Animal evidence on the organization of frontal lobe and limbic structures and pathways and evidence from frontal lobe patients have led to cognitive models which attempt to explain human-motivated abstract reasoning abilities. These models relate motivated information processing to the activation of specific frontal brain areas and circuits that are further related to ongoing autonomic changes.

The Wisconsin Card Sorting Test (WCST) has been generally considered a prototype examination of abstract reasoning and frontal lobe function. In the WCST, the subject has to match geometrical shapes on a target card to four standard cards with different geometrical shapes. The subject has to find a rule on the basis of positive or negative feedback upon the response. When the rule has been found, application of this rule provides positive feedback until (after 10 trials) the rule is suddenly changed. From this point on, the sequence of rule search followed by rule application is repeated. Perseverative responses occur when a subject is unable to switch to a new rule, but continues to apply the old rule.

Evidence has established that subjects with frontal lobe damage, elderly adults, and Attention Deficit Disordered Hyperactive children perform relatively poorly on the WCST. These subject groups detect fewer rules, and exhibit more perseveration than control subjects. From experimental studies in patients with prefrontal lesions, Dubois et al. (1995) concluded that two dysfunctions emerge in these patients: (1) a disruption of rule finding, because of the emergence of non-cognitive, rigid patterns of behavior and (2) inadequate feedback integration in the selection process of the appropriate response.

Support, in particular, for the first dysfunction has come from PCA studies of WCST scores in frontal patients, schizophrenic patients and control subjects. These studies have consistently extracted a main factor, which explained most of the variance. Scores such as conceptual level response and number of correct categories had negative loadings, while perseverative error scores had positive loadings on this factor. Moreover, this factor clearly discriminated between control and frontal lobe patients, or schizophrenic patients. Interpretations such as ‘perseveration’, ‘abstract thinking ability’, ‘concept formation’, ‘undifferentiated executive function’ and ‘flexibility’ have been proposed for this PCA component.

Other studies have also indicated that a deficit in frontal executive functions may deteriorate WCST performance. Neurophysiological studies, using PET scan techniques, indicated that WCST problem solving engages, in particular, the dorsolateral prefrontal cortex . Also Ragland et al. (1997) reported more selective dorsolateral prefrontal and inferior frontal regional cerebral blood flow activation in good WCST performers than in middle and bottom WCST performers. This evidence suggests that WCST problem solving is related to activation in left frontal, left prefrontal, and left temporal cortical areas.

In the literature, the WCST has often been conceptualized as a working memory task that invokes specific intermediary operations, including switching cognitive sets according to changing contingencies, rule learning, formation of conceptual sets, application of detected concepts, maintaining sets, and use of error information. Close inspection of the test trials reveals that the WCST requires two distinct types of problem-solving strategies: rule search and (after the rule has been found) rule application for 10 consecutive trials. In rule search, the subject has to deduce the relationship between the standard and target cards. This demands a complex, ‘open ended’ set of processes, such as, the inhibition of an earlier rule, testing of alternative rules, and updating after feedback. In contrast, after the rule has been found, rule application only requires a sequence of relatively simple, pre-planned operations, the subject only matches one dimension of the geometrical shapes of the target and standard cards and ignores the other dimensions.

Theoretical models assume that in novel or complex tasks, such as the WCST, a supervisory controller co-ordinates the selection of the intermediary operations. According to Norman and Shallice (1986) a supervisory attentional system allows for conscious attentional control to modulate performance. It operates by the allocation of attentional resources, which add to the activation values of selected operations and decrease the activation values of earlier operations. Norman and Shallice suggested that WCST perseverative responses in frontal lobe patients result from a deficit in the allocation and supervision of attention. This model is consistent with results of frontal patients which indicated that attention to and integration of feedback information in these patients is inadequate. Also Dunbar and Sussman (1995) concluded from experiments with normal subjects that WCST perseveration may result from an inability to exert attentional control resulting in a failure to update feedback information. The theory of Norman and Shallice attributes a main regulatory frontal lobe function to attentional processes during WCST rule search. Moreover, it suggests a complementary process that is sufficient for relatively simple or well-learned acts: automatic contention scheduling. This mechanism involves the automatic execution of an action sequence (schema) that does not require attention. As argued above, WCST rule application demands a similar process. It requires the pre-planned execution of a series of processing steps which together result in the application of a rule. Following Norman and Shallice’s theory, this rule application process may be automatically executed and may not require attentional resources.

Based on more recent animal brain research, Gray (1995a, b) has proposed a system of frontal/septo-hippocampal pathways that controls the automatic, pre-planned execution of step-by-step motor programs: the behavioral approach system. When a comparator process triggers a mismatch, this ongoing behavior is inhibited by the activation of a behavioral inhibition system which also increments arousal and attention. From a related animal research perspective, Pribram (1991) has argued that attentional processes in the frontal lobes and in the limbic system are closely connected to habituation, familiarization and orientation. A novel stimulus or a reinforcing stimulus such as positive feedback may disrupt habituation and elicit an orienting response. Moreover, it is well known that the frontal lobes have output pathways that project to the brain-stem, to control autonomic physiological support for anticipated behaviors and orienting responses. Hence, Pribram (1991) argued that an important part of the cortically and sub-cortically elicited orienting response is a set of viscero-autonomic responses, such as brief heart rate change, skin conductance change and change in respiratory rate. His research suggested to us that WCST rule application and rule search might also elicit viscero-autonomic responses. Below we will argue on the basis of the literature how such viscero-autonomic responses, in particular cardiac responses, may be associated with WCST performance.