Amnesia, Retrograde

Japanese pharmaceutical company Eisai, together with Oita University in Japan, has built what could be the world's first AI model that uses data from wearable devices to predict Alzheimer's disease, the most common form of dementia. Their research team embarked on a study to create a cost-effective, practical tool to pre-screen people suspected of developing the disease. Their findings were published in the journal Alzheimer's Research & Therapy. FINDINGS The study collected biological and lifestyle data from 122 individuals aged 65 and older with mild cognitive impairment or subjective memory impairment. Biological data, including physical activity, sleep, and heart rate, were collected from wristband sensors they were made to wear for seven days every three months from 2015 to 2019. The following lifestyle data were also collected from their medical consultations: employment status, frequency of going outdoors, means of transportation, number of days participating in community activity, and backgrounds (age, education history, history of alcohol use, and medical history). Moreover, participants underwent annual amyloid PET (positron emission tomography) examinations, which detect the accumulation of amyloid-beta protein in the brain – a crucial biomarker of Alzheimer's. Researchers developed a predictive model that combined three machine learning technologies: support vector machine, Elastic Net, and logistic regression, to integrate all the collected data. Its purpose is to determine how likely each participant will test positive by amyloid PET screening. An evaluation of the AI model showed that it has a "sufficient" capability to predict amyloid-beta protein accumulation. Through this model, the study was able to identify 22 factors that contribute to amyloid-beta protein accumulation: physical activity, sleep, heart rate, amount of conversation, age, length of education, living with or without children, means of transportation, presence of accompanying person for hospital visits, communication frequencies, and number of outings. WHY IT MATTERS Progress in Alzheimer's research led to the discovery of amyloid-beta protein accumulation in the brain as a significant biomarker of Alzheimer's. This further resulted in the development of therapeutic drugs targeting it. Still, for incurable diseases such as Alzheimer's, screening is imperative. Currently, testing is possible through amyloid PET and cerebrospinal fluid (CSF) testing, which are costly, limited, and invasive, according to Eisai and Oita University researchers. AI has been applied to explore ways to make Alzheimer's testing accessible for many, especially now that countries like Japan are ageing at a faster pace. While there are already studies that have applied AI to predict amyloid-beta protein accumulation, these have so far only used cognitive function tests, blood tests, and brain imaging tests. The latest research by the Eisai and Oita University team provides value to this growing area of study as it focuses on lifestyle and biological data. Following their pioneering work, the team sees a potential for wider application of their AI model to pre-screen people for Alzheimer's, particularly those with little access to amyloid PET and CSF testing. THE LARGER TREND The Japanese research team was not the first to contemplate using wearable devices to track or predict biomarkers of Alzheimer's. In 2020, Alzheimer’s Research UK announced a project to develop a wearable diagnostic device for the early detection of neurodegenerative diseases with funding from Microsoft founder Bill Gates. In recent years, more projects have been carried out to improve Alzheimer's detection by leveraging AI technology. Researchers from Australia's CSIRO and Queensland University of Technology recently came out with an AI-based benchmark for measuring brain atrophy, touted to be a global first. Fujifilm also developed an AI tool that was found to accurately predict patients who would progress to Alzheimer's within two years. Lotte Healthcare from South Korea recently announced a partnership with iMediSync to explore developing new AI-driven healthcare services, including screening for neuropsychiatric disorders. Meanwhile, Eisai continues its involvement in Alzheimer's research. Recently, it launched a new digital health business called Theoria, which has a specific focus on dementia. Launching in April, Theoria is coming out with its flagship solution, a risk prediction algorithm for the early detection of mild cognitive impairment.

Simply remembering events can trigger brain rhythms, even more so than when people are experiencing the actual event, says a new study. The findings could lay foundations for cognitive impairment therapy and help improve memory. Neurons produce rhythmic patterns of electrical activity in the brain. One of the unsettled questions in the field of neuroscience is what primarily drives these rhythmic signals, called oscillations. University of Arizona researchers have found that simply remembering events can trigger them, even more so than when people are experiencing the actual event. The researchers, whose findings are published in the journal Neuron, specifically focused on what are known as theta oscillations, which emerge in the brain's hippocampus region during activities like exploration, navigation and sleep. The hippocampus plays a crucial role in the brain's ability to remember the past. Prior to this study, it was believed that the external environment played a more important role in driving theta oscillations, said Arne Ekstrom, professor of cognition and neural systems in the UArizona Department of Psychology and senior author of the study. But Ekstrom and his collaborators found that memory generated in the brain is the main driver of theta activity. "Surprisingly, we found that theta oscillations in humans are more prevalent when someone is just remembering things, compared to experiencing events directly," said lead study author Sarah Seger, a graduate student in the Department of Neuroscience. The results of the study could have implications for treating patients with brain damage and cognitive impairments, including patients who have experienced seizures, stroke and Parkinson's disease, Ekstrom said. Memory could be used to create stimulations from within the brain and drive theta oscillations, which could potentially lead to improvements in memory over time, he said. UArizona researchers collaborated on the study with researchers from the University of Texas Southwestern Medical Center in Dallas, including neurosurgeon Dr. Brad Lega and research technician Jennifer Kriegel. The researchers recruited 13 patients who were being monitored at the center in preparation for epilepsy surgery. As part of the monitoring, electrodes were implanted in the patients' brains for detecting occasional seizures. The researchers recorded the theta oscillations in the hippocampus of the brain. The patients participated in a virtual reality experiment, in which they were given a joystick to navigate to shops in a virtual city on a computer. When they arrived at the correct destination, the virtual reality experiment was paused. The researchers asked the participants to imagine the location at which they started their navigation and instructed them to mentally navigate the route they just passed through. The researchers then compared theta oscillations during initial navigation to participants' subsequent recollection of the route. During the actual navigation process using the joystick, the oscillations were less frequent and shorter in duration compared to oscillations that occurred when participants were just imagining the route. So, the researchers conclude that memory is a strong driver of theta oscillations in humans. One way to compensate for impaired cognitive function is by using cognitive training and rehabilitation, Ekstrom said. "Basically, you take a patient who has memory impairments, and you try to teach them to be better at memory," he said. In the future, Ekstrom is planning to conduct this research in freely walking patients as opposed to patients in beds and find how freely navigating compares to memory with regard to brain oscillations. "Being able to directly compare the oscillations that were present during the original experience, and during a later retrieval of that is a huge step forward in the field in terms of designing new experiments and understanding the neural basis of memory," Seger said.

