The speed at which neurons in the brain transmit signals is much slower than the speed of light. Neurons communicate with each other through electrical impulses called action potentials, which involve the movement of ions across the neuronal membrane.
The speed of an action potential varies depending on factors such as the type of neuron and the properties of its axon (the long projection that carries the signal). However, on average, the speed of propagation of an action potential in the human nervous system ranges from about 1 to 100 meters per second (2 to 224 miles per hour).
To put this in perspective, the speed of light in a vacuum is approximately 299,792 kilometers per second (186,282 miles per second), which is about 1 billion times faster than the speed at which neurons transmit signals.
It's worth noting that the relatively slow speed of neural signals is not a limitation in the functioning of the brain. The brain's complex processing involves the integration of information from multiple neurons and regions, and the timing and patterns of neural activity play a crucial role in various cognitive processes. While the speed of individual neural impulses is much slower than the speed of light, the brain's overall computational power and capabilities arise from the vast interconnectedness and parallel processing of its billions of neurons.