Psychological Variables as Predictors of Perceived Ethnic Discrimination Among Minority and Immigrant Adolescents1

The occurrence of discrimination in the real world is difficult to determine objectively, as it is defined in part by intentions. The perception of discrimination may therefore be influenced by one's interpretation of the intentions of others. In order to examine psychological characteristics that influence the perception of ethnic discrimination, 164 Armenian, Mexican American, and Vietnamese adolescents completed measures of perceived discrimination (PD), self-esteem, mastery, depression/anxiety, intergroup competence, and ethnic identity, as well as demographic variables. A path analysis showed that higher depression/anxiety scores and lower intergroup competence predicted more PD; depression/anxiety and intergroup competence were in turn predicted by self-esteem and mastery, respectively. Birthplace and socioeconomic status had an indirect effect on PD, via intergroup competence. The results suggest the importance of psychological variables in the perception of discrimination.     

Individuation of Actions from Continuous Motion

Three studies explored how infants parse a stream of motion into distinct actions. Results show that infants (a) can perceptually discriminate different actions performed by a puppet and (b) can individuate and enumerate heterogeneous sequences of such actions (e.g., jump-fall-jump) when the actions are separated by brief motionless pauses, but (c) are not able to individuate such actions when embedded within a continuous stream of motion. Combined with previous research showing that infants can individuate homogeneous actions from an ongoing stream of motion, these findings suggest that infants can use repeating patterns of motion in the perceptual input to define action boundaries. Results have implications as well for infants' conceptual structure for actions.     

The role of CS-US contiguity in classical conditioning of the rabbit's nictitating membrane response to serial stimuli

The rabbit's nictitating membrane response was classically conditioned to a serial tone-light compound (CS1-CS2), in which the CS1-CS2 and CS2-US intervals were each manipulated over the values of 200, 400, 800, and 1600 msec in a between-groups, factorial design. In addition, at each level of the CS2-US interval, there was a control group that received CS2 and the US. Within the serial compound, the CS2 was found to be highly efficacious in that the CS2-US interval determined the rate of CR acquisition to the compound as a whole and to CS2 in particular. Moreover, CR probability during CS2 largely overlapped the performance of the corresponding single-stimulus controls. Outside the context of the compound, CR frequency on CS2 test trials fell below control levels at the 200- and 400-msec CS2-US intervals. The results can be interpreted as indicating that a generalization decrement or information loss occurred in transferring from compound training to CS2 testing. In addition, the theories of Rescorla and Wagner (In A. Black & W. F. Prokasy, Eds., Classical conditioning II, New York: Appleton-Century-Crofts, 1972) and Mackintosh (Psychological Review, 1975, 82, 276–298) may be extended to account for the present results.     

Community Violence and Youth: Affect, Behavior, Substance Use, and Academics

Community violence is recognized as a major public health problem (WHO, World Report on Violence and Health, 2002) that Americans increasingly understand has adverse implications beyond inner-cities. However, the majority of research on chronic community violence exposure focuses on ethnic minority, impoverished, and/or crime-ridden communities while treatment and prevention focuses on the perpetrators of the violence, not on the youth who are its direct or indirect victims. School-based treatment and preventive interventions are needed for children at elevated risk for exposure to community violence. In preparation, a longitudinal, community epidemiological study, The Multiple Opportunities to Reach Excellence (MORE) Project, is being fielded to address some of the methodological weaknesses presented in previous studies. This study was designed to better understand the impact of children’s chronic exposure to community violence on their emotional, behavioral, substance use, and academic functioning with an overarching goal to identify malleable risk and protective factors which can be targeted in preventive and intervention programs. This paper describes the MORE Project, its conceptual underpinnings, goals, and methodology, as well as implications for treatment and preventive interventions and future research.     

A Pilot Randomized Trial of an Online Parenting Skills Program for Pediatric Traumatic Brain Injury: Improvements in Parenting and Child Behavior

This pilot study examined changes in parenting skills and child behavior following participation in an online positive parenting skills program designed for young children with traumatic brain injury (TBI). Thirty-seven families with a child between 3 and 9 years of age who sustained a moderate to severe TBI were randomly assigned to one of two interventions: online parenting skills training (n = 20) or access to Internet resources on managing brain injury (n = 17). Parent–child interaction observations and parent ratings of child behavior were collected pre- and post-treatment. Generalized estimating equations and mixed models were used to examine changes in parenting skills and child behavior problems as well as the moderating role of family income on treatment response. Participants in the parenting skills group displayed significant improvements in observed positive parenting skills relative to participants in the Internet resource group. Income moderated improvements in parent ratings of child behavior, with participants in the low-income parenting skills group and high-income Internet resource group reporting the greatest improvements in behavior. This is the first randomized controlled trial examining online parenting skills training for families of young children with TBI. Improvements in positive parenting skills and child behavior support the utility of this intervention, particularly for families from lower socioeconomic backgrounds.     

