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A Cortical Network Sensitive to Stimulus Salience in a Neutral Behavioral Context Across Multiple Sensory Modalities
Ist Teil von
Journal of neurophysiology, 2002-01, Vol.87 (1), p.615-620
Ort / Verlag
United States: Am Phys Soc
Erscheinungsjahr
2002
Quelle
Free E-Journal (出版社公開部分のみ)
Beschreibungen/Notizen
1 Institute of Medical Science,
2 Department of Medical Imaging, and
3 Department of Surgery, University of
Toronto; and 4 Toronto Western Research
Institute, Toronto Western Hospital, Toronto, Ontario M5T 2S8, Canada
Downar, Jonathan,
Adrian P. Crawley,
David
J. Mikulis, and
Karen D. Davis.
A Cortical Network Sensitive to Stimulus Salience in a Neutral
Behavioral Context Across Multiple Sensory Modalities. J. Neurophysiol. 87: 615-620, 2002. Stimulus
salience depends both on behavioral context and on other factors such
as novelty and frequency of occurrence. The temporo-parietal junction
(TPJ) responds preferentially to behaviorally relevant stimuli and is
thought to play a general role in detecting salient stimuli. If so, it
should respond preferentially to novel or infrequent events, even in a
neutral behavioral context. To test this hypothesis, we used
event-related functional magnetic resonance imaging (fMRI) to identify
brain regions sensitive to the novelty of visual, auditory, and tactile
stimuli during passive observation. Cortical regions with a greater
response to novel than familiar stimuli across all modalities were
identified at two sites in the TPJ region: the supramarginal gyrus
(SMG) and superior temporal gyrus. The right inferior frontal gyrus
(IFG), right anterior insula, left anterior cingulate cortex (ACC), and left inferior temporal gyrus also showed sensitivity to novelty. The
novelty-sensitive TPJ activation in SMG overlaps a region previously
identified as sensitive behavioral context. This region may play a
general role in identifying salient stimuli, whether the salience is
due to the current behavioral context or not. The IFG activation
overlaps regions previously identified as responsive to nonnovel
sensory events regardless of behavioral context. The IFG may therefore
play a general role in stimulus evaluation rather than a specific role
in identifying novel stimuli. The ACC activation lies in a region
active during complex response-selection tasks, suggesting a general
role in detecting and/or planning responses to salient events. A
frontal-parietal-cingulate network may serve to identify and evaluate
salient sensory stimuli in general.