Neonatal ventral hippocampus lesions disrupt extra-dimensional shift and alter dendritic spine density in the medial prefrontal cortex of juvenile rats

Recent data showed that neonatal ventral hippocampus (VH) lesions, an approach used to model schizophrenia symptoms in rodents, produce premature deficits of working memory believed to be associated with early medial prefrontal cortex (mPFC) maldevelopment. This experiment expands the investigation of mPFC integrity in juvenile rats with neonatal VH lesions by assessing behavioral flexibility and dendritic spine density. Sixteen Sprague-Dawley male pups received bilateral microinjections of ibotenic acid in the VH or SHAM surgery on postnatal day (PND) 6. On PND 29 and 30, rats were subjected to a spatial shift task in a cross-maze; an attentional set-shifting task was then administered on two consecutive days, between PND 33 and PND 35. Rats were sacrificed at PND 36 and dendritic spine density in the mPFC was assessed using Golgi-Cox staining procedure. Results revealed impaired extra-dimensional shift in VH-lesioned rats and inconsistent reversal discrimination outcomes. Although lesioned animals displayed intact performance in the spatial shift, rates of perseverative responses were higher than normal in this task. Neonatal VH damage resulted in lower dendritic spine density in the mPFC than measured in control brains; however, no significant correlation was found between this outcome and behavioral data. Juvenile morphological and cognitive perturbations are consistent with the early emergence of mPFC anomalies following neonatal VH lesions. Results are discussed in relation with potential common mechanisms linking pre- and post-pubertal onsets of behavioral dysfunction.     

To Watch is to Work: a Review of NeuroImaging Data on Tool Use Observation Network

Neuropsychology Review - Since the discovery of mirror neurons in the 1990s, many neuroimaging studies have tackled the issue of action observation with the aim of unravelling a putative homolog...     

Psychophysiological Synchrony During Verbal Interaction in Romantic Relationships

Previous studies about romantic relationships have shown that the reciprocal influence between partners occurs not only at the behavioral and socio‐emotional levels, but also at the psychophysiological level. This reciprocal influence is expressed in a pattern of physiological synchrony between partners (i.e., coordinated dynamics of the physiological time series). The main aim of the present study was to explore the presence of a pattern of physiological synchrony in electrodermal activity (EDA) during a couple interaction task. A second objective was to compare the synchrony levels during a negative interaction condition versus a positive interaction condition. Finally, we analyzed the association between synchrony and self‐perception of empathy, dyadic empathy, and relationship satisfaction. Thirty‐two couples (64 individuals) participated in this study. Each couple performed a structured interaction task while the EDA of both partners was being registered. The quantification of synchrony was based on the cross‐correlation of both members' EDA time‐series. In order to control for coincidental synchrony, surrogate datasets were created by repeatedly shuffling the original data of spouses X and Y of a dyad and computing synchronies on the basis of the shuffled data (pseudosynchrony values). Our results confirmed the presence of significant EDA synchrony during the interaction. We also found that synchrony was higher during the negative interactions relative to the positive interactions. Additionally, physiological synchrony during positive interaction was higher for those couples in which males scored higher in dyadic empathy. The clinical implications of these findings are discussed.     

Links between parental psychological violence, other family disturbances, and children's adjustment

In a sample of 143 parent-child dyads from two-parent and separated families, this investigation documented the links between parental psychological violence and separation or divorce, severity of parental conflict, triangulation of the child in this conflict, and polarized parent-child alliances. The unique and combined contributions of all these variables to children's behavior problems were also assessed. Participants were parents, mostly mothers, and their 10-12-year-old child. They were recruited through schools, community organizations, and newspapers. Questionnaires were administered at home. Findings suggest that separated families undergo more relational disturbances than two-parent families (more severe conflicts, more triangulation, stronger parent-child alliances), but the amount of parental psychological violence was similar in both groups. Psychological violence was associated with the severity of parental conflict, especially in two-parent families. Triangulation of the child in parental conflict was another correlate of psychological violence. Once all variables were controlled for, psychological violence remained the only significant correlate of children's externalized behavior problems. These findings raise the importance of preventing psychological violence toward children, especially in families plagued with severe parental conflicts.     

