Grip force as a functional window to somatosensory cognition

Abstract

Analysis of grip force signals tailored to hand and finger movement evolution and changes in grip force control during task execution provide unprecedented functional insight into somatosensory cognition. Somatosensory cognition is the basis of our ability to act upon and to transform the physical world around us, to recognize objects on the basis of touch alone, and to grasp them with the right amount of force for lifting and manipulating them. Recent technology has permitted the wireless monitoring of grip force signals recorded from biosensors in the palm of the human hand to track and trace human grip forces deployed in cognitive tasks executed under conditions of variable sensory (visual, auditory) input. Non-invasive multi-finger grip force sensor technology can be exploited to explore functional interactions between somatosensory brain mechanisms and motor control, in particular during learning a cognitive task where the planning and strategic execution of hand movements is essential. Sensorial and cognitive processes underlying manual skills and/or hand-specific (dominant versus non-dominant hand) behaviors can be studied in a variety of contexts by probing selected measurement loci in the fingers and palm of the human hand. Thousands of sensor data recorded from multiple spatial locations can be approached statistically to breathe functional sense into the forces measured under specific task constraints. Grip force patterns in individual performance profiling may reveal the evolution of grip force control as a direct result of cognitive changes during task learning. Grip forces can be functionally mapped to from-global-to-local coding principles in brain networks governing somatosensory processes for motor control in cognitive tasks leading to a specific task expertise or skill. Under the light of a comprehensive overview of recent discoveries into the functional significance of human grip force variations, perspectives for future studies in cognition, in particular the cognitive control of strategic and task relevant hand movements in complex real-world precision task, are pointed out.

Measures of Maximal Tactile Pressures during a Sustained Grasp Task Using a TactArray Device Have Satisfactory Reliability and Concurrent Validity in People with Stroke

“…The planning and execution of hand function rely on the complex interactions between somatosensation, motor control, and appropriately modulated grip forces during object manipulation [ 120 ]. Thus, the analysis of the measures of tactile pressures or forces from the TactArray device provides critical insight onto our ability to interact with objects through touch to gain better understanding of the functional interactions between somatosensory pathways in the brain and motor control.…”

Spatiotemporal Modeling of Grip Forces Captures Proficiency in Manual Robot Control

“…Finally, the control of the human hand by the brain has evolved as a function of environmental constraints in interaction with the other sensory systems, and grip force profiles are a direct reflection of the complex cognitive and behavioral synergies these interactions have produced. Sensory cues provided by somatosensation, vision, hearing, and smell play an important role in grip force scaling [1]. When interacting with objects of uncertain properties providing insufficiently reliable somatosensory feed-back, individuals use somatosensory memory representations from previous trials to plan grip forces [68], and patients with massive somatosensory loss can still scale and time grip forces and adjust them across different object handling tasks on the basis of memory-based, anticipatory and online control processes to compensate for the loss of somatosensory feedback [69].…”

“…Analysis of grip force signals tailored to hand and finger movement evolution for grip force control during task execution provides insight into the fundamental mechanisms of somatosensory cognition [1]. Recent technology has permitted the wireless monitoring of grip force signals recorded from biosensors in the palm of the human hand to track and trace human grip forces deployed in image-guided precision tasks under conditions of restricted sensory input [2,3].…”

“…Such grip force sensing permits profiling operator strategies and, at the same time, exploring functional interactions between somatosensory and motor control during the strategic planning and execution of hand movements, with a potential for generating benchmarks for human-robot interaction [4][5][6]. Somatosensory cognition is the basis of our ability to manipulate and transform physical objects [1,7], to recognize them on the basis of touch alone [8,9], and to grasp them with the right amount of force for lifting, manipulation, or transformation [10][11][12][13][14]. Sensorial and cognitive processes underlying hand-specific grip force variations (dominant versus non-dominant hand) in manual tasks have been studied in a variety of contexts by selectively probing multiple measurement locations in the fingers and palm of the human hand [12][13][14][15][16][17].…”

The Grossberg Code: Universal Neural Network Signatures of Perceptual Experience

“…The synthesis of multiple sensory cues in the brain improves the accuracy and speed of behavioral responses [38]. Task-relevant visual, auditory and tactile signals are experienced together in motor tasks [39], and pioneering work in neurophysiology from the 1960ies has shown convergence of visual, auditory, and somatosensory signals at the level of the pre-frontal cortex in cats [40]. Also, visual signals can bypass the primary visual cortex to directly reach the motor cortex, which is immediately adjacent and functionally connected to the somatosensory cortex [41].…”