There is no Left Brain/Right Brain dichotomy
■ Dopamine is a pleasure chemical
Dopamine has many functions in the brain, from supporting concentration to regulating the production of breast milk. Even in its most closely associated functioning it is usually considered to be involved in motivation (wanting) rather than the feeling of pleasure itself.
■ Low serotonin causes depression
A concept almost entirely promoted by pharmaceutical companies in the 1980s and 90s to sell serotonin-enhancing drugs like Prozac. No consistent evidence for it.
■ Video games, TV violence, porn or any other social spectre of the moment "rewires the brain"
Everything "rewires the brain" as the brain works by making and remaking connections. This is often used in a contradictory fashion to suggest that the brain is both particularly susceptible to change but once changed, can't change back.
■ We have no control over our brain but we can control our mind
The mind and the brain are the same thing described in different ways and they make us who we are. Trying to suggest one causes the other is like saying wetness causes water.