Abstracts - Association for Chemoreception Sciences

#P356 POSTER SESSION VII:
OLFACTORY PSYCHOPHYSICS &
CLINICAL STUDIES; CENTRAL OLFACTION
Odor Coding in the Human Brain: Effect of Expectation
Jane Plailly 1 , James D Howard 2 , Jay A Gottfried 2,3
1
UMR 5020 CNRS - Université Lyon 1 Lyon, France,
2
Department of Neurology, Northwestern University Feinberg
School of Medicine Chicago, IL, USA, 3 Department of Psychology,
Northwestern University Weinberg College of Arts and Sciences
Evanston, IL, USA
There is limited evidence to suggest that cognitive context shapes
odor quality perception. Freeman and colleagues have proposed
that odor expectation induces spatial patterns or “templates” in
the olfactory bulb, that set up subsequent perception of the input.
To explore putative mechanisms of odor template matching in the
human brain, we conducted a multivariate functional magnetic
resonance imaging (fMRI) study to investigate whether odorevoked
ensemble activity in primary olfactory (piriform) cortex
(PC) depends on which odor subjects expect to smell. Odor
expectation was manipulated using semantically congruent or
incongruent picture cues that preceded delivery of odor.
Behavioral analysis based on 6 subjects (and 6 odorants)
demonstrated a robust expectancy effect: odor detection was
faster in congruent trials (e.g., mint picture / mint odor) than in
incongruent trials (e.g., rose picture / mint odor) (P