Patients with amnesia 'live in the present'January 16, 2007Scientists at the Wellcome Trust Centre for Neuroimaging, University College London, have shown that people with damage to the hippocampus, the area of the brain that plays a crucial role in learning and memory, not only have trouble remembering the past but also in imagining new and future experiences. Damage to the hippocampus can be caused by a lack of oxygen to the brain, for example during a cardiac arrest, or various other illnesses such as limbic encephalitis or Alzheimer's disease. It has been known for some time that selective damage to the hippocampus can lead to amnesia, with patients unable to recall past events. However, by asking patients to describe imaginary experiences, the research team led by Dr Eleanor Maguire found that the patients' ability to construct fictitious events was also severely impaired. The research is published today in the Proceedings of the National Academy of Sciences. The researchers asked the patients to imagine and then describe in detail situations in commonplace settings, such as a beach, pub and forest, as well as potentially plausible future events such as a Christmas party or a future meeting with a friend. "We found that the role played by the hippocampus in processing memory was far broader than merely reliving past experiences," says Dr Maguire, a Wellcome Trust Senior Research Fellow at UCL. "It also seems to support the ability to imagine any kind of experience including possible future events. In that sense, people with damage to the hippocampus are forced to live in the present." "Furthermore, the patients reported that they were unable to visualise the whole experience in their mind's eye, seeing instead just a collection of separate images," explains Dr Maguire. Dr Maguire and her colleagues believe that the findings suggest a common mechanism that might underpin both recalling real memories and how we visualise imaginary and future experiences, with the hippocampus providing the spatial context or environmental setting into which the details of our experiences are bound. Wellcome Trust |
|||||||||||||||||||||
| Related Hippocampus Current Events and Hippocampus News Articles New discovery about the formation of new brain cells The generation of new nerve cells in the brain is regulated by a peptide known as C3a, which directly affects the stem cells' maturation into nerve cells and is also important for the migration of new nerve cells through the brain tissue, reveals new research from the Sahlgrenska Academy published in the journal Stem Cells. New Down syndrome treatment suggested by Stanford/Packard study in mice At birth, children with Down syndrome aren't developmentally delayed. But as they age, these kids fall behind. Memory deficits inherent in Down syndrome hinder learning, making it hard for the brain to collect experiences needed for normal cognitive development. Cognitive dysfunction reversed in mouse model of Down syndrome A study by neuroscientist William C. Mobley, MD, PhD, chair of the Department of Neurosciences at the University of California, San Diego School of Medicine, and colleagues at Stanford University Medical School has demonstrated a possible new approach to slowing the inevitable progression of cognitive decline found in Down's syndrome. New neuroimaging analysis technique identifies impact of Alzheimer's disease gene in healthy brains Brain imaging can offer a window into risk for diseases such as Alzheimer's disease (AD). A study conducted at the University of Kansas School of Medicine demonstrated that genetic risk is expressed in the brains of even those who are healthy, but carry some risk for AD. Theory about long and short-term memory questioned by UCL scientists The long-held theory that our brains use different mechanisms for forming long-term and short-term memories has been challenged by new research from UCL, published today in PNAS. Weizmann Institute scientists reveal how some aromas are bound up in our memories From Proust's Madeleines to the overbearing food critic in the movie Ratatouille who's transported back to his childhood at the aroma of stew, artists have long been aware that some odors can spontaneously evoke strong memories. Estrogen therapy likely must be given soon after menopause to provide stroke protection For estrogen replacement to provide stroke protection, it likely must be given soon after levels drop because of menopause or surgical removal of the ovaries, scientists report in the Journal of Neuroscience. Aiming to avoid damage to neurocognitive areas of the brain during cranial radiation Radiation oncologists at Rush University Medical Center are intent on finding ways to avoid damage to the critically important hippocampus and limbic circuit of the brain when cranial radiation is required to treat existing or potential metastatic cancers. Fighting Sleep, Penn Researchers Reverse the Cognitive Impairment Caused By Sleep Deprivation A research collaboration led by biologists and neuroscientists at the University of Pennsylvania has found a molecular pathway in the brain that is the cause of cognitive impairment due to sleep deprivation. Why antidepressants don't work for so many More than half the people who take antidepressants for depression never get relief. More Hippocampus Current Events and Hippocampus News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||