Neural Mechanisms Underlying Human Grasp And Manipulation
Funder
National Health and Medical Research Council
Funding Amount
$396,100.00
Summary
We rely on hand function in a multitude of simple tasks that we tend to take for granted but that are essential in our everyday lives; some examples are turning on a tap, doing up shoelaces, or holding a cup. Many people in the community are disabled by impaired hand function resulting from lesions of the central nervous system or peripheral nerve lesions. The size of the problem is enormous; manual dexterity is affected in approximately 20,000 new stroke patients each year in Australia as well ....We rely on hand function in a multitude of simple tasks that we tend to take for granted but that are essential in our everyday lives; some examples are turning on a tap, doing up shoelaces, or holding a cup. Many people in the community are disabled by impaired hand function resulting from lesions of the central nervous system or peripheral nerve lesions. The size of the problem is enormous; manual dexterity is affected in approximately 20,000 new stroke patients each year in Australia as well as in other neurological diseases such as neuropathies, nerve injuries, cerebral palsy and many others. The broad aim of this study is to investigate the poorly understood neural mechanisms that underlie sensorimotor control of hand function. We will target a specific aspect of manual dexterity that is crucial for the execution of common everyday tasks, like pouring liquid from a bottle, in which the digits are subjected to torsional loads. In order to maintain stable grasps, the motor control system must rapidly and automatically adjust the grip forces employed to meet the demands imposed by the changing torsion. This is only possible because of sensory feedback from the hand, a large component of which arises from the cutaneous mechanoreceptive afferent fibres. In the first two years we will use a combined approach of neural recording from peripheral nerves in anaesthetised monkeys and psychophysics experiments in normal humans to answer the general question: how does the population of cutaneous afferents provide precise feedback about torsion on the digits? In the third year we will perform key experiments in humans, using microneurography to record from their peripheral nerves. This will establish any differences between human and monkey mechanoreceptors.Read moreRead less
Neural Mechanisms In Tactile, Kinaesthetic And Pain Sensation
Funder
National Health and Medical Research Council
Funding Amount
$644,113.00
Summary
Our knowledge of the world around us depends upon our sensory systems which provide a series of windows on the world, enabling the mind and brain to sample information about selected events through the energy forms that impinge upon us. Much of this sensing process takes place through our special sense systems such as the eye, the ear, and the taste and olfactory systems. However, other crucial sensory systems are more generalized throughout the body and are referred to as the somatic sensory sy ....Our knowledge of the world around us depends upon our sensory systems which provide a series of windows on the world, enabling the mind and brain to sample information about selected events through the energy forms that impinge upon us. Much of this sensing process takes place through our special sense systems such as the eye, the ear, and the taste and olfactory systems. However, other crucial sensory systems are more generalized throughout the body and are referred to as the somatic sensory systems. These include our senses of touch, temperature, pain and body position, the last of which is known as our kinaesthetic sense. Our research into the neural mechanisms in sensation and perception is concerned with the tactile, kinaesthetic and pain senses. Although many thousands of nerve fibres travel in the nerves arising from particular regions of the skin or from individual muscles or joints, the sensory nerve fibres that serve these forms of sensation fall into fewer than ten broad classes, made up of five major tactile classes, two or three major kinaesthetic classes, and two broad groups of fibres that mediate pain sensation. However, there is quite striking evidence that when single fibres of these different classes are activated in conscious human subjects, there are marked differences among the fibre classes in their capacity to generate a perceptual response. Under the new NH and MRC grant we propose to examine the transmission and processing of input signals from these fibre classes at the highest levels of the brain, in particular, within the cerebral cortex, in order to reveal the neural mechanisms responsible for their differential perceptual contributions. The proposed analysis will provide fundamental insights into the neural basis for perceptual recognition and will provide information that may be important for our eventual understanding of the disorders of sensory perception that characterize psychiatric conditions such as schizophreniaRead moreRead less