The perception of human faces is affected by different facial features. For example, older faces are processed differently to younger ones and faces expressing diverse emotions are also processed differently. Research shows that angry faces are more attended to compared to neutral or other expressive faces, which is known as the ‘threat advantage’. This is evidenced by research on the late positive potential (LPP). The LPP is an event-related potential (ERP) component associated with affective processing, which seems to strongly respond to threats. The literature has indicated that older faces can elicit larger LPPs compared to young and neutral faces, and the LPP is more sensitive to emotional faces. The current experiment investigated subjective ratings in addition to the LPP in response to neutral and angry faces of young and old individuals, to examine how facial age influences the perception of anger. In a facial rating task, both the young and the old angry faces were rated as threatening faces, while old neutral faces were indicated to be more threatening than young neutral faces. Similarly, participants had a higher LPP for old angry faces. This data, in combination, suggests a higher emotional salience of old angry faces compared to either young angry or (young or old) neutral faces.

The late positive potential (LPP) is an event-related potential (ERP) component associated with increased affective processing which seems to strongly respond to threats and to be sensitive to emotional faces. Some studies indicate that the LPP is modulated by anxiety symptoms, while others fail to find support for these observations. The facial width-to-height ratio (FWHR) is a facial-masculinity metric that refers to cheekbone width, divided by upper facial height (top of the lip to between the brows). Consequently, FWHR has by some researchers been proposed to serve as a cue of threat. For example, high FWHR and diverse emotional faces (e.g., angry faces) are perceived as more threatening than low FWHR faces. Individuals with social anxiety are thought to be biased towards the threat. The literature has indicated that high FWHR faces in combination with angry facial expression can elicit larger LPPs compared to low FWHR and neutral faces. The current experiment investigated subjective ratings in addition to the LPP in response to high and low FWHR faces in combination with an angry and neutral expression, to examine how different facial morphology and affective cues influence the perception of threat to individuals with high social anxiety. This data, in combination, suggests that high FWHR is a salient threat-related social stimulus that might have a firm influence on the perception of other peoples’ faces. Initial results do not support a significant relationship between increased LPP modulation in individuals with high social anxiety compared to individuals with low social anxiety. However, it opens up for discussion regarding how social anxiety should be approached in future LPP research.

Aggressive behaviour can be defined as actions that are believed and intended to cause harm to another individual that does not desire to be the target of such actions. Different situations can warrant aggressive behaviour, such as when an individual is posed with a threat. Aggressive behaviour is one of the ways individuals can deal with threats arising from their environments, and furthermore, aggressive behaviour can also be used to deal with social threats that arise from the interaction between two members of the same species. Aggressive behaviour is correlated with higher emotional arousal, and individuals that illustrate aggressive tendencies should be more sensitive to arousal when confronted with a social threat. This thesis acts upon this notion by hypothesizing that individuals who score higher on a tendency for aggression measurements should exhibit higher emotional arousal when exposed to a cue of social threat. Cues of social threats are thought to be induced by exposing the participant to either an angry face or a face with a high facial width to height ratio. The emotional response is measured with electroencephalography, more specifically looking at the late positive potential. No support for the hypothesis was found between high and low aggression groups. The facial width to height ratios proposed nature of being a cue of social threat becomes contested as the results were conflicting regarding the robustness of the facial width to height ratio’s effect. Even if there were no statistically significant differences found between the two groups, it might not be subject for dismissal as the sample population could be considered a low aggression population overall.

