Hemispheric Substrates of Affect: A Developmental Model
Nathan A. Fox University of Maryland
Richard J. Davidson State University of New York Purchase, New York
Little theory or research is currently available on the psychobiology of affective development. While a growing body of literature is accumulating on behavioral components of affective changes over the first year of life and on the psychobiology of emotion in adults, systematic efforts to integrate these domains are just beginning. In the developmental domain, current research is focused upon the ontogeny of affect expressions and the socialization of emotions (e.g., Campos & Stenberg, 1978; Izard, Hubner, Risser, McGinnes, & Dougherty, 1980; Malatesta & Haviland, 1982; Oster, 1978). Clinical and experimental neuropsychological data with adults have revealed relations between activation in particular brain regions and the perception and expression of certain emotions. The manner in which developmental changes in emotional behavior are related to maturational changes in certain brain structures associated with emotion is largely unknown. However, data are available that allow us to propose an empirically based, albeit speculative, model of the developmental relations between affective response systems and underlying neural substrates.
This model draws support from recent work on hemispheric specialization for emotion in adults and the application of this data base and associated methodology to the study of emotion in the first year of life. It is also informed by evolutionary considerations of the critical role of approach and avoidance systems in the behavior of organisms. These two major inputs have recently converged in both animal and human data on differential patterns of cerebral asymmetry for certain positive and negative emotions (e.g., Davidson, in press; Denenberg, 1981; Tucker, 1981). This model also emerges from an understand-