Functional and Anatomical Comparison

Here we present a proof of concept that our resulting dendrograms encode parcella- tions with both anatomical and functional meaning by comparing our results against an anatomical atlas and a functional study. To make the comparisons we extracted a parcellation from each subject’s dendrogram using the horizontal cut criterion since it showed good accuracy in Sect. 3.1. We manually searched for parcellations with a minimum of 36 parcels and a maximum of 150. This was made to get parcellations with coarse granularity while having at least the amount of parcels in the anatomical atlas of Desikan [5].

Anatomical Comparison

To assess if some anatomical structures were present in the dendrogram and if our resulting parcels were subdividing them, we compared the extracted parcellation with the Desikan atlas [5]. It’s important to remark that each subject in the HCP already has this atlas computed. We projected the Desikan regions over our parcels and then calculated: how many of our parcels were inside each projection and how many of them had more than 90% of its area inside the projection. Comparisons with eight regions of the Desikan atlas for the single-subject and the groupwise case are in Figs. 4-left and 5 respectively. Table 1 shows the fraction of parcels inside of each projections that were well contained. Our division of the inferior frontal cortex differs from the Desikan’s [5] (regions 1 and 2 in Fig. 5). However, it’s similar to that of Anwander et al. [1]. In particular, our orange and cyan parcels inside regions 1 and 2 correspond with their blue and green parcels in Fig. 4, panels I, II, IV and V [1]. The Insula; Motor and Sensory cortex (regions 3, 4 and 5 in Fig. 5) were well subdivided for both single subject and groupwise parcellations.

Single subject parcellations created with our technique, alongside both anatomical

Fig. 4 Single subject parcellations created with our technique, alongside both anatomical (left) and functional (right) comparisons from Sect. 3.3. Motor and Sensory Cortex (regions 4 and 5) appear to be found and their subdivision is consistent with the motor strip mapping in HCP

< Prev   CONTENTS   Source   Next >