 One theory supposes that this defect reduces the individual's ability to selectively inhibit fear responses from the amygdala, leading to anxiety.There are several theories, however, on how this impairment ultimately affects those with ADHD.In studies with rodents, the prefrontal cortex, specifically the medial prefrontal cortex (mPFC) has been implicated in the processing of information lasting from milliseconds to several seconds, while the hippocampus has been implicated in the processing of information for longer time scales – such as minutes to hours.