Online research in philosophy

Explanations of how psychological capacities are carried out often invoke functional brain areas. I argue that such explanations cannot succeed. Psychological capacities are carried out by identifiable entities and their activities in the brain, but functional brain areas are not the relevant entities. I proceed by assuming that if functional brain areas did carry out psychological capacities, then these brain areas could be included in descriptions of mechanisms. And if functional brain areas participate in mechanisms, then they must engage in activities. A number of ways in which we might understand the claim that functional brain areas engage in activities are examined. None are successful, and so one conclusion is that functional brain areas do not participate in mechanisms. Consequently, they are not the entities that carry out psychological capacities.

In recent years evolutionary psychologists have developed and defended the Massive Modularity Hypothesis, which maintains that our cognitive architecture—including the part that subserves ‘central processing’ —is largely or perhaps even entirely composed of innate, domain-specific computational mechanisms or ‘modules’. In this paper I argue for two claims. First, I show that the two main arguments that evolutionary psychologists have offered for this general architectural thesis fail to provide us with any reason to prefer it to a competing picture of the mind which I call the Library Model of Cognition. Second, I argue that this alternative model is compatible with the central theoretical and methodological commitments of evolutionary psychology. Thus I argue that, at present, the endorsement of the Massive Modularity Hypothesis by evolutionary psychologists is both unwarranted and unmotivated.

A spate of recent anti-localizationist publications have re-ignited the old debate about the localization of function. Many of the recent attacks on localization, however, are directed at what I will argue to be a narrow and outmoded view of localization, and thus have little conceptual or empirical impact. What I hope to present here is an analysis of functional localization that more adequately reflects the sophistication and complexity of its use in neuroscientific research, both historically and recently. Proceeding first by way of contrast, I examine theanti-localizationist positions of holism andequipotentiationism. Then, I present a four-fold analysis of localization according to physical scope, physical kind, functional scope, and functional kind. Next, I turn to a discussion of the heuristic value oflocalization in deciphering structure-functionrelationships. Finally, I hope to show that the overall view of functional localization that emerges from these considerations constitutes a much more elusive target than its critics assume. It serves to mitigate, and insome instances even defeat, some forms ofanti-localizationist criticisms.

The "method of deficit analysis" in functional localization research is a method for inferring localization of brain function on the basis of evidence of abnormal behavior plus evidence concerning brain damage location. Such inferences involve two steps: first, a functional deficit analysis of the neurologically impaired patient, and second, localization of function in the normal brain. It is argued that psychological theory is required for adequate functional deficit analysis, both for the identification of the relevant functional components of the system as well as for the explanation of the behavioral pathology in terms of a deficit in one of these components.

Part of understanding the functional organization of the brain is understanding how it evolved. This talk presents evidence suggesting that while the brain may have originally emerged as an organ with functionally dedicated regions, the creative re-use of these regions has played a significant role in its evolutionary development. This would parallel the evolution of other capabilities wherein existing structures, evolved for other purposes, are re-used and built upon in the course of continuing evolutionary development (“exaptation”: Gould & Vrba 1982). There is psychological support for exaptation in cognition (e.g. Cosmides 1989), theoretical reason to expect it (Anderson 2003; in press-a; in press-b) and neuroanatomic evidence that the brain evolved by preserving, extending, and combining existing network components, rather than by generating complex structures de novo (Sporns & Kötter 2004). However, there has been little evidence that integrates these perspectives, bringing such an account of the evolution of cognitive function into the realm of cognitive neuroscience (although see, e.g., Barsalou 1999).

Quartz (2002) argues that some recent findings about the evolution of the brain (Finlay & Darlington, 1995) are inconsistent with evolutionary psychologists’ massive modularity hypothesis. In substance, Quartz contends that since the volume of the neocortex evolved in a concerted manner, natural selection did not act on neocortical systems independently of each other, which is a necessary condition for the massive modularity of our cognition to be true. I argue however that Quartz’s argument fails to undermine the massive modularity hypothesis.

Description: The massive redeployment hypothesis (MRH) is a theory about the functional organization of the human cortex, offering a middle course between strict localization on the one hand, and holism on the other. Central to MRH is the claim that cognitive evolution proceeded in a way analogous to component reuse in software engineering, whereby existing components—originally developed to serve some specific purpose—were used for new purposes and combined to support new capacities, without disrupting their participation in existing programs.

Abstract: The massive redeployment hypothesis (MRH) is a theory about the functional topography of the human brain, offering a middle course between strict localization on the one hand, and holism on the other. Central to MRH is the claim that cognitive evolution proceeded in a way analogous to component reuse in software engineering, whereby existing components-originally developed to serve some specific purpose-were used for new purposes and combined to support new capacities, without disrupting their participation in existing programs. If the evolution of cognition was indeed driven by such exaptation, then we should be able to make some specific empirical predictions regarding the resulting functional topography of the brain. This essay discusses three such predictions, and some of the evidence supporting them. Then, using this account as a background, the essay considers the implications of these findings for an account of the functional integration of cognitive operations. For instance, MRH suggests that in order to determine the functional role of a given brain area it is necessary to consider its participation across multiple task categories, and not just focus on one, as has been the typical practice in cognitive neuroscience. This change of methodology will motivate (even perhaps necessitate) the development of a new, domain-neutral vocabulary for characterizing the contribution of individual brain areas to larger functional complexes, and direct particular attention to the question of how these various area roles are integrated and coordinated to result in the observed cognitive effect. Finally, the details of the mix of cognitive functions a given area supports should tell us something interesting not just about the likely computational role of that area, but about the nature of and relations between the cognitive functions themselves. For instance, growing evidence of the role of “motor” areas like M1, SMA and PMC in language processing, and of “language” areas like Broca’s area in motor control, offers the possibility for significantly reconceptualizing the nature both of language and of motor control.

sides of the argument. MRH is supported by some case studies of redeployment, and an empirical review of 135..