Grant: Operating Grant

Diseases and disorders of the nervous system make up the largest class of medical problems in the world. One way to address this huge problem is study basic brain mechanisms so that we can then try to understand how they are affected by multiple diseases. For example, sensory-motor transformations underlay most aspects of daily living, work, and leisure, and are affected by nearly all diseases, disorders, and injuries to the brain. Most of what we know about such basic brain processes comes from animal studies. Despite advances in human brain science, it is still very limited in what it can test, for example it cannot differentiate between different neurons in an area of the brain, and it often forces unnatural behaviors, like fixing the head in place or making subjects lie down. For this reason neural recordings in monkeys are still needed, because they are very close to the human in brain and behavior. However, monkey studies have often times been limited by the need to test very simple behaviors in rather unnatural conditions, and by two-dimensional approximations to the real three-dimensional (3-D) motion. Here, we propose to use a monkey model to examine some of the most fundamental questions of sensorimotor control with the use of a new method for analyzing neural activity recorded during naturally variable 3-D behaviors (especially with the head free to move naturally). This will enable us to describe how visual signals are processed, stored and converted into neural commands for eye and head movements. We will also study how the brain encodes future sequences of coordinated movement, and we will test, for the first time, if a specific part of parietal cortex is involved in sensorimotor integration for head control. Importantly, this new work will allow us to obtain very precise quantitative measurements from more natural behaviors that should therefore apply more closely to real-world situations than most previous neural recordings of this type.