The Electrophysiological Evidence Of The Dissociation Between Hypothesis Generation, Hypothesis Testing And Selection In Numerical Inductive Reasoning

Inductive reasoning is viewed as a form of hypothesis generation and hypothesis selection or testing. In this study, the relationship of these sub-processes was investigated. A number series completion task was employed, which required abstracting a rule hidden in three numbers and deciding whether the fourth number was congruent to the rule.In the first experiment, it was expected that hypothesis generation processing would be dissociated to hypothesis testing, and these two sub-processes would be affected by task difficulty differently. The Event-related potentials (ERPs) results indicated that the wave elicited by the 3rd number was larger than the 1st and 2nd number on N1 and P3 components. Task difficulty had a significant effect on the amplitude of N2 and P3 for the 2nd number, but not 3rd number. These results reflected the dissociation between hypothesis generation and hypothesis testing, supporting the corresponding hypothesis generation-testing model.In the second experiment, three conditions, namely, baseline, part-induction, and complete-induction, were designed by using different cues and operation of numbers, and the above sub-processes were examined.The event-related potentials (ERPs) indicated the following:(1) the baseline condition elicited a smaller P2 than the two induction conditions for the first number; (2) a larger P2 was evoked by the part-induction condition than the other two conditions, a larger parietal P3 was elicited by the two induction conditions, and a larger negative slow wave was evoked by the part-induction condition than the baseline condition for the second number; and (3) the complete-induction condition evoked a smaller P1 than the baseline condition, a larger P3 than the other two conditions, and a negative slow wave that was different from the other two conditions for the third number.These results suggest different electrophysiological correlates with the different sub-processes of inductive reasoning, thus, validating the hypothesis generation and selection or testing model of inductive reasoning.