Annmarie MacNamara

Event-Related Potentials, Emotion, and Emotion Regulation: An Integrative Review

Progress in the study of emotion and emotion regulation has increasingly been informed by neuroscientific methods. This article focuses on two components of the event-related potential (ERP)—the P300 and the late positive potential (LPP)—and how they can be used to understand the interaction between the more automatic and controlled processing of emotional stimuli. Research is reviewed exploring: the dynamics of emotional response as indexed at early and late latencies; neurobiological correlates of emotional response; individual and developmental differences; ways in which the LPP can be utilized as a measure of emotion regulation. Future directions for the application of ERP/electroencephalogram (EEG) in achieving a more complete understanding of emotional processing and its regulation are presented.

Tell Me About It: Neural Activity Elicited by Emotional Pictures and Preceding Descriptions

Emotional pictures elicit enhanced parietal positivities beginning around 300 ms following stimulus presentation. The magnitude of these responses, however, depends on both intrinsic (stimulus-driven) and extrinsic (context-driven) factors. In the present study, event-related potentials were recorded while participants viewed unpleasant and neutral pictures that were described either more neutrally or more negatively prior to presentation; temporospatial principal components analysis identified early and late positivities: Both emotional images and descriptions had independent and additive effects on early (334 ms) and midlatency (1,066 ms) positivities, whereas the latest positivity (1,688 ms) was sensitive only to description type. Results are discussed with regard to the time course of automatic and controlled processing of emotional stimuli.

Anxiety and spatial attention moderate the electrocortical response to aversive pictures

Aversive stimuli capture attention and elicit increased neural activity, as indexed by behavioral, electrocortical and hemodynamic measures; moreover, individual differences in anxiety relate to a further increased sensitivity to threatening stimuli. Evidence has been mixed, however, as to whether aversive pictures elicit increased neural response when presented in unattended spatial locations. In the current study, ERP and behavioral data were recorded from 49 participants as aversive and neutral pictures were simultaneously presented in spatially attended and unattended locations; on each trial, participants made same/different judgments about pictures presented in attended locations. Aversive images presented in unattended locations resulted in increased error rate and reaction time. The late positive potential (LPP) component of the ERP was only larger when aversive images were presented in attended locations, and this increase was positively correlated with self-reported state anxiety. Findings are discussed in regard to the sensitivity of ERP and behavioral responses to aversive distracters, and in terms of increased neural processing of threatening stimuli in anxiety.

The dynamic allocation of attention to emotion: simultaneous and independent evidence from the late positive potential and steady state visual evoked potentials.

Emotional stimuli capture and hold attention without explicit instruction. The late positive potential (LPP) component of the event related potential can be used to track motivated attention toward emotional stimuli, and is larger for emotional compared to neutral pictures. In the frequency domain, the steady state visual evoked potential (ssVEP) has also been used to track attention to stimuli flickering at a particular frequency. Like the LPP, the ssVEP is also larger for emotional compared to neutral pictures. Prior work suggests that both the LPP and ssVEP are sensitive to top-down manipulations of attention, however the LPP and ssVEP have not previously been examined using the same attentional manipulation in the same participants. In the present study, LPP and ssVEP amplitudes were simultaneously elicited by unpleasant and neutral pictures. Partway through picture presentation, participants attention was directed toward an arousing or non-arousing region of unpleasant pictures. In line with prior work, the LPP was reduced when attention was directed toward non-arousing compared to arousing regions of unpleasant pictures; similar results were observed for the ssVEP. Thus, both electrocortical measures index affective salience and are sensitive to directed (here: spatial) attention. Variation in the LPP and ssVEP was unrelated, suggesting that these measures are not redundant with each other and may capture different neurophysiological aspects of affective stimulus processing and attention.

