Figure 6
From: Multiple Kernel Learning Model for Relating Structural and Functional Connectivity in the Brain

Investigation of the Impact of Altering the Scale-specificity of the Parameters π′s. Two studies are conducted where the first study (a) looks at the impact of changing the scale-specificity of the π′s and the second study (b) looks at the impact of a larger-scale alteration when the components of individual π matrices are themselves altered. (a) This sub-figure depicts the result of swapping each of the π i matrices with the last matrix, i.e., with π16. For example, the first data point shows the mean performance when π1 is swapped with π16, the second data point corresponds to the case when π2 is swapped with π16 and so on for each of the 16 π i matrices being swapped with the last matrix π16. Thus the last data point corresponds to the case when the original order was retained. The error bars represent the standard deviation. The results suggest scale-specificity of the learned parameters, i.e., in the sense that the performance degrades drastically if the π matrices of one scale are swapped with a π matrix of a distant scale. (b) The histogram of Pearson correlations depicts the performance when all the π i matrices are stacked together and the rows of the resulting stacked Π-matrix are swapped randomly 250 times. Such global alteration drastically degrades the performance. Together, these results indicate that the learned parameters do not predict FCs by chance but play a crucial role in the MKL model.