Neuroscientific insights into the development of analogical reasoning

Abstract

Analogical reasoning, or the ability to find correspondences between entities based on shared relationships, supports knowledge acquisition. As such, the development of this ability during childhood is thought to promote learning. Here, we sought to better understand the mechanisms by which analogical reasoning about semantic relations improves over childhood and adolescence (e.g. chalk is to chalkboard as pen is to…?). We hypothesized that age-related differences would manifest as differences in the brain regions associated with one or more of the following cognitive functions: (1) controlled semantic retrieval, or the ability to retrieve task-relevant semantic associations; (2) response control, or the ability to override the tendency to respond to a salient distractor; and/or (3) relational integration, or the ability to consider jointly two mental relations. In order to test these hypotheses, we analyzed patterns of fMRI activation during performance of a pictorial propositional analogy task across 95 typically developing children between the ages of 6 and 18 years old. Despite large age-related differences in task performance, particularly over ages 6-10 but through to around age 14, participants across the whole age range recruited a common network of frontal, parietal and temporal regions. However, activation in a brain region that has been implicated in controlled semantic retrieval - left anterior prefrontal cortex (BA 47/45) - was positively correlated with age, and also with performance after controlling for age. This finding indicates that improved performance over middle childhood and early adolescence on this analogical reasoning task is driven largely by improvements in the ability to selectively retrieve task-relevant semantic relationships.

Figure 1

(a) Analogy Task. Participants indicated which of the four choices was associated with an item in analogous fashion to the relation shared between the top two items. In this example, the refrigerator is associated with the milk carton (i.e., refrigerator stores the milk carton) in an analogous way to the dress and the closet items. On each trial, a semantic lure (e.g., cow), a perceptual lure (e.g., clock), and an unrelated lure (e.g., tennis racket) were included. Thus, participants’ correct choice was based on understanding the correct semantic association and disregarding irrelevant semantic or perceptual information. (b) Semantic matching task. Participants decide which of the four choices share a semantic relationship with a target object. In this example, the pen is used to write on the notepad, and thus is the item with the strongest semantic association. On each semantic trial, a perceptual lure (e.g., a shower curtain) as well as two unrelated lures were included. Thus, participants had to understand that the correct choice was based on semantic, rather than just perceptual, associations

Figure 2

Accuracy improved with age (a), while response times decreased (b) for both semantic (red) and analogy (blue) trials. The number of errors on analogy trials decreased with age (c), and semantic lures (yellow) were more common than perceptual lures (purple), which were themselves more common than unrelated lures (green) across all ages (c). Lines for all plots represent 95% confidence intervals around predicted values using a quadratic model

Figure 3

Whole‐brain activation patterns on average across all participants for the contrasts of semantic greater than fixation (yellow), analogy greater than fixation (red), and analogy greater than semantic (blue). Overlapping regions are shown in orange, green, purple and pink according to the Venn diagram, and all results are constrained to be within regions liberally activated by the semantic or analogy tasks. Statistical tests are permutation tests, and thresholds are set using a cluster defining threshold of Z > 2.3 and are family‐wise error‐corrected at p < .05. Thresholded and unthresholded maps are available in NeuroVault at http://neurovault.org/collections/1658

Figure 4

Whole‐brain activation patterns showing regions that show an increase in activation with age across all participants. Results for the semantic greater than fixation contrast are shown in yellow, analogy greater than fixation in red, and regions for which both are increasing are shown in orange. There were no regions that showed a within‐person differential increase in activation during analogy trials compared to semantic trials. All results are constrained to be within regions liberally activated on average by the semantic or analogy tasks. Statistical tests are permutation tests, thresholds are set using a cluster defining threshold of Z > 2.3 and are family‐wise error‐corrected at p < .05. Thresholded and unthresholded maps are available in NeuroVault at http://neurovault.org/collections/1658

Figure 5

Whole‐brain analysis showing regions that demonstrate an increase in activation with accuracy on analogy trials across all participants after correcting for the effects of age. Only the contrast of semantic greater than fixation (shown in yellow) showed a significant correlation in left aLIPC (a). Panel (b) illustrates how activation in this region correlates with (i) age and (ii) accuracy on analogy trails after correcting for the effects of age. Very similar patterns are shown when activation on analogy trials are extracted from this region (c). All results are constrained to be within regions liberally activated on average by the semantic or analogy tasks. No regions in the right hemisphere or the medial aspect of the left hemisphere passed the threshold for significance. Statistical tests are permutation tests, thresholds are set using a cluster defining threshold of Z > 2.3 and are family‐wise error‐corrected at p < .05. Thresholded and unthresholded maps are available in NeuroVault at http://neurovault.org/collections/1658