Editing Split-brain (section)

=== Functional plasticity ===

Following a stroke or other injury to the brain, functional deficiencies are common. The deficits are expected to be in areas related to the part of the brain that has been damaged; if a stroke has occurred in the motor cortex, deficits may include paralysis, abnormal posture, or abnormal movement synergies.<ref>{{cite journal |last1=Nudo |first1=R. J. |last2=Plautz |first2=E. J. |last3=Frost |first3=S. B. | year = 2001 | title = Role of adaptive plasticity in recovery of function after damage to motor cortex. [Review] | journal = Muscle & Nerve | volume = 24 | issue = 8| pages = 1000–1019 | doi=10.1002/mus.1104|pmid=11439375 |s2cid=32457492 }}</ref> Significant recovery occurs during the first several weeks after the injury. However, recovery is generally thought not to continue past six months. If a specific region of the brain is injured or destroyed, its functions can sometimes be transferred and taken over by a neighboring region. There is little functional plasticity observed in partial and complete callosotomies; however, much more plasticity can be seen in infant patients receiving a [[hemispherectomy]], which suggests that the opposite hemisphere can adapt some functions typically performed by its opposite pair. A study performed by Anderson et al. (2005) proved a correlation between the severity of the injury, the age of the individual, and their cognitive performance. It was evident that there was more neuroplasticity in older children—even if their injury was extremely severe—than in infants who suffered moderate brain injury.<ref name="Anderson 2005 1374–1382">{{cite journal|last1=Anderson|first1=Vicki|first2=Cathy |last2=Catroppa |first3=Sue |last3=Morse |first4=Flora |last4=Haritou |first5=Jeffrey |last5=Rosenfeld |author-link5=Jeffrey Rosenfeld |title=Functional Plasticity or Vulnerability after Early Brain Injury|journal=Pediatrics|year=2005|volume=11|issue=6|pages=1374–1382|doi=10.1542/peds.2004-1728|pmid=16322161|s2cid=25849302}}</ref> In some incidents of any moderate to severe brain injury, it mostly causes developmental impairments and in some of the most severe injuries it can cause a profound impact on their development that can lead to long-term cognitive effects. In the aging brain, it is extremely uncommon for neuroplasticity to occur; "olfactory bulb and hippocampus are two regions of the mammalian brain in which mutations preventing adult neurogenesis were never beneficial, or simply never occurred".<ref name="Anderson 2005 1374–1382"/>
[[File:WIKI PICTURE.png|left|thumb|291x291px|The picture is about a normal brain and a person with a split brain]]