Bupropion (BUP) is an efficacious pharmacologic aid for individuals attempting to quit tobacco smoking (Wilkes., 2008), yet little is known about the effects of BUP on neural responses to either smoking cues (SC) or affective cues (AC), stimuli that are known to promote smoking and relapse to smoking for those attempting to quit. In fact, only one published study has assessed BUP’s effects on neuroelectrical event-related responses (ERPs) to SC or AC (Versace, Stevens, Robinson, Cui, Deweese, Engelmann, et al., 2019), and this study did not detect any neural effects of BUP, relative to placebo. It is important to note that Versace et al. (2019) study’s smokers were instructed to focus their attention solely on large color pictures of SC or AC that were presented for several seconds, something that may differ from conditions in which BUP might alter brain responses to SC. In contrast, several studies have assessed the effects of BUP on functional magnetic resonance imaging (fMRI)-assessed brain activity, with several finding that BUP enhanced activation of the nucleus accumbens during the anticipation of a brief (140-460ms) monetary target (Ikeda et al., 2019) and in the right middle and inferior frontal gyri, right caudate, and bilateral precuneus during AC presentation (Robertson et al 2007), while several others found reductions in activation in the left ventral striatum, right medial orbitofrontal cortex, and bilateral anterior cingulate cortex during presentation of SC (Culbertson et al., 2011), and reductions in the activation of right orbitofrontal cortex, left dorsomedial prefrontal cortex, right ventromedial prefrontal cortex, right anterior cingulate cortex, right inferior frontal cortex, right amygdala/parahippocampal area, right caudate, right fusiform gyrus, and left posterior cingulate during AC presentation (Robertson et al 2007). The inconsistencies across these studies may reflect underlying effects of the task used to assess the participant (i.e., context of the task). Thus, it is reasonable to hypothesize that the effects of BUP SC and AC on brain reactivity depend on assessment context and task demands. Few studies have assessed the effects of BUP on brain responses to SC and AC when they are briefly presented distractors, as opposed to the primary focus of sustained attention. This study demonstrates the importance of task context for SC and AC presentation to detect the effects of BUP. By neglecting context-specific effect, the field is missing measurable targets for drug efficacy. This is the 1st study to find an BUP induced LPP reduction. The data is obtained from smokers who were randomly assigned to a BUP (n=24) group or a placebo group (n=66) and assessed prior to and after 14 days on BUP or PLA capsules while still smoking at their typical rate.

The DSM-IV characterizes dissociation as “disruption in the usually integrated functions of consciousness, memory, identity, or perception of the environment” (American Psychiatric Association, 1994, p. 477) and it has been tenuously linked with trauma, but “lacks a single, coherent referent … that all investigators in the field embrace” (Cardena, 1994). It is known that dissociation is a spectrum (Bernstein and Putnam, 1986; Shor, Orne, and O’Connell, 1962; Spiegel, 1963; Tellegen and Atkinson, 1974), and low levels of dissociation can be a part of normal functioning, allowing us to do two things at once (Butler, Duran and Jasiukitis, 1996), but higher levels can interfere with daily functioning. The present study used survey techniques to investigate the link between dissociation and trauma. Survey results showed a significant correlation between trauma and dissociation. The current investigation also used the high temporal and spatial resolution of electroencephalographic techniques to identify the neurophysiological correlates of dissociation. Specifically, the current investigation recorded early and late event-related potentials in participants who rated high and low in dissociation while they viewed affective pictures in order to determine if there were electrophysiological differences in responses to emotional stimuli. Electroencephalographic results were nonsignificant, but trends indicated that high dissociators showed a heightened response to affective photos at P1 and the late positive potential compared with low dissociators. If the results are thought to be reliable, the trends may indicate that high dissociators were not actively dissociating during the task, and because high dissociators have usually experienced trauma, they are more sensitive to emotional stimuli. Further research is needed to support these theories.

Uncertainty represents a robust threat that can amplify aversive experiences and exaggerate negative expectations about uncertain future outcomes. Mindfulness – an open and receptive attention to present moment experiences -- has been shown to facilitate adaptive regulation when faced with a variety of distinct emotional threats. Reduced experiential avoidance and equanimity in the face of unpleasant emotional experiences have been theorized as central to these emotional regulatory benefits. The present study explored whether dispositional mindfulness would promote adaptive responses to uncertainty during the anticipation of, and after exposure to emotional stimuli, as indicated by self-reports and neural (event-related potential) markers of anticipation and appraisal. Participants were exposed to stimulus cues that informed them about the valence of a subsequent emotional picture as neutral, aversive, or uncertain. Consistent with past research, uncertainty during the anticipation of an emotional stimulus amplified unpleasant stimulus appraisals, and participants demonstrated biased expectations to associate uncertainty with aversiveness. Dispositional mindfulness was associated with lower expectations for unpleasant stimuli, and was found to amplify the effect of uncertainty on a cortical marker of stimulus appraisal called the late positive potential (LPP). Traits that contrasted with mindfulness predicted opposite patterns of association with these measures. However, these findings were directly the opposite of findings from past research. A theoretically defensible explanation is discussed for these findings and suggestions were made for future research on the role of mindfulness on ERP variability. The results from the present study contribute to a growing body of evidence that suggests that uncertainty during the anticipation of potentially negative future outcomes can exert a potent downstream influence on emotional anticipation and appraisal processes. Further research is needed to clarify the role of dispositional mindfulness during emotional stimulus anticipation and appraisal following uncertainty.

