Right hemisphere brain damage impairs strategy updating
Right hemisphere brain damage impairs strategy updating - Wer i will get girls for free sex chat
These findings demonstrate that reorganization of language function, and the degree to which reorganization facilitates aphasia recovery, is dependent on the size and site of the lesion.
If this is the case, then the relationship between left hemisphere activity and language performance may be indirect, in that both are actually dependent on the severity and size of the stroke itself, as well as the availability of left hemisphere tissue adjacent to the critical areas.
Recovery rates vary greatly, for reasons that are poorly understood .
The relationships between lesion site, activity pattern changes, and recovered language functions remain unclear.
In neuroimaging studies, patterns of increased activation during language tasks in chronic aphasia have been broadly consistent across studies.
In a meta-analysis of neuroimaging studies, collapsing across a wide range of language tasks, we found that people with aphasia consistently overactivated perilesional regions in the left hemisphere, as well as right hemisphere regions that were homotopic to the left hemisphere language network .
With regard to direct biological mechanisms underlying plasticity in language networks, relatively few specific hypotheses have been put forth.
While some investigators, including ourselves, have previously described different patterns of reorganization (e.g., compensatory “takeover” by a new area), these descriptions do not generally hypothesize a specific biological basis for these changes.Damage in different language nodes may influence whether local plasticity is possible and whether right hemisphere recruitment is beneficial.However, the relationships of both lesion size and location to patterns of remapping are poorly understood.Additionally, right hemisphere recruitment identified in neuroimaging studies may not be a consequence of plasticity at all.In neurologically healthy control subjects, right hemisphere activation has been shown to increase as a function of task difficulty [22, 23].The great virtue of specific biological hypotheses is that they generate specific testable predictions, especially with regard to the timing of plasticity, the relationship of specific lesion features such as size and location to the pattern of reorganization, and the relationship of brain changes to behavioral outcomes.