Aging brings many changes, from visible wrinkles and graying hair to less obvious declines in sensory functions.
While the gradual loss of vision and hearing is well-documented and often discussed, another critical sense—touch—also deteriorates as we age.
Recent research published in the journal Frontiers in Aging Neuroscience led by a team of researchers from Aix Marseille University, provides a comprehensive look at how tactile sensitivity varies across different body parts and changes over the lifespan [1].
Their findings highlight a nuanced picture of sensory aging, offering intriguing insights and practical implications.
The scope of the study
The study focused on three key areas of the body: the fingertip, the forearm, and the cheek.
These regions were chosen because they represent different types of skin—glabrous (hairless) skin on the fingertip and hairy skin on the forearm and cheek.
Ninety-six healthy women, aged 20 to 75, participated in the research, undergoing a series of tactile sensitivity tests [1].
Two primary tests were conducted:
- Tactile detection threshold test: Using calibrated monofilaments, researchers measured the minimum force required for participants to detect a touch on each of the three skin sites.
- Tactile spatial discrimination test: Participants used their fingertips to distinguish between different spacing of grooves on plates, assessing their ability to discern fine spatial details [1].
Key findings
The results revealed a clear decline in tactile sensitivity on the fingertip with age. Younger participants (mean age 22) had a significantly lower detection threshold, meaning they could detect lighter touches than older participants (mean age 72).
Similarly, spatial discrimination abilities also diminished with age, indicating a reduced capacity to perceive fine details through touch.
Interestingly, the study found no significant age-related decline in tactile sensitivity on the forearm or cheek [1].
These areas maintained high sensitivity levels across all age groups, suggesting that the decline in touch sensitivity with age is more pronounced in glabrous skin than in hairy skin.
Expert insights
Dr. Jean-Marc Aimonetti, the lead author of the study, emphasizes the importance of these findings. “Our research shows that while tactile sensitivity in the fingertip declines with age, other areas like the cheek remain highly sensitive. This suggests that different types of skin age differently, which has significant implications for both clinical assessments and daily activities.”
Dr. Rochelle Ackerley, a co-author, adds, “The preservation of sensitivity in hairy skin could be due to various factors, including lower exposure to environmental wear and tear compared to the hands. It’s crucial to understand these differences to develop targeted interventions that can help maintain tactile function in older adults.” [1]
Implications for daily life
The decline in touch sensitivity, particularly in the fingertips, can have practical consequences.
For older adults, reduced tactile function can impact everyday activities such as buttoning a shirt, typing on a keyboard, or even recognizing objects by touch. This can lead to a decrease in manual dexterity and independence.
However, the study also brings a cautiously optimistic view. The preservation of tactile sensitivity in other areas of the body means that not all hope is lost [1].
For instance, the cheek’s high sensitivity could be leveraged in developing new touch-based interfaces or communication methods for the elderly.
The need for further research
The study was conducted on a relatively small and homogenous group—healthy women aged 20 to 75.
Future research should include a more diverse population, including men and individuals with varying health conditions, to better understand the broader implications of tactile aging.
Additionally, more precise and varied tactile tests could help refine our understanding of how touch sensitivity changes across different body parts and under different conditions.
For example, developing new materials for monofilaments or exploring other forms of tactile stimuli could provide deeper insights.
The research provides a balanced view of the aging process. It highlights the inevitability of sensory decline but also points to areas where sensitivity remains intact.
This dual perspective is essential in crafting interventions and policies aimed at improving the quality of life for older adults.
[1] Frontiers in Aging Neuroscience. Relations between tactile sensitivity of the finger, arm, and cheek skin over the lifespan showing decline only on the finger
