Sensorimotor transformation deficits for smooth pursuit in first-episode affective psychoses and schizophrenia.
BACKGROUND
Smooth pursuit deficits are an intermediate phenotype for schizophrenia that may result from disturbances in visual motion perception, sensorimotor transformation, predictive mechanisms, or alterations in basic oculomotor control. Which of these components are the primary causes of smooth pursuit impairments and whether they are impaired similarly across psychotic disorders remain to be established.


METHODS
First-episode psychotic patients with bipolar disorder (n = 34), unipolar depression (n = 24), or schizophrenia (n = 77) and matched healthy participants (n = 130) performed three smooth pursuit tasks designed to evaluate different components of pursuit tracking.


RESULTS
On ramp tasks, maintenance pursuit velocity was reduced in all three patients groups with psychotic bipolar patients exhibiting the most severe impairments. Open loop pursuit velocity was reduced in psychotic bipolar and schizophrenia patients. Motion perception during pursuit initiation, as indicated by the accuracy of saccades to moving targets, was not impaired in any patient group. Analyses in 138 participants followed for 6 weeks, during which patients were treated and psychotic symptom severity decreased, and no significant change in performance in any group was revealed.


CONCLUSIONS
Sensorimotor transformation deficits in all patient groups suggest a common alteration in frontostriatal networks that dynamically regulate gain control of pursuit responses using sensory input and feedback about performance. Predictive mechanisms appear to be sufficiently intact to compensate for this deficit across psychotic disorders. The absence of significant changes after acute treatment and symptom reduction suggests that these deficits appear to be stable over time.
Center for Cognitive Medicine, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
Rebekka
R
Lencer
James L
JL
Reilly
Margret S
MS
Harris
Andreas
A
Sprenger
Matcheri S
MS
Keshavan
John A
JA
Sweeney
D000293:Adolescent; D000328:Adult; D000341:Affective Disorders, Psychotic / Q000150:complications* / Q000188:drug therapy; D014150:Antipsychotic Agents / Q000494:pharmacology / Q000627:therapeutic use; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009039:Motion Perception / Q000502:physiology; D009483:Neuropsychological Tests; D015835:Ocular Motility Disorders / Q000188:drug therapy / Q000209:etiology*; D010775:Photic Stimulation / Q000379:methods; D011569:Psychiatric Status Rating Scales; D011597:Psychomotor Performance / Q000187:drug effects / Q000502:physiology*; D011698:Pursuit, Smooth / Q000187:drug effects / Q000502:physiology*; D011930:Reaction Time; D012559:Schizophrenia / Q000150:complications* / Q000188:drug therapy; D014794:Visual Fields; D055815:Young Adult
D014150:Antipsychotic Agents