In chapter six of Do Zombies Dream of Undead Sheep, we learn that there is evidence for brain remapping in blind patients. These patients seem to be “making up” for their missing sense of vision by rewriting regions that would normally be associated with vision to allow them to have stronger capabilities for senses they can use, like sound. Brain remapping is an exciting topic because it has many clinical applications, like rehabilitation techniques for patients who are recovering from strokes.
Last month, Murata, Higo, Hayashi, Nishimura, Sugiyama, Oishi, Tsukada, Isa, and Onoe (2015) published exciting findings regarding remapping the brain in macaque monkeys. These monkeys suffered from Manual Dexterity Deficit (MDD) after a lesion to their primary motor cortex. This is a region that is especially important for fine movements, such as picking up and using small objects. Everyday, the researchers had the monkeys performing a simple small-object retrieving task. In this task, researchers taught the monkeys to pick up a piece of potato through a narrow vertical slit. The task was twenty trials long, lasting about half an hour per day. Trials took place over the course of a month.
Over time, the Murata et al. (2015) noticed that the monkeys were becoming better and better at the task, as expected. They used PET scanning and PPI analysis to record the brain activity in the monkeys and compared it to each monkey’s brain activity before the lesions. They found an interesting time-dependent interaction between two brain regions associated with movement. At the beginning of the recovery, the monkeys showed more activity in the ventral premotor cortex than before the lesion. This part of the brain is rather distant than the location of the lesion, which is somewhat surprising. The ventral premotor cortex is necessary for the ability to discriminate between one’s own body and one’s surroundings (Bekrater-Bodmann, Foell, & Kamping, 2011). In the later stages of recovery, however, PPI analysis indicated strengthening connections between the lesion site and areas of the motor cortex closest to the lesion.
Remapping the brain is particularly interesting because all of the possible clinical implications! Knowing the temporal significance of recovery can help us develop new rehabilitation techniques and drugs to help stroke patients who suffer from damage to the motor cortex.
Bekrater-Bodmann, R., Foell, J., & Kamping, S. (2011). The Importance of Ventral Premotor Cortex for Body Ownership Processing. The Journal of Neuroscience, 31(26), 9443-9444.
Murata, Y., Higo, N., Hayashi, T., Nishimura, Y., Sugiyama, Y., Oishi, T., Tsukada, H., Isa, T., & Onoe, H. (2015). Temporal Plasticity Involved in Recovery from Manual Dexterity Deficit after Motor Cortex Lesion in Macaque Monkeys. The Journal of Neuroscience, 35(1), 84-95.
Verstynen, T., & Voytek, B. (2014). Do zombies dream of undead sheep?: A neuroscientific view of the zombie brain.