The neural correlates of implicit sequence learning in schizophrenia

Neuropsychology. 2007 Nov;21(6):761-77. doi: 10.1037/0894-4105.21.6.761.


Twenty-seven schizophrenia spectrum patients and 25 healthy controls performed a probabilistic version of the serial reaction time task (SRT) that included sequence trials embedded within random trials. Patients showed diminished, yet measurable, sequence learning. Postexperimental analyses revealed that a group of patients performed above chance when generating short spans of the sequence. This high-generation group showed SRT learning that was similar in magnitude to that of controls. Their learning was evident from the very 1st block; however, unlike controls, learning did not develop further with continued testing. A subset of 12 patients and 11 controls performed the SRT in conjunction with positron emission tomography. High-generation performance, which corresponded to SRT learning in patients, correlated to activity in the premotor cortex and parahippocampus. These areas have been associated with stimulus-driven visuospatial processing. Taken together, these results suggest that a subset of patients who showed moderate success on the SRT used an explicit stimulus-driven strategy to process the sequential stimuli. This adaptive strategy facilitated sequence learning but may have interfered with conventional implicit learning of the overall stimulus pattern.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Brain Mapping*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Neuropsychological Tests
  • Photic Stimulation / methods
  • Positron-Emission Tomography / methods
  • Reaction Time / physiology
  • Schizophrenia / diagnostic imaging
  • Schizophrenia / pathology*
  • Schizophrenia / physiopathology*
  • Serial Learning / physiology*