the "twitchy" horror movie special effect?

Question

The effect in which the motions of the monster are twitchy and violent jerks instead of a normal fluid motion that is normal walking. My question is what is this effect called specifically? Within the industry I suppose, the jargon. In case I am not specifying enough what I am referring to you can witness this effect in movies such as the first "grudge" on the security camera when you see the shadow walking "twitchingly" toward the tv and in probably the best example in the "House on Haunted Hill" 1999 remake, when the "un-dead medical staff" are twitchingly walking on the security camera as Mr.Price watches it approach his wife. My friend briefly told me once that since the human brain interprets movements at certain frames per second and expects certain fluid motion that the "twitch" effects tend to frighten people. I am extremely interested in finding out more, any help to point me in the right direction to some resources would be much appreciated! Thank you..

Answer 1

I think this effect may be jump cuts, but I'm not positive

Answer 2

I love Tom Savini. He started doing special effects make-up for horror movies back in the 70(s). Truely a genius in his genre. He's been involved in Day of the Dead,Friday the 13th (original), Friday the 13th : The Final Chapter, and Texas Chainsaw Massacre 2. Check him out for inspiration!

Answer 3

I think you're right, for the effect, and not for any other p urpose than to cause more fright. I think it's also a call to realism, since visions have been remarked to be more "twitchy" than fluid by those who say they have received them.