posted 07-13-2004 05:56 PM            

As I stated in my recent article, I think they should be mandatory on all instruments as an additional channel.

Check them out when you get to the APA conference. They are well worth the money. I have not used any other manufacture's motion sensor so can't comment specifically on them.

Jack

posted 07-14-2004 12:32 AM         

Like Jack, I utilize Lafayette's LX4000 with the piezo-sensor movement pad. Personally, I don't think an examiner should leave home without one.

It is not, in my opinion though, THE answer in detecting all physical countermeasures- but it sure goes a long way.

Interestingly, since I routinely inform my clients of the senors presence as well as the recordings made- the majority of my clients remain noticably still. However there are a few who 'have to try' just to see if the sensor really works.

The 'downside' (if there is one) is not being able to isolate 'the source of the movement'(as an anal contraction will effectively create a reaction on the sensor line not unlike a leg rotation-lift) and time (as automatic re-centering of the sensor line makes for a difficult assessment as to 'how long'the contraction/movement was occuring. Now some judgements can be made here as there may be upward spike at the initial movement followed by a downward spike or vice versa during release/ relaxation of the muscular tension).

Confronting the client with un-necessary movements,invokes the same replies as always which invaribly is "No I didn't" or "Sorry but I didn't realize I was moving" or "I didn't mean to move" etc, etc. I've even heard"I didn't blink my eyes because you told me not to move."

Obviously,Im sure,the vast majority of examiners prefer to reach a conclusion as opposed to writing "No Opinion" or "Inconclusive" reports, and I would add thatI prefer not to write 'purposeful-non-cooperation' without being able to substanially support that the 'movement' was puposely made and "intended" to disrupt or distort the psychophysiological tracings.

Hope my comments help in your decision, and I might add that I believe it was Jeff Foxworthy who said 'jus-git-er-done' and the saying could apply to your purchase of a movement sensor.

posted 07-14-2004 07:58 AM            

The LX 4000 is excellent and very sensitive. The cable should not be bent or else risk breaking it, but that goes with anything. Take care of your equipment.

I highly recommend the LX 4000 pad.

Jim

P.S. On a side note, Bob made comment about not being able to isolate location of movement. What does it matter? When a normal movement pattern during testing is established in testing and you arrive at a CQ (or any other non-RQ) and massive changes occur, where none other exists..... Duh CM's!? Comes to mind... Happy hunting!