Previously reappraised: the lasting effect of description type on picture-elicited electrocortical activity

To examine whether reappraisal modifies responses to subsequent encounters with stimuli, participants viewed neutral and unpleasant pictures that were preceded by negative or neutral descriptions which served as reappraisal frames. A half an hour later, the same pictures were presented, without preceding frames; EEG was recorded and participants rated each picture on arousal and valence. In line with previous work, unpleasant compared to neutral pictures elicited more positive early- (359u2009ms), mid- (1074u2009ms) and late-latency (2436u2009ms) centrally-distributed ERP components. Pictures previously preceded by negative compared to neutral reappraisal frames were rated as more unpleasant and more emotionally arousing; these pictures elicited a larger mid-latency (1074u2009ms) occipital positivity. Together, the data suggest that reappraisal exerts an enduring effect on both subjective and neural responses to stimuli.

Working memory load reduces the late positive potential and this effect is attenuated with increasing anxiety

Emotion regulation decreases the processing of arousing stimuli, as indexed by the late positive potential (LPP), an electrocortical component that varies in amplitude with emotional arousal. Emotion regulation increases activity in the prefrontal areas associated with cognitive control, including the dosolateral prefrontal cortex (DLPFC). The present study manipulated working memory load, known to activate the DLPFC, and recorded the LPP elicited by aversive and neutral IAPS pictures presented during the retention interval. The LPP was larger on low-load compared to high-load trials, and on trials with aversive compared to neutral pictures. These LPP data suggest that emotional content and working memory load have opposing effects on attention to distracting stimuli. State anxiety was associated with reduced modulation of the LPP by working memory load. Results are discussed in terms of competition for attention between emotion and cognition and suggest a relationship between DLPFC activation and the allocation of attentional resources to distracting visual stimuli–a relationship that may be disrupted with increasing anxiety.

Event-related induced frontal alpha as a marker of lateral prefrontal cortex activation during cognitive reappraisal.

Electrocortical activity, typically used to track the effects of cognitive reappraisal on the processing of emotional stimuli, has not been used to index the prefrontal-cortex-mediated regulatory mechanisms responsible for these effects. In the present study, we examined the novel possibility that induced frontal alpha (i.e., 8–13xa0Hz), shown to reflect the inhibition and disengagement of task-relevant cortical regions, may be quantified to explore cortical activation that is specifically enhanced during cognitive reappraisal. For this purpose, 44 participants viewed unpleasant and neutral pictures followed by auditory instructions to either continue viewing the picture or reduce their emotional response to the picture by making the picture seem less emotional (i.e., cognitive reappraisal). In line with previous work, unpleasant pictures elicited a larger late positive potential (LPP) than did neutral pictures. Also corroborating previous work, the mid-latency LPP was reduced when pictures were cognitively reappraised. However, the present study showed for the first time that whereas unpleasant pictures elicited higher frontal alpha power bilaterally than did the neutral pictures, frontal alpha power was reduced (indicative of more activation and cognitive control) during cognitive reappraisal of both picture types over the left hemisphere. Taken together, the LPP and event-related induced frontal-alpha findings contribute unique information about the distinct neural substrates and cognitive processes underlying reappraisal.

Electrocortical and ocular indices of attention to fearful and neutral faces presented under high and low working memory load

Working memory load reduces the late positive potential (LPP), consistent with the notion that functional activation of the DLPFC attenuates neural indices of sustained attention. Visual attention also modulates the LPP. In the present study, we sought to determine whether working memory load might exert its influence on ERPs by reducing fixations to arousing picture regions. We simultaneously recorded eye-tracking and EEG while participants performed a working memory task interspersed with the presentation of task-irrelevant fearful and neutral faces. As expected, fearful compared to neutral faces elicited larger N170 and LPP amplitudes; in addition, working memory load reduced the N170 and the LPP. Participants made more fixations to arousing regions of neutral faces and faces presented under high working memory load. Therefore, working memory load did not induce avoidance of arousing picture regions and visual attention cannot explain load effects on the N170 and LPP.