L
Laurence P. Karper
Researcher at Lehigh Valley Hospital
Publications - 28
Citations - 4487
Laurence P. Karper is an academic researcher from Lehigh Valley Hospital. The author has contributed to research in topics: Ketamine & Wisconsin Card Sorting Test. The author has an hindex of 13, co-authored 28 publications receiving 4239 citations. Previous affiliations of Laurence P. Karper include Veterans Health Administration & Yale University.
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Journal ArticleDOI
Subanesthetic effects of the noncompetitive NMDA antagonist, ketamine, in humans: Psychotomimetic, perceptual, cognitive, and neuroendocrine responses.
John H. Krystal,Laurence P. Karper,John Seibyl,Glenna K. Freeman,Richard C. Delaney,J. Douglas Bremner,George R. Heninger,Malcolm B. Bowers,Dennis S. Charney +8 more
TL;DR: These data indicate that N-methyl-D-aspartate antagonists produce a broad range of symptoms, behaviors, and cognitive deficits that resemble aspects of endogenous psychoses, particularly schizophrenia and dissociative states.
Journal ArticleDOI
Interactive effects of subanesthetic ketamine and haloperidol in healthy humans.
John H. Krystal,Deepak Cyril D'Souza,Laurence P. Karper,A. Bennett,Anissa Abi-Dargham,Abi-Saab D,Cassello K,M. B. Bowers,Vegso S,George R. Heninger,Dennis S. Charney +10 more
TL;DR: Haloperidol pretreatment reduced impairments in executive cognitive functions produced by ketamine as measured by proverb interpretations and the Wisconsin Card Sorting Test, but it failed to block the capacity of ketamine to produce psychosis, perceptual changes, negative symptoms, or euphoria in healthy subjects.
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Interactive effects of subanesthetic ketamine and subhypnotic lorazepam in humans.
John H. Krystal,Laurence P. Karper,A. Bennett,Deepak Cyril D'Souza,Anissa Abi-Dargham,K. Morrissey,Abi-Saab D,J. D. Bremner,M. B. Bowers,Raymond F. Suckow,Stetson P,George R. Heninger,Dennis S. Charney +12 more
TL;DR: Data suggest that subhypnotic lorazepam and ketamine show a spectrum of interactive effects, ranging from antagonism to potentiation.
Journal ArticleDOI
Dissociation of ketamine effects on rule acquisition and rule implementation: possible relevance to NMDA receptor contributions to executive cognitive functions
John H. Krystal,A. Bennett,D. Abi-Saab,Aysenil Belger,Laurence P. Karper,D. Cyril D’Souza,Deborah S. Lipschitz,Anissa Abi-Dargham,Dennis S. Charney +8 more
TL;DR: This report contains two studies designed to examine N-methyl-D-aspartate (NMDA) receptor contributions to the executive components of WCST performance, which further implicates NMDA receptors in executive cognitive functions associated with the frontal cortex.
Journal ArticleDOI
Dose-Related Ethanol-like Effects of the NMDA Antagonist, Ketamine, in Recently Detoxified Alcoholics
John H. Krystal,Ismene L. Petrakis,Elizabeth Webb,Ned L. Cooney,Laurence P. Karper,Sheila N. Namanworth,Philip Stetson,Louis Trevisan,Dennis S. Charney +8 more
TL;DR: The production of ethanol-like subjective effects by ketamine supports the potential clinical importance of NMDA receptor antagonism among the mechanisms underlying the subjective effects of ethanol in humans.