Tsai, Man ChiMan ChiTsai2025-12-032025-12-032025http://hdl.handle.net/20.500.11861/26257169 pagesGrounded in Embodied Cognition and Dual Process Theory, motor activities shape System 1 (intuitive) and System 2 (deliberative) thinking tendencies, influencing decision-making behavior. Previous research studied the impact of tactile engagement via touchscreen interaction versus indirect pointing interaction through mouse usage in simple selection tasks and online purchasing related of tangible products, leaving a research gap in regarding intangible task like stock investment, which involve risk assessment and uncertainty in decision-making. Study 1 employed a between-group design where participants engaged in stock portfolio allocation in a laboratory setting. It was hypothesized that touchscreen users would perceive lower risks and make bolder decisions while spending less time on tasks and relying less on textual information. Results showed that touchscreen users exhibited higher systematic risk with no difference in perceived risk when controlling for task interest, and viewed the task as less realistic. However, contrary to hypotheses, they spent more time focusing on textual information when total task time was controlled. Study 2 involved a two-week stock trading simulation using a within-group design under dynamic market conditions, providing a more realistic approximation of investment behavior. Participants reported lower perceived risk for buy trades while trading on touchscreens, although, no significant differences in systematic risk were found, contrarily to Study 1. Touchscreen users also rated the task as less realistic and demonstrated higher hedonic orientation when controlling for stock investment experience and device usage habits, respectively. Across both studies, touchscreen users demonstrated a tendency to take greater risks than anticipated compared to mouse users. These results support the notion that the interaction modality shapes cognitive processes related to risk perception, leading to increased risk-taking in complex contexts. Touchscreen interaction promotes System 1 thinking, influencing risk assessment and decision-making behavior. Future research should examine strategies to help users make informed decisions that align with their expectations, particularly for risk-sensitive products.enInteraction ModalityEmbodied CognitionDual Process TheoryRisk PerceptionOnline InvestmentDecision-MakingHuman-Computer InteractionThesis