Atheists, by definition, do not believe in the existence of any gods or deities. Since the concept of the soul is often tied to religious or spiritual beliefs, many atheists do not believe in the existence of a soul either.
For atheists who do not believe in a soul, the idea of consciousness and the mind can be explained through naturalistic and scientific perspectives. According to these views, consciousness and the mind are emergent properties of the brain's complex neural processes. In other words, consciousness is a product of the brain's activity, and it arises from the interactions of billions of neurons and their networks.
From a scientific standpoint, various studies and evidence suggest that our thoughts, emotions, memories, and other mental processes are all products of the brain's physical and chemical activities. Changes in brain function due to injury, disease, or chemical imbalances can significantly alter an individual's personality and behavior, supporting the idea that consciousness is intimately connected to the brain.
The perception of the self, individuality, and subjective experiences can be explained by the complex interactions of the brain's neural networks. While the mind is incredibly complex and there is still much to learn about consciousness, scientific research provides a materialistic explanation for mental processes without resorting to the notion of a soul.
It's important to note that atheism is a broad category encompassing various worldviews and philosophical perspectives. Not all atheists will necessarily hold the same views on consciousness and the mind, but the absence of belief in a higher power often leads them to seek naturalistic explanations for phenomena that others might attribute to a soul or the supernatural.