Increased brain size in humans may allow for greater capacity for specialized expertise. Expanded cortical regions The two major perspectives on primate brain evolution are the concerted and mosaic approaches. In the concerted evolution approach, cortical expansions in the brain are considered to be a by-product of a larger brain, rather than adaptive potential. Studies have supported the concerted evolution model by finding cortical expansions between macaques and marmosets are comparable to that of humans and macaques. Researchers attribute this result to the constraints on the evolutionary process of increasing brain size. In the mosaic approach, cortical expansions are attributed to their adaptive advantage for the species. Researchers have attributed hominin evolution to mosaic evolution. Simian primate brain evolution studies show that specific cortical regions associated with high-level cognition have demonstrated the greatest expansion over primate brain evolution. Sensory and motor regions have showcased limited growth. Three regions associated with complex cognition include the frontal lobe, temporal lobe, and the medial wall of the cortex. Studies demonstrate that the enlargement in these regions is disproportionately centered in the temporoparietal junction (TPJ), lateral prefrontal cortex (LPFC), and anterior cingulate cortex (ACC). The TPJ is located in the parietal lobe and is associated with morality, theory of mind, and spatial awareness. Additionally, the Wernicke's area is located in the TPJ. Studies have suggested that the region assists in language production, as well as language processing. The LPFC is commonly associated with planning and working memory functions. The Broca's area, the second major region associated with language processing, is also located in the LPFC. The ACC is associated with detecting errors, monitoring conflict, motor control, and emotion. Specifically, researchers have found that the ACC in humans is disproportionately expanded when compared to the ACC in macaques. Fossils show that although Homo sapiens''' total brain volume approached modern levels as early as 300,000 years ago, parietal lobes and cerebella grew relative to total volume after this point, reaching current levels of variation at some point between the approximate dates of 100,000 and 35,000 years ago. Studies on cortical expansions in the brain have been used to examine the evolutionary basis of neurological disorders, such as Alzheimer's disease. For example, researchers associate the expanded TPJ region with Alzheimer's disease. However, other researchers found no correlation between expanded cortical regions in the human brain and the development of Alzheimer's disease. Cellular, genetic, and circuitry changes Human