Examining tensions between the past and present uses of scientific concepts can help clarify their contributions as tools in experimental practices. This point can be illustrated by considering the concepts of mental imagery and hallucinations: despite debates over their respective referential reliabilities remaining unresolved within their interdependent histories, both are used as independently stable concepts in neuroimaging experiments. Building on an account of how these concepts function as tools structured for pursuit of diverging goals in experiments, this paper explores this (...) tension by re-examining the continued reliance of each concept on inverse characterisations inherited from the nominally-discarded ‘mediator-view’ of sensory-like mental phenomena (SLMP). In doing so, I seek to demonstrate how examining unresolved tensions can help highlight that entrenched associations can remain both integral to, and obscured by, the uses of concepts as goal-directed tools within experimental practices. (shrink)

The psychopathological phenomenon of delusions of influence comprises variable disturbances of the self-environment-border leading to the feeling of external influence on thoughts, feelings, impulses or behaviors. Delusions of influence are a hallmark in psychotic illness, but nevertheless, attenuated forms can also appear in healthy individuals. Here we present a newly developed paradigm to induce and assess feelings of external influence during instructed imaginations in healthy individuals. In the current study, we asked 60 healthy individuals to visually imagine different objects. To (...) induce feelings of external influence, we applied one of three different physical setups, and informed the participants whether or not an external influence was attempted during the respective trial. The physical setup as well as the information given to the participants alone were able to modulate the feeling of external influence in all three interventions. The impact of information significantly exceeded the impact of the physical setup on the ratings of experienced external influence. Moreover, the response latency correlated with the estimated feeling of external influence. Additional analyses addressed the influence of the emotional content of imagined objects and examined the intensity and emotional valence of the imaginations. Further supplemental analyses correlated external influence estimation of the participants with other psychopathological measures. In conclusion, this study endorses a quantitative model of psychopathological characteristics, in this case feelings of external influence that can be induced by external cues. (shrink)