Collaboration takes place everywhere in everyday life, and exposure to the ideas of others is a core process in collaboration. In this study, we investigated whether exposure to other people's ideas facilitates idea generation: 123 participants were asked to list as many ideas as possible to increase turnout in one of three conditions: constant exposure, intermittent exposure, or no exposure. Participants in the no exposure condition generated ideas without exposure to other's ideas. In the constant exposure condition, one of the sets of ideas generated by participants in the no exposure condition was presented on every trial. In the intermittent exposure condition, ideas were only presented in trials 1, 4, and 7. As a result, there was no significant difference in the number of ideas generated between conditions. The conditions under which exposure to the ideas of others facilitates idea generation were discussed.

Memory retrieval is the basis of idea generation. We hypothesized that people retrieve more original knowledge by search-ing for a commonality between unrelated objects than by thinking about an object itself. Seventy-seven undergraduatesfrom Nagoya University were assigned to one of three conditions: a commonality search and either of two control condi-tions. In the first session, the participants in the commonality search condition listed a feature shared by a pair of wordspresented; those in the control conditions listed a feature associated with a word presented. In the second session, all par-ticipants were asked to list the words associated with the features they identified in the previous session. Results showedthat the features and the words listed in the commonality search condition were more original than those in either controlcondition. We concluded that the method we proposed is effective in retrieving original knowledge for idea generation.

We investigated how people find commonalities between unrelated objects as a basis of generating creative ideas by ex-amining the relationship between performances on commonality search and alternative categorization tasks. We predicteda positive correlation between performances on the two tasks because one needs to focus on some obscure features ofobjects to do both tasks well. Thirty-one undergraduates were asked to engage in both commonality search and alternativecategorization tasks. They were asked to list as many as commonalities between nine unrelated object pairs for 90 secondsfor each pair. They were then asked to list as many categories as possible that each of five objects belong to for 60 secondsper object. The results showed a significant positive correlation between the performances on these tasks. We concludedthat commonality search and alternative categorization both focus on obscure features of objects.

The purpose of the present study was to investigate the effects of addressee of verbalization, self or other, on insight problem solving. Thirty-five participants were assigned to one of the three conditions: toward-self verbalization, toward-other verbalization, or irrelevant verbalization (control). A 3-minute verbalization phase was inserted after 5 minutes of solving the T-puzzle. The participants were asked to write down their thoughts during the first 5 minutes as a record in the toward- self verbalization condition, and as an instruction for other participants in the toward-other verbalization condition. The participants in the control condition were required to write down their concerns. After that, they were asked to engage in the puzzle again for 10 minutes. The results showed a detrimental verbalization effect while allowed a wide range of effects for the self vs other distinction going in either direction. We are using this study as a basis for a pre-registered repo

We investigated how people examined the self or anothers learning history using a complex dynamic control task. Thirty-eight undergraduates were assigned to self or self-as-instructed-other conditions. Participants were asked to performthe task twice and describe their thinking as they examined the learning history provided in the second session. Theparticipants in the self condition were provided with their own learning history, whereas those in the self-as-instructed-other condition were presented with their learning history as if it were anothers. We compared their performance on thecontrol and structure tests between conditions. The results showed that performance on the control test improved oversessions regardless of the condition. The results also showed that the participants in the self-as-instructed-other conditionengaged in evaluation or guessing more often than those in the self condition, suggesting that there are differences in howpeople examine a persons learning history depending on its source.

The purpose of this study was to clarify the cognitive processes of commonality search between unrelated objects. Specifically, we investigated the relationship between the performance of the commonality search task and that of the alternative categorization task. We hypothesized that one needs to focus on obscure features of objects to do both tasks well and that there would therefore be a positive correlation between the performances on the two tasks. We also compared the performance of the commonality search task with that of the alternative categorization to investigate exploratorily how each task promotes creative thinking. Thirty-one participants were asked to engage in two tasks: the commonality search task and the alternative categorization task. In the commonality search task, they were asked to list as many commonalities as possible between nine unrelated object pairs within 90 seconds for each pair. In the alternative categorization task, they were asked to list as many categories as possible to which each of the five objects belonged, within 60 seconds for each object. Although There was a significant positive correlation between the numbers of answers on these tasks. The additional results showed that there was no significant difference between the two tasks in terms of average saliency score or the first answer, but the saliency of the commonality search task was significant lower than the alternative categorization task in the second answer. We discussed the similarities and differences between the two tasks and the potential use of the commonality search task as a way to promote creative thinking.

There has been a debate on the process of insight problem solving. The special-process view posits that insight problemsolving processes are implicit unlike non-insight problem solving. The business-as-usual view, on the other hand, assumesthat the same processes as non-insight problem solving are involved in insight problem solving. To reconcile them, we canrely on the evidence on the verbal overshadowing effect on insight problem solving. However, there is a methodologicalproblem on how to determine whether the verbal overshadowing effect has emerged. The purpose of the present studywas to solve the problem using Bayes Factors. We reanalyzed the data presented in the previous studies examining theeffects of verbalization on insight problem solving. The results showed that some studies inappropriately concluded thatthe verbal overshadowing effect was not obtained. We also discussed possible moderating variables of the effect.

Previous studies have shown that underlining sentences while reading is an effective comprehension strategy that many people use spontaneously. We examined which components of this underlining strategy could facilitate comprehension. The effects on comprehension of lined traces and hand movement were examined independently. Eighty-two undergraduates were assigned to one of the four conditions: both traces and movement, movement and no trace, traces and no movement, and neither trace nor movement. After reading the expository text as instructed for ten minutes, participants were instructed to solve a Sudoku puzzle as a distracter task for three minutes. They were then asked to summarize, title, and generate three keywords for the text in ten minutes. The results showed that hand movement facilitated appropriate summarization and that lined traces enhanced appropriate titling. We interpreted the results in terms of cognitive load theory and external memory aid.