Melasma Causes. Melasma is usually caused by the sun, hormones in birth control pills, hormone replacement therapy, medications and pregnancy. When Melasma is caused by pregnancy it is called chloasma. In some women, when the skin is exposed to sunlight, brown blotches of excess pigment form due to the interaction with hormones or chemicals. Melasma is believed to be hereditary and woman with darker skin tones tend to be more at risk for this disorder.
Some research suggests that the hippocampus may participate only in consolidation processes lasting a few years. The entorhinal cortex, on the other hand, gives evidence of temporally graded changes extending up to 20 years, suggesting that it is this region that participates in memory consolidation over decades. The entorhinal cortex is damaged in the early stages of Alzheimerâs disease.
The analysis of the anatomical and physical bases of learning and memory is one of the great successes of modern neuroscience. Thirty years ago little was known about how memory works, but now we know a great deal. This Chapter will discuss four issues that are central to learning and memory. First, what are the different types of memory? Second, where in the brain is memory located? One possibility is that human memory is similar to the memory chip in a personal computer (PC), which stores all the memory in one location.