sentences:  They also tested the idea of cultural brand identity and its impact on reward prediction error signals.With Brooks King-Casas and colleagues, Montague later applied the same social exchange approach as a probe of Borderline Personality Disorder, and these efforts have been used to provide a new probe of psychopathology.Montague and colleagues have further investigated the computational nature of dopamine as well as serotonin signals by making the first measurements of sub-second dopamine and serotonin fluctuations in the striatum of conscious human subjects.