Human Hand Function: Conclusion

TL;DR

Human hand is a tool that has two functions: sensor and motor

Summary

 

• Hand Function Categories: The framework divides hand function into four categories along a sensorimotor continuum, ranging from tactile sensing to non-prehensile skilled movements. This structure helps analyze the factors influencing human manual performance.
• Dual Role of the Hand: The hand serves two main functions—sensory and motor. It acts both as a movable sensory organ and a vehicle for motor activity, often performing both roles simultaneously, such as when sensing the ripeness of fruit while preparing to pick it up.
• Tactile Sensing: At the sensory end, the hand can process tactile inputs even without movement. Active haptic sensing, which involves deliberate exploration, provides more detailed information about objects, allowing people to select and manipulate based on the desired level of precision.
• Interplay Between Sensory and Motor Functions: Sensory feedback is crucial for precise motor activities. Without it, movements such as grasping become less efficient, and objects can slip from the fingers.

 

Critical Research Questions in Tactile and Haptic Sensing:

• Extending Multichannel Models: Exploring whether multichannel models of tactile sensation, currently focused on vibrotactile sensation, can be applied to other tactile experiences.
• Space-Time Interactions: Investigating spatiotemporal tactile illusions to understand how timing and spatial parameters affect tactile perception, which can inform tactile display design.
• Organization of Sensory Inputs: Studying how the sensory systems organize multiple inputs from the hand, including the role of Gestalt principles in tactile and haptic perception.
• Frames of Reference in Tactile Perception: Understanding the complex influence of different frames of reference on the tactile perception of spatial patterns.
• Higher-Level Cognitive Processes: Researching somatosensory attention and memory, including the distinction between implicit and explicit memory in manual experiences.
• Multisensory Integration: Developing global models that encompass all senses, recognizing that haptic perception often occurs alongside vision and audition.