A bidirectional associative memory explanation of posttraumatic stress disorder

Network theory is a relatively recent explanatory development to improve ou r understanding of emotions and emotional disorders. Connectionist neural n etworks are introduced as mathematically well-defined network theories that have been suggested as PTSD models, partly because of their ability to for m and retrieve memories. Explanatory requirements that a comprehensive PTSD theory must have are reviewed. A connectionist neural network system calle d the bidirectional associative memory (BAM) is extended to encode emotion and cognition and is then shown to satisfy all PTSD explanatory requirement s and consequently constitutes a comprehensive PTSD theory. Empirical work pertaining to a fundamental assumption that learning alters brain structure in ways that can be detected by neuroimaging is reviewed. Novel prediction s are made, and relevance to neuroscience is discussed. (C) 1999 Elsevier S cience Ltd.