Acquisition and extinction of differential responses to signals paired with shock or shock omission in goldfish: Evidence for truly discriminated avoidance learning

Goldfish trained to discriminate between signals paired with shock (S?) and signals paired with shock omission (S+) with a linear presentation procedure, originally learned (OL) to control the signal state of a shuttle box and showed a decided preference for the S+ signal. In Experiment 1, following OL, groups had one OL signal replaced (S+ or S?), both signals replaced (S+ and S?), or the OL signals reversed (S+ and S? reversed) and were then tested in a transfer training procedure. In transfer, groups with one signal replaced maintained discriminated performance at OL levels; the S+ replaced group was slightly superior to the S? replaced group on the first day of transfer. With both OL signals replaced, discrimination dropped to chance performance levels, whereas, with OL signal shock pairing reversed, discrimination performance dropped below chance levels. In Experiment 2, following OL, extinction procedures consisted of turning off the shocker (0% shock) or of shocking 100% or a random 25% of the trials. A fourth extinction procedure (R,) retained the trial start response-dependent shock-omission contingency, but shock differentiating the S+ and S? signals was eliminated entirely. Extinction of the S+/S? discrimination was measured both during extinction training per se and with reversal retraining of the S+/S? discrimination later. Groups for which the OL S+ was paired with shock during extinction extinguished on both measures, but groups for which the OL S? was paired with shock omission did not extinguish, especially as shown by the reversal test procedure. Theoretical implications and the implications for several conditioning procedures are discussed.     

Interstimulus interval determines whether ethanol produces conditioned place preference or aversion in mice

DBA/2J mice were exposed to a distinctive floor stimulus (CS+) and ethanol (2 g/kg) in a place conditioning paradigm. A different floor stimulus (CS?) was presented with saline. Mice injected just before or 30 min before CS exposure (Groups 0, ?30) showed conditioned place preference, whereas mice injected right after exposure to the CS (Group 5) displayed place aversion (Experiment 1). None of the other groups (?120, ?60, 15, 60) showed place conditioning. Handling and saline injection given just before or after CS exposure were unable to produce place conditioning (Experiment 2). However, there was a positive relationship between ethanol concentration (10% vs. 20%) and test performance, suggesting that peritoneal irritation influences place conditioning (Experiment 3). Overall, these findings support the suggestion that intraperitoneal injection of ethanol produces an initial short-duration aversive effect that is followed by a longer lasting positive motivational effect.     

Childhood emotional abuse and disordered eating among undergraduate females: mediating influence of alexithymia and distress

OBJECTIVE: Drawing from stress-vulnerability and trauma theory (e.g., Rorty & Yager, 1996), this paper presents a model of associations among child emotional abuse (CEA), alexithymia, general distress (GD), and disordered eating (DE). This study extended previous research on psychological outcomes of child physical and sexual abuse to explore those of CEA using measures of specific emotionally abusive acts. METHOD: Five hundred and eighty-eight female university students completed self-report surveys consisting of measures of CEA, alexithymia, depression, anxiety, and DE. Structural equation modeling was used to test this conceptual model. RESULTS: Comparison between measurement models suggested that bulimic behavior is a separate construct from restrictive eating behaviors and body dissatisfaction. In the structural model with the best fit, the association between CEA and DE was mediated by alexithymia and GD (i.e., a component of depression and anxiety). Specifically, CEA was associated with alexithymia, which was further related to GD. Then, restrictive eating behaviors and attitudes mediated the relation between GD and bulimic behaviors. By analyzing a second, nested model, this latter pathway was shown to be important. CONCLUSION: While the best-fitting model is only one of many possibilities, these results point to a weak-but significant-complex relation between CEA and DE. They are associated through a series of mediating relations in a multivariate model including alexithymia and GD. The current study supports research suggesting that child emotional abuse can have a negative impact on its survivors. Treatment of those survivors manifesting disordered eating should be holistic, as opposed to targeted towards specific symptoms.     

Developing preservice teachers’ sensitivity and confidence: a service-learning experience at a homeless shelter

ABSTRACT

This article describes how early childhood preservice teachers can develop sensitivity toward and confidence in working with children who are homeless through a service learning project. The 14 weeks intervention provided an opportunity for undergraduate early childhood teacher candidates to gain real-life experience working with among the most vulnerable of all children—those who are homeless. Results of this project suggest that through implementing art integrated literacy activities with children in a homeless shelter, teacher candidates alter their deficit views of homelessness and at the same time develop confidence in their ability to work with homeless children and their families.     

Discrete mathematics in deaf education: a survey of teachers' knowledge and use

The study documents what deaf education teachers know about discrete mathematics topics and determines if these topics are present in the mathematics curriculum. Survey data were collected from 290 mathematics teachers at center and public school programs serving a minimum of 120 students with hearing loss, grades K-8 or K-12, in the United States. Findings indicate that deaf education teachers are familiar with many discrete mathematics topics but do not include them in instruction because they consider the concepts too complicated for their students. Also, regardless of familiarity level, deaf education teachers are not familiar with discrete mathematics terminology; nor is their mathematics teaching structured to provide opportunities to apply the real-world-oriented activities used in discrete mathematics instruction. Findings emphasize the need for higher expectations of students with hearing loss, and for reform in mathematics curriculum and instruction within deaf education.     

Teaching Probability for Conceptual Change La Enseñanza De La Probabilidad Por Cambio Conceptual

This work presents a theoretical proposal for a methodology for the teaching of probability theory. The theoretical proposal has a dual inspiration: (1) the epistemological approach of Lakatos (1978b) regarding the quasi-empirical nature of mathematical theories; (2) the perspective of conceptual change for the teaching-learning process, as formulated by Strike and Posner (1992). The scientific content taught and the didactic methods used in the classroom should, according to this proposal, respect and conform to this dual inspiration. We also present an evaluation of the methodology in a real context: six Spanish high school classes of students aged 14–15. The main purpose of the research was to answer this question: Is our didactic proposal more effective than traditional methodology? We operatively identify the concept of traditional teaching, and establish several indicators of effectiveness: the mastery of elementary probability calculations, the quality of intuitive reasoning in probability, and the conceptual and attitudinal change produced. We found significant differences on all indicators, except for attitudinal change, in favour of the group that followed our proposal.     

First-grade cognitive abilities as long-term predictors of reading comprehension and disability status

In a sample of 195 first graders selected for poor reading performance, the authors explored four cognitive predictors of later reading comprehension and reading disability (RD) status. In fall of first grade, the authors measured the children's phonological processing, rapid automatized naming (RAN), oral language comprehension, and nonverbal reasoning. Throughout first grade, they also modeled the students' reading progress by means of weekly Word Identification Fluency (WIF) tests to derive December and May intercepts. The authors assessed their reading comprehension in the spring of Grades 1-5. With the four cognitive variables and the WIF December intercept as predictors, 50.3% of the variance in fifth-grade reading comprehension was explained: 52.1% of this 50.3% was unique to the cognitive variables, 13.1% to the WIF December intercept, and 34.8% was shared. All five predictors were statistically significant. The same four cognitive variables with the May (rather than December) WIF intercept produced a model that explained 62.1% of the variance. Of this amount, the cognitive variables and May WIF intercept accounted for 34.5% and 27.7%, respectively; they shared 37.8%. All predictors in this model were statistically significant except RAN. Logistic regression analyses indicated that the accuracy with which the cognitive variables predicted end-of-fifth-grade RD status was 73.9%. The May WIF intercept contributed reliably to this prediction; the December WIF intercept did not. Results are discussed in terms of a role for cognitive abilities in identifying, classifying, and instructing students with severe reading problems.