Vision and Balance
|
|
Observe what happens to the people attempting to walk through the illusion tunnel, which is confusing their ambient vision system and affected the gait and balance.
Balance is maintained from the interaction of three systems: the visual, the vestibular, and the proprioceptive systems. Approximately 20 percent of the nerve fibers in the eyes interact with the vestibular system. Your eyes gives you a picture of the world and where you are in relation to other things in it.
Two Visual Pathways
1. "What" visual pathway
Also known as the focal, central or Parvocellular pathway is responsible for object identification, and allows you to focus on a specific object in your visual field, for interpetation in the occipital lobe.
2. "Where" visual pathway
Also known as the ambient/peripheral or Magnocellular pathway is responsible for spatial information, balance, coordination and peripheral awareness. This information is shared with the occipital lobe, in addition to links to the cerebellum and balance areas of the brain. Using ambient vision, we can automatically change our posture and gait to walk uphill, or engage in a badminton game with by planning our motor movement to execute each shot.
Functionally, the integration of these 2 systems allow us to look at the road ahead of us (focal vision/What) and be aware of the car to our left(ambient/Where). It also allows us to be focused on a word in reading, but still make accurate saccades to the next word.
Frequently the visual can become faulty following a neurological event, such as a Traumatic Brain Injury. Patients may become over-centrally focused. Symptoms such as decreased balance, decreased reading accuracy and poor spatial awareness a midline shift or toe/heel walking can be reported. They might also report becoming “over-stimulated” by visual information.
Two Visual Pathways
1. "What" visual pathway
Also known as the focal, central or Parvocellular pathway is responsible for object identification, and allows you to focus on a specific object in your visual field, for interpetation in the occipital lobe.
2. "Where" visual pathway
Also known as the ambient/peripheral or Magnocellular pathway is responsible for spatial information, balance, coordination and peripheral awareness. This information is shared with the occipital lobe, in addition to links to the cerebellum and balance areas of the brain. Using ambient vision, we can automatically change our posture and gait to walk uphill, or engage in a badminton game with by planning our motor movement to execute each shot.
Functionally, the integration of these 2 systems allow us to look at the road ahead of us (focal vision/What) and be aware of the car to our left(ambient/Where). It also allows us to be focused on a word in reading, but still make accurate saccades to the next word.
Frequently the visual can become faulty following a neurological event, such as a Traumatic Brain Injury. Patients may become over-centrally focused. Symptoms such as decreased balance, decreased reading accuracy and poor spatial awareness a midline shift or toe/heel walking can be reported. They might also report becoming “over-stimulated” by visual information.