Addressing challenges of high spatial resolution UHF fMRI for group analysis of higher ‐order cognitive tasks: An inter‐sensory task directing attention between visual and somatosensory domains

This study addresses these challenges using an inter‐sensory cognitive task which modulates top‐down attention at graded levels between the visual and somatosensory domains. At the individual level, highly focal functional activation to the task and task difficulty (modulated by attention levels) were detectable due to the high CNR at UHF. However, to assess group level effects, both anatomical an d functional variability must be considered during analysis. We demonstrate the importance of surface over volume normalisation and the requirement of no spatial smoothing when assessing highly focal activity. Using novel group analysis on anatomically parcellated brain regions, we show that in high er cognitive areas (parietal and dorsal‐lateral‐prefrontal cortex) fMRI responses to graded attention levels were modulated quadratically, whilst in visual cortex and VIP, responses were modulated linearly. These group fMRI responses were not seen clearly using conventional second‐level GLM an alyses, illustrating the limitations of a conventional approach when investigating such focal responses in higher cognitive regions which are more anatomically variable. The approaches demonstrated here complement other advanced analysis methods such as multivariate pattern analysis, allowing UHF to be fully exploited in cognitive neuroscience.

Source: Human Brain Mapping - November 15, 2018 Category: Neurology Authors: Kevin M. Aquino, Rodika Sokoliuk, Daisie O. Pakenham, Rosa Maria Sanchez ‐Panchuelo, Simon Hanslmayr, Stephen D. Mayhew, Karen J. Mullinger, Susan T. Francis Tags: RESEARCH ARTICLE Source Type: research