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Electrophysiological and brain imaging studies have shown that different populations of neurons contribute to perceptual decision making. Perceptual judgment is a complicated process that has several subprocesses, including the final step of a discrete choice among available possibilities. Using the psychophysical paradigm of difference scaling combined with functional magnetic resonance imaging, we identify an area within a distributed representation that is consistently invoked in perceptual decision. Difference judgments based on visual (color, form, and motion) cues and auditory cues show that a population of neurons in the posterior banks of the intraparietal sulcus (PIPS) is consistently activated for perceptual judgment across visual attributes and sensory modalities, suggesting that those neurons in PIPS are associated with perceptual judgment.