Classical Views on Frontal Lobe Function

Initiation of an action sequence can occur in an unintended fashion. This is well shown by the existence of certain types of action lapses called ‘capture errors’ (Reason, 1979; Norman, 1981), as, for instance, William James's (1890) famous example of going upstairs to change and discovering himself in bed. Such errors tend to occur when one is preoccupied with some other line of thought, as Reason (1984) has shown. Action initiation is occurring in parallel with some other activity. Unintended actions do not, though, occur only when they are inappropriate. They can be both appropriate and unmonitored. This fits with the suggestion made early in chapter 13 that the control of which subsystems will be devoted to what task is often carried out in a decentralised fashion.

Actions such as these can be contrasted with ones that are preceded by ‘an additional conscious element in the shape of a fiat, mandate or expressed consent’, to quote William James (1890). When we decide or choose or intend or concentrate or prepare, decentralised control of the operation of particular subsystems does not appear to be the sole principle operating. How does the control of either of these types of action relate to the discussions on congitive control at the beginning of chapter 13? Such phenomenological contrasts by themselves provide only a very shaky basis for theorising.