TY - JOUR TI - Humans strategically shift decision bias by flexibly adjusting sensory evidence accumulation AU - Kloosterman, Niels A AU - de Gee, Jan Willem AU - Werkle-Bergner, Markus AU - Lindenberger, Ulman AU - Garrett, Douglas D AU - Fahrenfort, Johannes Jacobus A2 - Frank, Michael J VL - 8 PY - 2019 DA - 2019/02/06 SP - e37321 C1 - eLife 2019;8:e37321 DO - 10.7554/eLife.37321 UR - https://doi.org/10.7554/eLife.37321 AB - Decision bias is traditionally conceptualized as an internal reference against which sensory evidence is compared. Instead, we show that individuals implement decision bias by shifting the rate of sensory evidence accumulation toward a decision bound. Participants performed a target detection task while we recorded EEG. We experimentally manipulated participants’ decision criterion for reporting targets using different stimulus-response reward contingencies, inducing either a liberal or a conservative bias. Drift diffusion modeling revealed that a liberal strategy biased sensory evidence accumulation toward target-present choices. Moreover, a liberal bias resulted in stronger midfrontal pre-stimulus 2—6 Hz (theta) power and suppression of pre-stimulus 8—12 Hz (alpha) power in posterior cortex. Alpha suppression in turn was linked to the output activity in visual cortex, as expressed through 59—100 Hz (gamma) power. These findings show that observers can intentionally control cortical excitability to strategically bias evidence accumulation toward the decision bound that maximizes reward. KW - perceptual decision-making KW - decision bias KW - electroencephalography KW - neural oscillations KW - drift diffusion modeling KW - neural excitability JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -