"Cerebral Involution" is a tidy medical term for grey matter atrophy, or shrinking of the grey matter of a particular area of the brain. Since it is indicated that is bilateral, that means it affects both the left and right hemisphere. Keep in mind that shrinking of the grey matter atrophy may not necessarily equate to reduced function. Despite this, reduced function is directly correlated to shrinking grey matter *or* damage to a particular section of the brain.
The paretial lobe is responsible for the following:
Touch Sensation (Pain, Temperature, etc.)
Understanding Spatial Orientation
Reading and Writing
I hope this helps.