@article {Kloosterman229989, author = {Niels A. Kloosterman and Jan Willem de Gee and Markus Werkle-Bergner and Ulman Lindenberger and Douglas D. Garrett and Johannes Jacobus Fahrenfort}, title = {Humans strategically shift decision bias by flexibly adjusting sensory evidence accumulation in visual cortex}, elocation-id = {229989}, year = {2018}, doi = {10.1101/229989}, publisher = {Cold Spring Harbor Laboratory}, abstract = {Decision bias is traditionally conceptualized as a flexible internal reference against which sensory evidence is compared. Here, in contrast, we show that experimental manipulation of decision bias adjusts the rate of evidence accumulation in visual cortex towards one of the choice alternatives. Participants performed a visual detection task during EEG recordings. We experimentally manipulated participants{\textquoteright} response criterion using different stimulus-response reward contingencies, inducing liberal and conservative decision biases in different conditions. Drift diffusion modeling of choice behavior revealed that an experimentally induced liberal decision bias specifically biased the rate of sensory evidence accumulation towards {\textquoteleft}yes{\textquoteright} choices. In visual cortex, the liberal bias manipulation suppressed prestimulus 8{\textemdash}12 Hz (alpha) power, which in turn boosted cortical stimulus-related activity in the 59{\textemdash}100 Hz (gamma) range. Together, these findings show that observers can intentionally control cortical excitability to strategically bias evidence accumulation towards the decision bound that maximizes reward within a given ecological context.}, URL = {https://www.biorxiv.org/content/early/2018/04/06/229989}, eprint = {https://www.biorxiv.org/content/early/2018/04/06/229989.full.pdf}, journal = {bioRxiv} }