Symptoms of anxiety and anger are often described as some sort of energetic sensation in my chest and sometimes face or arms.  Are these sensations an 'illusion' from neural activity strictly in the brain which projects sensations on their body or is there also neural activity in my chest, face or arms that they're 'actually' sensing?  If so what is the nature of that activity. If not and the sensations are just an 'illusion' how is the brain creating that illusion.  Also why does stretching seem to calm or make this sensation more pleasant?
Are the physical sensations of an emotion due to neural activity strictly in the brain or also in the body?
cognitive psychology;neurobiology;perception;emotion;cognitive neuroscience