Perceptual lateralization on the Rod-and-Frame Test in young and older adults

Abstract

Introduction

There is an overall left visual field/right hemisphere advantage in young adults for masked, tachistoscopically presented images on the Rod-and-Frame Test (RFT). This study explored potential age-related lateralization differences in processing of visual context on the RFT.

Methods

The 35 young and 33 older adults aligned a rod surrounded either by no frame, a vertical, or leftward/rightward tilted frame to their perceived vertical. Algebraic errors of rod alignment were used to derive the rod-and-frame effect (RFE) and asymmetry index.

Results

Young adults had frequent indirect effects, mostly to the right-tilted frame, while older adults hardly produced any. Compared with nontilted frames, young adults displayed larger alignment errors with left-tilted frames; however, older adults exhibited this same effect for both frame tilt conditions. Young adults had smaller RFE values than older adults for the right-tilted frame, with no age-related difference in RFE for the left-tilted frame or asymmetry index. The negative asymmetry index was statistically different from the true vertical only in young adults.

Conclusion

There is an age-related reduction in the right hemisphere processing of left-sided visual contexts on the RFT. Such findings can assist clinicians to improve interpretation of RFT findings in clinical patients.

Keywords:

• Aging
• asymmetry
• Computerized Rod-and-Frame Test (CRFT)
• right hemisphere processing

Acknowledgements

Many thanks to Jefferey Bagust for developing and providing the computerized RFT software.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All data generated during this study are available from the corresponding author on request.