Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
Department of Movement Sciences, KU Leuven, Leuven, Belgium.
J Neurophysiol. 2023 Oct 1;130(4):871-882. doi: 10.1152/jn.00145.2023. Epub 2023 Aug 23.
Touch generated by our voluntary movements is attenuated both at the perceptual and neural levels compared with touch of the same intensity delivered to our body by another person or machine. This somatosensory attenuation phenomenon relies on the integration of somatosensory input and predictions about the somatosensory consequences of our actions. Previous studies have reported increased somatosensory attenuation in elderly people, proposing an overreliance on sensorimotor predictions to compensate for age-related declines in somatosensory perception; however, recent results have challenged this direct relationship. In a preregistered study, we used a force-discrimination task to assess whether aging increases somatosensory attenuation and whether this increase is explained by decreased somatosensory precision in elderly individuals. Although 94% of our sample ( = 108, 21-77 yr old) perceived their self-generated touches as weaker than externally generated touches of identical intensity (somatosensory attenuation) regardless of age, we did not find a significant increase in somatosensory attenuation in our elderly participants (65-77 yr old), but a trend when considering only the oldest subset (69-77 yr old). Moreover, we did not observe a significant age-related decline in somatosensory precision or a significant relationship of age with somatosensory attenuation. Together, our results suggest that aging exerts a limited influence on the perception of self-generated and externally generated touch and indicate a less direct relationship between somatosensory precision and attenuation in the elderly individuals than previously proposed. Self-generated touch is attenuated compared with externally generated touch of identical intensity. This somatosensory attenuation has been previously shown to be increased in elderly participants, but it remains unclear whether it is related to age-related somatosensory decline. In our preregistered study, we observed a trend for increased somatosensory attenuation in our oldest participants (≥69 yr), but we found no evidence of an age-related decline in somatosensory function or a relationship of age with somatosensory attenuation.
与由他人或机器施加于身体的同等强度的触觉相比,我们自主运动产生的触觉在感知和神经层面上都会减弱。这种躯体感觉衰减现象依赖于躯体感觉输入的整合和对自身动作所产生的躯体感觉后果的预测。先前的研究报告称,老年人的躯体感觉衰减增加,提出过度依赖运动预测来补偿与年龄相关的躯体感觉感知下降;然而,最近的结果对这种直接关系提出了挑战。在一项预先注册的研究中,我们使用力辨别任务来评估衰老是否会增加躯体感觉衰减,以及这种增加是否可以用老年人躯体感觉精度下降来解释。尽管我们的样本中 94%(=108,21-77 岁)的人无论年龄大小,都认为自己产生的触摸比外部产生的同等强度的触摸(躯体感觉衰减)弱,但我们没有发现老年参与者(65-77 岁)的躯体感觉衰减显著增加,但当仅考虑最年长的一组(69-77 岁)时,存在这种趋势。此外,我们没有观察到躯体感觉精度与年龄相关的显著下降,也没有观察到年龄与躯体感觉衰减之间的显著关系。综上所述,我们的结果表明,衰老对自身产生的和外部产生的触摸感知的影响有限,并表明老年人的躯体感觉精度与衰减之间的关系不如之前提出的那样直接。与外部产生的同等强度的触摸相比,自身产生的触摸会减弱。先前的研究表明,这种躯体感觉衰减在老年参与者中增加,但尚不清楚它是否与与年龄相关的躯体感觉下降有关。在我们预先注册的研究中,我们观察到最年长的参与者(≥69 岁)的躯体感觉衰减有增加的趋势,但我们没有发现躯体感觉功能与年龄相关的下降或年龄与躯体感觉衰减之间的关系的证据。