By analyzing minute emotional reactions in real-time during normal conversation, FIML practice disrupts the consolidation, or more often the reconsolidation, of “neurotic” responses.
In FIML, a neurotic response is defined as “an emotional response based on a misinterpretation.” The misinterpretation in question can be incipient (just starting) to long-seated (been a habit for years).
The response is disrupted by FIML practice and, thus, tends not to consolidate or reconsolidate, especially after several instances of learning that it is not valid.
A neurotic response is a response based on memory. The following study on fear memories supports the above explanation of FIML practice.
Memories become labile when recalled. In humans and rodents alike, reactivated fear memories can be attenuated by disrupting reconsolidation with extinction training. Using functional brain imaging, we found that, after a conditioned fear memory was formed, reactivation and reconsolidation left a memory trace in the basolateral amygdala that predicted subsequent fear expression and was tightly coupled to activity in the fear circuit of the brain. In contrast, reactivation followed by disrupted reconsolidation suppressed fear, abolished the memory trace, and attenuated fear-circuit connectivity. Thus, as previously demonstrated in rodents, fear memory suppression resulting from behavioral disruption of reconsolidation is amygdala-dependent also in humans, which supports an evolutionarily conserved memory-update mechanism. (Source: Disruption of Reconsolidation Erases a Fear Memory Trace in the Human Amygdala)
We say that FIML practice also stops incipient consolidation of misinterpretations because FIML is designed to prevent the formation of neurotic responses as they happen.