Leituras pela manhã - acerca do papel da imaginação na extinção de memórias ameaçadoras

... que espoletam comportamentos desadaptados de medo e ansiedade.

Attenuating Neural Threat Expression with Imagination

The current study bridges the gap between the clinic and the laboratory and, in doing so, demonstrates that a scientific interrogation of imagination’s role in fear regulation may provide novel insight into how threat memories are represented, accessed, and modified by mental action.

Drawing across this wide range of evidence, we propose the following mechanism: imagination of the conditioned threat stimulus will activate stimulus-specific perceptual representations that will, in turn, engage the neurocircuitry that underlies threat acquisition: the vmPFC, hippocampus, amygdala, and NAc. In the absence of any danger, repeated imaginings will have the same effect as actual exposures—neural and physiological responses to the conditioned threat stimulus will diminish.

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Nothing in the real world can be perfectly represented by the brain, but a “good enough” approximation allows one to predict and navigate their environment. Imagination is a process by which information about one’s environment can be simulated and reorganized in order to improve predictions and learn under reduced risk. Imagination, when reduced to this basic functionality, is not unique to humans. Animals demonstrate deliberation when making choices, and this deliberation is thought to be analogous to imagined simulations of possible outcomes (Redish, 2016). Moser and Moser (2011) demonstrate that the resting mouse will both “replay” past actions and “preplay” future ones in a maze task. Furthermore, 

Takahashi et al. (2013) show that rats imagine outcomes when inferring paths through a mechanism that requires the integration of reinforcement histories of environmental cues via the orbitofrontal cortex. The human brain, however, may use imagination to draw upon richer experiences and cognitive frameworks in order to influence memory, learning, emotion, decision making, expectations, and beliefs. In this way, imagination is a process that can inform the study of cognition and behavior in both human and non-human animals.

This investigation has strong implications for the treatment of anxiety and threat-related disorders. While the integration of imagination with exposure therapy is not new, our approach to threat simulation is. Clinical applications of imagination are not pure exposure tools: patients have expectations of recovery, they sometimes are trained to control their breath, and imagination may be combined with cognitive restructuring techniques, or other talk-based therapies (Craske et al., 2014). In this experiment, the only difference between the real and imagined extinction procedure is the existence of the external stimulus. This allowed us to directly test whether stimulus re-exposure is critical to extinction learning, or whether it can be internally simulated. We conclude that an internal simulation of a real-world experience can alter the way one responds to that situation in the future. Indeed, imagined exposures to threatening stimuli are effective in the reduction of learned threat responses and evoke a network of brain activation similar to real extinction. These novel findings bridge a long-standing gap between clinical practice and cognitive neuroscience. Once a topic reserved only for poets and philosophers, imagination is now being regarded by psychologists as an important cognitive tool for both decision-making and emotion regulation.