The dynamics of successive induction in larval zebrafish

Charles Sherrington identified the properties of the synapse by purely behavioral means—the study of reflexes—more than 100 years ago. They were subsequently confirmed neurophysiologically. Studying reflex interaction, he also showed that activating one reflex often facilitates another, antagonistic one: successive induction, which has since been demonstrated in a wide range of species, from aphids to locusts to dogs and humans. We show a particularly orderly example in zebrafish (Danio rerio) larvae; the behavior (locomotion) of larvae is low in dark and intermediate in light, but low in light and substantially higher in dark when dark followed light. A quantitative model of a simple dynamic process is described that readily captures the behavior pattern and the effects of a number of manipulations of lighting conditions.     

Analysis of Hispanic representation and conceptualization in psychology and law research

Hispanics are now the largest minority group in the United States, yet research examining the impact this will have on the American legal system is limited. The first purpose of this article was to synthesize the studies that have been conducted, which have found that Hispanics have a perspective toward the police, the courts and the law, and jury decision making that is unique from those of Caucasians and other ethnic groups. The second purpose of this article was to analyze whether psychology and law research has been conducted in a manner conducive to identifying this unique Hispanic perspective. An analysis of 800 articles published in five psychology and law journals revealed that, while Hispanics were typically conceptualized properly, the proportion of articles devoted to the Hispanic perspective is disturbingly low. To increase understanding of the Hispanic perspective, psychology and law researchers must increase the amount of empirical attention given to Hispanics.     

Blocking in rabbit eyeblink conditioning is not due to learned inattention: Indirect support for an error correction mechanism of blocking

Blocking is a classical conditioning task in which prior training to one cue such as a tone reduces learning about a second cue such as a light, when subsequently trained as a tone-light compound. Blocking has been theorized to come about through a US-modulated error correction mechanism, by Rescorla &; Wagner (1972) as well as through a mechanism of learned inattention as theorized by Mackintosh (1973). In the case of eyeblink conditioning, an error correction mechanism has been hypothesized to take place in the cerebellum while some form of inattention has been hypothesized to take place in the hippocampal region. The hypothesis we., are testing is whether the mechanism of learned inattention is involved in blocking in rabbit eyeblink conditioning. If blocking in eyeblink conditioning is produced by a mechanism of learned inattention, then training to a previously blocked cue should be slower than training to that cue in a naïve animal. Rabbits that had received tone training followed by tone-light training exhibited blocking. Rabbits that had been previously blocked to the light acquired conditioned responses to the light at the same rate as naïve rabbits. This finding failed to support the hypothesis that blocking in rabbit eyeblink conditioning is due to learned inattention, but does support the Rescorla-Wagner mechanism of error correction. The present finding along with previous work on error correction mechanism in the cerebellar-brainstem circuit (Kim et al., 1998) lend support to the theory that blocking, at least in rabbit eyeblink conditioning, seems to be due to an error correction mechanism rather than a learned inattention mechanism.     

Cognitive Vulnerabilities as Mediators between Emotional Abuse and Depressive Symptoms

This study tested whether childhood parental emotional abuse and peer emotional bullying serve as antecedents of depression in adolescence and identified the cognitive mechanisms involved in this process. It was hypothesized that the experience of emotional abuse would predict depressive symptoms via development of rumination and negative inferences. A 3-wave longitudinal study was carried out with 998 adolescents (471 girls and 526 boys) between 13 and 17 years of age. Results showed that emotional abuse by parents and peers at Time 1 predicted a worsening of several cognitive vulnerabilities at Time 2. In addition, brooding mediated between the experiences of abuse and the increase of depressive symptoms at Time 3. Thus, findings suggest that the experiences of childhood emotional abuse by parents and peers serve as antecedents to develop a negative cognitive style, vulnerability that, once developed, is a risk factor for the onset of depressive symptoms in adolescence.     

Indirect Effects of Functional Communication Training on Non-Targeted Disruptive Behavior

The purpose of this study was to evaluate the effects of functional communication training (FCT) on the occurrence of non-targeted disruptive behavior. The 10 participants were preschool-aged children with developmental disabilities who engaged in both destructive (property destruction, aggression, self-injury) and disruptive (hand flapping, spinning in circles, shrill laughter, screaming, crying) behaviors. Only destructive behavior was targeted for the functional analyses and FCT, but data were also collected on disruptive behaviors. All procedures were conducted in the participants’ homes by their mothers with investigator coaching. Phase 1 consisted of conducting a functional analysis within a multielement design. Phase 2 consisted of conducting FCT with demand fading and repeated extinction baselines within a reversal design. Single-case data are provided for 3 participants, and summary data are provided for all 10 participants. Results of phase 1 showed that all participants’ destructive and disruptive behavior was maintained, at least in part, by negative reinforcement. Results of phase 2 showed that both destructive behavior and non-targeted disruptive behavior occurred at lower levels during FCT when compared to the functional analysis demand condition and baseline conditions, suggesting that FCT was effective in decreasing both target destructive behavior and non-targeted disruptive behaviors.