Patients with forms of dementia can also have deficits in facial recognition and the ability to recognize human emotions in the face. In a meta-analysis of nineteen different studies comparing normal adults with dementia patients in their abilities to recognize facial emotions, the patients with frontotemporal dementia were seen to have a lower ability to recognize many different emotions. These patients were much less accurate than the control participants (and even in comparison with Alzheimer's patients) in recognizing negative emotions, but were not significantly impaired in recognizing happiness. Anger and disgust in particular were the most difficult for the dementia patients to recognize.