Just's areas of expertise include psycholinguistics, object recognition, and autism, with particular attention to cognitive and neural substrates.

Marcel Just, Tom Mitchell, and colleagues at Carnegie Mellon University are conducting research on "thought identification" using fMRI.

[1] Using machine learning techniques, they have been able to identify patterns of brain activation that are reliably associated to the concept of different objects.

[4] Evidence for this theory has been found in functional neuroimaging studies on autistic individuals[5] and by a brain wave study that suggested that adults with ASD have local overconnectivity in the cortex and weak functional connections between the frontal lobe and the rest of the cortex.

[6] Marcel Just also co-developed with Sashank Varma 4CAPS, a cognitive architecture that specifies how different cortical regions of the brain collaborate to perform specific tasks.