Effects of response-independent stimuli on fixed-interval and fixed-ratio performance of rats: a model for stressful disruption of cyclical eating patterns

Binge eating is often associated with stress-induced disruption of typical eating patterns. Three experiments were performed with the aim of developing a potential model for this effect by investigating the effect of presenting response-independent stimuli on rats’ lever-pressing for food reinforcement during both fixed-interval (FI) and fixed-ratio (FR) schedules of reinforcement. In Experiment 1, a response-independent brief tone (500-ms, 105-dB, broadband, noisy signal, ranging up to 16 kHz, with spectral peaks at 3 and 500 Hz) disrupted the performance on an FI 60-s schedule. Responding with the response-independent tone was more vigorous than in the absence of the tone. This effect was replicated in Experiment 2 using a within-subject design, but no such effect was noted when a light was employed as a disrupter. In Experiment 3, a 500-ms tone, but not a light, had a similar effect on rats' performance on FR schedules. This tone-induced effect may represent a release from response-inhibition produced by an aversive event. The implications of these results for modeling binge eating are discussed.     

Flipping the Script: When Service-Learning Recipients Become Service-Learning Givers

Urban education is a complex system that is often shrouded in stereotypes, labels, and barriers. Service-learning is well-entrenched in suburban institutions, but is a fledgling or grassroots organization in the urban education community. Often, suburban service-learning initiatives have taken the tone of community service in that it is often directed (albeit often inadvertently) at lower socio-economic families (e.g., to help the homeless, fill the food banks for the hungry, participate in clothing drives). Such initiatives leave some urban students feeling disenfranchised, powerless, and dependent. However, critical service-learning in urban schools can provide a connection to the community, as well as a sense of empowerment, confidence, and intrinsic motivation (Mitchell, 2007 Mitchell, T. (2007). Critical service-learning as social justice education: A case study of the citizen scholars program. Equity & Excellence in Education, 40, 101–112.[Taylor & Francis Online] , [Google Scholar]). When urban students see themselves as vital, powerful participants in giving back instead of being given to, they become critical partners, young leaders, and civically engaged citizens. Therefore, in this article, Pam, a middle school educator, and Tamara, a service-learning partner, examine how a teacher can institute critical service-learning programs in an urban classroom. By highlighting a teacher's intrinsic and extrinsic shifts, practical applications, and students' collaborations and reflections, this article illustrates how to move to critical service-learning in urban contexts. This examination has implications for how specific critical service-learning components can help teachers work with students to move toward socio-emotional growth.     

Construct validity of the universal nonverbal intelligence test (UNIT)

Data from 104 public school children were analyzed to determine the psychometric and conceptual soundness of a new model-based measure of intellectual functioning: the Universal Nonverbal Intelligence Test (UNIT; Bracken & McCallum, in press). The UNIT was designed to assess the construct of intelligence for at-risk children who are limited English language proficient. The UNIT and subtests from the Woodcock-Johnson-Revised Tests of Cognitive Ability (WJ-R; Woodcock & Johnson, 1989) were administered in counterbalanced order using standardized procedures. Spearman-Brown reliability coefficients provided evidence of the UNIT'S reliability: Global score coefficients ranged from .86 (Reasoning Quotient) to .93 (Symbolic Quotient). Confirmatory factor analyses of the UNIT provided evidence for a two-factor structure. Exploratory factor analyses of the UNIT with the WJ-R yielded support for the UNIT'S measurement of memory and reasoning constructs, although the many subconstructs assessed by the WJ-R and the UNIT preclude a simple interpretation. Correlations among UNIT global scores with age and with composite scores of the WJ-R provide additional evidence of the UNIT'S construct validity.