Dave's Research

The use of a mental rotation reaction time paradigm to measure the effects of upper cervical adjustments on cortical processing: a pilot study.

Objectives: 1) to investigate the potential usefulness of a mental rotation paradigm in providing an objective measure of spinal manipulative therapy. 2) 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.

Study Design: Prospective, single blind, randomized, controlled trial.

Setting: Chiropractic college clinical training facility.

Participants: 36 chiropractic student volunteers with clinical evidence of upper cervical joint dysfunction.

Intervention: 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 due to practice effects.

Outcome measures: 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 following the intervention time were significantly greater for the experimental group as compared to the control group, as indicated by a one-tailed, two sample, equal variance t-test, (p=<0.05).

Conclusion: This study has demonstrated a significant improvement in a complex reaction time task following an upper cervical adjustment. These results provide evidence that upper cervical adjusting may affect cortical processing.

Key Indexing Terms: chiropractic; upper-cervical toggle adjustment; manipulation; mental rotation; reaction time; cerebral dysfunction; cervical spine dysfunction.