TUESDAY, July 11, 2023 -- Children with autism have well-known difficulties with social interactions, but a new study is highlighting another area where they can struggle: memory. Researchers found that compared with their peers, school-age kids with autism showed more difficulty managing memory tasks. They often had a hard time remembering faces — something seen in past studies — but also in recalling words and other types of information. What's more, the researchers were able to trace the memory deficits to particular brain circuitry that was "hyperconnected." The findings suggest that memory challenges may be a bigger issue for kids with autism than generally recognized. And that should be taken into consideration at school and in services for those children, the researchers say. Kids with "high-functioning" autism often go to mainstream schools and receive the same instruction as their peers, said lead author Jin Liu , a postdoctoral researcher at Stanford University School of Medicine, in California. But, she said, the new findings suggest that even though those children may have high IQs, they can still struggle with memory issues. "So they may need extra help," Liu said. Autism is a developmental brain disorder that, to varying degrees, impairs communication and social skills. Some kids have milder difficulties, but others are profoundly affected — speaking little, if at all, and getting wrapped up in repetitive, obsessive behaviors. Some children have intellectual disabilities, while others have average or above-average IQs. When it comes to memory issues, research has been fairly limited. Some studies have found that kids with autism can have a harder time remembering faces, compared with typically developing children. Less is known about whether they tend to have broader difficulties with memory. It's an important question, Liu said, because memory skills are key to school and work performance. They also play an under-appreciated role in social relationships, she noted. Socializing is complex, and requires people to draw upon many skills, including episodic memory — recalling the details of an event, like your first day at school, and the emotions associated with it. Even the seemingly simple memory for objects can matter for school kids' interactions, Liu pointed out — if, for example, a child with autism has a hard time remembering that a classmate's backpack looks like theirs, but is not theirs. For the new study — published July 10 in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging — Liu and her colleagues recruited 25 children with autism and 29 typically developing kids. All were between the ages of 8 and 12, and had average to above-average IQ. On average, kids with autism scored lower on standard memory tests, versus the comparison group. The tests gauged kids' ability to recognize whether they'd seen an image or heard a word before, and their ability to recall the details of those past experiences. Some images were of faces and others were completely "non-social" — that is, included no people. The researchers also found another performance difference. Among kids without autism, face and non-social memory were typically consistent: If one was good, so was the other. But among kids with autism, the two did not always match up. Face memory might be worse than non-social memory, for example. Some clues as to why turned up when the researchers used functional MRI scans to track the children's brain activity. Among kids with autism, two distinct brain "circuits" were linked to memory difficulties. Problems with general memory were traced to hyperactivity in the hippocampus, a brain structure well known to be involved in memory. But struggles with face memory were tied to a brain area called the posterior cingulate cortex, which has a role in social abilities and the capacity to distinguish oneself from other people. That does not, however, prove that abnormal activity in those brain circuits actually cause kids' memory problems, Liu said. To parents, the findings might not come as a surprise. They know their kids best, Liu said, and may well have noticed any difficulties with general memory. The study does not answer the question of how to best help kids with memory difficulties. But it does raise awareness, said Alycia Halladay , chief science officer for the nonprofit Autism Science Foundation. "This study emphasizes the need to look beyond the core autism symptoms when evaluating the needs of individuals on the spectrum," said Halladay, who was not involved in the study. She agreed that memory challenges can have far-reaching effects, not only on things like school performance but also daily living and well-being. "It's important to understand these memory impairments, even in those who do not have an intellectual disability," Halladay said. Sources Jin Liu, PhD, postdoctoral scholar, psychiatry and behavioral sciences, Stanford University School of Medicine, Stanford, Calif. Alycia Halladay, PhD, chief science officer, Autism Science Foundation, Scarsdale, N.Y. Biological Psychiatry: Cognitive Neuroscience and Neuroimaging , July 10, 2023, online Posted July 2023