Aging and Sensitivity to Illusory Target Motion With or Without Secondary Tasks

Area of Science:

• Neuroscience
• Human Factors
• Gerontology

Background:

• Older adults often struggle to filter out irrelevant sensory information compared to younger adults.
• This age-related difference in sensory processing may impact motor control and perceptual tasks.

Purpose of the Study:

• To quantify age-related differences in ignoring inaccurate visual cues using a motion interception task.
• To investigate the influence of visual illusions on motor performance in young and older adults.
• To determine if increased cognitive or sensorimotor load exacerbates sensitivity to visual illusions in older adults.

Main Methods:

• A motion interception task was administered to healthy young (18-34 years) and older (60-82 years) adults.
• Participants tapped descending discs on a screen, with illusory motion induced by a moving background.
• Secondary tasks (standing on foam, tone counting) were introduced to assess cognitive and sensorimotor load.

Main Results:

• Older adults exhibited greater sensitivity to the illusory motion caused by the moving background compared to younger adults.
• The introduction of secondary tasks did not significantly alter the influence of the background motion on performance.
• Performance decrements in older adults were more pronounced when visual cues were misleading.

Conclusions:

• Older adults are more profoundly affected by visual illusions in a motion interception task, suggesting a reduced ability to ignore irrelevant sensory information.
• Age-related declines in proprioceptive and vestibular function may lead to an increased reliance on visual input, heightening susceptibility to visual illusions.
• The findings highlight age-related differences in multisensory integration and the challenges older adults face in dynamic visual-motor tasks.