Introduction: Deceptive intentions may be realized by imparting false (simple deception) or true (manipulative truth) information. Both forms of deception require inferring others' thoughts and are underpinned by the theory of mind (TOM) neural system. Manipulative truth is thought to more strongly recruit these processes. However, the organization of functional interactions underlying simple deception and manipulative truth remains unclear. Materials and Methods: We performed psychophysiological interaction analysis for a key node in the TOM system, the right temporoparietal junction (rTPJ), using functional MRI data obtained from 23 volunteers (14 men and 9 women, age range 18-45 years) during the sender-receiver game. During the game, participants sent true, simple deceptive, or manipulative truthful messages to another player according to their own choice. A Bayesian approach to statistics was employed to perform statistical inference and define voxels with significant changes in functional interactions. Results: We observed functional interactions between nodes of the TOM system (bilateral TPJ, left precuneus, left dorsomedial prefrontal cortex, and right superior temporal sulcus) characterizing both forms of deception. We identified an increment in functional interactions of the rTPJ with the left TPJ (lTPJ) and right precuneus associated with manipulative truth. Furthermore, we demonstrated that a higher rate of manipulative truthful actions was associated with weaker functional interactions between the rTPJ and lTPJ, left precuneus, and left dorsomedial prefrontal cortex. Discussion: Compared with simple deception, manipulative truth is associated with a higher demand for socio-cognitive processes that contributes to the cognitive load of this form of deception. Impact statement This study contributes significantly to our understanding of the fundamental characteristics of socio-cognitive brain mechanisms. Analysis of psychophysiological interactions is highly relevant to the neurophysiology field to promote a shift from studying local activity changes in brain structures to elucidating the activity-related characteristics of functionally connected regions. The presented research for the first time demonstrates functional interactions between nodes of the theory of mind system underpinning deception through communication of false information and telling the truth to deceive (manipulative truth). Understanding the neural substrates of deception may be applied in the forensic field to develop techniques for detecting deception.
Keywords: deception; fMRI; manipulative truth; psychophysiological interactions analysis; sender-receiver game; theory of mind.