Task-modulated “what” and “where” pathways in human auditory cortex

Abstract

Human neuroimaging studies suggest that localization and identification of relevant auditory objects are accomplished via parallel parietal-to-lateral-prefrontal ''where'' and anterior-temporal-toinferior-frontal ''what'' pathways, respectively. Using combined hemodynamic (functional MRI) and electromagnetic (magnetoencephalography) measurements, we investigated whether such dual pathways exist already in the human nonprimary auditory cortex, as suggested by animal models, and whether selective attention facilitates sound localization and identification by modulating these pathways in a feature-specific fashion. We found a double dissociation in response adaptation to sound pairs with phonetic vs. spatial sound changes, demonstrating that the human nonprimary auditory cortex indeed processes speech-sound identity

Objective phonological and subjective perceptual characteristics of syllables modulate spatiotemporal patterns of superior temporal gyrus activity

“…The importance of aSTG in sublexical language processing is consistent with other functional imaging research (Ahveninen et al, 2006;Guenther et al, 2004;Hewson-Stoate et al, 2006;Uppenkamp et al, 2006). With the evidence that the aSTG is associated with the 'what' auditory stream and the fact that this area is activated by specific types of language Meyers et al, 2000;Noesselt et al, 2003) and non-language auditory stimuli (Altmann et al, 2007;Barrett and Hall, 2006;Koelsch et al, 2002;Patterson et al, 2002;Warren and Griffiths, 2003), certain authors have proposed that areas within the aSTG are important for categorizing behaviorally relevant classes of auditory objects (Obleser et al, 2006).…”

“…The STG was divided into two regions: one anterior of Heschl's gyrus (HG) (aSTG) and the other which included HG and regions posterior to HG (mpSTG). This division was based upon recent MEG data that implicate the area just anterior to HG as sensitive to change in phoneme content (i.e., "what" auditory stream) and the area just posterior to HG as sensitive to change in phoneme location (i.e., "where" auditory steam; Ahveninen et al, 2006). The aSTG ROI was manually defined on each individual participant's brain by defining the regions along the inferior bank of the Sylvian fissure anterior to HG, extending medial to the circular sulcus, lateral to the crest of the STG gyrus and anterior to the temporal pole.…”

“…By means of MEG, areas in the anterior portion of the left temporal gyrus have been identified as important and specific for syllable recognition and discrimination (Ahveninen et al, 2006). Similar areas have been found to correlate with the intelligibility of systematically distorted speech (Davis and Johnsrude, 2003).…”

“…Such speech features are acoustically complex, requiring processing at many cortical levels including bottom-up sensory and top-down higher order language areas (Bonte et al, 2006). Intracranial recordings, functional magnetic resonance imaging (fMRI), positron emission tomography (PET) and magnetoencephalography (MEG) studies suggest that cortical areas important for syllable perception include areas within the frontal and parietal cortices, the middle temporal gyrus, and regions in the superior temporal gyrus (STG) that lie anterior and posterior to the primary auditory cortices, including the planum polare (PP) and Brodmann's area (BA) 22 (Ahveninen et al, 2006;Scott and Wise, 2004;Uppenkamp et al, 2006;Guenther et al, 2004).…”

Attentional Modulation of Spatial Integration of Pain: Evidence for Dynamic Spatial Tuning

“…However, the spatial structure of the receptive field changes as a function of time and can be modulated by cognitive factors such as attention (Compte and Wang, 2006). Task dependent tuning of receptive fields is found across visual (McAdams and Maunsell, 1999), auditory (Ahveninen et al, 2006), and somatosensory (Hayes et al, 1981) systems. Such tuning is associated with altered perceptual experiences as indicated by more frequent and more accurate detection of stimuli (Braun et al, 2002;Quraishi et al, 2006).…”