Phantom percepts: Tinnitus and pain as persisting aversive memory networks

TLDR

Phantom perception is the conscious awareness of a percept without external stimulus, arising from high‑frequency gamma activity in deafferented sensory cortex and sustained by memory mechanisms that reinforce associated distress. The authors propose a working model for the origin of phantom tinnitus and pain based on neuroscience and clinical research, and argue that dynamic overlapping brain networks should be targeted for treatment. The model posits that gamma‑band activity becomes a conscious percept only when linked to larger co‑activated self‑awareness and salience brain networks. Learning mechanisms link the phantom percept to distress, reflected by co‑activation of a nonspecific distress network comprising the anterior cingulate cortex, anterior insula, and amygdala.

Abstract

Phantom perception refers to the conscious awareness of a percept in the absence of an external stimulus. On the basis of basic neuroscience on perception and clinical research in phantom pain and phantom sound, we propose a working model for their origin. Sensory deafferentation results in high-frequency, gamma band, synchronized neuronal activity in the sensory cortex. This activity becomes a conscious percept only if it is connected to larger coactivated “(self-)awareness” and “salience” brain networks. Through the involvement of learning mechanisms, the phantom percept becomes associated to distress, which in turn is reflected by a simultaneously coactivated nonspecific distress network consisting of the anterior cingulate cortex, anterior insula, and amygdala. Memory mechanisms play a role in the persistence of the awareness of the phantom percept, as well as in the reinforcement of the associated distress. Thus, different dynamic overlapping brain networks should be considered as targets for the treatment of this disorder.