Does the brain have a clock and can it be sped up?

Question

Before i start, I'm an engineer and have very limited knowledge on biology and neuroscience. My question is, does the brain have a clock like a computer where it has a set processing speed?

Clocks in CPUs can be overclocked to increase processing speed and I am wondering if the brain has something similar. The average human reaction time is around 0.25ms, Is it possible to react faster to stimuli and not only react but perceive surroundings faster than others. What I mean is while everyone perceives 1 second to be 1 second long, Is it possible to focus and stretch 1 second out mentally to 3-5 seconds and move/think/react faster as a result?

How could this theoretically be achieved too? BCI headset, Chip implant in the brain, serum or chemically?

Answer 1

While the brain is often compared to a computer (sometimes even rightfully), one key aspect people often overlook is that the brain is inherently analog, whereas computers are inherently digital:

All a computer really does in any single operation is to combine 0's and 1's really really fast - and the faster it's able to do that, the faster it will generally be.

A brain however, fundamentally works by combining a multitude of signal inputs with varying strength's and each single operation (encoded by a single neuron) will give output depending on the weighted sum of all inputs.
Such a 'single operation' in itself is reasonably fast, whats make a brain 'slow' is the propagation of the signal to next neuron/operation: Brains are orders of magnitudes bigger than computer chips and instead of metal/wires they use concentration gradients to propagate the electrical signals. Of course it's possible to increase the speed on individual connections between neurons by insulating them, which nature already does.

However, you can't just 'overclock' the whole brain, because there's simply not enough space to add 'full insulation' to every single connection between two neurons (of which there a lot: ~100 billion neurons, with a couple thousand connections each) and because electrical signal propagation by concentration gradients will always be slower than by wires.

I guess if would replace all neuronal connections with metal wires and some concentration gradient to power/voltage/frequency converter using nanobots, you could potentially speed up the brain - or just built cyborgs instead.

Also, not really what you asked - but there IS a clock in the (mammalian) brain and changing it speed, will seriously mess with your day/night or sleep rhythm.

Answer 2

The answer to your question could be yes or no, determining how you define "clock speed".

First, the title of the question is partially misleading since when you talk about a biological "clock", most people will assume you're referring to sleep/wake, night/day, or melatonin-related (daily cycle) activity. (Turns out your question is about speeding up neural processing power).

Brains (neural networks) are a highly parallel asynchronous architecture (as far as the research suggests). There's no centralized "clock" - every input-to-output chain reaction happens at the speed the hardware supports. It's well known that this architecture imposes some fundamental limits on humans, the easiest example being reaction time (you can confirm this with a few quick searches). In this regard, the answer to your question would be "no".

Think of a neuron as being a machine with n inputs and 1 branchable output (see https://www.reddit.com/r/askscience/comments/2yl5jh/how_does_one_neuron_with_multiple_synapses_decide/ on how axons implement a single output which can be branched). The neuron's architecture is event-driven on the inputs. This produces 2 main limits: the calculation step (how quickly the neuron handles the event and sends an output signal on its axon), and propagation speed (how quickly the signal travels).

This leaves 2 clear options: optimize the neuron cell for a faster calculation step, or optimize the propagation speed (think of this as upgrading all your 10/100 Mbps cables to 1/10 Gbps).