The parietal cortex has a causal role in ambiguity computations in humans

Area of Science:

• Neuroscience
• Cognitive Science
• Decision Science

Background:

• Decision-making under ambiguity presents a significant challenge for humans.
• The parietal cortex's role in processing ambiguity is not fully understood.
• Previous research links parietal activity to ambiguity but lacks causal evidence.

Purpose of the Study:

• To investigate the causal role of the parietal cortex in computing ambiguous probabilities.
• To determine how parietal cortex activity relates to uncertainty estimation during decision-making.
• To explore the interaction between the parietal cortex and other brain regions like the midcingulate cortex (MCC).

Main Methods:

• Utilized functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation combined with electroencephalography (TMS-EEG).
• Assessed participants' assignment of objective probabilities to ambiguous options.
• Intervened using TMS-EEG to disrupt parietal cortex activity and observed effects on decision-making and neural oscillations.

Main Results:

• Parietal cortex activity correlated with objective ambiguity levels and a tendency to underestimate uncertainty.
• Disruption of the parietal cortex led to increased uncertainty evaluation of decision options.
• Intervention decreased midcingulate cortex (MCC) oscillations during outcome evaluation and lateral frontal oscillations related to value.

Conclusions:

• The parietal cortex plays a causal role in computing uncertainty during ambiguous decision-making.
• Parietal cortex function influences how individuals perceive and weigh uncertain probabilities.
• Findings elucidate the neural mechanisms underlying human decision-making under ambiguity.