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

Multiple Choice

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

A) It is age related - beginning when an individual is approximately 60 years old.
B) When unused or redundant neural pathways are pruned
C) Significant loss of dendritic interconnectivity
D) When neuron loss reaches the peak of 25,000 eliminated neurons daily