Does heaven exist? With well over 100,000 plus recorded and described spiritual experiences collected over 15 years, to base the answer on, science can now categorically say yes. Furthermore, you can see the evidence for free on the website allaboutheaven.org.

Available on Amazon
also on all local Amazon sites, just change .com for the local version (.co.uk, .jp, .nl, .de, .fr etc.)


This book, which covers Visions and hallucinations, explains what causes them and summarises how many hallucinations have been caused by each event or activity. It also provides specific help with questions people have asked us, such as ‘Is my medication giving me hallucinations?’.

Available on Amazon
also on all local Amazon sites, just change .com for the local version (.co.uk, .jp, .nl, .de, .fr etc.)

Observations placeholder

Effects of acute tryptophan depletion on prefrontal-amygdala connectivity while viewing facial signals of aggression



Type of Spiritual Experience


The solution is to eat for health.The sources of tryptophan can be found by followng the tryptophan link. 

A description of the experience

Biol Psychiatry. 2012 Jan 1;71(1):36-43. doi: 10.1016/j.biopsych.2011.07.033. Epub 2011 Sep 13.

Effects of acute tryptophan depletion on prefrontal-amygdala connectivity while viewing facial signals of aggression.

Passamonti L1, Crockett MJ, Apergis-Schoute AM, Clark L, Rowe JB, Calder AJ, Robbins TW.

  • 1Unità di Ricerca Neuroimmagini, Consiglio Nazionale delle Ricerche, Catanzaro, Italy. l.passamonti@isn.cnr.it


Reduced levels of serotonin (5-HT) within prefrontal cortex (PFC)-amygdala circuits have long been implicated in impulsive aggression. However, whether lowering 5-HT alters the dynamic interplay between the PFC and the amygdala has not been directly tested in humans. It is known that manipulating 5-HT via acute tryptophan depletion (ATD) causes variable effects on brain responses to a variety of emotional stimuli, but it remains unclear whether ATD affects functional connectivity in neural networks involved in processing social signals of aggression (e.g., angry faces).


Thirty healthy individuals were enrolled in a randomized, double-blind, placebo-controlled ATD study. On each treatment, brain responses to angry, sad, and neutral faces were measured with functional magnetic resonance imaging. Two methods (psycho-physiological-interaction in a general linear model and dynamic causal modeling) were used to assess the impact of ATD on the functional connectivity between PFC and amygdala.


Data from 19 subjects were available for the final analyses. A whole-brain psycho-physiological-interaction in a general linear model showed that ATD significantly modulated the connectivity between the amygdala and two PFC regions (ventral anterior cingulate cortex and ventrolateral PFC) when processing angry vs. neutral and angry vs. sad but not sad vs. neutral faces. Dynamic causal modeling corroborated and extended these findings by showing that 5-HT depletion reduced the influence of processing angry vs. neutral faces on circuits within PFC and on PFC-amygdala pathways.


We provide strong support for neurobiological accounts positing that 5-HT significantly influences PFC-amygdala circuits implicated in aggression and other affective behaviors.

Copyright © 2012 Society of Biological Psychiatry. All rights reserved.

PMID: 21920502

The source of the experience


Concepts, symbols and science items



Science Items

Activities and commonsteps