The Holy Grail of computer science? While it is true that the human brain is used in a comparative way to know how a machine works, the truth is that the operation of computers and human brains does not look like anything. This could change thanks to computer technology that uses light to mimic the functionality of neuronal synapses, opening the way for hardware that combines the speed of modern processors with the efficiency of a computer's intellectual capacity. Ready for the brain of the future?

Computers combine electrical impulses with small on / off switches for their functions; In neurons, on the other hand, chemistry distributes impulses through the channels known as synapses (connections between neurons). The difference is considerable in terms of memory and power consumption, since no hardware comes close to the efficiency and storage capabilities of a human brain.

Now, a team of researchers from the Universities of Oxford, Exeter (United Kingdom) and Münster (Germany), has managed to go a step further by creating a photonic integrated circuit that acts as a synapse.

"The development of computers that function like the human brain has been a holy grail of scientists for decades." Through a network of neurons and synapses, the brain can process and store huge amounts of information simultaneously, using a few tens of watts. of power, conventional computers can not approach this type of performance, "explains Harish Bhaskaran, co-author of the work published in the journal Science Advances.

In computers, there are processor units that control logic and memory. In the human brain, we do not have a CPU or a hard disk, it is about chemical processes.

And, depending on factors such as strength or frequency of the wave, increases in neurotransmitters can continue the message by jumping to other neurons, stopping or accelerating the signal.

Described as synaptic plasticity, changes in this point of control can explain how we learn and process new information, strengthening some circuits while allowing others to wither.

The so-called neuromorphic engineering aims to replicate this way of combining processing and memory in a system, bringing biology and artificial intelligence closer together, that is, microprocessors can be configured more like the human brain than traditional computer chips.

The key has been to build a processor that does the same thing as synapses. "Since synapses outnumber neurons in the brain by about 10,000 to 1, any brain-machine must be able to replicate some form of synaptic mimicry. That's what we've done here," says Wolfram Pernice, co-author of the investigation.

The artificial synapse or synaptic emulation is based on structures made of a phase change material (PCM), which stores and releases significant amounts of energy as it changes from one state to another (solid↔liquid).

The light waves are channeled through the material, with optical pulses changing the PCM in such a way that it imitates the plasticity of a synapse. Although the concept is not new, it is the first time that it has been put into practice.

Neuromorphic light-based processors appear to be the perfect combination of mind and machine. We assist the future of artificial intelligence and information technology.