The Aging Brain

 

Combining internet research and critical thinking, you will explore key milestones and potential concerns related to the aging brain. This assignment is designed to help you demonstrate your understanding of how this essential organ changes over time. Begin by selecting any two ages you are interested in learning more about, then:

Compare and contrast brain development and function at both ages. For example, you might look at the brain at two years old versus nine years old.

Summarize the cognitive abilities and/or possible age-related effects for each group.
 

Sample Answer

 

 

 

 

 

 

 

Comparing Brain Development and Function: Age 40 vs. Age 70

 

FeatureAge 40 (Midlife)Age 70 (Later Adulthood)
Physical Brain StructureBrain volume begins to subtlely decline (≈5% per decade), particularly in the frontal lobe (executive function) and hippocampus (memory). The rate of shrinkage is still relatively slow.Rate of brain shrinkage often increases, with more pronounced volume loss in the frontal lobe and hippocampus. White matter (connections) integrity also noticeably declines, resulting in slower communication.
NeurochemistryLevels of key neurotransmitters, like dopamine (associated with attention and motor control), begin a subtle decline (≈10% per decade from early adulthood).Decline in neurotransmitter function and density is more significant, which is linked to a notable slowing of cognitive and motor processes.
Cognitive StrategyReliance on efficient, fast processing and the application of crystallized knowledge. The brain is still highly effective at multitasking and rapid information processing.Increased reliance on bilateral brain activation (using both hemispheres for tasks usually done by one) to compensate for specific areas that are less efficient. The brain favors pattern recognition and synthesis of knowledge.

Cognitive Abilities

 

Crystallized Intelligence (Knowledge): Continues to build, often reaching a peak in the late 40s to 60s. This includes vocabulary, verbal abilities, and accumulated knowledge.

Emotional Understanding: Peaks in midlife, demonstrating superior ability to evaluate others' emotional states and navigate complex social situations.

Processing Speed: Starts a subtle decline. While still very fast, there may be a slight slowing compared to the 20s or 30s.

 

Possible Age-Related Effects

 

Slight Memory Lapses: Minor, non-disruptive difficulties with episodic memory (remembering recent events) and word-finding ("tip-of-the-tongue" phenomenon) become more frequent.

Executive Function: Very subtle decline in multitasking ability or sustaining attention in highly distracting environments.

Risk Factors: Lifestyle factors, such as midlife obesity, hypertension, or Type 2 diabetes, begin to significantly accelerate the rate of cognitive decline and increase the risk for later dementia.

 

Age 70 (Later Adulthood)

 

At 70, cognitive function is typically characterized by a wealth of knowledge paired with a measurable reduction in speed and efficiency.

 

Cognitive Abilities

 

Crystallized Intelligence (Wisdom): Often at its absolute peak (peaking in the late 60s or 70s). The individual possesses extensive vocabulary, semantic memory (memory for facts), and a lifetime of experiential knowledge, often referred to as wisdom.

Verbal Abilities: Vocabulary and knowledge of word meaning are often more extensive than in younger adults.

Abstract Reasoning: While some aspects of fluid reasoning may decline, the ability to connect varied sources of information and see the "bigger picture" remains a relative strength due to accumulated experience.

 

Possible Age-Related Effects

 

Processing Speed: This is the most noticeable change. There is a clear and consistent slowing of the ability to quickly process and transform information, which affects performance on timed tests.

Fluid Intelligence & Working Memory: Significant decline in working memory (holding and manipulating information short-term) and selective attention (the ability to ignore irrelevant information).

Episodic Memory: Greater difficulty with the accuracy of source memory (remembering where you learned a piece of information) and the level of detail in recalled episodic events.

Increased Risk: The risk of developing Mild Cognitive Impairment (MCI) or dementia (such as Alzheimer's disease) rises dramatically in the 70s and beyond, moving from a subtle decline into a potentially pathology-driven loss of function.