Left prefrontal cortex control of novel occurrences during recollection: a psychopharmacological study using scopolamine and event-related fMRI

Neuroimage. 2006 Oct 15;33(1):286-95. doi: 10.1016/j.neuroimage.2006.06.044. Epub 2006 Aug 17.

Abstract

Recollection and familiarity represent two processes involved in episodic memory retrieval. We investigated how scopolamine (an antagonist of acetylcholine muscarinic receptors) influenced brain activity during memory retrieval, using a paradigm that separated recollection and familiarity. Eighteen healthy volunteers were recruited in a randomized, placebo-controlled, double-blind design using event-related fMRI. Participants were required to perform a verbal recognition memory task within the scanner, either under placebo or scopolamine conditions. Depending on the subcondition, participants were required to make a simple recognition decision (old/new items) or base their decision on more specific information related to prior experience (target/non-target/new items). We show a drug modulation in left prefrontal and perirhinal cortex during recollection. Such an effect was specifically driven by novelty and showed an inverse correlation with accuracy performance. Additionally, we show a direct correlation between drug-related signal change in left prefrontal and perirhinal cortices. We discuss the findings in terms of acetylcholine mediation of the familiarity/novelty signal through perirhinal cortex and the control of the relative signal strength through prefrontal cortex.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Color
  • Double-Blind Method
  • Female
  • Humans
  • Image Processing, Computer-Assisted
  • Magnetic Resonance Imaging
  • Male
  • Mental Recall / drug effects*
  • Mental Recall / physiology*
  • Muscarinic Antagonists / pharmacology*
  • Oxygen / blood
  • Parasympathetic Nervous System / drug effects
  • Parasympathetic Nervous System / physiology
  • Prefrontal Cortex / drug effects*
  • Prefrontal Cortex / physiology*
  • Reaction Time / drug effects
  • Reading
  • Scopolamine / pharmacology*
  • Space Perception / physiology
  • Stereotaxic Techniques

Substances

  • Muscarinic Antagonists
  • Scopolamine
  • Oxygen