The Seven Sins of Evolutionary Psychology - Konrad Lorenz Institute

Gerhard Meisenbergmodular systems and the developmentally malleable‘association cortex’.This dichotomy is too simple to be useful. Thereare various types of functional organization in thevast expanses of association cortex. First, there is thecognitive system proper that FODOR opposes to themodules of the sensory–motor periphery. The coreconstituent of the cognitive system is working memory,with short-term memory buffers and executivecontrol systems to manipulate the information thatis held in the buffers (BADDELEY/LOGIE 1999). Presumably,the neuronal populations that form thebuffers are able to respond with sustained activitychanges to external stimuli (GOLDMAN-RAKIC 1995).The information held in the buffers at any one timecan be described as a mental representation, a mentalmodel, or a cognitive map, depending on the researchtradition and the theorist’s preferences. Thisinformation can be entered into and retrieved fromlong-term declarative memory through the medialtemporal lobe system. Presumably the mental representationsin the buffers of working memory are theonly elements of the mind that are consciously experiencedand accessible to introspection (BADDELEY/ANDRADE 1998). Modules cannot be introspectedbecause they keep no records of their activities. Intelligenceis best defined as the ability to manipulatethe information that is held in the buffers of workingmemory (KYLLONEN/CHRISTAL 1990).Association cortex is also involved in rapid, nonconscioussensory–motor processing. The elaborationof visually-guided movements in areas of theparietal cortex is the most thoroughly studied example(BATISTA et al. 1999; COLBY/DUHAMEL 1996).These functions are not ‘primary’ modules of thekind that FODOR and the evolutionary psychologistshave in mind because they are not strictly hardwired.They are learned by a neural substrate that isstrategically located and structurally pre-designedfor this kind of learning. We can call them modularized,as opposed to truly modular functions, or wecan call them ‘secondary’ modules if we like. Exceptfor their learned rather than hard-wired nature, secondarymodules have most or all of the propertiesthat FODOR uses to define (primary) modules.Modularized functions may have been learnedwith conscious effort before becoming modularized.This is certainly the case for car-driving routines.Studies on eye movement conditioning in the parietalcortex of monkeys have also produced evidencefor reinforcement systems that may possibly be usedto guide learning in the absence of cognitive input(PLATT/GLIMCHER 1999). I agree with P&P that someof the modular functions that are commonly citedby evolutionary psychologists, including the classicalexample of language, are modularized ratherthan truly modular.Even many of the instinctive behaviors studied byethologists depend on learning. Thus, in classicalimprinting the sensory template on which the keystimulus is fitted can mature only with proper sensoryinput. The goslings that became imprinted onKonrad LORENZ (LORENZ 1935) were born with acrude sensory template that specified no more thana large moving object that makes noises. What exactlymother goose looks like has to be learned. Inthis case the motor output is quite rigid, but the sensorytemplate has to be fleshed out through learning.In the case of language, a rather pliable neuralsubstrate is strategically located between the auditorycortex and the motor outputs to the vocal apparatus.This neural substrate seems to be pre-formattedfor making categorical distinctions betweensounds, words, and word meanings, and for recognizinghierarchical relationships. In deaf-mutes thissame substrate imposes categorical distinctions andhierarchical relationships on visual inputs duringthe learning of sign language (NEVILLE et al. 1998;NISHIMURA et al. 1999), in apparent violation ofFODOR’s definition that modules are informationallyencapsulated. That we are dealing with fairly generalproperties of the neural substrate, rather than theunique features of a language module, is also suggestedby the observation that compared to righthemispherethinking, left-hemisphere thinking ingeneral depends on categorical distinctions,bounded entities, and hierarchical relationships betweenthese entities (CORBALLIS 1991; DEGLIN/KINS-BOURNE 1996). This is the reason why the left hemispheresthat write target articles and commentariestry so hard to define categorical distinctions betweensubcortical circuits and association cortex, or betweenmodular and modularized systems althoughin reality we are most likely dealing with a continuum.There may be few if any brain functions thatare 100% hard-wired or 100% arbitrarily learned.It is possible that there is a tendency for undifferentiatedcortex to evolve into hard-wired modules.The primate visual system has a complex hard-wiringwith at least 30 ‘centers’ that are involved in specializedfunctions such as motion detection, colorvision, shape recognition, face recognition, and therecognition of biological movements (VAN ESSEN/DEYOE 1995). We may speculate that this vast system,which is now largely hard-wired, evolved from apoorly-differentiated substrate that originally per-Evolution and Cognition ❘ 32 ❘ 2001, Vol. 7, No. 1