The Role of Temporal Cortex and Superior Colliculus in Attention Networks: A Human and Macaque Comparison

Abstract

The significance of temporal cortex areas in attention control, which has traditionally been neglected in conventional attention research, has gained prominent attention thanks to the efforts of numerous research groups. The concept of a temporal attention network has been increasingly supported by a growing body of evidence, lending more credence to its existence. In particular, the significance of the fundus of the superior temporal sulcus (FST) and the posterior inferotemporal region (PIT) has ignited debates around anatomical and functional homologue between humans and macaques. In our series of projects, we have deconstructed this conversation to provide clarifying insights that go beyond semantics, unveiling distinct functional dynamics of these regions. In the first project, we detected occipito-temporal areas activations in concomitance to a covert attentional task, consistent with cortical areas at the posterior portion of the temporal cortex reported in other recent studies. Furthermore, we identified task-related activations in the Superior Colliculus (SC), in addition to evidence in favour of somatosensory-driven activations in the deep layers of the SC. In the second project we investigated stimulus-independent attentional effects in the human FST and surrounding temporal areas in response to a covert attentional task. We found strong lateralization of attention-related signals in FST, PIT and neighboring areas for motion and white noise stimuli. We observed significant activations related to attentional shifts to the contralateral visual field in the Superior Colliculus, and a significant effect for motion but not for white noise stimuli for the ‘attend vs ignore’ contrast. These results detail temporal nodes of attention that were largely unnoticed in earlier studies on covert shifts of visual attention in humans. In the third project we provided evidence supporting the idea that FST is a functionally homologous area in monkey and humans. We described its connectivity with critical hubs in the attention control network such as the SC, the frontal eye fields (FEF), and regions of the intraparietal sulcus (IPS) in macaques and confirmed these findings in humans. Moreover, we investigated the functional connectivity of PIT in humans, the second temporal cortex area recently reported to be a key player in human and macaque attention control. We discovered that PIT was also connected to areas which are crucial for attention control, such as FEF, LIP and SC. Finally, we studied which regions of the human brain exhibit stronger connectivity with either one of these areas. We found that FST exhibits stronger connectivity with regions of the dorsal attention network whereas PIT shows stronger connectivity with regions of the ventral attention network. In conclusion, we present evidence suggesting that the FST is functionally homologous in humans and macaques, proposing a resolution on the existing disparity in literature about the counterpart of this region in humans. Furthermore, FST exhibits a unique functional role which makes it distinct from PIT. Both regions in humans have a clear and consistent connections with other well-established cortical attention networks, while in monkeys the frontal and parietal connections are more pronounced for FST. In macaques the FST is strongly connected to the SC, while in humans both FST and PIT are connected to the SC. This supports the notion that this temporal hub for attention control is relatively preserved across species in its subcortical connections, while its cortical connections are more species- specific, with greater divergence in the human brain

Die Dissertation ist gesperrt bis zum 26. November 2026 !