The Non-Immortal Soul view is different and contends that – biblically speaking – the word “soul” applies to the entire person. When God first created Adam in Paradise, He “breathed into his nostrils the breath of life, and man became a living soul” (Genesis 2:7). Thus man doesn’t have a separate soul, but rather he is a soul (see also Joshua 10:35, 37, 39; Lev. 23:30; Acts 27:37, KJV). After man sinned, his entire person, or soul, became mortal, or subject to death. When a sinner dies, he or she returns to the dust, and “the breath of life” returns to God. This “breath” is not a conscious entity, but is the spark of life that exists in everything alive. At death, the sinner is truly dead – unconscious, asleep, waiting for the resurrection. This view is sometimes called “soul sleep.”
One compelling piece of evidence comes from brain scans of expert musicians. There’s been a lot of research done on how musician brains differ from the brains of ordinary people. One specific study used a particular brain scan called Diffusion MRI, which gives us information about tissues and fibers inside the scan region in an non-invasive way. The study suggested that the estimated amount of practice an expert piano player did in childhood and adolescence was correlated with the white matter density in regions of the brain related to finger motor skills, visual and auditory processing centers, and others. Most significantly, there was a direct correlation between how many hours they practiced and how dense their white/myelin matter was.