[彭蒙惠英语] 人类心思看得更透(3)
A Clearer View of the Human Mind (3)
Mind reading has become a serious scientific endeavor. How is it done? With a gigantic magnet!
Memory
Tracking precisely what happens in the brain as people experience sights, sounds, smells, tastes and touch could reveal how memories get started, where they go to be analyzed for their emotional significance, where they are stored and how they are recalled.
Brain chemistry
The brain runs on electricity generated by positively charged sodium ions. Therefore the goal of the University of Illinois at Chicago's new machine is to observe the electrical charges racing through individual brain cells as they communicate.
When a neuron receives information from neighboring neurons and decides to act, it opens pumps on its surface that allow sodium ions to flood in. A tiny jolt of electricity quickly builds up then zooms down the neuron's long axon, passing the information to other neurons. The neuron's sodium pumps then close, and other pumps clear the sodium out of the cell so it can be ready to fire again.
The massive magnetic field of a powerful MRI machine aligns the nuclei of the atoms in the same direction, much as a magnet pulls a compass needle. When the nuclei are allowed to relax, they emit characteristic radio frequency signals that tell observers what kind of atoms they are and what they are doing.
Promising potential
If it lives up to its promise, the machine will spot the first neurons that fire almost instantaneously and track where the communication links go from there.
" What we'd like to understand-and what we're working on-is what happens on a single event, a single thought," Thulborn said. "And we've been able to do this . It turns out that if you look at a single thought versus average thoughts, then in fact you get a different view of how the brain functions."
Vocabulary Focus
zoom (v) ---to move very quickly
emit (v) ---to send out a beam, noise, smell or gas
Specialized Terms
nucleus (n) --- （原子）核 the central part of an atom, usually made up of protons and neutrons
compass (n) --- 罗盘；指南针 a device for finding direction which has a freely moving needle that always points to magnetic north
