In his 2012 book How to Create a Mind, Ray Kurzweil argues that specialized brain cells called spindle neurons give humans unique emotional and moral capabilities. He contends that these unusually shaped cells allow us to experience complex feelings such as love and make sophisticated moral judgments in ways other animals cannot.
But newer research tells a different story. Continue reading to learn about spindle neurons and what scientists have discovered in recent years.
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Spindle Neurons
In How to Create a Mind, Ray Kurzweil points to specialized brain structures that enable uniquely human capabilities. He highlights spindle neurons—specialized brain cells with extensive connections spanning the entire brain—as crucial for processing complex emotions such as love, moral judgment, and aesthetic appreciation. Humans have approximately 80,000 of these cells, while great apes have far fewer and other mammals lack them entirely.
These neurons become active during intense emotional experiences, such as looking at a romantic partner or hearing your child cry. Their extensive connectivity allows higher-level emotions to integrate information from diverse brain regions, though they don’t engage in rational problem-solving—which explains why you can’t consciously control experiences such as falling in love or your emotional responses to music. Human infants develop spindle neurons between four months and three years of age, coinciding with the emerging capacity for moral reasoning and emotional understanding. According to Kurzweil, this timing suggests that our most sophisticated emotional and moral capabilities depend on pattern recognition.
| Spindle Neurons Might Be Less Uniquely Human Than Expected Research on spindle neurons, or Von Economo neurons, has advanced since Kurzweil wrote this book in 2012. At the time, scientists knew that spindle neurons were large, unusually shaped brain cells found in areas associated with social emotions and self-awareness, and that they existed in humans and apes, but their function remained mysterious. Since then, researchers have managed to record the electrical signals from living human spindle neurons, monitoring how they communicate with other parts of the brain. They found that spindle neurons fire differently than other brain cells, suggesting they process information in unique ways, though scientists are still working to understand what this means for cognition. Scientists have also found that spindle neurons aren’t limited to primates, as once thought. Multiple whale species, including humpback, sperm, and killer whales, have these neurons, as do elephants. These animals share traits such as large brains, complex social behaviors, and long periods of learning. Along with the discovery that these neurons likely evolved independently in different animal species millions of years apart, this suggests spindle neurons might be less specialized to uniquely human experiences, as Kurzweil surmises, and more an evolutionary innovation for processing social information in large, complex brains. |
Explore Further
In his book, Kurzweil presents his theory that the mind emerges from hierarchical pattern recognition in the neocortex. To explain what makes the human brain so good at this process, Kurzweil identifies four features that make the brain’s pattern recognition system so effective. One of these features is spindle neurons. Kurzweil explains that, when these neurons work together with neuroplasticity, motivational systems, and continuous learning, the brain creates the full spectrum of human cognitive abilities through simple, repeated pattern recognition structures.
To learn more about this process and better understand how spindle neurons contribute to it, take a look at Shortform’s guide to How to Create a Mind.
