Sensing form - finger gaiting as key to tactile object exploration - a data glove analysis of a prototypical daily task

Abstract

Background Motor hand skill and associated dexterity is important for meeting the challenges of daily activity and an important resource post-stroke. In this context, the present study investigated the finger movements of right-handed subjects during tactile manipulation of a cuboid, a prototypical task underlying tactile exploration. During one motor act, the thumb and fingers of one hand surround the cuboid in a continuous and regular manner. While the object is moved by the guiding thumb, the opposed supporting fingers are replaced once they reach their joint limits by free fingers, a mechanism termed finger gaiting. Methods For both hands of 22 subjects, we acquired the time series of consecutive manipulations of a cuboid at a frequency of 1 Hz, using a digital data glove consisting of 29 sensors. Using principle component analysis, we decomposed the short action into motor patterns related to successive manipulations of the cuboid. The components purport to represent changing grasp configurations involving the stabilizing fingers and guiding thumb. The temporal features of the components permits testing whether the distinct configurations occur at the frequency of 1 Hz, i.e. within the time window of 1 s, and, thus, taxonomic classification of the manipulation as finger gaiting. Results The fraction of variance described by the principal components indicated that three components described the salient features of the single motor acts for each hand. Striking in the finger patterns was the prominent and varying roles of the MCP and PIP joints of the fingers, and the CMC joint of the thumb. An important aspect of the three components was their representation of distinct finger configurations within the same motor act. Principal component and graph theory analysis confirmed modular, functionally synchronous action of the involved joints. The computation of finger trajectories in one subject illustrated the workspace of the task, which differed for the right and left hands. Conclusion In this task one complex motor act of 1 s duration could be described by three elementary and hierarchically ordered grasp configurations occurring at the prescribed frequency of 1 Hz. Therefore, these configurations represent finger gaiting, described until now only in artificial systems, as the principal mechanism underlying this prototypical task. Trial registration clinicaltrials.gov, NCT02865642, registered 12 August 2016.

Distinguishing transient from persistent tactile agnosia after partial anterior circulation infarcts – Behavioral and neuroimaging evidence for white matter disconnection

“…This vulnerability is due to the complex sequential motor acts adapted to the explored objects, which requires temporally synchronous dynamic movements as well as concomitant asynchronous dynamic movements across distinct groups of finger joints. This motor sequence is termed finger gaiting and secures objects within the hand during exploration as has been verified using digital data gloves ( Krammer et al, 2020 ). Roland and Mortensen detailed this type of human somatosensory exploration in the form of a model with input–output relationships during tactile exploration, encompassing kinesthesia, macrogeometry, size and shape ( Roland & Mortensen, 1987 ).…”

“…The findings reported here are valid for apperceptive tactile agnosia due to an elementary sensori-motor disorder, but not for associative tactile agnosia, which may dependent rather on a lateralized neuronal network to the right hemisphere ( Balsamo et al, 2008 , Platz, 1996 , Veronelli et al, 2014 ). The elementary multifinger task underlying extraction of somatosensory information is independent of fast and dynamic exploration and of brain lateralization ( Krammer et al, 2020 , Craddock and Lawson, 2009 , Yamashita, 2015 ). In contrast, tool use involves similar anterior parietal areas, but predominantly in the left hemisphere ( Orban and Caruana, 2014 ).…”

“…Specific tasks required to discriminate macroscopic somatosensory stimuli seem to be very vulnerable, causing particular activity limitations ( Carey and Matyas, 2011 , Kim and Choi-Kwon, 1996 , Han et al, 2002 , Smith et al, 1983 , Tyson et al, 2008 , Welmer et al, 2008 ). In the case of object shape recognition, the limitations are due to mechanisms underlying the dynamic exploratory finger movements ( Krammer et al 2020 ). The disruption of tactile object recognition (TOR) can be due to either apperceptive or associative disorders, and affects the recognition of macroscopic and microscopic object features or qualities like hardness or softness amongst others.…”

Manipulator Control System Based on Flexible Sensor Technology

“…In general, the position of the flexible sensor on the data glove is divided into three parts: (1) the installation of the finger joint to measure the amount of movement in the metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints as the gesture changes; (2) the installation on the fingertips to measure pressure; and (3) the carpal movements were detected in each part of the palm, as shown in Figure 7 [ 113 ]. The number of sensors is related to the degree of freedom to be measured and, in general, a position requires a flexible sensor.…”

Mindfulness in the focus of the neurosciences - The contribution of neuroimaging to the understanding of mindfulness

“…An example of an empirical belief would be probabilistic modeling of the sensori-motor hand skill of object exploration, which relies on extracting the first three components from a digital data glove. Analyzing the principal component with around 80% variance would enable us to describe finger positions in space over time and thus designate the type of the multifinger task as finger gaiting (Krammer et al, 2020 ). Structurally, the probabilistic map of the brain lesion (part of a distributed cortical neuronal network) predicted recovery from tactile agnosia vs. persistent disorder over the long-term with 90% accuracy (Abela et al, 2019 ).…”