Midbrain activity shapes high-level visual properties in the primate temporal cortex

Recent fMRI experiments identified an attention-related region in the macaque temporal cortex, here called the floor of the superior temporal sulcus (fSTS), as the primary cortical target of superior colliculus (SC) activity. However, it remains unclear which aspects of attention are processed by fSTS neurons and how or why these might depend on SC activity. Here, we show that SC inactivation decreases attentional modulations in fSTS neurons by increasing their activity for ignored stimuli in addition to decreasing their activity for attended stimuli. Neurons in the fSTS also exhibit event-related activity during attention tasks linked to detection performance, and this link is eliminated during SC inactivation. Finally, fSTS neurons respond selectively to particular visual objects, and this selectivity is reduced markedly during SC inactivation. These diverse, high-level properties of fSTS neurons all involve visual signals that carry behavioral relevance. Their dependence on SC activity could reflect a circuit that prioritizes cortical processing of events detected subcortically.

Automated summary

Recent fMRI experiments have identified the floor of the superior temporal sulcus (fSTS) in the macaque temporal cortex as the primary cortical target of superior colliculus (SC) activity in relation to attention. The inactivation of SC decreases attentional modulations in fSTS neurons by increasing their activity for ignored stimuli and decreasing their activity for attended stimuli. Furthermore, SC inactivation leads to a reduction in the selectivity of fSTS neurons for particular visual objects.