%0 Journal Article %A Arindam Bhattacharjee %A Christoph Braun %A Cornelius Schwarz %T Humans use a temporally local code for vibrotactile perception %D 2021 %R 10.1523/ENEURO.0263-21.2021 %J eneuro %P ENEURO.0263-21.2021 %X Sensory environments are commonly characterized by specific physical features, which sensory systems might exploit using dedicated processing mechanisms. In the tactile sense, one such characteristic feature is frictional movement, which gives rise to short-lasting (<10ms), information-carrying integument vibrations. Rather than generic integrative encoding (i.e. averaging or spectral analysis capturing the ‘intensity’ and ‘best frequency’), the tactile system might benefit from, what we call a ‘temporally local’ coding scheme that instantaneously detects and analyzes shapes of these short-lasting features. Here, by employing analytic psychophysical measurements, we tested whether the prerequisite of temporally local coding exists in the human tactile system. We employed pulsatile skin indentations at the fingertip that allowed us to trade manipulation of local pulse shape against changes in global intensity and frequency, achieved by adding pulses of the same shape. We found that manipulation of local pulse shape has strong effects on psychophysical performance, arguing for the notion that humans implement a temporally local coding scheme for perceptual decisions. As we found distinct differences in performance using different kinematic layouts of pulses, we inquired whether temporally local coding is tuned to a unique kinematic variable. This was not the case, since we observed different preferred kinematic variables in different ranges of pulse shapes. Using an established encoding model for primary afferences and indentation stimuli, we were able to demonstrate that the found kinematic preferences in human performance, may well be explained by the response characteristics of Pacinian corpuscles (PC), one class of human tactile primary afferents.Significance StatementSensory systems may exploit specific physical features characteristic for the sensory signal at hand. Recent evidence from rodents showed that very short (‘local’) signatures in vibrotactile signals may carry significant amount of texture information; this motivated us to investigate whether the human tactile system is able to exploit information carried by short-duration pulse shapes. We demonstrate that the humans are indeed able to extract information from local pulse shapes. We also present evidence that local cues may be perceptually more effective than the classic ‘global’ variables intensity and frequency. We tag this encoding scheme as ‘temporally local code’ in analogy to the ‘spatially local code’, long assumed to be implemented in the visual system. %U https://www.eneuro.org/content/eneuro/early/2021/10/08/ENEURO.0263-21.2021.full.pdf