Abstract
The prevailing opinion emphasizes fronto-parietal network (FPN) is key in mediating general fluid intelligence (gF). Meanwhile, recent studies show that human MT complex (hMT+), located at the occipito-temporal border and involved in 3D perception processing, also plays a key role in gF. However, the underlying mechanism is not clear, yet. To investigate this issue, our study targets visuo-spatial intelligence, which is considered to have high loading on gF. We use ultra-high field magnetic resonance spectroscopy (MRS) to measure GABA/glutamate concentrations in hMT+ combined with resting-state fMRI functional connectivity (FC), behavioral examinations including hMT+ perception suppression test, and a gF subtest for its visuo-spatial component. Our findings show that both GABA in hMT+ and frontal-hMT+ functional connectivity significantly correlate with the performance of visuo-spatial intelligence. Further, serial mediation model demonstrates that the effect of hMT+ GABA on visuo-spatial gF is fully mediated by the hMT+ frontal FC. Together, our findings highlight the importance in integrating sensory and frontal cortices in mediating the visuospatial component of general fluid intelligence.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
↵# Co-first author
We are grateful for the excellent and very helpful comments from three reviewers, and deeply revised the original manuscript. Summary as follow: 1.In the revised version, we emphasize the de-redundancy function of hMT+ in visual-spatial intelligence, while weaken the significance of hMT+ in MD systems. 2.Three important correlations: BDT and SI, BDT and small threshold, BDT and large threshold, have been placed in the main text, and showed in Fig. 3 e-g. 3.We have added the V1 FC-behavior analysis. 4.We have made a correlation matrix to report all values (SI, BDT, GABA in hMT+ and V1, Glu in hMT+ and V1). 5.We have revised the title: GABA-ergic inhibition in human hMT+ predicts visuo-spatial intelligence mediated through the frontal cortex(Original Title: GABA-ergic inhibition in human MT predicts visuo-spatial intelligence mediated by reverberation with frontal cortex). Because we did not show the reverberation, only show functional connectivity. 6.We have replaced the misleading references. 7.We have improved the quality of figures and tables.
