As we grow older, our memory tends to change, and for some older adults, this decline in memory can be faster than for others.
Researchers at the University of Arizona have conducted a study to understand the reasons behind this variation in memory decline, and their findings shed light on how our brains store information and why memory changes with age.
The human brain is a complex organ responsible for many functions, including memory. Memory allows us to store and retrieve information, and it plays a crucial role in our daily lives. One specific part of the brain associated with memory is the hippocampus, which also helps us navigate our surroundings.
Researchers have long been interested in how the hippocampus functions and how it may be linked to memory decline in older adults. To investigate this, they drew inspiration from studies conducted on rats by Professor Carol Barnes.
Barnes’ work focused on specialized cells in the hippocampus known as “place cells,” which activate when an individual enters a specific location. These place cells help create a mental map of different spaces in our environment.
Building on Barnes’ research, the University of Arizona team conducted their study with 25 younger adults and 22 older adults, all of whom were healthy.
The participants engaged in a virtual reality experiment where they memorized layouts and locations of shops in two virtual cities displayed on a computer screen.
Simultaneously, researchers scanned their brains using functional magnetic resonance imaging (fMRI) to capture neural signals in the hippocampus.
Key Findings
The study confirmed that older adults, on average, showed neural representations that struggled to differentiate between different environments compared to younger adults. This suggests that the hippocampus’s ability to create distinct mental maps may decrease with age, affecting spatial memory.
The researchers discovered an age-independent factor that impacts memory retention. Neurons in the hippocampus perform different functions, with some responding to environmental shapes and others to ground colors or features.
When these neurons overlap in function, the accuracy of representing the environment can be compromised, leading to lower-quality neural signals. Importantly, this factor is not linked to age alone, as individuals with poor memory performance, regardless of age, may show low-fidelity neural signals.
The study also highlighted an age-dependent factor related to the quality of neural signals coming from other brain regions into the hippocampus.
Even high-performing older adults in the study exhibited a decrease in the quality of incoming neural signals into the hippocampus. This reduction in signal quality was associated with age and poorer spatial memory.
Understanding how memory changes with age is crucial, especially in predicting memory decline in people diagnosed with dementia. The study’s findings provide valuable insights into the factors influencing memory, including the role of the hippocampus and the quality of neural signals.
In the future, the research team plans to replicate the study using immersive virtual reality experiments that incorporate body-based cues and navigation, aiming for a more naturalistic approach to studying memory and spatial awareness.
In summary, this study helps us better comprehend why some older adults experience memory decline, offering potential avenues for further research and a deeper understanding of the human brain’s complexities.
If you care about dementia, please read studies about low choline intake linked to higher dementia risk, and how eating nuts can affect your cognitive ability.
For more information about brain health, please see recent studies that blueberry supplements may prevent cognitive decline, and results showing higher magnesium intake could help benefit brain health.
The research findings can be found in PNAS.
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