Neuroscience of hallucinations

Normal everyday procedures like getting an MRI (Magnetic Resonance Imaging) have been used to find out more about auditory and verbal hallucinations. "Functional magnetic resonance imaging (fMRI) and repetitive transcranial magnetic stimulation (rTMS) were used to explore the pathophysiology of auditory/verbal hallucinations (AVHs)" Throughout the exploring through MRI's of patients,there were "lower levels of hallucination-related activation in Broca’s area strongly predicted greater rate of response to left temporoparietal rTMS." What these findings could suggest is that "dominant hemisphere temporoparietal areas are involved in expressing AVHs, with higher levels of coactivation and/or coupling involving inferior frontal regions reinforcing underlying pathophysiology."

Also through fMRI's, it is found that there can be better understandings on why hallucinations happen in the brain, by understanding emotion's and cognition and how it can prompt physical reactions that can help result in a hallucination. It suggests the theory that "motivations in the body and mind can drive us to certain behaviors that we act in, such as survival instinct and intuition" and that they can work in a hand in hand like fashion. It can also be viewed as a symbolic "homeostasis" that can have adverse effects by having these hallucinations and / or mental illnesses. The amygdala has also been seen to relate to this finding by contributing a "declarative judgement of emotional salience" as well as affecting both "efferent and afferent representational levels of affective autonomic responses in the brain".

Pathophysiological mechanisms
"The left superior temporal cortex, which supports linguistic functions, has consistently been reported to activate during auditory–verbal hallucinations in schizophrenia patients" The Charles Bonnet Syndrome supports the visual cortex deafferentiation proposal. There is irritation in the visual cortex when hallucination occur, which could suggest why it is reported that images that are not real are seen. Although many sufferers of the Charles Bonnet Syndrome are elderly, it can occur in anyone. The reticular activation system can be used to support the neurotransmitters (dopamine and norepinephrine) effect on hallucinations.