Vinod Goel

Modeling other minds

Nine normal volunteers performed a ‘theory of mind’ task while their regional brain blood flow pattern was recorded using the PET [15O]H2O technique. Control conditions induced subjects to attend to the visual and semantic attributes of known objects. In a third condition, subjects had to infer the function of an unfamiliar object from its form. In the ‘theory of mind’ condition, subjects had to infer function based on the form of both familiar and unfamiliar objects and in addition, model the knowledge and rationality of another mind about the function of these objects. Performance during the ‘theory of mind’ condition evoked the activation of a distributed set of neural networks with prominent activation of the left medial frontal lobe (Brodmann area 9) and left temporal lobe (Brodmann areas 21, 39/19, 38). This result suggests that when inferential reasoning depends on constructing a mental model about the beliefs and intentions of others, the participation of the prefrontal cortex is required. When access to such knowledge is affected by central nervous system dysfunction, such as that found in autism, modeling other minds may prove difficult.

The structure of design problem spaces

It is proposed that there are important generalizations about problem solving in design activity that reach across specific disciplines. A framework for the study of design is presented that (a) characterizes design as a radial category and fleshes out the task environment of the prototypical cases; (b) takes the task environment seriously; (c) shows that this task environment occurs in design tasks, but does not occur in every nondesign task; (d) explicates the impact of this task environment on the design problem space; and (e) demonstrates that, given the structure of the information-processing system, the features noted in the problem spaces of design tasks will not all occur in problem spaces where the task environment is vastly different. This analysis leads to the claim that there are a set of invariant features in the problem spaces of design situations that collectively constitute a design problem space. Protocol studies are reported in which the problem spaces of three design tasks in architecture, mechanical engineering, and instructional design are explored and compared with several protocols from nondesign problem-solving tasks.

Explaining modulation of reasoning by belief

Although deductive reasoning is a closed system, ones beliefs about the world can influence validity judgements. To understand the associated functional neuroanatomy of this belief-bias we studied 14 volunteers using event-related fMRI, as they performed reasoning tasks under neutral, facilitatory and inhibitory belief conditions. We found evidence for the engagement of a left temporal lobe system during belief-based reasoning and a bilateral parietal lobe system during belief-neutral reasoning. Activation of right lateral prefrontal cortex was evident when subjects inhibited a prepotent response associated with belief-bias and correctly completed a logical task, a finding consistent with its putative role in cognitive monitoring. By contrast, when logical reasoning was overcome by belief-bias, there was engagement of ventral medial prefrontal cortex, a region implicated in affective processing. This latter involvement suggests that belief-bias effects in reasoning may be mediated through an influence of emotional processes on reasoning.

The functional anatomy of humor: segregating cognitive and affective components

Humor, a unique human characteristic, is critical in thought, communication and social interaction. Successful jokes involve a cognitive juxtaposition of mental sets, followed by an affective feeling of amusement; we isolated these two components of humor by using event-related fMRI on subjects who listened to auditorily presented semantic and phonological jokes (puns) and indicated whether or not they found the items amusing. Our findings suggest that whereas there are modality-specific pathways for processing the juxtaposition of mental sets necessary for the appreciation of jokes, a common component of humor is expressed in activity in medial ventral prefrontal cortex, a region involved in reward processing.

Neuroanatomical correlates of aesthetic preference for paintings.

A study was conducted to determine the neuroanatomical correlates of aesthetic preference for paintings using fMRI. Subjects were shown representational and abstract paintings in different formats (original, altered, filtered), and instructed to rate them on aesthetic preference. Our primary results demonstrated that activation in right caudate nucleus decreased in response to decreasing preference, and that activation in bilateral occipital gyri, left cingulate sulcus, and bilateral fusiform gyri increased in response to increasing preference. We conclude that the differential patterns of activation observed in the aforementioned structures in response to aesthetic preference are specific examples of their roles in evaluating reward-based stimuli that vary in emotional valence.