The facial width-to-height ratio (fWHR) is a measure of the cheekbone width divided by the height of the face from the upper lip to the brows. The metric is hypothesised to have evolved as an intra-sexual competition mechanism in males, where large fWHRs are thought to signal both threat and aggression. The fWHR is suggested to subtly resemble angry facial expressions, which, in turn, also signal threat. The late positive potential (LPP) and the vertex positive potential (VPP) are two event-related potentials (ERPs) especially sensitive to emotional content. Studies have also found that viewing angry compared to neutral facial expressions elicit a stronger response on the LPP. However, no study has tested how responses to the fWHR and angry facial expressions elicit changes in the LPP or VPP. In this study, participants firstly rated how threatening faces were with either low or high fWHRs with neutral or angry facial expressions. Secondly, EEG-activity was recorded during a picture-viewing task of the same faces. In the first task, participants rated the faces with angry facial expressions as more threatening compared to all other faces, regardless of fWHR, although the high fWHRs were rated as more threatening than the low fWHRs. In the second task, LPP and VPP mean amplitudes were significantly higher for the angry, high fWHR face compared to all other faces tested. This suggests that an additive effect of both angry facial expressions and high fWHRs together creates the highest threat level in both subjective ratings as well as in ERP mean amplitudes. Further ERP research is needed on the relationship between fWHRs and anger to establish how the two features work both separately and together.

Cognitive reappraisal is an emotion regulation strategy that has been shown effective in down-regulating negative emotions in both psychological and electrophysiological measures. Although there are many studies on cognitive reappraisal, only recently have there been studies differentiating between various ways of employing the strategy. This event-related potential (ERP) study sets out to compare the efficiency and temporal dynamics of three cognitive reappraisal techniques – situation-focused reappraisal, social distancing, and temporal distancing – by measuring their effects on emotional responses to aversive pictures, as indexed by the affective ERP component the late positive potential (LPP). EEG data was recorded from 17 participants. The results revealed no significant differences between emotion regulation strategies and baseline for the total ERP epoch (3,000 ms). When differentiating between early (400-800 ms), mid (800-1,500 ms), and late (1,500-3,000) periods of the epoch, significance was found in some conditions, but since no significant overall LPP activity was found, these numbers are difficult to interpret.

The aim of the current paper is to examine the association between ideology and disgust sensitivity. Studying disgust offers an to assess how judgments have evolved over time due to a “gut” sense of danger. This emotion also plays a role in moral judgment: individuals label moral wrongdoings as disgusting which elicits a specific facial expression. For this reason, disgust has recently been found to be a plausible emotion involved in political decision-making. Studies indicate that liberals and conservatives rely on respective moral foundations that influence their choices. Haidt et al. (2009) argue that liberals’ views on morality are based primarily on harm/care and fairness/reciprocity, whereas conservatives’ views on morality show a more even distribution across the foundations, including those endorsed by liberals, as well as ingroup/loyalty, authority/respect and sanctity. Schnall et al. (2008) suggest a causal relationship between feelings of disgust and moral convictions. People often rely on moral reasoning when they do not have an intuitive response or when their intuition is conflicting. The current study examined this complex relationship by assessing disgust sensitivity while simultaneously manipulating emotional state through the use of emotionally disgusting and neutral pictures. Electroencephalographic (EEG) event related brain potentials (ERPs) were used as the primary index of emotional processing. The results indicated a main effect for electrode site location and for picture image, as expected. Results did not show an interaction between disgust sensitivity and ideology, or any mediating factors, suggesting that there may be no statistically significant differences in disgust sensitivity between liberals and conservatives. These results suggest that the core differences between conservatives and liberals may be exaggerated. Limitations and directions for future research are discussed.

Reappraisal is a cognitive emotion regulation strategy that induces a reduction in the arousal response elicited by both unpleasant and pleasant stimuli.One form of reappraisal is that of temporal distancing. Temporal distancing is the cognitive tool that allows the individual to perceive the stimuli in a broader temporal perspective.Reappraisal’s impact on the arousal response can be measured by assessing the amplitude of the event-related potential (ERP) component the late positive potential(LPP), a centro-parietal slow-wave ERP beginning around 350 ms post-stimulus and sustaining for up to several seconds. The aim of this study was to test various temporal-related perspectives in order to see their effect on the LPP. The analysis of the data suggests that a decrease in the amplitude of the LPP in response to emotionally unpleasant facial stimuli corresponds to adopting a temporal distancing strategy, regardless of the exact temporal distance chosen.