Parietal influence on temporal encoding indexed by simultaneous transcranial magnetic stimulation and...

Area of Science:

• Neuroscience
• Cognitive Psychology
• Psychophysics

Background:

• Contingent negative variation (CNV) from electroencephalography (EEG) may indicate temporal encoding.
• Previous interpretations are limited by concurrent decision-making and action preparation.
• Repetitive transcranial magnetic stimulation (rTMS) of the right supramarginal gyrus (rSMG) previously lengthened perceived visual stimulus duration.

Purpose of the Study:

• To replicate the effect of rTMS on perceived duration.
• To investigate the neural correlates of temporal encoding using simultaneous EEG.
• To determine if CNV indexes stimulus duration encoding.

Main Methods:

• Replication of rTMS on the rSMG during visual stimulus duration encoding.
• Simultaneous electroencephalography (EEG) recording of N1 and CNV components.
• Correlation analysis between rTMS effect size, CNV amplitude, and response bias.

Main Results:

• rTMS stimulation of the rSMG increased perceived stimulus duration.
• EEG recordings showed increased N1 and CNV amplitudes post-rTMS.
• CNV amplitude, not N1, positively correlated with the rTMS-induced duration change and negatively with response bias.

Conclusions:

• The findings support the role of the rSMG in basic temporal encoding.
• CNV amplitude appears to specifically index stimulus duration encoding.
• A feedforward mechanism from parietal to prefrontal regions may mediate temporal encoding.
• Distinct early and late phases of temporal encoding processes are suggested.