Which of the following conditions is an example of a disorder that can arise in properly functioning brains breaking down over time?

Alzheimer's Disease is a neurodegenerative disorder characterized by the progressive decline of cognitive functions including memory and reasoning. This condition exemplifies how a brain, which may have functioned well initially, gradually deteriorates, leading to significant impairment over time. The pathology of Alzheimer's involves the accumulation of amyloid plaques and tau tangles, which disrupt normal brain function.

Schizophrenia, while primarily classified as a mental health disorder, also shows evidence of brain changes that can occur over time. Patients may experience symptoms such as hallucinations or delusions, and research suggests there can be structural brain abnormalities, including variations in brain volume and connectivity. These changes indicate that even though the disorder manifests differently than neurodegenerative diseases, it reflects a breakdown in typically functioning neural processes.

Neither dyslexia nor certain other conditions mentioned involves a progressive decline in brain function in the same sense. Dyslexia is a specific learning disability that affects reading and language processing, not necessarily resulting from age-related deterioration of the brain.

Thus, the correct answer encompasses both Alzheimer's Disease and Schizophrenia, as both can involve a breakdown of previously healthy brain function over time.