Atheists, by definition, do not believe in the existence of a god or gods. As such, their beliefs about the soul vary depending on their individual perspectives and philosophical positions. Atheism is not a unified belief system, and atheists may hold a wide range of views on metaphysical and spiritual matters.
Some atheists may reject the concept of the soul altogether, seeing it as a product of religious and supernatural beliefs. From their perspective, humans are complex biological organisms with no inherent, immaterial essence or soul.
From a scientific perspective, living organisms, including humans, are the result of biological processes. Life is sustained through various physiological and biochemical functions that allow cells and tissues to function, grow, and reproduce. In the case of humans, our consciousness and self-awareness are believed to arise from the complexity of our brain and nervous system.
When a person dies, their body undergoes decomposition, and the biological processes that sustained life cease to function. The person's consciousness, self-awareness, and all mental and emotional aspects are believed to end with the death of the brain. Different cultures and religious beliefs have various interpretations of what happens after death, but from an atheistic perspective, there is typically no belief in an afterlife or continuation of the individual's consciousness beyond death.
It's important to recognize that atheism doesn't offer a single, definitive answer to questions about the soul or the afterlife. Individual atheists may have diverse beliefs about these matters, just as individuals with religious beliefs hold varying views on similar topics. Atheism is primarily a position on the existence of deities and does not encompass specific beliefs about the soul or the afterlife.