Semantic interference on a phonological task in illiterate subjects

Previous research suggests that learning an alphabetic written language influences aspects of the auditory-verbal language system. In this study, we examined whether literacy influences the notion of words as phonological units independent of lexical semantics in literate and illiterate subjects. Subjects had to decide which item in a word- or pseudoword pair was phonologically longest. By manipulating the relationship between referent size and phonological length in three word conditions (congruent, neutral, and incongruent) we could examine to what extent subjects focused on form rather than meaning of the stimulus material. Moreover, the pseudoword condition allowed us to examine global phonological awareness independent of lexical semantics. The results showed that literate performed significantly better than illiterate subjects in the neutral and incongruent word conditions as well as in the pseudoword condition. The illiterate group performed least well in the incongruent condition and significantly better in the pseudoword condition compared to the neutral and incongruent word conditions and suggest that performance on phonological word length comparisons is dependent on literacy. In addition, the results show that the illiterate participants are able to perceive and process phonological length, albeit less well than the literate subjects, when no semantic interference is present. In conclusion, the present results confirm and extend the finding that illiterate subjects are biased towards semantic-conceptual-pragmatic types of cognitive processing.     

Contributions of the dorsal hippocampus and the dorsal subiculum to processing of idiothetic information and spatial memory

It is well established that the dorsal hippocampal formation is crucial for spatial memory in rats. However, little is known about the distinct functions of the dorsal hippocampus and the dorsal subiculum. To examine the role of the dorsal hippocampus and the dorsal subiculum, Long-Evans rats with excitotoxic lesions (NMDA) of the dorsal hippocampus (DH), the dorsal subiculum (DS), or both (DHDS), and controls were trained on a nonmatching-to-place task. Then, to identify the strategy used by each group, they were tested on the same task in the dark with the T-maze being rotated between the sample and the test runs. In the light, rats with combined lesions were impaired. In the dark, groups DH, DS, and controls performed near chance level except in trials without rotation, suggesting the use of a sense of direction. The same rats were trained on a radial-arm maze task. In the light, where proximal visual cues were accessible, combined lesions affected performance whereas in the dark, it was impaired by all lesions. This experiment demonstrated that the dorsal subiculum and the dorsal hippocampus play a crucial role in processing idiothetic information and/or in maintenance of this information in memory.     

Task-set reconfiguration suspends perceptual processing: evidence from semantic priming during the attentional blink

When two visual targets, Target 1 (T1) and Target 2 (T2), are presented among a rapid sequence of distractors, processing of T1 produces an attentional blink. Typically, processing of T2 is markedly impaired, except when T1 and T2 are adjacent (Lag 1 sparing). However, if a shift of task set--a change in task requirements from T1 to T2--occurs, this sparing is reduced substantially. With a semantic priming technique, in which T1 could be either related or unrelated to T2, the priming of T2 by T1 diminished markedly at Lag 1, when the transition between T1 and T2 involved a switch in either location (Experiments 1 and 2) or task (Experiment 3), but remained unaffected at other lags. These results suggest that perceptual processing of T2 cannot be carried out in parallel with task-set reconfiguration.     

Disruption of short-term memory by changing and deviant sounds: support for a duplex-mechanism account of auditory distraction

The disruption of short-term memory by to-be-ignored auditory sequences (the changing-state effect) has often been characterized as attentional capture by deviant events (deviation effect). However, the present study demonstrates that changing-state and deviation effects are functionally distinct forms of auditory distraction: The disruption of visual-verbal serial recall by changing-state speech was independent of the effect of a single deviant voice embedded within the speech (Experiment 1); a voice-deviation effect, but not a changing-state effect, was found on a missing-item task (Experiment 2); and a deviant voice repetition within the context of an alternating-voice irrelevant speech sequence disrupted serial recall (Experiment 3). The authors conclude that the changing-state effect is the result of a conflict between 2 seriation processes being applied concurrently to relevant and irrelevant material, whereas the deviation effect reflects a more general attention-capture process.     

Comparing models of helper behavior to actual practice in telephone crisis intervention: a Silent Monitoring Study of Calls to the U.S. 1-800-SUICIDE Network

Models of telephone crisis intervention in suicide prevention and best practices were developed from a literature review and surveys of crisis centers. We monitored 2,611 calls to 14 centers using reliable behavioral ratings to compare actual interventions with the models. Active listening and collaborative problem-solving models describe help provided. Centers vary greatly in the nature of interventions and their quality according to predetermined criteria. Helpers do not systematically assess suicide risk. Some lives may have been saved but occasionally unacceptable responses occur. Recommendations include the need for quality assurance, development of standardized practices and research relating intervention processes to outcomes.