On the relationship between psychology and neurobiology: Levels in the cognitive and biological sciences.

摘要

In this dissertation I offer an account of the relationship between psychology and neurobiology. I do this in terms of two types of levels, levels of organization and levels of explanation. A hierarchy of levels of organization orders the entities and activities that are found in nature. Alternatively, the different ways of describing those things that we find in nature are placed at levels of explanation. The thesis of my dissertation is that these two types of levels need to be used together in order to understand the relationship between psychology and neurobiology. Neurobiological entities are located at the appropriate levels of organization. The descriptions offered in cognitive psychology of the capacities that humans have are located at a level of explanation above the neurobiological levels of organization. Selecting the correct levels of organization entails identifying the types of entities and the types of activities that are able to carry out psychological capacities. Based upon this requirement the appropriate levels of organization are the level where neurons and their activities occur and the level where macromolecules and their activities are found. The activities at these two levels of organization carry out the psychological capacities that are described by cognitive psychology at a higher level of explanation. In the first part of the dissertation (chaps. 1--2) I develop and defend a hierarchy of levels of organization that is based upon Wimsatt's account of levels of organization. In the second part of the dissertation (chaps. 3--4) I use Marr's account of levels of explanation as the basis for my analysis of levels of explanation. I argue that the type of description that is offered in cognitive psychology is the type that belongs at Marr's highest level of explanation. In the final part of the dissertation (chaps. 5--6) I combine these two different hierarchies, levels of organization and 4 levels of explanation, into a two-dimensional framework. This entails locating the lowest level of explanation at one, or in this case two, of the levels of organization. Therefore, the hierarchy of levels of explanation is composed of different kinds of descriptions of the entities and activities that are found at the neuronal and macromolecular levels of organization.