Figure 1: Auditory cortical processing stages and illustrated hypotheses.
From: Different forms of effective connectivity in primate frontotemporal pathways
(a) Schematic of the known macaque auditory cortical hierarchy. For the definition of abbreviations for the different auditory cortical fields, see ref. 49. More ventral to these auditory regions (in the upper bank of the superior temporal sulcus, STS) are multisensory regions and further ventral (in the fundus and lower bank of the STS) are visual areas. (b,c) Illustrated hypotheses of aSTP effective connectivity. (b) Hypothesis 1 illustrates that stimulation of aSTP (red arrows) results mainly in anterior temporal lobe activity. (c) Hypothesis 2 illustrates that aSTP stimulation (red arrows) also activates orbital/medial frontal cortex (OFC/MPFC). Note that stimulation of other brain areas such as the lateral belt can help to evaluate to what extent combined microstimulation and fMRI recapitulates key findings from neuronal tractography studies. Thereby, in both hypotheses, we illustrate findings that could be consistent with neuronal tractography results, such as: ventrolateral prefrontal cortex (VLPFC) projections from anterior lateral belt fields5,25 in blue arrows and dorsolateral prefrontal cortex (DLPFC) projections from caudal lateral belt fields5,25 in green arrows; also shown in yellow arrows are aSTS projections to OFC or medial prefrontal cortex (MPFC)8,27; see text for further details.