Dissociation of Mechanisms Underlying Syllogistic Reasoning

A key question for cognitive theories of reasoning is whether logical reasoning is inherently a sentential linguistic process or a process requiring spatial manipulation and search. We addressed this question in an event-related fMRI study of syllogistic reasoning, using sentences with and without semantic content. Our findings indicate involvement of two dissociable networks in deductive reasoning. During content-based reasoning a left hemisphere temporal system was recruited. By contrast, a formally identical reasoning task, which lacked semantic content, activated a parietal system. The two systems share common components in bilateral basal ganglia nuclei, right cerebellum, bilateral fusiform gyri, and left prefrontal cortex. We conclude that syllogistic reasoning is implemented in two distinct systems whose engagement is primarily a function of the presence or absence of semantic content. Furthermore, when a logical argument results in a belief-logic conflict, the nature of the reasoning process is changed by recruitment of the right prefrontal cortex.

The seats of reason? An imaging study of deductive and inductive reasoning

WE carried out a neuroimaging study to test the neuro-physiological predictions made by different cognitive models of reasoning. Ten normal volunteers performed deductive and inductive reasoning tasks while their regional cerebral blood flow pattern was recorded using [15O]H2O PET imaging. In the control condition subjects semantically comprehended sets of three sentences. In the deductive reasoning condition subjects determined whether the third sentence was entailed by the first two sentences. In the inductive reasoning condition subjects reported whether the third sentence was plausible given the first two sentences. The deduction condition resulted in activation of the left inferior frontal gyrus (Brodmann areas 45, 47). The induction condition resulted in activation of a large area comprised of the left medial frontal gyrus, the left cingulate gyrus, and the left superior frontal gyrus (Brodmann areas 8, 9, 24, 32). Induction was distinguished from deduction by the involvement of the medial aspect of the left superior frontal gyrus (Brodmann areas 8, 9). These results are consistent with cognitive models of reasoning that postulate different mechanisms for inductive and deductive reasoning and view deduction as a formal rule-based process.

Anatomy of deductive reasoning

Much of cognitive research on deductive reasoning has been preoccupied with advocating for or against visuospatial (mental model theory) or linguistic/syntactic (mental logic theory) models of logical reasoning. Neuroimaging studies bear on this issue by pointing to both language-based and visuospatial systems being engaged during logical reasoning, and by raising additional issues not anticipated by these cognitive theories. Here, the literature on the neural basis of deductive reasoning from the past decade is reviewed. Although these results might seem chaotic and inconsistent, we identify several interesting patterns and articulate their implications for cognitive theories of reasoning. Cognitive neuroscience data point away from a unitary system for logical reasoning and towards a fractionated system dynamically reconfigured in response to specific task and environmental cues.

Motivating the Notion of generic design within information-processing theory: the design problem space

The notion of generic design, although it has been around for 25 years, is not often articulated; such is especially true within Newell and Simons (1972) information-processing theory (IPT) framework. Design is merely lumped in with other forms of problem-solving activity. Intuitively, one feels there should be a level of description of the phenomenon that refines this broad classification by further distinguishing between design and nondesign problem solving. However, IPT does not facilitate such problem classification. This article makes a preliminary attempt to differentiate design problem solving from nondesign problem solving by identifying major invariants in the design problem space.

Smarter Than We Think When Our Brains Detect That We Are Biased

Human reasoning is often biased by stereotypical intuitions. The nature of such bias is not clear. Some authors claim that people are mere heuristic thinkers and are not aware that cued stereotypes might be inappropriate. Other authors claim that people always detect the conflict between their stereotypical thinking and normative reasoning, but simply fail to inhibit stereotypical thinking. Hence, it is unclear whether heuristic bias should be attributed to a lack of conflict detection or a failure of inhibition. We introduce a neuroscientific approach that bears on this issue. Participants answered a classic decision-making problem (the “lawyer-engineer” problem) while the activation of brain regions believed to be involved in conflict detection (anterior cingulate) and response inhibition (lateral prefrontal cortex) was monitored. Results showed that although the inhibition area was specifically activated when stereotypical responses were avoided, the conflict-detection area was activated even when people reasoned stereotypically. The findings suggest that people detect their bias when they give intuitive responses.