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.     

Intergenerational predictors of diurnal cortisol secretion in early childhood

The present study examined potential intergenerational links that may contribute to atypical patterns of diurnal cortisol secretion in early childhood. Salivary cortisol samples were collected across 1 waking day in 36 pre‐school children whose mothers are participants in an ongoing longitudinal project. Hierarchical Linear Modeling (HLM) identified statistically significant predictors of individual differences in daily cortisol trajectories. Children displayed relatively low post‐awakening values and flatter cortisol trajectories across the day as a function of unsupportive maternal behaviour, second‐hand smoke and maternal histories of social withdrawal in childhood. These results suggest that individual differences in young children's pattern of diurnal cortisol are associated with a variety of current and historical maternal characteristics and behaviours. The identification of intergenerational predictors of children's diurnal neuroendocrine functioning may provide new insights into the transfer of health and developmental risk from parent to child. Copyright © 2007 John Wiley & Sons, Ltd.     

Vulnerability to loneliness among fathers of children with autism spectrum disorder: The role of interpersonal and familial resources

Fathers of children with autism spectrum disorder (ASD) might be at increased risk of becoming lonely. In the current study, we explored the differences in loneliness between fathers of children with and without ASD and identified interpersonal and familial resources (social support, family cohesion, and family adaptability) that might be related to levels of loneliness. Using a cross-sectional design, 348 fathers (of 114 children with ASD and 234 without) completed a series of questionnaires. Fathers of children with ASD reported higher levels of loneliness and lower levels of social support and family cohesion. A moderated mediation model indicated that the interaction between social support and family cohesion mediated the association between ASD group (i.e., ASD vs. non-ASD) and fathers' loneliness. Findings suggest the importance of interpersonal and familial resources (e.g., perceived social support and family cohesion) for family members at risk of loneliness.     

The subliminal mere exposure effect does not generalize to structurally related stimuli.

R.F. Bornstein (1994) questioned whether subliminal mere exposure effects might generalize to structurally related stimuli, thereby providing evidence for the existence of implicit learning. Two experiments examined this claim using letter string stimuli constructed according to the rules of an artificial grammar. Experiment 1 demonstrated that brief, masked exposure to grammatical strings impaired recognition but failed to produce a mere exposure effect on novel structurally related strings seen at test. Experiment 2 replicated this result but also demonstrated that a reliable mere exposure effect could be obtained, provided the same grammatical strings were presented at test. The results suggest that the structural relationship between training and test items prevents the mere exposure effect when participants are unaware of the exposure status of stimuli, and therefore provide no evidence for the existence of implicit learning.     

Search strategies in decision making: the success of “success”

Examination of search strategies has tended to focus on choices determined by decision makers' personal preferences among relevant cues, and not on learning cue‐criterion relationships. We present an empirical and rational analysis of cue search for environments with objective criteria. In such environments, cues can be evaluated on the basis of three properties: validity (the probability that a cue identifies the correct choice if cue values differ between alternatives); discrimination rate (the proportion of occasions on which a cue has differing values); and success (the expected proportion of correct choices when only that cue can be used). Our experiments show that though there is a high degree of individual variability, success is a key determinant of search. Furthermore, a rational analysis demonstrates why success‐directed search is the most adaptive strategy in many circumstances. Copyright © 2004 John Wiley & Sons, Ltd.     

Multisensory integration in multiple reference frames in the posterior parietal cortex

Spatial information processing takes place in different brain regions that receive converging inputs from several sensory modalities. Because of our own movements—for example, changes in eye position, head rotations, and so forth—unimodal sensory representations move continuously relative to one another. It is generally assumed that for multisensory integration to be an orderly process, it should take place between stimuli at congruent spatial locations. In the monkey posterior parietal cortex, the ventral intraparietal (VIP) area is specialized for the analysis of movement information using visual, somatosensory, vestibular, and auditory signals. Focusing on the visual and tactile modalities, we found that in area VIP, like in the superior colliculus, multisensory signals interact at the single neuron level, suggesting that this area participates in multisensory integration. Curiously, VIP does not use a single, invariant coordinate system to encode locations within and across sensory modalities. Visual stimuli can be encoded with respect to the eye, the head, or halfway between the two reference frames, whereas tactile stimuli seem to be prevalently encoded relative to the body. Hence, while some multisensory neurons in VIP could encode spatially congruent tactile and visual stimuli independently of current posture, in other neurons this would not be the case. Future work will need to evaluate the implications of these observations for theories of optimal multisensory integration.Edited by: Marie-Hélène Giard and Mark Wallace     

The Cultural Adaptation of a Community‐Based Child Maltreatment Prevention Initiative

A unique primary prevention effort, Strong Communities for Children (Strong Communities), focuses on changing attitudes and expectations regarding communities' collective responsibilities for the safety of children. Findings from a 6‐year pilot of the initiative in South Carolina have shown promise in reducing child maltreatment, but efforts to adapt the initiative to different cultural contexts have been lacking. No models exist for adapting an initiative that takes a community‐level approach to ensuring children's safety. Thus, this article addresses the gap by providing an overview of the original initiative, how the initiative was adapted to the Israeli context, and lessons learned from the experience. Building on conceptualizations of cultural adaptation by Castro et al. (Prevention Science, 5, 2004, 41) and Resnicow et al. (Ethnicity and Disease, 9, 1999, 11), sources of nonfit (i.e., sociodemographic traits, political conflict, government services, and the presence and role of community organizations) were identified and deep and surface structure modifications were made to the content and delivery. Ultimately, this article describes the adaption and dissemination of a community‐based child maltreatment prevention initiative in Tel Aviv, Israel, and addresses researchers' calls for more publications describing the adaptation of interventions and the procedures that need to be implemented to achieve cultural relevance.