Many studies have found ___________ in people with a history of violent behaviour, including people convicted of arson and other violent crimes and people who attempt suicide by violent means.
low serotonin turnover
Follow-up studies on people released from prison have found that those with lower serotonin turnover had a ____ probability of further convictions for violent crimes.
The effects are not sufficiently powerful that we could use blood tests to make important decisions about individuals, such as which prisoners should be eligible for ____.
The results of low serotonin turnover are less clear for aggressive behaviour in the ____ ____ (where extreme violence is uncommon).
It is possible to alter serotonin synthesis by changes in ____. Neurons synthesise serotonin from tryptophan, an amino acid found in small amounts in proteins.
____ crosses the blood-brain barrier by an active transport channel that it shares with phenylalanine and other large amino acids. Thus, a diet high in other amino acids impairs the brains ability to synthesise serotonin.
Considering these results, it would seem prudent for anyone with aggressive or suicidal tendencies to reduce consumption of aspartame (NutraSweet, which is 50% ____) and maize (American corn), which is high in ____ and low tryptophan.
Much of the variation in serotonin activity, and therefore violence, relates to ____.
People vary in the gene that controls ____ ____, the enzyme that converts tryptophan into serotonin. People with less active forms of this enzyme are more likely than average to report frequent anger and aggression.
When researchers have used drugs or diet to ____ serotonin levels, some people felt depressed, others became more aggressive or impulsive, and those with previous drug problems reported a craving for drugs.
Serotonin's role is not specific to aggression. A better hypothesis is it high levels of serotonin ____ a variety of impulses, and low levels remove inhibitions.
Although most studies imply that serotonin inhibits aggressive behaviour, the brain releases serotonin ____ aggressive behaviour. Apparently, a low level of serotonin activity prior to aggression magnifies the response when serotonin is suddenly released at the start of an aggressive encounter.
Both experiences and genetics modify activity in the ____, one of the main areas for regulating anxiety.
The response to an unexpected loud noise, known as the ____ ____, is extremely fast. Auditory information goes 1st to the cochlea nucleus in the medulla and from there directly to an area in the pons that commands tensing the muscles, especially the neck muscles.
Tensing the neck muscles is important because it neck so ____ to injury.
Information reaches the ____ within 3 to 8 ms after a loud noise, and then the full startle reflex occurs in less than 2/10 of a second.
Although you don't have to learn to fear loud noises, your current mood or situation modifies your reaction. Your startle reflex is more ____ if you are already tense.
People with ____________, who are certainly known for their intense anxiety, show a much enhanced startle reflex.
post-traumatic stress disorder
Psychologist measure variations in the startle reflex is a gauge of ____ or ____.
fear or anxiety
Results of such studies consistently show that after animals have learned to associate a stimulus with shock, that stimulus becomes a ____ ____, and presenting the fear single just before a sudden loud noise enhances the startle response.
Conversely, a stimulus previously associated with a pleasant stimuli or the absence of danger becomes a ____ ____ that decreases the startle reflex.
Investigators have determined that the ____ is important for enhancing the startle reflex.
Many cells in the amygdala, especially in the basolateral and central nuclei, get input from pain fibres as well as vision or hearing, so the circuitry is well-suited to establish ____ ____.
Some cells in the amygdala respond strongly to ____, others to ____, and still others to surprises in either direction.
rewards : punishments
Output from the amygdala to the hypothalamus controls ____ fear responses, such as increased BP.