TELEPATHV si
smallest chunk of the brain that can be reliably analyzed by an fMRI
machine is called a "voxel." But each voxel corresponds to several million neurons, so the sensitivity of an fMRI machine is not good enough
to isolate individual thoughts.
Science fiction sometimes uses a "universal translator," a device
that can read a person's thoughts and then beam them directly into another's mind. In some science fiction novels alien telepaths place
thoughts into our mind, even though they can't understand our language. In the 1976 science fiction movie Futureworld a woman's dream
is projected onto a TV screen in real time. In the 2004 Jim Carrey
movie, Eternal Sunshine of the Spotless Mind, doctors pinpoint painful
memories and erase them.
"That's the kind of fantasy everyone in this field has," says neuroscientist John Haynes of the Max Planck Institute in Leipzig, Germany.
"But if that's the device you want to build, then I'm pretty sure you
need to record from a single neuron."
Since detecting signals from a single neuron is out of the question
for now, some psychologists have tried to do the next best thing: to reduce the noise and isolate the fMRI pattern created by individual objects. For example, it might be possible to identify the fMRI pattern
created by individual words, and then construct a "dictionary of
thought."
Marcel A. Just of Carnegie-Mellon University, for example, has
been able to identify the fMRI pattern created by a small, select group
of objects (e.g., carpentry tools). "We have 12 categories and can determine which of the 12 the subjects are thinking of with 80 to 90% accuracy," he claims.
His colleague Tom Mitchell, a computer scientist, is using computer technology, such as neural networks, to identify the complex
brain patterns detected by fMRI scans associated with performing certain experiments. "One experiment that I would love to do is to find
words that produce the most distinguishable brain activity," he notes.
But even if we can create a dictionary of thought, this is a far cry
from creating a "universal translator." Unlike the universal translator,
which beams thoughts directly into our mind from another mind, an
smallest chunk of the brain that can be reliably analyzed by an fMRI
machine is called a "voxel." But each voxel corresponds to several million neurons, so the sensitivity of an fMRI machine is not good enough
to isolate individual thoughts.
Science fiction sometimes uses a "universal translator," a device
that can read a person's thoughts and then beam them directly into another's mind. In some science fiction novels alien telepaths place
thoughts into our mind, even though they can't understand our language. In the 1976 science fiction movie Futureworld a woman's dream
is projected onto a TV screen in real time. In the 2004 Jim Carrey
movie, Eternal Sunshine of the Spotless Mind, doctors pinpoint painful
memories and erase them.
"That's the kind of fantasy everyone in this field has," says neuroscientist John Haynes of the Max Planck Institute in Leipzig, Germany.
"But if that's the device you want to build, then I'm pretty sure you
need to record from a single neuron."
Since detecting signals from a single neuron is out of the question
for now, some psychologists have tried to do the next best thing: to reduce the noise and isolate the fMRI pattern created by individual objects. For example, it might be possible to identify the fMRI pattern
created by individual words, and then construct a "dictionary of
thought."
Marcel A. Just of Carnegie-Mellon University, for example, has
been able to identify the fMRI pattern created by a small, select group
of objects (e.g., carpentry tools). "We have 12 categories and can determine which of the 12 the subjects are thinking of with 80 to 90% accuracy," he claims.
His colleague Tom Mitchell, a computer scientist, is using computer technology, such as neural networks, to identify the complex
brain patterns detected by fMRI scans associated with performing certain experiments. "One experiment that I would love to do is to find
words that produce the most distinguishable brain activity," he notes.
But even if we can create a dictionary of thought, this is a far cry
from creating a "universal translator." Unlike the universal translator,
which beams thoughts directly into our mind from another mind, an