In two groups, positive feedback was provided on some trials such that listeners believed their response was correct.
However, even if the two stimuli are close to one another, on some trials the noise in the perception of the auditory stimulus will sometimes lead to the perception of distinct causes.
On some trials one of the objects changed position after movement onset.
On some trials, one of the pre-masks at the location of the upcoming search objects grew rapidly in size, creating the appearance of a "looming" target or distractor.
On some trials, we changed the difficulty of one option mid-trial to invite (but not force) the monkey to change his mind.
For both architectures we test the novel hypothesis that participants break the decision rules on some trials, making a response based on only one stimulus even though task instructions require them to consider both.
To simulate the reduced sensitivity to high spatial frequencies, on some trials we blurred our stimuli.
On some trials, subjects report seeing the stimuli, while on others they don't.
On some trials a cue typically predicting a standard was in fact followed by an unexpected novel stimulus.
On some trials, participants bore the full brunt of a loss if the risky reward was chosen and lost.
On some trials, several seconds prior to stimulus onset, a cue indicated which task was to be performed.
