Use of a mental rotation reaction-time paradigm to measure the effects of upper cervical adjustments on cortical processing: a pilot study.
OBJECTIVE
To investigate the potential usefulness of a mental rotation paradigm in providing an objective measure of spinal manipulative therapy. To determine if cortical processing, as indicated by response time to a mental rotation reaction-time task, is altered by an upper cervical toggle recoil adjustment.


METHODS
Prospective, double-blind, randomized, controlled trial.


METHODS
Chiropractic college clinical training facility.


METHODS
Thirty-six chiropractic student volunteers with clinical evidence of upper cervical joint dysfunction.


METHODS
Participants in the experimental group received a high-velocity, low-amplitude upper cervical adjustment. A non-intervention group was used to control for improvement in the mental rotation task as a result of practice effects.


METHODS
Reaction time was measured for randomly varying angular orientations of an object appearing either as normal or mirror-reversed on a computer screen.


RESULTS
The average decrease in mental rotation reaction time for the experimental group was 98 ms, a 14.9% improvement, whereas the average decrease in mental rotation reaction time for the control group was 58 ms, an 8. 0 improvement. The difference scores after the intervention time were significantly greater for the experimental group compared with the control group, as indicated by a one-tailed, 2-sample, equal variance Student t test, (P < 05).


CONCLUSIONS
The results of this study have demonstrated a significant improvement in a complex reaction-time task after an upper cervical adjustment. These results provide evidence that upper cervical adjustment may affect cortical processing.
Kelly
D D
DD
Research Department, New Zealand School of Chiropractic, Auckland, New Zealand.
Murphy
B A
BA
Backhouse
D P
DP
D000328:Adult; D002574:Cervical Vertebrae / Q000503:physiopathology*; D003071:Cognition / Q000502:physiology; D004311:Double-Blind Method; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D020393:Manipulation, Spinal / Q000379:methods*; D010865:Pilot Projects; D011336:Probability; D011446:Prospective Studies; D011930:Reaction Time; D012016:Reference Values; D012680:Sensitivity and Specificity; D013122:Spinal Diseases / Q000175:diagnosis / Q000534:rehabilitation*