Effects of subanesthetic doses of ketamine on sensorimotor information processing in healthy subjects.
Ketamine, an antagonist N-Methyl-D-Aspartate receptor, induces a broad range of anomalies in healthy subjects similar to those observed in psychosis. Previous studies have shown that information sensorimotor processing was impaired in patients with schizophrenia. The aim of the study was to assess the effects of subanesthetic doses of ketamine on behavior symptoms and information processing in healthy volunteers. A double-blind, crossover, placebo-controlled study was performed with eight subjects. Brief Psychiatric Rating Scale, Scale for the Assessment of Negative Symptoms, and Scale for the Assessment of Positive Symptoms assessed behavior changes. Information processing was assessed using a choice reaction time. Three experimental factors (stimulus intensity, stimulus response compatibility, and foreperiod duration) chosen to affect a different stage of information processing were manipulated. Our study has demonstrated that administration of ketamine produced significant effects on Brief Psychiatric Rating Scale, Scale for the Assessment of Negative Symptoms, and Scale for the Assessment of Positive Symptoms scores. Results on choice reaction time demonstrated a significant longer reaction time under ketamine. Effects of stimulus intensity and compatibility stimulus response were similar under ketamine and under placebo. Moreover, there was a specific interaction between ketamine and foreperiod. This interaction indicated that foreperiod's effect was more prolonged under ketamine (29 ms) than under placebo (17 ms). These results showed that the clinical effects of ketamine were associated with schizophrenic-like impairments on choice reaction time in healthy subjects.
Micallef
Joëlle
J
Center de Pharmacologie Clinique et d'Evaluations Thérapeutiques et Service de Pharmacologie Clinique, UMR-CNRS-FRE-Université de la Méditerranée, Développement et Pathologie du Mouvement, Hôpital de la Timone, Marseille, France.
Guillermain
Yves
Y
Tardieu
Sophie
S
Hasbroucq
Thierry
T
Possamaï
Camille
C
Jouve
Elisabeth
E
Blin
Olivier
O
D000328:Adult; D000704:Analysis of Variance; D000778:Anesthetics, Dissociative / Q000008:administration & dosage* / Q000009:adverse effects; D001143:Arousal / Q000187:drug effects / Q000502:physiology; D010054:Brief Psychiatric Rating Scale / Q000706:statistics & numerical data; D002755:Choice Behavior / Q000187:drug effects / Q000502:physiology; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007649:Ketamine / Q000008:administration & dosage* / Q000009:adverse effects; D008297:Male; D008606:Mental Processes / Q000187:drug effects* / Q000502:physiology; D011597:Psychomotor Performance / Q000187:drug effects* / Q000502:physiology; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D012559:Schizophrenia / Q000139:chemically induced; D018709:Statistics, Nonparametric
D000778:Anesthetics, Dissociative; D007649:Ketamine