Adjustments of response threshold during task switching: a model-based functional magnetic resonance imaging study

Area of Science:

• Neuroscience
• Cognitive Psychology

Background:

• Response threshold adjustments in decision-making involve the fronto-striatal network (pre-SMA, striatum) and subthalamic nucleus (STN).
• Previous research links speed-accuracy trade-offs to pre-SMA/striatum activation and response conservatism to STN activation.

Purpose of the Study:

• Investigate the role of pre-SMA, striatum, and STN in trial-by-trial response threshold adjustments during human task switching.
• Examine how different cue types (repeat vs. switch) influence response thresholds and associated neural activation patterns.

Main Methods:

• Utilized a cued-trials task-switching paradigm in human participants.
• Measured brain activation using fMRI (implied) and analyzed its correlation with response threshold variability across cue types.

Main Results:

• Switch cues led to more conservative thresholds and higher right STN activation compared to repeat cues.
• Repeat cues showed higher pre-SMA and striatal activation.
• Individual differences in response threshold correlated with pre-SMA activation (higher activation, lower threshold).
• Striatal activation showed this relationship only for repeat cues.

Conclusions:

• Pre-SMA influences the striatum to lower response thresholds under liberal conditions (repeat cues).
• Right STN activation increases response caution under conservative conditions (switch cues).
• Neural models of response threshold adjustment are crucial for understanding executive control in task switching.