A method to fuse fMRI tasks through spatial correlations: Applied to schizophrenia

Abstract

Single task analysis methods of functional MRI brain data, though useful, are not able to evaluate the joint information between tasks. Data fusion of multiple tasks that probe different cognitive processes provides knowledge of the joint information and may be important in order to better understand the complex disorders such as schizophrenia. In this article, we introduce a simple but effective technique to fuse two tasks by computing the histogram of correlations for all possible combinations of whole brain voxels. The approach was applied to data derived from healthy controls and patients with schizophrenia from four different tasks, auditory oddball (target), auditory oddball (novel), Sternberg working memory, and sensorimotor. It was found that in four out of six task combinations patients’ intertask correlations were more positively correlated than controls’, in one combination the controls showed more positive correlations and in another there was no significant difference. The robustness of this result was checked with several testing techniques. The four task combinations for which patients had more positive correlation occurred at different scanning sessions and the task combination that showed the opposite result occurred within the same scanning session. Brain regions that showed high intertask correlations were found for both groups and regions that correlated differently between the two groups were identified. The approach introduced finds interesting results and new differential features that cannot be achieved through traditional methods.

Quantifying the Interaction and Contribution of Multiple Datasets in Fusion: Application to the Detection of Schizophrenia

“…In addition, the sequences of stimuli were designed such that they would produce orthogonal blood-oxygen-level dependent responses for each of the three stimuli [64], [65]. For this task, the regressor was created by modeling the target and standard stimuli as delta functions convolved with the default SPM HRF in addition to their temporal derivatives [22]. Subject averaged contrast images between the target versus the standard tones were used as the feature for this task.…”

“…A total of 84 probes, 42 targets and 42 foils was obtained per scan and the prompt-encode-probe conditions were run twice for each set size in a pseudo-random order [63]. For this task, the regressor was created by convolving the probe response block for the three digit set with the default SPM HRF [22]. This was done for both runs of the probe response and the average map was used as the feature for this task.…”

“…A total of 15 increase-and-decrease blocks were alternated with 15 fixation blocks, with each block lasting 16 seconds in duration [63]. For this task, the regressor was created by convolving the entire increase-and-decrease block with the default SPM HRF [22]. The responses for each subject were averaged over the separate runs and the average map was used as the feature for this task.…”

Single subject prediction of brain disorders in neuroimaging: Promises and pitfalls

“…This can increase confidence in conclusions about the functional significance of brain regions and of activation changes in brain disease. In addition, the combination of function and structure may provide more informative insights into both altered brain patterns and connectivity in brain disorders (McCarley et al, 2008; Michael et al, 2009; Sui et al, 2011). These findings suggest that most studies favor only one data type or do not combine modalities in an integrated manner, and thus miss important changes which are only partially detected by each modality (Calhoun and Adali, 2009).…”

The MCIC Collection: A Shared Repository of Multi-Modal, Multi-Site Brain Image Data from a Clinical Investigation of Schizophrenia

“…Initially the sensory motor (SM) task was used for assessing and controlling between-site, within-site and within-subject variability (Michael et al 2009a). However, the findings showed robust medication effects in the motor cortex(C.…”