My Father Keeps Having These Mini Type Seizures Or Something

My father keeps having these mini type seizures or something like that. He knows when they are coming on and he just kind of goes out of it...doesn't loose consciousness but his head tilts to the side his hands begin to shake and he doesn't answer to anyone calling his name. These last for only a few seconds and then he comes out of it asking what happened. He has only had 3 episodes in the last 4 months and neurological, heart and brain scans come back negative. He just recently had another while driving and luckily there were others in the vehicle who could take the steering wheel. Please, can you help or direct us somewhere?