Speaker
Description
Everyday tasks require a series of actions aimed at achieving goals, with decision-making processes guiding timing, execution, and adjustment of actions in response to changes. We investigated how decision-making processes relate to motor-control, and – in particular – to motor-response execution. Participants completed visual lexical decision tasks where they were instructed to categorize strings of letters as words or pseudowords by pressing buttons with their thumbs. Single-trial electromyographic (EMG) traces were used to partition reaction times (RTs) into pre-motor (PMTs) and motor times (MTs). In a first experiment, participants were directed to prioritize either speed or accuracy. This speed-accuracy tradeoff (SAT) manipulation affected both PMTs and MTs, with the latter effect hinting towards the involvement of online response control mechanisms in the overall SAT effects. Pseudowords elicited slower responses compared to words, impacting both PMTs and MTs. Crucially, there was no interaction between lexicality and SAT conditions, suggesting independent underlying mechanisms. In a second study, the proportion of pseudowords (and words) (.25, .50, or .75) was manipulated across blocks, in order to manipulate response bias, over and above the lexical status of the stimuli. Although data collection is still ongoing, the predictions point towards a reversal of the lexicality effect on MTs, when pseudowords are the most frequent stimuli, due to the reduction of the inherent uncertainty characterizing these stimuli. In general, these results provide insight into the functional specification of the decisional elements within motor-response execution as well as links connections with response monitoring and confidence.
| If you're submitting a poster, would you be interested in giving a blitz talk? | No |
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| If you're submitting a symposium, or a talk that is part of a symposium, is this a junior symposium? | No |
