Communication relies on an alignment of meaning. For example, when talking about something as mundane as daily routine, we tend to think about things like morning preparations, meals, work, family time, and sleep. An overlap in these associations fosters a sense of understanding and connection among interlocutors. Occasionally, a topic can evoke atypical or entirely random associations, which other people find hard to understand. In psychopathology, incoherent communication is central to a diagnostic ascription of Formal Thought Disorder, where it is assumed to reflect the disorganization of thought processes. Formal Thought Disorder is associated with higher illness severity, poor prognosis, and impairments in social and global functioning, yet it remains one of the least understood symptoms in psychosis (all the more so in other disorders), with no established treatments.
One key open issue is that most research on formal thought disorder focuses on communication impairments and not on actual thoughts. Indeed, elucidating covert thought dynamics is a challenging endeavor since thought processes cannot be measured directly. The overall aim of 'Dynamics of thought and thought disorders' (DynaT) was to study mechanisms of formal thought disorder, and dissociate impairments in thought dynamics from impairments in the communication or expression of thought, through the use of state-of-the-art methods, including mathematical modeling and machine learning analysis of neural activity.
To achieve this overarching aim, DynaT pursued three specific objectives investigated in three separate studies. The first specific objective focused on the analysis of mechanisms of formal thought disorder in psychosis, particularly focusing on the interaction between abnormalities in associative memory structure (i.e. are concepts linked to one another in an abnormal way?), its retrieval (whether a concept meaningfully constrains the retrieval of another concept), and the monitoring and regulation of speech (i.e. how well can people withhold the expression of atypical associations or incoherent thoughts). The second specific objective focused on elucidating the finding that people with formal thought disorder often have difficulty disengaging from dominant local associations that intrude the stream of speech and disrupt the global communicative intent (e.g. "my mother, father, son, and Holy Ghost"). The third specific objective of DynaT involved investigating whether other people without psychosis who suffer from any psychiatric symptoms can also exhibit incoherence in thought or speech.
