Wondering Why Decisions Take Time? Here's Why Human Thought Has A Speed Limit

The human brain, which is often referred to as the greatest achievement in the course of evolution, surprisingly cannot process information as fast as the amount of sensory data it is exposed to. The peripheral nervous system takes environmental information at a rate of over 1 billion bits per second, while our brains can process only 10 bits per second, according to a new research published in the journal Neuron. This discrepancy reveals fascinating insights into human cognition and raises profound questions about how we perceive and interact with the world. At first glance, the brain's ability to process just 10 bits per second may seem underwhelming.

For perspective, this rate pales in comparison to modern internet speeds. "We become annoyed when the WiFi in our home falls to 100 megabits per second because this interferes with streaming shows on Netflix," according to the authors of the study, Caltech's Jieyu Zheng and Markus Meister. In stark contrast, the human brain processes a billion-bit data stream at dial-up internet speed, yet manages to work reasonably well in real-time applications. To reach this number, the scientists considered tasks such as solving Rubik's Cubes or memorizing shuffled decks of cards. Dividing the number of bits for these tasks by the time needed to complete them, they determined that even memory champions who set record times process information at the same snail's pace of 10 bits per second.

Why is Brain Processing So Slow?

This seems a strange limitation for the brain's filtering mechanism. If a single neuron can wire at a rate fast enough to encode 10 bits per second, why does the brain, with its billions of neurons, still process information at such a restricted rate? The study suggests that this is evolutionary, based on the very survival tasks early organisms had to complete.

The first nervous systems, intended to guide creatures towards food or away from predators, had to function on a one-task-at-a-time basis. This single-task focus enabled prompt, decisive action. Modern humans, despite the ability to abstractly think, may have been left with this limitation. Even in such complex tasks that require multitasking, like driving, the brain is essentially juggling its attention between distinct subtasks rather than processing them simultaneously.

Dual-Mode Operation of the Brain

According to the authors, the human brain works on two modes at once. That is, as follows:

1. Outer Brain: It perceives and aggregates tremendous amounts of sensory data-the colors, the sounds, and the textures surrounding the environment.

2. Inner Brain: A minuscule fraction of the same data at a concentrated pace of 10 bits per second gets processed.

The frontier for neuroscience is to understand how these two systems communicate. When driving, the brain is switching focus constantly from traffic signals to the speedometer to potential hazards. Future research could unravel how the "inner brain" decides which bits to prioritize in those high-stakes scenarios.

Also Read: Can You Rewire Your Brain? 6 Ways To Do It

'Cocktail Party Problem' in the Brain

Humans' inability to process multiple trains of thought simultaneously, popularly known as the "cocktail party problem," underscores this limitation. For instance, it is almost impossible to follow multiple conversations simultaneously at a noisy gathering. Evolution may have optimized the nervous system for making a single decision at a time-an advantage when survival depended on determining whether to fight or flee.

Today, the single-minded quality of this cognitive system helps sustain attention but impedes our capacity to multitask. This particular evolutionary trade-off continues to mold the human mind; it affects every aspect of it, from linguistic processing to dealing with high-stress situations.

How Does the Brian Breaks Down Language Processing?

Another experiment gives a clear view of how the brain processes information in speech. Scientists, by using electrodes implanted in the brains of patients suffering from epilepsy, found that it takes the brain 600 milliseconds to think of a word, apply grammatical rules, and say it.

They recorded activity in Broca's area—a critical region for language production—and identified three distinct steps:

Word Recall: Occurring at 200 milliseconds.

Application of Grammar: Takes 320 milliseconds to occur.

Phonology or Sound Organization: Takes 450 milliseconds to occur.

This further supports that the brain operates on a step-by-step approach. Amazing as it might be able to generate speech continuously in a span of milliseconds, the brain's operation does follow a strictly linear approach; its bottleneck of 10 bits per second does not differ from one activity to another.

This new understanding of the brain's speed limit opens doors for further research. How does the inner brain prioritize specific tasks? How might this bottleneck influence artificial intelligence systems designed to mimic human thought processes?

Implications stretch beyond neuroscience. In the era of multitasking, this study underlines the importance of attentional focus. As Zheng so aptly put it, study of real-life situations like driving may be one of the best ways to learn how the brain accommodates changing priorities in real-time.

How You Can Improve Your Brain's Mental Flexibility

Improving the speed of your thoughts and processing requires improving cognitive functions and strategies that enhance mental agility. Here are some ways to optimize your brain's processing power:

Regular Exercise: Physical activity promotes better blood flow to the brain, enhancing cognitive functions. Aerobic exercises like running or swimming improve memory and focus, allowing for quicker thinking.

Mindfulness and Meditation: The practice of mindfulness meditation enhances attention and reduces mental clutter. They help train your brain to focus on one task at a time, thus enhancing processing efficiency.

Mental Stimulation: Engage in activities that challenge your brain, such as puzzles, memory games, or learning a new skill. These exercises stimulate neural connections, sharpening your processing speed.

Adequate Sleep: Sleep is important for cognitive function. The brain is best able to process information quickly and efficiently when it is well rested.

Healthy Diet: A diet rich in antioxidants, omega-3s, and vitamins supports brain health, enhancing overall mental speed.

This is counterintuitive, for the brain takes in information at a mere 10 bits per second, but such is the depth and efficiency of human cognition that it can work through this very effectively. Extraneous data will be filtered out, and focus will be placed where it matters the most: survival, adaptation, and communication.

Although our mental "speed limit" may be maddening for those who multitask, it speaks to the stunning advancement of the human mind—a machine designed for clarity, precision, and survival in an overwhelmingly complex world.

The unbearable slowness of being: Why do we live at 10bits/s? Neuron. 2024