• 74. Baby IQs Surprising
Two separate studies last year confirmed that infants are a lot smarter than we thought they were.
In the first study, psychologist Marie Cheour and colleagues at the University of Turku in Finland found that infants just two days old can distinguish anomalies in speech while they sleep. In an overnight experiment, 15 newborns slept while a computer played a common Finnish vowel repeatedly along with a sound that's never used in Finnish. A second group of infants heard nothing; a third group heard nonspeech sounds. The next morning, the researchers recorded the brain waves of all the groups as the computer played. Only those newborns exposed to the audio program of speech sounds during sleep showed a response to the anomalous vowels, suggesting that they had learned to discriminate between the two kinds of sounds while they slumbered.
In a second study, developmental psychologist György Gergely of the Hungarian Academy of Science in Budapest found that infants decide just how much to imitate. A 1988 study had shown that 14-month-old infants will imitate odd behavior—even the odd act of turning on a special lamp by touching it with the head. Gergely decided to show two groups of infants that same act in two different contexts. When one group saw a woman turn on the lamp with her head while her hands were free, most imitated her. When another group saw the woman turn on the lamp with her head while using her hands to hold a blanket around her, most chose to turn on the lamp with their hands, not their head. They evidently figured the demonstrator in the second setting used her head only because her hands were not free. "It seems babies do a lot of figuring out of whether it is wise to imitate or not, based on their own situation," Gergely says. — Ingfei Chen
• 56. (Rat) Mind Control
|Researchers can control a rat's movement by sending signals to the radio receiver in the rat's backpack. The signals go into three electrodes in the rat's brain, and one of the electrodes provokes surges of pleasure, causing the rats to run and jump in areas they would normally avoid. But some prudence is hardwired: Even this bliss can't convince them to jump from a dangerous height. |
Photograph by Constance Giamo
Rats and mice don't have much trouble learning to navigate mazes. But what if you want one to follow a complex path it has never seen? In April John Chapin, a neuroscientist at the SUNY Downstate Medical Center in Brooklyn, New York, and his colleagues said they had managed to do just that by creating phantom signals in the rat's brain.
Chapin studies the part of the brain that interprets signals received by touch-sensitive parts of a body. "If you pick up a paper cup with too little force, you drop it," Chapin says, "but use too much force, and you crush it." Understanding this signaling may lead to artificial limbs that can transmit a sense of touch to the brain.
Chapin steered the rats with the help of two electrodes inserted into each rat's left and right cortex; the electrodes sent signals mimicking sensations from the left and right whiskers. A third electrode, running to the brain's pleasure center, incited the rats to move forward and rewarded them for making the proper turn.
The studies, funded by the Department of Defense, might someday be used to put rats to work gathering information in hazardous or contaminated areas. Although remotely controlled rats may never replace well-trained dogs in rescue situations, they already have a leg up on conventional robots. "Robots have a hard time scrambling over rough terrain," Chapin says. "Rats have that problem licked." — Jeffrey Winters