Cortical Activation to Auditory Mismatch Elicited by Frequency Deviant and Complex Novel Sounds: A PET Study

• Published in: NeuroImage (Orlando, Fla.) Vol. 17; no. 1; pp. 231 - 239
• Main Authors: Müller, B.W., Jüptner, M., Jentzen, W., Müller, S.P.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.09.2002; Elsevier Limited
• Subjects: Acoustic Stimulation; Adult; Auditory Cortex - diagnostic imaging; Auditory Cortex - physiology; Auditory Perception - physiology; auditory processing; Cerebrovascular Circulation - physiology; Discrimination (Psychology) - physiology; Electroencephalography; Functional Laterality - physiology; Humans; Image Processing, Computer-Assisted; Magnetoencephalography; Memory, Short-Term - physiology; mismatch negativity; novelty processing; P3a; positron emission tomography; Temporal Lobe - blood supply; Temporal Lobe - physiology; Tomography, Emission-Computed; Visual Perception - physiology; mismatch negativity; novelty processing; auditory processing; positron emission tomography; P3a
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1006/nimg.2002.1176

The analysis of auditory deviant events outside the focus of attention is a fundamental capacity of human information processing and has been studied in experiments on Mismatch Negativity (MMN) and the P3a component in evoked potential research. However, generators contributing to these components are still under discussion. Here we assessed cortical blood flow to auditory stimulation in three conditions. Six healthy subjects were presented with standard tones, frequency deviant tones (MMN condition), and complex novel sounds (Novelty condition), while attention was directed to a nondemanding visual task. Analysis of the MMN condition contrasted with the standard condition revealed blood flow changes in the left and right superior temporal gyrus, right superior temporal sulcus and left inferior frontal gyrus. Complex novel sounds contrasted with the standard condition activated the left superior temporal gyrus and the left inferior and middle frontal gyrus. A small subcortical activation emerged in the left parahippocampal gyrus and an extended activation was found covering the right superior temporal gyrus. Novel sounds activated the right inferior frontal gyrus when controlling for deviance probability. In contrast to previous studies our results indicate a left hemisphere contribution to a frontotemporal network of auditory deviance processing. Our results provide further evidence for a contribution of the frontal cortex to the processing of auditory deviance outside the focus of directed attention.