Stepping out of the room, Kat closed the door softly and joined Painter in the neighboring observation room. High-backed chairs surrounded a conference table.
“She’s asleep.” Kat sank into one of the chairs with a sigh.
“Maybe you should, too. It will be a few more hours until Gray’s plane lands in India.”
She nodded. “I’ll check with the sitter who’s watching Penelope, then crash for a couple of hours.”
The door to the outer hall opened. They both turned to see Lisa Cummings and the center’s pathologist, Malcolm Jennings, enter the room. The two, dressed in matching white laboratory smocks and blue scrubs, were in an animated but whispered conversation. Lisa had her hands shoved in the pockets of her smock, pulling the coat tight to her shoulders, a sign of deep concentration. She had put her long blond hair up into a French braid. The pair had spent the last hour in the MRI suite, going over results.
From their heated, excited chatter—full of medical jargon beyond Painter’s comprehension—they had come to some conclusions, though not necessarily a consensus.
“Neuromodulation of that scale without glial cell support?” Lisa said with a shake of her head. “The stimulation of the nucleus basalis, of course, makes sense.”
“Does it?” Painter asked, drawing their attention.
Lisa seemed to finally see Painter and Kat. Her shoulders relaxed, and her hands left her pockets. A whispery smile feathered her features as her gaze met his. One of her hands trailed across Painter’s shoulders as she passed and took one of the seats.
Malcolm took the last remaining seat. “How’s the child doing?”
“Asleep for the moment,” Kat said.
“So what have we learned?” Painter asked.
“That we’re moving through a landscape both new and old,” Malcolm answered cryptically. He slipped on a pair of glasses, tinged slightly blue for reading computer screens with less eyestrain. He settled them in place and opened a laptop he’d carried under one arm. “We’ve compiled the MRI scans of the child and my analysis of the skull. Both devices are the same, though the child’s is more sophisticated.”
“What are they?” Kat asked.
“For the most part, they’re TMS generators,” Malcolm answered.
“Transcranial magnetic stimulators,” Lisa elaborated, though that didn’t help much.
Painter shared a confused expression with Kat. “Why don’t you start at the beginning?” he asked. “And use small words.”
Malcolm tapped the side of his head with a pen. “Then we’ll start here. The human brain. Composed of thirty billion neurons. Each neuron communicates to its neighbors via multiple synapses. Creating roughly one million billion synaptic connections. These connections, in turn, create a very large number of neural circuits. And by large, I mean in the order of ten followed by a million zeros.”
“A million zeros?” Painter said.
Malcolm looked over the edge of his glasses at Painter. “To give you some scale. The total number of atoms in the entire universe is only ten followed by eighty zeros.”
At Painter’s shocked reaction, Malcolm nodded. “So there’s a vast amount of computing power locked in our skulls that we’re only beginning to comprehend. We’ve just been scratching the surface.” He pointed toward the window. “Someone out there has been delving much deeper.”
“What do you mean?” Kat asked, her expression showing worry for the girl.
“With our current technology, we’ve been making tentative strides into this new frontier. Like sending probes into space, we’ve been slipping electrodes into brains. All input into the brain is via electrical impulses. We don’t see with our eyes. We see with our brains. It’s why cochlear implants work to return hearing to the deaf. The implant turns sounds into electrical impulses, which are passed to the brain via a microelectrode inserted into the auditory nerve. Over time, the cortex learns to reinterpret this new signal, and like learning a new language, the deaf begin to hear.”
Malcolm waved to his laptop. “The human brain—being electrical, being malleable to new signals—has an innate ability to connect to machines. In some regards, that makes us perfect natural-born cyborgs.”
Painter frowned. “Where are you going with all this?”
Lisa placed a hand atop his. “We’re already there. The division between man and machine is already blurred. We now have microelectrodes so small that they can be inserted into individual neurons. At Brown University in 2006, they inserted a microchip into a paralyzed man’s brain, linked by a hundred of these microelectrodes. Within four days of practicing, the man—through his thoughts alone—could move a computer cursor on a screen, open e-mail, control a television, and move a robotic arm. That’s how far we’ve breeched the frontier.”
Painter glanced to the window. “And someone’s gone farther than that?”
Both Lisa and Malcolm nodded.
“The device?” Painter asked.
“A step above anything we’ve seen. It has nanofilament electrodes so tiny that it’s hard to say where the device ends and the child’s brain begins. But the basic function is well known. From studies done at Harvard University on rats, we know that TMS devices promote the growth of neurons—though, oddly, only in areas involved with learning and memory. We still don’t understand why. But what we do know is that magnetic stimulation can also turn on and off these neurons like a switch. Children are especially pliable in this manner.”
“So if I understand this all correctly, someone has wired such a device to the child, stimulated nerve growth in a specific area, and now controls its functioning like a switch.”
“Generally speaking, yes,” Malcolm said. “They’ve tapped deep into that vast neural network I described. Only with the magnetic-stimulation of new neurons, they’ve expanded that network even farther. And if I’m right, I’d say they’ve focused that expansion in a very narrow area.”
“What makes you say that?”
“There’s a law in neurology. Hebb’s law. That basically states nerves that fire together, wire together. By stimulating one site in the brain, they are reinforcing it harder and harder.”
“But to what end?” Painter asked.
Malcolm shared a worried glance with Lisa. He wanted her to explain.
She sighed. “I spoke to the psychologist, Zach Larson, who examined the girl when she was first brought in. From her nonresponsiveness, repetitive behavior, and sensitivity to stimulation, Zach is certain the girl is autistic. And from the behavior you described at the safe house, probably an autistic savant.”