Outline 5.2 Re-evaluating the auditory where stream
- how and where
- how pathway could be similar to the language dorsal pathway, because motor interaction is needed for expressing
To-Do’s
- 55b vs FEF erklären
- theorie aufstellen, dass FEF mehr spatial und 55b mehr language ist
- dass beides wichtig ist
- how vs where
- hickok sensorimtoro iuntegration vielleicht mehr 55b
5.2 Re-evaluating the auditory where stream
5.2.1 The Spatial Link (‘Where’-Stream)
In the visual domain, FEF is strongly coupled with 7PC/7Am; in the auditory domain, however, FEF recruits inferior parietal regions (PF, PFop, PFcm) in the partial correlation, while still correlating with motion-sensitive area MST, possibly reflecting FEF’s role in supramodal motion integration. This dissociation aligns with the literature and with known differences in auditory and visual spatial network topology. The direct coupling with multisensory convergence hub TPOJ1 further supports this argumentation. Together, these patterns suggest that FEF functions as a shared supramodal controller that recruits modality-appropriate parietal regions. Rauschecker & Scott (2009) - Nature Neuroscience show that the auditory dorsal stream is spatial; the present analysis extends this view to the prefrontal level, proposing FEF as the attentional hub for audition.
Taken together, the selective coupling of FEF with inferior parietal and motion-sensitive regions positions it as the prefrontal controller of the auditory ‘where’-stream, operating through modality-appropriate cortical pathways.
5.2.2 The Motor Link (‘How’-Stream)
The FEF’s strongest direct connections in the auditory domain are premotor and frontal opercular (SCEF, 55b, area 43, FOP1, and FOP3) rather than the superior parietal regions associated with visual spatial attention. This is consistent with the view proposed by Hickok and Poeppel (2004), in which the dorsal auditory stream serves sound-to-action mapping rather than spatial localisation alone. This creates an honest tension: is FEF primarily a ‘where’ hub or a ‘how’ hub? The dominance of motor connections suggests that the dorsal stream may be better understood as a spatial-motor integration pathway, with FEF coordinating both spatial orienting and motor-action preparation, a view in which ‘where’ and ‘how’ are not mutually exclusive but complementary aspects of top-down auditory control.
5.2.3 55b as an Auditory-Motor Relay
Comparing 55b to FEF, 55b shows strong coupling with both FEF and IFJa, as well as regions of the ‘what’-stream. Notably, 55b maintains direct functional access to A4 and A5, whereas FEF does not, suggesting a functional division of labour: FEF encodes higher-order spatial information, while 55b serves as its acoustic relay into the auditory hierarchy. 55b may thus receive spatial commands from FEF and translate them into the semantic-auditory system. This is further supported by 55b’s stronger coupling with motor areas relative to FEF. Together, these findings suggest the dorsal stream is not monolithic but reflects a dissociation between FEF as a supramodal spatial-motor controller and 55b as an auditory-language integration hub.