Using transcranial direct current stimulation (tDCS) to influence decision criterion in a target detection paradigm

Area of Science:

• Cognitive Neuroscience
• Psychology
• Neurostimulation

Background:

• Perceptual learning and face recognition are modeled by psychological theories.
• Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique.

Purpose of the Study:

• To investigate if anodal tDCS over the dorsolateral prefrontal cortex (DLPFC) modulates the decision criterion (C) in a target detection task.
• To test if tDCS affects C and not d-prime (d') based on psychological theory.

Main Methods:

• Two between-subjects, double-blind experiments (n=112) were conducted.
• Participants performed a target detection task with artificial checkerboard (Exp 1a) and face stimuli (Exp 1b).
• Anodal tDCS was applied over the DLPFC (Fp3 site) for 10 minutes at 1.5 mA, compared to a sham condition.

Main Results:

• In sham groups, a higher decision criterion (C) was used for familiar versus random backgrounds.
• Anodal tDCS significantly reduced or reversed this difference in C for both familiar and random backgrounds.
• tDCS did not affect d-prime (d'), indicating no change in sensitivity.

Conclusions:

• Anodal tDCS over the DLPFC modulates the decision criterion (C) in target detection tasks.
• These findings advance understanding of tDCS effects on stimulus representation and decision-making.
• The results support the application of psychological theories to predict tDCS effects.