Magnitude-sensitive reaction times reveal non-linear time costs in multi-alternative decision-making

Area of Science:

• Decision Neuroscience
• Behavioral Economics
• Comparative Cognition

Background:

• Optimality analyses predict reaction times are insensitive to absolute stimulus magnitude in value-based choices.
• Empirical evidence in binary choices contradicts this, showing magnitude-sensitive reaction times.
• Existing theories struggle to disentangle explanations like time costs or subjective utility.

Purpose of the Study:

• To extend theoretical analysis of geometric time-discounting to ternary choice settings.
• To experimentally investigate magnitude-sensitivity in ternary decisions across species.
• To differentiate between potential explanations for observed reaction time patterns.

Main Methods:

• Developed theoretical models for optimal policies under various time cost and utility functions in ternary choices.
• Designed and conducted experiments involving humans and slime molds making ternary decisions.
• Analyzed reaction time data for sensitivity to stimulus magnitude and other factors.

Main Results:

• Extended geometric time-discounting theory to ternary choices.
• Provided novel experimental evidence of magnitude-sensitive reaction times in humans and slime molds for ternary decisions.
• Found geometric discounting to be the primary explanation for observed magnitude sensitivity.

Conclusions:

• Geometric discounting offers a robust explanation for magnitude-sensitive reaction times in multi-alternative decisions.
• This finding has implications for understanding decision-making across diverse taxa.
• The study highlights the importance of considering time discounting in choice behavior.