FN400 and sustained negativity reveal a premise monotonicity effect during semantic category-based induction

The default-interventionist model underlies premise typicality weakening the premise diversity effect during category-based induction: Event-related potentials evidence

The diversity effect during category-based induction (CBI) means that the more diverse the evidence, the higher will be the conclusion's inductive strength. However, it is influenced by the premise typicality. Three competitive cognitive processing models account for this influence: (1) The pre-emptive conflict resolution model assumes that only premise typicality activates; (2) the parallel-competitive model assumes that premise typicality and diversity activate in parallel; and (3) the default-interventionist model assumes that a default response of premise diversity first activates and is subsequently followed by premise typicality, or premise typicality activates first, followed by premise diversity. The timing of premise typicality affecting the diversity effect during CBI was measured using event-related potentials to determine which cognitive model best explains this influence. Similar to previous studies, non-diverse premise inductive tasks involving two typical premise categories were compared with diverse premise inductive tasks involving a typical and an atypical category. The results showed that non-diverse conditions had higher "correct" response proportions, greater inductive strength, higher "definitely" response proportions, and shorter reaction times than diverse conditions, showing that premise typicality weakens the diversity effect. Moreover, the diverse premises elicited larger P2, smaller FN400, and greater frontal post-N400-positivity amplitudes than non-diverse premises, suggesting that premise diversity was facilitated during a relatively early time window and revised by premise typicality in a later window. These results support the default-interventionist in nature during thinking and reasoning.

Common and distinctive cognitive processes between categorization and category-based induction: Evidence from event-related potentials

Categorization involves forming equivalence classes of discriminable entities, whereas category-based induction (CBI) involves employing categorical knowledge to generalize novel properties. Previous studies have suggested either common or distinctive cognitive processing between categorization and CBI. However, no study has compared cognitive processes with the same stimuli sets using event-related potentials (ERPs), which help to determine the cognitive processes with a high temporal solution. In this study, we compared the ERP responses to categorization and CBI using two separate experiments (i.e., generic and specific conclusions), with the same task materials. Results from both experiments identified distinctive cognitive processing between categorization and CBI based on a greater proportion of "definitely" responses and smaller amplitudes of sustained negativity during categorization. These observations suggest that categorization involves decreased conflict monitoring and control than CBI under single-premise conditions. Contrastingly, categorization and CBI elicited similar FN400 amplitudes in both experiments, which suggests a common cognitive process between them. These findings present the common and distinctive cognitive processes between categorization and CBI.

How types of prior knowledge and task properties impact the category-based induction: diverging evidence from the P2, N400, and LPC effects

Category-based induction task was combined with ERP to unravel whether prior knowledge and property interact when inferring on genes or diseases. Larger P2 amplitudes for near taxonomic/causal distances relative to far ones, as well as larger LPC for taxonomic relation relative to thematic relation, are found in both gene and disease tasks. However, smaller N400 is found for taxonomic relation in gene task and thematic relation in disease task, respectively, and larger LPC at 700-850 ms for near taxonomic distance in the gene task and near causal distance in the disease task. These results suggested that the category-based inductive reasoning is context-sensitive, and there may be four stages of category-based inductive reasoning: the early automatic comparison of features/relations (P2), features/relations generalization process (N400), the extraction of common relationship/rule (LPC at 550-700 ms), the inference generation (LPC at 700-850 ms).

P3a amplitude is related to conclusion specificity during category-based induction

Category-based induction involves the generalization of a novel property (conclusion property) to a new category (conclusion category), based on the knowledge that a category exemplar (premise category) has the respective novel property. Previous studies have shown that conclusion specificity (i.e., specific [S] or generic categories [G]) influences category-based induction. However, the timing of brain activity underlying this effect is not well known, especially with controlling the similarities of premise and conclusion categories between S and G arguments. In this study, the event-related potential (ERP) responses to category-based induction between S and G arguments were compared under both congruent (+, premise and conclusion categories are related) and incongruent (-, premise and conclusion categories are unrelated) arguments; additionally, the similarities of premise and conclusion categories between S and G arguments were controlled. The results showed that replicating this effect, S+ arguments have increased “strong” response rates compared to G+ arguments, suggesting that category-based induction is contingent on factors beyond matched similarities. Moreover, S arguments have more liberal inductive decision thresholds than G arguments, which suggest that conclusion specificity affects the inductive decision reflected by inductive decision thresholds. Furthermore, G+ arguments elicit greater P3a amplitudes than S+ arguments, which suggest greater attention resources allocation to the review of decisions for G+ arguments than that for S+ arguments. Taken together, the conclusion specificity effect during semantic category-based induction can be revealed by “strong” response rates, inductive decision thresholds, and P3a component after controlling the premise-conclusion similarity, providing evidence that category-based induction rely on more than simple similarity judgment and conclusion specificity would affect category-based induction.

Neural Oscillation Profiles of a Premise Monotonicity Effect During Semantic Category-Based Induction

A premise monotonicity effect during category-based induction is a robust effect, in which participants are more likely to generalize properties shared by many instances rather than those shared by few instances. Previous studies have shown the event-related potentials (ERPs) elicited by this effect. However, the neural oscillations in the brain underlying this effect are not well known, and such oscillations can convey task-related cognitive processing information which is lost in traditional ERP analysis. In the present study, the phase-locked and non-phase-locked power of neural oscillations related to this effect were measured by manipulating the premise sample size [single (S) vs. two (T)] in a semantic category-based induction task. For phase-locked power, the results illustrated that the premise monotonicity effect was revealed by anterior delta power, suggesting differences in working memory updating. The results also illustrated that T arguments evoked larger posterior theta-alpha power than S arguments, suggesting that T arguments led to enhanced subjectively perceived inductive confidence than S arguments. For non-phase-locked power, the results illustrated that the premise monotonicity effect was indicated by anterior theta power, suggesting that the differences in sample size were related to a change in the need for cognitive control and the implementation of adaptive cognitive control. Moreover, the results illustrated that the premise monotonicity effect was revealed by alpha-beta power, which suggested the unification of sentence and inference-driven information. Therefore, the neural oscillation profiles of the premise monotonicity effect during semantic category-based induction were elucidated, and supported the connectionist models of category-based induction.