AP Psychology Chapter Summary

* * It was believed earlier that the brain was only influenced by genes and was unchangeable. We know now that the idea of environmental enrichment vs. deprivation can modify the brain. There are two effects of the environment on physiological processes. They are brain plasticity and environmental stressors and damage in the hippocampus region. * * * Effect 1: Environmental effects on dendritic branching (brain plasticity) *
Environmental stimulation refers to the way the environment provides stimulation in the form of social interaction and learning opportunities for animals and humans.

Experiences are processed in the brain's nervous system, and stimulating environments will result in increased numbers of synapses
Both types are quite frequent in humans but the long allele is slightly more frequent (57%) * Results: Researchers found that participants who carried a mutation of the 5-HITT gene and who had experienced many stressful events were more likely to become depressed after stressful events than those participants who carried the normal 5-HTT gene. * -this gene could indicate a vulnerability to depression after stress and the researchers speculated whether the gene could moderate individual responses to environment * Evaluation: A large proportion of the population carries the mutation of the 5-HTT gene that makes the, susceptible to depression after traumatic events, it can be difficult to conclude that the gene is a major contribution to depression. The study showed a correlation between the presence of a 5-HITT short allele and depression but it is not possible to establish a cause-effect