Contextual features in the developing hippocampus: A representational similarity analysis.

Functional divisions of labor in support of memory have been reported along the anterior-posterior axis of the hippocampus. However, little is known about how the developing hippocampus represents associative memories along this axis. The present research employed representational similarity analysis to ask whether developmental differences exist in the extent to which the anterior versus the posterior hippocampus represent features of the context and associative memories. Functional magnetic resonance imaging data were collected during the retrieval phase of an associative recognition task from 8-year-olds, 10-year-olds, and adults (N = 58). Participants were asked to retrieve pairs of items, which were presented either in the same location as during encoding or in a flipped location. In the anterior hippocampus and only for adults, pattern similarity between the two studied pair conditions was greater than pattern similarity between studied pairs presented in the same location and novel pairs. In contrast, this difference was not significant in the posterior hippocampus. Older, but not younger, children showed a similar, albeit attenuated, similarity pattern to that of adults, but measures of patterns similarity predicted associative recognition across ages. In addition, exploratory analyses showed that similarity patterns in the adult posterior, but not anterior, hippocampus tracked the order of the runs. Overall, the results suggest functional and developmental dissociations in processing different contextual features, with the anterior hippocampus responding to salient and rapid-changing features and the posterior hippocampus responding to slower-changing features of the context.

The impact of dementia and mild memory impairment (MMI) on intimacy and sexuality in spousal relationships.

BACKGROUND: Sexuality and intimacy in couples in which one partner is affected by dementia has been widely researched. Few studies have explored these issues in couples where one partner is affected by mild memory impairment (MMI) or mild cognitive impairment (MCI). The objectives of this study were to (1) identify and contrast issues of intimacy and sexuality that spousal caregivers of persons with MMI and dementia may experience, and (2) identify future lines of research in this population. METHODS: Fourteen dementia and nine MMI spousal caregivers participated in focus groups conducted between 2008 and 2009 at the Stanford/VA Alzheimer's Research Center. Content analyses were conducted to identify themes. RESULTS: Five themes emerged: communication, marital cohesion, affectional expression, caregiver burden, and ambiguity concerning the future of the relationship. Dementia caregivers reported more difficulties with communication, cohesion, and perceptions of increased burden than their MMI counterparts. Both groups indicated reduced sexual expression due to physical limitations; substitute activities including hand-holding, massaging, and hugging were noted. Both groups reported difficulty anticipating the future of the relationship due to present stressors. While dementia caregivers could consider future romantic relationships with others, MMI caregivers were primarily able to consider future relationships only for companionship and emotional intimacy. CONCLUSION: Early therapeutic interventions may assist couples in modifying activities, behaviors, and expectations about the future of the relationship. Such modifications may help maintain relationship satisfaction, decrease burden, preserve quality of life, and delay time-to-placement. Extending time-to-placement could have cost savings implications for families and the healthcare system.