The neural processes underlying perceptual decision making in humans: recent progress and future directions

Area of Science:

• Neuroscience
• Cognitive Science
• Mathematical Psychology

Background:

• Animal neurophysiology identified neural 'decision variables' integrating noisy sensory data for adaptive action.
• Mathematical psychology predicted these decision variables, guiding the search in human brains.

Purpose of the Study:

• To review progress in tracing perceptual decision dynamics in humans using neuroimaging.
• To investigate the neural basis of decision formation in perceptual tasks.
• To highlight limitations of non-invasive techniques and present novel findings.

Main Methods:

• Review of functional imaging and electrophysiology studies on human decision-making.
• Analysis of event-related potentials (ERPs) during continuous-monitoring perceptual tasks (intensity change detection, motion discrimination).
• Focus on a specific neural signal, the centro-parietal positivity (CPP).

Main Results:

• A neural instantiation of the decision variable, the CPP, was directly traced in ERPs.
• The CPP reflects a domain-general process, independent of specific sensory or motor task demands.
• CPP dynamics correlate with decision outcomes and reaction times.

Conclusions:

• The CPP serves as a neural correlate of the theoretical decision variable in humans.
• Simple experimental designs can reveal this neural process, advancing decision-making research.
• Findings have implications for understanding normal and abnormal human decision-making.