Feeds

Memristors can maybe learn like synapses

Human-brain-like computers, annihilation of humanity one step closer

Top three mobile application threats

Memristors can potentially learn like synapses and be used to build human brain-like computers according to Wei Lu, a University of Michigan scientist.

He thinks that two CMOS circuits connected by a memristor is analogous to two neurons in the brain connected by a synapse. It is thought that synaptic connections strengthen as the neurons either side fire and so brain 'circuits' are established, which constitutes the basis of human learning.

A memristor is resistant to electricity and retains its electrical state when power is switched off - a memory resistor. It can be made more or less resitive by putting a voltage across it. The resistance level is retained when power is switched off.

Lu thinks that cats can process information faster than supercomputers because they process data in parallel instead of in tens of thousand linear streams as in a modern supercomputer - though this seems a strained analogy because the tens of thousands of cores in a supercomputer do act in parallel.

He says a cat brain can recognise a face 83 times faster than a supercomputer because, he posits, synapses are switches that can interconnect thousands of neurons and can change their state to set up and modify brain circuits, such as those involved in facial recognition.

Lu says that a supercomputer, although it can have tens of thousands of processing cores, has little connectivity between them, and so is only good for crunching the data involved in simple tasks with a limited set of variables. This again seems a little forced to us; simulating an atomic explosion is a simple task with limited variables?

But let's suppose that Lu is right and press on. He's connected two CMOS curcuits by a silver and silicon Memristor and powered the two CMOS circuits on and off with varying time gaps between them. The memristor alters its state differently depending on the timing of the powering of the CMOS circuits.

This is said to be the same behaviour as that shown by synapses, called "spike timing plastic dependency", which is thought to be the possible basis for memory and learning in human and other mammalian brains.

The synaptic connection between neurons becomes stronger or weaker, as the time gap between when they are stimulated becomes shorter or longer. In the same way, the shorter the time interval the lower the resistance of the memristor to electricity flowing across it between the two CMOS circuits.

A 20 millisecond time interval between the two CMOS circuits caused a resistance level roughly half that of a 40 millisecond gap. Lu said: "Cells that fire together wire together... The memristor mimics synaptic action.

"We show that we can use voltage timing to gradually increase or decrease the electrical conductance in this memristor-based system. In our brains, similar changes in synapse conductance essentially give rise to long term memory."

He now wants to build prototype devices with tens of thousands of such CMOS circuit/memristor elements, and see if the collection can start responding to stimuli, such as an image of a face, in coherent and dependable ways.

There's more information here and here. Lu's paper or letter is published in NanoLetters and is accessible for a fee. ®

Combat fraud and increase customer satisfaction

More from The Register

next story
Samsung Galaxy S5 fingerprint scanner hacked in just 4 DAYS
Sammy's newbie cooked slower than iPhone, also costs more to build
Microsoft lobs pre-release Windows Phone 8.1 at devs who dare
App makers can load it before anyone else, but if they do they're stuck with it
Leaked pics show EMBIGGENED iPhone 6 screen
Fat-fingered fanbois rejoice over Chinternet snaps
Feast your PUNY eyes on highest resolution phone display EVER
Too much pixel dust for your strained eyeballs to handle
Report: Apple seeking to raise iPhone 6 price by a HUNDRED BUCKS
'Well, that 5c experiment didn't go so well – let's try the other direction'
US mobile firms cave on kill switch, agree to install anti-theft code
Slow and kludgy rollout will protect corporate profits
Rounded corners? Pah! Amazon's '3D phone has eye-tracking tech'
Now THAT'S what we call a proper new feature
Oh no, Joe: WinPhone users already griping over 8.1 mega-update
Hang on. Which bit of Developer Preview don't you understand?
Zucker punched: Google gobbles Facebook-wooed Titan Aerospace
Up, up and away in my beautiful balloon flying broadband-bot
Sony battery recall as VAIO goes out with a bang, not a whimper
The perils of having Panasonic as a partner
prev story

Whitepapers

Designing a defence for mobile apps
In this whitepaper learn the various considerations for defending mobile applications; from the mobile application architecture itself to the myriad testing technologies needed to properly assess mobile applications risk.
3 Big data security analytics techniques
Applying these Big Data security analytics techniques can help you make your business safer by detecting attacks early, before significant damage is done.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Securing web applications made simple and scalable
In this whitepaper learn how automated security testing can provide a simple and scalable way to protect your web applications.