Importantly, emotion recognition ability decreased with age which was for positive emotions compensated by TRP. No significant effects of TRP on emotion recognition were identified for the whole sample. Additionally, during story reading, activation in insula and supramarginal gyrus was increased after TRP intake. With 5-HTP, immoral behavior without negative consequences was rated as more reprehensible.
In a double-blind placebo-controlled fMRI study with 77 healthy adults, we investigated the influence of a 4 week TRP enriched diet and an acute 5-hydroxytryptophan (5-HTP) intake on two social-cognitive tasks, a moral evaluation and an emotion recognition task. Reduced TRP availability leads to weaker impulse control ability and higher aggression, while TRP supplementation promotes confidence. Its precursor is the essential amino acid tryptophan (TRP).
Understanding of emotions and intentions are key processes in social cognition at which serotonin is an important neuromodulator.