Weberian adaptation to steady fields of light. Under these conditions, they also can be interpreted as being an approximation to the incremental cone response. A detailed methodology is presented for making appropriate measurements and calculations of cons contrasts for any light source, especially color monitors.