As a cognitive neuroscientist with a strong interest in the aging process, I've spent many years studying the intricate changes that occur in the brain as we age. The question you've asked is a complex one and touches on a variety of physiological, cognitive, and psychological aspects of aging. Let's delve into the subject.
Step 1: English Answer
When we age, several changes occur in the brain that can impact cognitive function. Here are some key points to consider:


1. Neuronal Loss: The most obvious physical change is a reduction in the number of neurons. This loss is particularly pronounced in areas of the brain responsible for learning and memory, such as the hippocampus.


2. Brain Shrinkage: As you've mentioned, brain-scan technology has shown that the brain tends to shrink with age. This atrophy is due to the loss of neurons and the reduction in the size of the brain's white matter, which consists of the fatty myelin sheaths that insulate nerve fibers and aid in the speed of signal transmission.


3. Synaptic Changes: Synapses, the connections between neurons, also decrease with age. This can lead to slower information processing and reduced cognitive flexibility.


4. Cerebrovascular Changes: The blood vessels in the brain can become less efficient, leading to reduced oxygen and nutrient supply to brain cells, which can impair their function.


5. Neurotransmitter Alterations: Aging can affect the levels of neurotransmitters, the chemical messengers that transmit signals in the brain. Changes in these levels can influence mood and cognitive abilities.


6. Cognitive Decline: While not universal, many individuals experience a decline in cognitive abilities, particularly in areas such as memory, attention, and problem-solving skills. Short-term memory is often one of the first to be affected.

7.
Neuroinflammation: There is an increase in inflammation within the brain as we age, which can contribute to cognitive decline and the development of neurodegenerative diseases.

8.
Plasticity Reduction: The brain's ability to adapt and reorganize itself, known as neuroplasticity, tends to decrease with age. This can make it more challenging to learn new skills or recover from brain injuries.

9.
Lifestyle Factors: It's important to note that lifestyle can significantly influence the aging process. Regular physical exercise, a healthy diet, mental stimulation, and social engagement can help to mitigate some of the cognitive decline associated with aging.

10.
Disease and Genetics: Certain diseases, such as Alzheimer's, can accelerate cognitive decline. Additionally, genetic factors play a role in how an individual's brain ages.

In conclusion, while the aging process does bring about changes that can negatively impact cognitive function, it's not a uniform experience for everyone. There are many strategies that can be employed to support brain health and potentially slow the rate of cognitive decline.

**read more >>

Our memory starts to fail, especially the short-term form of memory ability that is so crucial for learning new things. Brain-scan technology reveals aging can cause the brain to shrink. ... The challenge for aging individuals is to reduce the rate of their decline.Nov 14, 2012read more >>