A System for Relational Reasoning in Human Prefrontal Cortex

Abstract

The integration of multiple relations between mental representations is critical for higher level cognition. For both deductiveand inductive-reasoning tasks, patients with prefrontal damage exhibited a selective and catastrophic deficit in the integration of relations, whereas patients with anterior temporal lobe damage, matched for overall IQ but with intact prefrontal cortex, exhibited normal relational integration. In contrast, prefrontal patients performed more accurately than temporal patients on tests of both episodic memory and semantic knowledge. These double dissociations suggest that integration of relations is a specific source of cognitive complexity for which intact prefrontal cortex is essential. The integration of relations may be the fundamental common factor linking the diverse abilities that depend on prefrontal function, such as planning, problem solving, and fluid intelligence.Reasoning depends on the ability to form and manipulate mental representations of relations between objects and events. For example, transitive inference (a type of deductive reasoning, in which the truth of the premises ensures the truth of the conclusion) requires the ability to integrate two relations that share an element (e.g., given that Bill is taller than Charles and Abe is taller than Bill, it follows that Abe is taller than Charles). Similarly, in drawing analogies (a type of inductive reasoning, in which the initial premises determine the plausibility of the conclusion), relational reasoning is also essential (e.g., in the problem "person is to house as bear is to what?" the shared roles, dweller and dwelling, constrain the inferred answer, "cave"). Problem solving and planning also necessarily depend on relational integration. For example, using the elementary problem-solving strategy of difference reduction (Newell & Simon, 1972) requires integration of a difference between the present state and the goal state (a relation, such as "this wall lacks a coat of paint") with the expected change that would be produced by an operator applied to the present state (a second relation, such as "painting the wall will add a coat of paint"). Forming subgoals by means-ends analysis also requires integration of multiple relations (e.g.

The role of prefrontal cortex in working-memory capacity, executive attention, and general fluid intelligence: An individual-differences perspective

“…The Duncan et al (1995) and Waltz et al (1999) findings are consistent with the few imaging studies that have been conducted to examine the neural substrates of nonverbal, fluid reasoning in healthy adults. Early stud-ies measured regional cerebral blood flow (rCBF) during the performance of Raven's matrices test (Risberg & Ingvar, 1973;Risberg, Maximilian, & Prohovnik, 1977).…”

“…Indeed, the limited neuropsychological and neuroimaging research on other forms of g-loaded analytical reasoning, such as deductive reasoning, provides converging evidence for an important role for WM and dPFC. For example, patients with focal PFC damage performed worse than those with focal anterior temporal damage on deductive reasoning tasks that required integrating information across statements (Waltz et al, 1999 , PFC patients performed at chance (M = 20% correct), whereas temporal patients and controls performed equivalently (Ms = 87% and 86%, respectively). Thus, PFC damage severely limited patients' ability to make transitive inferences when two relations had to be simultaneously maintained and integrated for solution.…”

“…Although based on few subjects, the Duncan et al (1995) findings suggest the useful research strategy of matching subject groups on their conventional IQ scores (or, even better, on Gc measures) and then testing for PFC-related deficits that are specific to Gf-loaded tasks. Waltz et al (1999) took a different but equally interesting approach. They tested six patients with focal frontal damage and six patients with focal temporal damage on different categories of problems adapted from Raven's test.…”

The discovery and comparison of symbolic magnitudes

“…Reliable success is not achieved by any species except humans, and not until preschool age (Andrews & Halford, 1998;Halford, 1984;Halford, 1993). Piagetian transitive inference is heavily dependent on a mature and intact human frontal cortex (Waltz et al, 1999). We have recently extended the BART model to enable it to use its learned representations to solve abstract transitive inference problems (Chen, Lu, & Holyoak, 2013).…”

Manipulation of working memory information is impaired in Parkinson's disease and related to working memory capacity.

“…As known from patients with frontal lobe damage, for example, deficits may result from the complexity of working memory processing required by a task, even if the number of items to be processed remains constant (Waltz, Knowlton, & Holyoak, 1998;Waltz et al, 1999). Thus, the question arises of whether a similar effect will emerge in PD patients in a manipulation task.…”