Mother-infant interactions and regional brain volumes in infancy: an MRI study

Background: It is generally agreed that the human brain is responsive to environmental influences, and that the male brain may be particularly sensitive to early adversity. However, this is largely based on retrospective studies of older children and adolescents exposed to extreme environments in childhood. Less is understood about how normative variations in parent-child interactions are associated with the development of the infant brain in typical settings. Method: To address this, we used magnetic resonance imaging to investigate the relationship between observational measures of mother-infant interactions and regional brain volumes in a community sample of 3-6 month old infants (N=39). In addition, we examined whether this relationship differed in male and female infants. Results: We found that lower maternal sensitivity was correlated with smaller subcortical grey matter volumes in the whole sample, and that this was similar in both sexes. However, male infants who showed greater levels of positive communication and engagement during early interactions had smaller cerebellar volumes. Conclusion These preliminary findings suggest that variations in mother-infant interaction dimensions are associated with differences in infant brain development. Although the study is cross-sectional and causation cannot be inferred, the findings reveal a dynamic interaction between brain and environment that may be important when considering interventions to optimize infant outcomes

Impulsive Control for Continuous-Time Markov Decision Processes: A Linear Programming Approach

International audienc

Approximations for partially observed Markov decision processes

Due to copyright restrictions, the access to the full text of this article is only available via subscription.This chapter studies the finite-model approximation of discrete-time partially observed Markov decision process. We will find that by performing the standard reduction method, where one transforms a partially observed model to a belief-based fully observed model, we can apply and properly generalize the results in the preceding chapters to obtain approximation results. The versatility of approximation results under weak continuity conditions become particularly evident while investigating the applicability of these results to the partially observed case. We also provide systematic procedures for the quantization of the set of probability measures on the state space of POMDPs which is the state space of belief-MDPs