Brain Parts’ Functions: Alzheimer’s Symptoms & Brain Damage

Explore averaged MRI brain scans of Alzheimer’s cell loss and see how the functions of damaged brain parts correlate with typical Alzheimer’s symptoms. At The Emergent Universe, an online interactive science museum about emergence.

Understand the Patterns

Symptoms of Cell Loss

By grouping brain scan data from many individuals according to each individual’s degree of cognitive decline, we can create a picture of the typical pattern of cell loss. Here we compare the average cell loss during one year for subjects with mild cognitive impairment (50% of whom are expected to be diagnosed with Alzheimer’s in the next 5 years) and with Alzheimer’s dementia.

Roll over each damaged area of the brain to learn about the functions it controls and typical Alzheimer’s symptoms that may reflect damage in this area.


The hippocampus, which plays a key role in the formation and maintenance of memories, is typically attacked very early in Alzheimer’s. This suggests why forgetting – what was just said, recent events, new acquaintances – is an early symptom of this disease.

Medial temporal lobe

This is an area of the temporal lobe that is associated with high level visual processing, including recognition of places and faces. Very common Alzheimer’s symptoms include getting lost in familiar places and failing to recognize known individuals.


Alzheimer’s cell loss also typically causes an enlargement of the ventricles, fluid filled cavities in the brain that allow for the circulation of cerebrospinal fluid.


This is the cerebellum, a region of the brain that helps you coordinate movements. While the effect of Alzheimer’s on the cerebellum is thought to be minimal, the data shown here indicate statistically significant loss to this region. It is not known if losses in this region could be related to the coordination issues that often appear in mid- to late- stage Alzheimer’s.

Frontal lobe

The frontal lobe is largely responsible for logical reasoning. Damage to this area may explain the inability of many Alzheimer’s sufferers to plan, think logically, or solve complex problems.

Lateral temporal lobe

The temporal lobe is involved in interpreting sensory input, and, in the left hemisphere, it is important for language. A characteristic symptom of early- and mid-stage Alzheimer’s is the inability to recall simple familiar words.

Rear of lateral temporal lobe

The rear of the temporal lobe is typically attacked later in Alzheimer’s. This region is associated with both speaking and understanding speech, faculties that often deteriorate dramatically in mid- to late- stage Alzheimer’s.

Parietal lobe

This area, called the parietal lobe, is responsible for processing tactile sensations, integrating sensory information, and interpreting spatial relationships. People with mid- and late- stage Alzheimer’s often have difficulties with spatial perceptions, for example, mistaking dots in a floor pattern for pieces of trash or thinking a person on television is in the room.