Apart from perceptions, mental images are the most frequent experiences of the conscious mind. Mentation can be understood as a process which consists in the manipulation of recalled or imagined mental images. The scientific literature related to this process is relatively scant. This article reviews the relevant original and recent neurophysiological data in such a way as to enable the presentation of a synthetic theory of the neuronal mechanisms that form mental images. Recurrent axons and some reproductive efferent connections constitute the neural circuitry essential for imagery. These connections enable the reverberating, circular arousal of the upper levels of the hierarchical structure active during previous perceptions. The recalling of a mental image evokes an accompanying electromagnetic field. The investigation of its functional role is a challenge for contemporary neural scientists.

Keywords: mental image, Memory, imagery, electrical activity, Electromagnetic field