TY - JOUR T1 - Neuronal control of the fingertips is socially configured in touchscreen smartphone users JF - bioRxiv DO - 10.1101/064485 SP - 064485 AU - Myriam Balerna AU - Arko Ghosh Y1 - 2016/01/01 UR - http://biorxiv.org/content/early/2016/08/22/064485.abstract N2 - As a common neuroscientific observation, the more a body part is used, the less variable the corresponding computations become. We here report a more complicated scenario concerning the fingertips of smartphone users. We sorted 21-days histories of touchscreen use of 57 volunteers into social and non-social categories. Sensorimotor variability was measured in a laboratory setting by simple button depressions and scalp electrodes (electroencephalogram, EEG). The ms range trial-to-trial variability in button depression was directly proportional to the number of social touches and inversely proportional to non-social touches. Variability of the early tactile somatosensory potentials was also proportional to the number of social touches, but not to non-social touches. The number of Apps and the speed of touchscreen use also reflected this variability. We suggest that smartphone use affects elementary computations even in tasks not involving a phone and that social activities uniquely reconfigure the thumb to touchscreen use.Impact Statement Unconstrained behavior on a smartphone is a powerful predictor of neuronal functions measured in the laboratory and the details of the smartphone-neuronal association challenges the established ideas of brain plasticity. ER -