From Executive Mechanisms Underlying Perception and Action to the Parallel Processing of Meaning

The dominant conceptualization of working memory distinguishes mechanisms that handle auditoryverbal and visuospatial representations from central executive resources that control and guide them. A straightforward case can be made that executive mechanisms evolved initially in the service of directing attention to salient environmental stimuli or events and selecting adaptive actions under the guidance of affective markers. In this paper, "working-memory capacity" is viewed as an emergent property of interactions between specialist subsystems with no homunculus-like executive. Mental capability could well have advanced via the differentiation of a single multimodal subsystem into additional new specialist subsystems that process not just verbal and spatial representations but also subsystems specialized to manipulate different kinds of meaning. The resulting overall mental architecture would devolve control of action and speech to peripheral mechanisms while allowing central subsystems to focus attention and decision making on meaning. According to this hypothesis, increased mental capability is dually based on the development of more abstract representations and on the observation that the more subsystems there are, the more the mind can do at one and the same time: only the most advanced mental architecture can control walking, talking, and thinking at one and the same time.