Hebb's Neural Networks Support the Integration of Psychological Science.

Abstract In a recent paper and forthcoming volume, the former President of the American Psychological Association, Robert Sternberg, calls for an effort to reintegrate psychological science (Sternberg, in press; Sternberg & Grigorenko, 2001). In this paper we argue that D. O. Hebb, beginning with his technical volume in 1949 and continuing through a series of introductory textbooks, has convincingly presented the basis for such integration. The basis for this integration lies in understanding how genes and experience shape neural networks underlying human thoughts, feelings, and actions. Why has not Hebb's accomplishment been generally recognized as providing the needed integration for psychology? We suggest that the methods available to Hebb, mostly animal research and behavioural human experiments, were not sufficient to provide empirical methods for linking his conceptual nervous system to real events in the human brain. This methodology has now been provided by neuroimaging. While Hebb also recognized the importance of studying individual differences in intelligence and affect, there were also no methods for exploring the specific genes that were an important source of these differences. The human genome project has provided new methods for exploring this issue. Hebb's basic idea, together with the new methodological tools and new disciplines (e.g., cognitive, affective, and social neuroscience), all based on network views, give abundant evidence of the value of employing the converging operations strategy advocated by Sternberg and Grigorenko (2001). It is important that psychology recognize the need for integrating cognitive, affective and, social neuroscience with psychology, because many of the theoretical questions that need to be addressed by neuroimaging and genetic studies are exactly those that a century of psychologists have explored. The neuroscience approach provides crucial constraints for psychological theories, but also benefits from a closer connection with the psychological level of analysis. The Challenge In their paper, Sternberg and Grigorenko (2001) argue for a milltiparadigmatic and multidisciplinary integrated psychology to replace what they regard as a badly fragmented discipline. They outline three bad habits that they regard as symptoms of the fragmentation of the field. These are: a) the use of single methodologies, b) the identification of scholars with the psychological subfields of social, clinical, etc., and c) adherence to single paradigms such as behaviourism, cognitivism or psychoanalysis. Their paper traces various efforts to provide a unified psychology by Kimble (1994), Staats (1999), Magnusson (2000), and others. They also propose their own ideas, including the importance of using converging methods selected from different levels of analysis and the important role of graduate training in producing needed skills for integrative research. They also discuss political and social reasons why some oppose integration, and what can be done by organizations to foster it. We believe that the scientific basis for the integration is already on the scene, and that potentially integrated efforts under the names of cognitive, affective, and social neuroscience have already appeared. Functional neuroimaging requires the use of a task to activate brain areas. The usual strictures in the design of such tasks stem from cognitive studies, and they are now being taught and used by imagers. In addition, the combination of fMRl, EEC measures and lesions provide a toolkit of methods. Although there are many disagreements about the appropriate converging methods and how to best analyze imaging data, there is little question that a new generation of imagers are employing sophisticated and convergent methods. In our paper, we trace the background to these efforts in the work of D. O. Hebb. We then summarize important new developments that have increased the applicability of Hebb's ideas to many new topics. …