Some lessons from classical “organic” psychiatry

1 Revised abstract 1 Revised abstract 2 Background 2 Background 3 Case 1 3 Case 1 4 Case 2 4 Case 2 5 Case 3 5 Case 3 6 Amnesia is not one thing 6 Amnesia is not one thing 7 Dementia and the Dysexecutive Sy S ndrome 7 Dementia and the Dysexecutive Syndrome 8 Neural networks fo f f r organic psychiatry r ? 8 Neural networks for organic psychiatry? 9 Notes and ref e e f f rences 9 Notes and references 1 Revised abstract Brain injuries and brain illnesses provide a very important empirical foundation for the construction of neural network models of brain functioning. If one wants to base such models on neuropsychological or neuropsychiatric data, it is of course essential that the clinical syndromes are described properly. A truly astonishing wealth of relevant observations has accumulated during the last decades. However, it can be argued that the basic understanding of these syndromes by the present generation of psychiatrists and neuropsychologists still suffers from the radical break with traditional European psychiatry which occurred when the new American diagnostic and classificatory system for psychiatry (DSM-III, DSM-IV) was launched and accepted as the new basis for psychiatric thinking. Especially when it comes to modelling brain systems of memory and emotion, the neural network research community should benefit from a review of some facts which were lost in that transition. In the present paper, which is based on a comprehensive update of the classical European diagnostic systems that I participated in some years ago, I focus on three such less well-known facts pertaining to memory and emotion: The classical so-called " frontal lobe syndrome " is not seldom caused by extra-frontal pathology. This fact, which has been known since the 1920's, clearly motivates a conceptual change. Emotional-Motivational Blunting Disorder (or EMD for short) is a construct designed to fulfil this purpose. The DSM alternatives are deficient in that they do not respect next point. It is extremely important to distinguish the emotional flattening seen in EMD from the emotional lability which is a common effect of many different brain pathologies. Many taxonomies create confusion on this point. Emotional lability is a component of what we call Astheno-Emotional Disorder, or AED for short. Mental fatiguability and memory disturbances (mainly due to concentration difficulties) are other core symptoms of AED. The use of the seemingly general term " Amnes(t)ic Syndrome " …