What causes the loss of "computational power" and the appearance of symptoms of old age to occur?

Question

Quizplus · Accepted Answer

The significant loss of dendritic interconnectivity is a major factor contributing to the loss of computational power in aged individuals. This can cause a decline in memory, attention, and other cognitive abilities. Age-related pruning of unused neural pathways and neuron loss also contribute, but the loss of dendritic interconnectivity is believed to play a bigger role in cognitive decline.

What Causes the Loss of "Computational Power" and the Appearance