Orbitofrontal cortex and dynamic filtering of emotional stimuli

Abstract

Event-related potentials (ERPs) were recorded in response to mildly aversive somatosensory and auditory stimuli. Patients with orbitofrontal lesions exhibited enhanced ERPs (i.e., P3 amplitudes), as compared with control subjects. Moreover, these patients did not habituate to somatosensory stimuli across blocks of trials. The results were specific to orbitofrontal damage, since patients with damage to the dorsolateral prefrontal cortex did not exhibit enhanced P3 amplitudes. These findings suggest that damage to the orbitofrontal cortex impairs the ability to modulate or inhibit neural responses to aversive stimuli. The findings are couched in terms of dynamic filtering theory, which suggests that the orbitofrontal cortex is involved in the selection and active inhibition of neural circuits associated with emotional responses.

The impact of orbital prefrontal cortex damage on emotional activation to unanticipated and anticipated acoustic startle stimuli

“…Thus, this is not an instance of patients showing a peculiar idiosyncratic response but, rather, a difference in amount. Our findings of greater self-reported fear and greater surprise behavior for patients are consistent with the findings of Rule, Shimamura, and Knight (2002), which showed that patients with orbitofrontal damage show central nervous system disinhibition. Our findings also lend support to the notion that the orbitofrontal cortex may act as a filtering system for sensory inputs (Shimamura, 2000).…”

The ongoing cognitive processing of exclusionary social events: Evidence from event-related potentials

“…This would further attenuate the overall P3b amplitude for 785 the first informational image in response to ETs in the exclusion block and minimize the effect that was evidenced in the shorter exclusion manipulations used previously (Crowley et al, 2010;Themanson et al, 2013). Evidence for this habituation and desen-790 sitization of ERPs has been found in other areas of P3b research (Rule, Shimamura, & Knight, 2002) and has been suggested for other exclusion-related ERP effects (Crowley et al, 2010). It is important to note that the decrease in P3b amplitude over the course of 795 the exclusion may not reflect habituation.…”

Mental rubbernecking to negative information depends on task context

“…Consistent with this possibility are the results of a recent functional magnetic resonance imaging (fMRI) study with only ENN_E and ENN_N trials (Johnson et al, 2005, Experiment 6B). There was more activity in the orbitofrontal cortex, an area thought to play a role in inhibitory processes (e.g., Rule, Shimamura, & Knight, 2002), when a neutral item was refreshed than when an emotional item was refreshed. Johnson et al (2005) referred to the disruptive effect of an emotional item on the refreshing of a target item as an instance of mental rubbernecking.…”