Why is the old age in a bad direction? It turned out to be a "compass" that disturbed the brain.

Some people have a good sense of direction, while others can't remember the roadAnd the sense of direction usually decreases with age, so older people are often more difficult to locate spatially than younger people, especially in unfamiliar environmentsWhat's the cause?recently, researchers at the German Center for Neurodegenerative Diseases (DZNE) and U.Sexperts have offered new insights into the causes of the phenomenonBased on their findings, the main cause of the spatial location error was that "noise" disturbed the brain's "compass" and led to inaccurate perceptions of movement speedThe findings, published in the journal Nature Communications, could help develop diagnostic tools for early detection of Alzheimer's diseasesignals from visual stimulation to muscle feedback to the vestibular system, the human brain uses a variety of sensory inputs to determine the position and guide us through the spaceAn important part of information processing occurs in the inner olfactory cortexIn this region of the brain's two hemispheres, there are special neurons that can produce psychological maps of the physical environmentAs a result, real-space information is converted into a data format that the brain can processhuman navigation system works wellBut this is not without its flawsDZNE scientists led by Lead Researcher Professor Thomas Wolbers of the German Center for Neurodegenerative Diseases worked with experts from the Massachusetts Institute of Technology and the University of Texas at Austin to design a specific experimentabout 60 cognitively healthy young and elderly people experienced virtual reality from a first-person perspective through a headset (HMD)As participants move in the real world, their postures (position and viewing direction) are tracked using the Vicon motion tracking system and converted to motion in the virtual environment (i.eposture changes), allowing them to walk around the virtual world and estimating their position sway using body-based visual cues and visual self-tips for path integration tasks, participants are asked to track their own location and direction by grabbing the sticks in the hands of the experimenters and moving along 10 different predefined but unmarked curved paths (see figure below) Each path has four intermediate stops that ask participants to stop and report their estimates of the direct distance and direction to the start of the path Each participant performed three repetitions on each path In addition, a subset of the six paths was executed three more times, instead of stopping in the middle of the first three stops, but only at the end of the path is just as important as the experimental setup for mathematical modeling of measurement data This is based on a method that describes the effects of interference location determination as noise "The human body and its sensory organs are far from perfect," Wolbers said As a result, information processing in the brain is affected by glitches that can be understood as noise With our mathematical model, we were able to understand the effects of various error sources and determine which distortion locations tracked the most and which had the least impact This source of error has never been studied in such detail "
found that errors in path integration are mainly caused by "internal noise accumulation" in information processing, which may be the result of inaccurate motion velocity perception "It should be noted that humans will visually estimate the distance covered based on the time and speed at which they have previously walked However, our study shows that the key source of error sway in determining location is not the perception of time, but random fluctuations in the speed information that enters the brain Wolbers said , the source of such errors dominates both young people (average age 22) and adults (average age 69) "Younger subjects were generally better at directing than older subjects What's more, internal noise increases with age This phenomenon is clearly the main cause of the lack of path integration and may also be the trigger for age-related orientation problems However, we do not yet know the exact source of this noise and why it increases with age "
previously, Wolbers has found that in cognitively healthy older adults, certain neurons in the inner olfactory cortex (so-called grid cells) are critical to spatial navigation, and that they emit irregularly (their activities are unstable), which is associated with age-related orientation difficulties The current results show that these instabilitys are not caused by the fault of the grid cells themselves, but by external noise Theproblem, therefore, is not the grid cell, but the flow of information that reaches the inner olfactory cortex This points to the possibility of early diagnosis of Alzheimer's disease " Alzheimer's disease is associated with early damage to the inner olfactory cortex Therefore, it is reasonable to believe that the disorientation disorders shown in Alzheimer's disease originate in this region of the brain, which is different from age-related disorientation, which is our current view "This provides an opportunity to distinguish between normal age-related orientation problems and targeted diseases caused by Alzheimer's disease, " Wolbers explains In the long run, our goal is to develop a diagnostic method that can detect Alzheimer's disease at an early stage "
References: ."