According to Ronald R. Hoy, a professor of neurobiology and behavior at Cornell University, the jumping spider is one of the smartest of all invertebrates. The inside of any spider is under pressure, like the air in a balloon because spiders move by pushing fluid through valves. They are hydraulic. If you insert an electrode into the spider’s brain, the insides might squirt out.
Dr. Hoy and his colleagues wanted to study jumping spiders because they are quite unique. For one, they do not wait in a sticky web for lunch. They seek out prey, stalk it and pounce. “They’ve essentially become cats,” Dr. Hoy said. And they do all this with a brain the size of a poppy seed and a visual system that is completely different from that of a mammal: two big eyes dedicated to high-resolution vision and six smaller eyes that pick up motion.
Dr. Hoy gathered four graduate students in various disciplines to solve the problem of recording activity in a jumping spider’s brain when it spots something interesting — a feat nobody had accomplished before. In the end, they not only managed to record from the brain, but discovered that one neuron seemed to be integrating the information from the spider’s two independent sets of eyes, a computation that might be expected to involve a network of brain cells.
The team used a 3-D printer to make a solid frame to hold the spider. They threaded an ultrathin metal wire into the tiny brain. The apparatus and technique allowed them to make a hole small enough to heal quickly, keeping the brain intact and inside the spider. Next they showed the spider images of prey and other spiders that attracted its interest. They used computer analysis to sort out the electrical activity in the brain picked up by the wire.
Dr. Hoy said the research opened new avenues of study into the brains of spiders and suggested an efficiency of brain computation that would no doubt interest roboticists and artificial intelligence specialists.