Modeling the effects of nicotine on a continuous performance task

We have developed a neurocomputational model of some attentional effects of nicotine. Our simulations reproduce results showing smoking abstinence to impair performance on a rapid visual information processing task involving detecting sequences of even or odd digits. Our model treats presence of nicotine as enhancement of modulatory acetylcholine signals, which focus attention on task-relevant stimuli. Our network includes cholinergic signals from nucleus basalis; working memory representations in dorsolateral prefrontal cortex; inputs to nucleus basalis from entorhinal cortex; and recency signals. Digits are represented at entorhinal, nucleus basalis, and dorsolateral levels, along with dorsolateral representations of the concepts even" and "odd." (C) 2003 Elsevier Science B.V. All rights reserved.