A deep joint sparse non-negative matrix factorization framework for identifying the common and subject-specific functional units of tongue motion during speech

•We presented a method to identify both common and subject-specific functional units within a material coordinate system from MRI.•We proposed to convert non-negative matrix factorization with sparse and manifold regularizations into modular structures.•We provided validation to demonstrate superior performance over the comparison methods on both simulated and in vivo tongue data.