Abstract
The mammalian tongue contains gustatory receptors tuned to basic taste types, providing an evolutionarily old hedonic compass for what and what not to ingest. Although representation of these distinct taste types is a defining feature of primary gustatory cortex in other animals, their identification has remained elusive in humans, leaving the demarcation of human gustatory cortex unclear. Here we used distributed multivoxel activity patterns to identify regions with patterns of activity differentially sensitive to sweet, salty, bitter, and sour taste qualities. These were found in the insula and overlying operculum, with regions in the anterior and middle insula discriminating all tastes and representing their combinatorial coding. These findings replicated at super-high 7 T field strength using different compounds of sweet and bitter taste types, suggesting taste sensation specificity rather than chemical or receptor specificity. Our results provide evidence of the human gustatory cortex in the insula.
Highlights
The mammalian tongue contains gustatory receptors tuned to basic taste types, providing an evolutionarily old hedonic compass for what and what not to ingest
Sweet receptors aid in selection of energy-rich nutrients and bitter receptors guard against the intake of the potentially noxious, serving as the basis for oral distaste and disgust[2]. These taste receptors are distributed throughout the sensory surface of the oral cavity, rodent imaging studies have shown that these receptor types come together to form distinct regions in primary gustatory cortex in the insula, forming a potential gustotopic map of basic taste types[3, 4]
By conjoining four basic taste discriminability maps, we found the anterior/ middle insula differentially responded to four basic tastes (Fig. 2b), which is consistent with putative primary gustatory cortex based on anatomical projections from the gustatory thalamus in nonhuman primates[23]
Summary
The mammalian tongue contains gustatory receptors tuned to basic taste types, providing an evolutionarily old hedonic compass for what and what not to ingest. We used distributed multivoxel activity patterns to identify regions with patterns of activity differentially sensitive to sweet, salty, bitter, and sour taste qualities These were found in the insula and overlying operculum, with regions in the anterior and middle insula discriminating all tastes and representing their combinatorial coding. Sweet receptors aid in selection of energy-rich nutrients and bitter receptors guard against the intake of the potentially noxious, serving as the basis for oral distaste and disgust[2] These taste receptors are distributed throughout the sensory surface of the oral cavity, rodent imaging studies have shown that these receptor types come together to form distinct regions in primary gustatory cortex in the insula, forming a potential gustotopic map of basic taste types[3, 4]. We examined whether discrete and/or distributed regions support specific taste qualities toward identifying the human gustatory cortex
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