A role for ERK MAP kinase in physiologic temporal integration in hippocampal area CA1

Recent studies demonstrate a requirement for the Extracellular signal Regulated Kinase (ERK) mitogen-activated protein kinase (MAPK) cascade in both the induction of long-lasting forms of hippocampal synaptic plasticity and in hippocampus-dependent associative and spatial learning. In the present studies, we investigated mechanisms by which ERK might contribute to synaptic plasticity at Schaffer collateral synapses in hippocampal slices. We found that long-term potentiation (LTP) induced with a pair of 100-Hz tetani does not require ERK activation in mice whereas it does in rats. However, in mice, inhibition of ERK activation blocked LTP induced by two LTP induction paradigms that mimicked the endogenous θ rhythm. In an additional series of studies, we found that mice specifically deficient in the ERK1 isoform of MAPK showed no impairments in tests of hippocampal physiology. To investigate ERK-dependent mechanisms operating during LTP-inducing stimulation paradigms, we monitored spike production in the cell body layer of the hippocampus during the period of θ-like LTP-inducing stimulation. θ-burst stimulation (TBS) produced a significant amount of postsynaptic spiking, and the likelihood of spike production increased progressively over the course of the three trains of TBS independent of any apparent increase in Excitatory Post-Synaptic Potential (EPSP) magnitude. Inhibition of ERK activation dampened this TBS-associated increase in spiking. These data indicate that, for specific patterns of stimulation, ERK may function in the regulation of neuronal excitability in hippocampal area CA1. Overall, our data indicate that the progressive increase in spiking observed during TBS represents a form of physiologic temporal integration that is dependent on ERK MAPK activity.     

Performance reactivity in a continuous-performance task: Implications for understanding post-error behavior

Although there has been considerable interest in the effects of errors on subsequent performance, relatively few studies have considered the effects of non-error events that contain some performance-relevant information, such as correct performance on critical trials. In the present article, we propose and assess a hypothesis of performance reactivity. In support of this hypothesis, we provide evidence of performance decrements following both incorrect and correct responses but not following performance-irrelevant events. More specifically, in a continuous response task (Sustained Attention to Response Task), we (1) replicate previous findings that errors of commission on rare NOGO trials produce decrements in subsequent performance, and (2) observe that correct withholds to NOGO trials produce decrements in subsequent accuracy relative to task-irrelevant tones. These results corroborate a hypothesis that some error-related effects on subsequent performance are not unique, but are instead a particularly salient version of a more general performance-reactivity effect.     

Comparing Mathematics Interventions: The Effects of Cover-Copy-Compare Alone and Combined with Performance Feedback on Digits Correct and Incorrect

The purpose of this study was to compare the isolated effects of cover-copy-compare (CCC) with the combined effects of CCC and two types of performance feedback (i.e., digits correct and incorrect per minute) on sixth grade students’ mathematics fluency and accuracy. An alternating treatments design was employed to compare treatments across 16 weeks. Participants included three general education sixth grade students whose teachers recommended them for additional help with mathematics calculation. No differentiation between treatments was demonstrated for any of the participants and individual differences pertaining to the number of sessions needed to reach and consistently perform at mastery levels were found. Follow-up data at 4 and 12 days following termination of the intervention phase indicated that all participants continued to perform at mastery levels. Generalization to a slightly more difficult mathematics skill yielded pre-intervention to post-intervention increases, albeit small. Students rated all three treatment conditions favorably.     

Memory impairments and hippocampal modifications in adult rats with neonatal isolation stress experience

Early life events have profound consequences. Our research demonstrates that the early life stress of neonatal isolation (1-h individual isolation on postnatal days 2-9) in rats has immediate and enduring neural and behavioral effects. Recently, we showed neonatal isolation impaired hippocampal-dependent context conditioned fear in adult rats. We now expand upon this finding to test whether neonatal isolation impairs performance in inhibitory avoidance and in the non-aversive, hippocampal-dependent object recognition task. In addition to assessments of hippocampal-dependent memory, we examined if neonatal isolation results in cellular alterations in the adult hippocampus. This was measured with antibodies that selectively label calpain-mediated spectrin breakdown product (BDP), a marker of cytoskeletal modification that can have neuronal consequences. Neonatally isolated male and female rats showed impaired performance in both memory tasks as well as elevated BDP levels in hippocampal immunoblot samples. In tissue sections stained for BDP, the cytoskeletal fragmentation was localized to pyramidal neurons and their proximal dendrites. Interestingly, the hippocampal samples also exhibited reduced staining for the postsynaptic marker, GluR1. Neonatal isolation may render those neurons involved in memory encoding to be vulnerable to calpain deregulation and synaptic compromise as shown previously with brain injury. Together with our prior research showing enhanced striatal-dependent learning and neurochemical responsivity, these results indicate that the early experience of neonatal isolation causes enduring yet opposing region-specific neural and behavioral alterations.