FMRI Brain Scans May Peer Into the Brain's Future

By Eliza Strickland | January 22, 2009 8:39 am

brain blood vesselsWhen neuroscientists stare at the brain scans of their research subjects, they may not be getting a clear picture of what’s going on in those brains at one moment in time and how they’re responding to current stimuli–they may also be catching a glimpse of how the brains are preparing to respond to future events.

Scientists using techniques such as functional magnetic resonance imaging (fMRI) make the assumption that blood flow into a particular brain region is directly linked to the amount of activity in the cells of that region. This is because active cells need more oxygen, and blood ferries it to them [Nature News]. Now, a surprising new study has found that blood rushes to parts of the brain where the neurons haven’t yet jumped into action, and the researchers say this anticipatory response may be skewing the interpretation of fMRI scans.

In the study, published in Nature [subscription required], researchers trained monkeys to respond to visual stimuli, and measured their reactions with both fMRI scans and electrodes inserted into their brains. Sitting in darkness except for a light that switched on at regular intervals, the monkeys were trained to look away if it was red, and fix their gaze on the light if it shone green. When the timing of the pauses between the light flashes changed, blood flow still increased when the macaque expected a flash, but there was no subsequent increase in electrical activity from firing neurons [New Scientist].

Study coauthor Aniruddha Das says the findings suggest a previously unknown mechanism of brain arousal. “What caught us completely by surprise was that there was this huge anticipatory signal which appeared prior to us showing the visual stimulus,” Das says. The purpose of this could be to supply cortical arteries in the visual region in time for the upcoming stimulus, he says [Nature News]. As fMRI scans are increasingly used to investigate people’s emotional responses to a visual stimuli, future research in the burgeoning field will have to take care to avoid skewing the data. Although the findings “by no means call into question the whole body of fMRI research,” Das says they should cause fMRI researchers to rethink how they design and interpret their experiments [ScienceNOW Daily News].

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Image: Y. Sirotin & A. Das, showing blood flow in the brain in response to a visual stimulus

CATEGORIZED UNDER: Mind & Brain
MORE ABOUT: emotions, senses
  • http://clubneko.net nick

    I think what this study really goes to show is that our brains are much more complex than we give them credit for. It probably also shows how we are able to learn and adapt to repetitive and changing stimuli. For instance, fighters and video games tend to telegraph* their moves to an experienced player. But really, that’s our brains learning their patterns, and our brains then sensing the timing and rushing blood into place to deal with the move(s) that are expected. Experienced fighters learn their own signals (also known as infrasignal, mostly unconscious signals such as fidgeting), and when they know them well enough can use them to mis-direct an opponent.

    This could also explain “sub-conscious” reactions we have to things – such as hearing the screech of car tires nearby will usually cause one to tense up, as the brain is now expecting a crash (and if you are unlucky enough to be in a movie or video game, it will be followed by a disproportionately large explosion).

    All in all, this is probably one of the best survival traits developed by the brain – being ready ahead of time to cope with expected stimuli.

    *known as telegraph, because when you’re good enough the signal may as well be coming by telegraph and the movement followed by train. Especially in video games, since they can’t think on their virtual feet so you always know, down to about .2 seconds, what’s coming if you’ve played enough (Bruce Li had a reaction time of about .1 seconds, one of the best around).

  • SeanDudeMan

    This doesn’t surprise me in the least. Why wouldn’t the brain prep certain areas for stimulus if in the past it has experienced a similar event with a similar outcome? It makes total sense! It just makes me wonder: if a person is trained to assert that one specific stimulus could result in twenty different possible outcomes (no matter how outlandish they may be) ,each with an equal probability of occurring, would the brain respond to said stimulus by equally increasing flow to the twenty different “areas” in the brain that harbor that specific outcome? Here, I assume the brain would go through some kind of quantum “filing”, deciding which was most probable to occur given the specific circumstances and factors involved when the stimulus was encountered.

  • Bruce Voigt

    Mike the Headless Chicken -
    Mike the Headless Chicken (April 1945 – March 1947) was a Wyandotte rooster that lived for 18 months after its head had been cut off. …
    ———-

    It’s things like this that Science should pick up from and not that old untrue stuff. The amount of time and money waisted on brain research is staggering. I would highly recommend that ALL education start again using truth as it’s base.

    To reason with anything, one must first know the true reason!

    At its poles, a cell of anything contains the complete make up of the entity that produced that cell. The brain is new to evolution having it’s cells with four nuclei orbits producing eight poles instead of three orbits that produce the hexagon of life (us and the tree).

    A plant within it’s make up will contain a gaggle of instinct cells. I have not discovered where yet but I have discovered that they hang out at the base of a brain and spinal cord.

    We being the evolution of a plant or tree and having our bodies evolve with this separate and new species (brain) for reasons assume the brain runs our body. WELL IT DOES NOT “come on guys dump your garbage education and start over” And you might think about giving the kids back their tuition. Ford and Chrysler do!

    Bruce Voigt

  • Bruce Voigt

    QUOTE
    Growth of new brain cells requires ‘epigenetic’ switch
    January 8th, 2009 in Medicine & Health / Research
    New cells are born every day in the brain’s hippocampus, but what controls this birth has remained a mystery——-
    —————-

    A reaction will cause mutating chips of cold to collide with an air cell atomically creating heat. This heat interacts with hydrogen and oxygen of the air cell. These two gases require a host. The host will be the aura of life! The info cell of aura now becomes the nucleus and orbiting nuclei of a new water molecule. Mutating to a dividable water cell this phenomenon will contain the complete make-up of the entity from which the info cell came.

    The new water cell when consumed by life, changes to whatever consumed it. For whatever reason, leftovers that conform may survive to aid in evolution. We call these mutations, disease!

    The disease ‘Water on the Brain’ leaves a person with very little material brain and yet these people function quite well (transfer of info cells).

    Bruce Voigt

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