Recent studies that have taken images of the brain using functional Magnetic Resonance Imaging (fMRI) have shown there is an area of the frontal lobe particularly related to imagination. The outer layer of tissue (cortex) around a fold (sulcus) in the brain known as the paracingulate activates when you imagine yourself in a future scenario or imagine what others are thinking or feeling. We also know from studying patients with brain damage that the frontal lobe in general is important for complex human behaviours, such as planning and our sense of self.
The key role played by the paracingulate sulcus area in imagination suggests that it is also involved in reality monitoring. If this part of the brain functions poorly then it might influence your ability to differentiate reality from imagination – and so increase the likelihood that you could experience hallucinations.
ngd-What’s interesting about this is that a sulcus is a valley in the folds of the brain and the shorter the valley, the greater the likelihood of hallucinations.