Rats and Humans Can Optimally Accumulate Evidence for Decision-Making

Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA.
Science (Impact Factor: 33.61). 04/2013; 340(6128):95-8. DOI: 10.1126/science.1233912
Source: PubMed


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.

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    • "The impact of non-linear and non-stationary inputs on decision-making has traditionally received less attention, but recently there has been increasing interest from a number of perspectives. One aspect concerns the effect of fluctuations on fast time scales (e.g., Insabato, Dempere-Marco, Pannunzi, Deco, & Romo, 2014; Tsetsos, Usher, & McClelland, 2011; Brunton, Botvinick, & Brody, 2013), but our focus here is on the domain of slower time-scale changes. Early work in this domain examined temporal-order discrimination, where discriminative information is available only briefly, and therefore must be subsequently held in a decaying visual short-term memory (Heath, 1981). "
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    Full-text · Article · Mar 2016 · Cognitive Psychology
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    • "This model-based approach has proven valuable and has already revealed the critical role of the subthalamic nuclei for motor inhibition under conditions of ambiguity or risk (Cavanagh et al., 2011) and the effect of subthalamotomy on inhibitory behaviour (Obeso et al., 2014). Accurate fitting of the model in studies of animals and healthy participants often requires thousands of trials (Brunton et al., 2013). This would not be tolerated by patients with neurodegenerative disorders. "
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    • "In some cases, decisions about perfectly stable stimuli appear to involve perfect accumulation, as described by drift-diffusion and related models (Gold and Shadlen, 2000; Roitman and Shadlen, 2002; Brunton et al., 2013; Hanks et al., 2015). Under those conditions, deviations from perfect accumulation in the brain may be considered as inefficient, operating under other constraints "
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