ABSTRACT
Neuroscientists have developed a fascinating imaging technique. They produce pictures that, they claim, show which regions of the brain are active when we feel, when we perceive other persons, or when we make decisions. It is the aim of many neuroscientists to explain such mental phenomena by reducing them to neuronal events. The crucial step for fulfilling this objective would be to build an explanatory theory of the brain. Constructing such a theory is therefore a long-term aim of neuroscience, the achievement of which requires specific research strategies. Contemporary approaches in neuroscience deem it necessary to examine the activity of individual cells, of small cell groups, and of the dynamic organization of large neuronal networks. This activity is identified with the brain’s internal processing of signals (and information). According to the self-interpretation of the researchers, “invasive electrophysiology” is the branch of research concerned with how the brain processes signals in detail, and it is this kind of research which will lay the groundwork for an explanatory mechanistic theory of the brain. Other types of signals like fMRI do not have the same reputation of being relevant for an explanatory theory of the brain. Changes in blood oxygen level, for example, are evaluated as an indication that energy-demanding neuronal activities have occurred in corresponding areas, which is why more energy has been used and therefore more oxygen consumed. Assuming that this is the case, such a measurement would offer indications as to where to presume increased neuronal activity, but it could tell us nothing about what has actually occurred in these areas.
