Control of variation by reward probability

Two bar-press experiments with rats tested the rule that reducing expectation of reward increases the variation from which reward selects. Experiment 1 used a discrete-trial random-interval schedule, with trials signaled by light or sound. One signal always ended with reward; the other signal ended with reward less often. The 2 signals were randomly mixed. Bar-press duration (how long the bar was held down) varied more during the signal with the lower probability of reward. Experiment 2 closely resembled Experiment 1 but used a random-ratio schedule rather than a random-interval schedule. Again, bar-press duration varied more during the signal with the lower probability of reward. The results support the rule--the first well-controlled comparisons to do so.     

Oneself in practitioner research,with Vygotsky and Bakhtin

Practitioner action and reflection are understood as central to practitioner research in this paper. While Vygotskian-based premise highlights instructional practices and intervention as central to practitioner understanding, Bakhtin-based dialogical premise draws on relational constructs and attend to practitioner being, answerability and authorship. Vygotskian and Bakhtinian units of analysis used are viewed as means with which to conceive practitioner action/reflection and build a community of practitioners. Taken together, practitioner knowing is found inextricable with practitioner ontology, making practitioner research of ongoing instructional practices more human in line with Dewey.     

Listening rate and comprehension as a function of preference for and exposure to time-altered speech

We conducted experiments on the effects of brief prior exposure to time-altered speech on preferred listening rate and the rate listeners would select when asked to listen to speech as fast as possible with good compression (induced listening rate). In Exp. 1, 48 participants were exposed either to normal rate speech or to speech compressed to twice-normal rate. Brief exposure to twice-normal rate speech led to a faster induced listening rate than exposure to normal rate speech. In Exp. 2, 31 participants were briefly exposed to normal rate speech, speech compressed to twice-normal rate, or speech expanded to half-normal rate. The faster the rate of the exposure speech, the faster the induced rate. Speech compressed to twice-normal rate led to a faster induced listening rate than exposure to speech expanded to half-normal rate. Normal rate speech was intermediate between twice-normal and half-normal rate and did not differ significantly from them. Induced listening rate was a linear combination of listening rate preference and recent forced exposure to time-altered speech.     

The pursuit of muscularity among adolescent boys in Fiji and Tonga

The desire for muscularity is tied to Western views of the male gender role, which prescribe that men be strong, physically fit and athletically successful. Although, these ideals have been primarily studied among Western adolescent boys, there is emerging evidence that the same ideals are valued and promoted among males from the Pacific Islands. The aim of the present study was to examine body image concerns associated with muscularity and the reasons for these concerns among Fijian and Tongan adolescent boys. Semi-structured interviews were conducted with 24 Indigenous Fijian, 24 Indo-Fijian, and 24 Tongan boys aged between 13 and 20 years. A thematic analysis of boys’ narratives showed that the pursuit of muscularity was a dominant theme for many boys. Boys’ reasons for pursing muscularity included the attainment of strength and fitness, sporting performance, physical work, dominance, and health. These findings are examined in relation to previous research with Western adolescent boys.     

Body image attitudes and concerns among indigenous Fijian and European Australian adolescent girls

Research on body image has primarily been conducted among Western women who highly value the thin ideal body size. There has been limited research that has examined body image attitudes among Fijian adolescent girls who are exposed to both traditional sociocultural pressures that promote a larger body size and Western pressures that promote slimness. Using in-depth semi-structured interviews, we examined the factors associated with body image attitudes and concerns among a sample of 16 indigenous Fijian and 16 European Australian adolescent girls aged between 13–18 years. An inductive analysis of girls’ responses indicated that both groups of girls experienced body image concerns including body dissatisfaction, a preference for thinness and concerns associated with weight gain. These findings have implications for our understanding of the role of culture in shaping body image among girls and may prove useful in the development of future survey research that can be implemented among both Fijian and Western adolescents.