Rats and Humans Can Optimally Accumulate Evidence for Decision-Making

• Published in: Science (American Association for the Advancement of Science) Vol. 340; no. 6128; pp. 95 - 98
• Main Authors: Brunton, Bingni W., Botvinick, Matthew M., Brody, Carlos D.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 05.04.2013; The American Association for the Advancement of Science
• Subjects: Animals; Audition; Auditory tasks; Behavior, Animal - physiology; Behavioral neuroscience; Biological and medical sciences; Cognition & reasoning; Cognition. Intelligence; Decision making; Decision Making - physiology; Decision making. Choice; Evidence; Fundamental and applied biological sciences. Psychology; Human; Humans; Learning. Memory; Memory; Modeling; Models, Psychological; Nervous system; Neurosciences; Noise; Parametric models; Perception; Photic Stimulation; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Rats; Rats - psychology; Signal noise; Task Performance and Analysis; Time constants; Visual Perception; Visual tasks; Accumulator; Human; Rat; Noise; Decision making; Interspecific comparison; Memory; Rodentia; Cognition; Experimental study; Accumulation; Vertebrata; Hearing; Mammalia; Animal; Perception; Mathematical model
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1233912

The gradual and noisy accumulation of evidence is a fundamental component of decision-making, with noise playing a key role as the source of variability and errors. However, the origins of this noise have never been determined. We developed decision-making tasks in which sensory evidence is delivered in randomly timed pulses, and analyzed the resulting data with models that use the richly detailed information of each trial's pulse timing to distinguish between different decision-making mechanisms. This analysis allowed measurement of the magnitude of noise in the accumulator's memory, separately from noise associated with incoming sensory evidence. In our tasks, the accumulator's memory was noiseless, for both rats and humans. In contrast, the addition of new sensory evidence was the primary source of variability. We suggest our task and modeling approach as a powerful method for revealing internal properties of decision-making processes.