Attention and affect in dysphoria: Insights from startle reflex modulation and cardiac deceleration

Reduced approach disposition in familial risk for depression: Evidence from time-frequency alpha asymmetries

Despite the promising role of alpha and delta power in reflecting reduced approach disposition in depression, to date, it is unclear whether these measures can be employed to identify at-risk individuals. Hence, the present study investigated affective disposition in 32 unaffected individuals with a family history of depression (23 F) and 30 individuals without a family history of depression (21 F) through a data-driven analysis of alpha and delta time-frequency power during the viewing of pleasant, neutral, and unpleasant pictures. Different patterns of posterior alpha asymmetry emerged within each group. Particularly, controls showed greater right posterior alpha desynchronization ~ 600 ms following emotional relative to neutral pictures presentation. Conversely, the group with a family history of depression showed greater posterior left alpha desynchronization only to unpleasant relative to neutral images in a later time window (> 900 ms). Hence, depression vulnerability seems to be characterized by a blunted reactivity to pleasant and delayed reactivity to unpleasant stimuli with a distinct posterior distribution relative to the controls. Finally, the two groups showed a comparable pattern of greater delta power to emotional relative to neutral cues. Overall, initial support was provided for the employment of time-frequency alpha power changes during affective processing in identifying blunted approach disposition in unaffected at-risk individuals.

Affective processing in dysphoria: Evidence from startle probe modulation of ERPs

The hypoactivation of the appetitive and defensive motivational systems in the brain is a feature of depression and might also represent a vulnerability factor for the disorder. A measure that can be employed to investigate both motivational systems is the electroencephalographic response to an acoustic startle probe during affective processing. Particularly, the amplitude of auditory event-related potentials (ERPs) components to the startle probe is smaller when the emotional context is more arousing. Neural responses to an unattended startle probe during an emotional passive viewing task of pleasant, neutral, and unpleasant pictures was employed to assess the activation of the approach and defensive motivational systems in a sample of individuals with (n = 24, 23 females) vs. without (n = 24, 23 females) dysphoria. The group without dysphoria showed a reduced startle-elicited N200 only in the context of pleasant relative to neutral pictures, indicating that the affective processing of the appetitive context might reduce the attentional resources needed to orient attention toward unattended non-salient stimuli. Conversely, the N200 amplitude was not attenuated for pleasant relative to neutral and unpleasant contexts in the group with dysphoria. Moreover, no within- or between-group differences emerged in the P300 amplitude. Taken together, the results of this study showed that depression vulnerability is characterized by reduced attention to pleasant contexts, suggesting a blunted affective processing of appetitive emotional stimuli.

Familial risk for depression is associated with reduced P300 and late positive potential to affective stimuli and prolonged cardiac deceleration to unpleasant stimuli

Despite evidence of abnormal affective processing as a key correlate of depression, specific attentional mechanisms underlying processing of emotions in familial risk for depression have yet to be investigated in a single study. To this end, the amplitude of the P300 and late positive potential (LPP) complex and cardiac deceleration were assessed during the passive viewing of affective pictures in 32 individuals who had family history of depression (without depressive symptoms) and in 30 controls (without depressive symptoms and family history of depression). Individuals with familial risk for depression revealed reduced P300-LPP amplitudes in response to pleasant and unpleasant stimuli relative to controls, and comparable P300-LPP amplitudes in response to pleasant and neutral stimuli. Controls, but not individuals with familial risk for depression, reported cardiac deceleration during the viewing of pleasant vs. neutral and unpleasant stimuli in the 0-3 s time window. Also, only individuals with familial risk for depression showed a prolonged cardiac deceleration in response to unpleasant vs. neutral stimuli. Overall, the present study provides new insights into the characterization of emotion-related attentional processes in familial risk for depression as potential vulnerability factors for the development of the disorder.

Rethinking the risk for depression using the RDoC: A psychophysiological perspective

Considering that the classical categorical approach to mental disorders does not allow a clear identification of at-risk conditions, the dimensional approach provided by the Research Domain Criteria (RDoC) is useful in the exploration of vulnerability to psychopathology. In the RDoC era, psychophysiological models have an important role in the reconceptualization of mental disorders. Indeed, progress in the study of depression vulnerability has increasingly been informed by psychophysiological models. By adopting an RDoC lens, this narrative review focuses on how psychophysiological models can be used to advance our knowledge of the pathophysiological mechanisms underlying depression vulnerability. Findings from psychophysiological research that explored multiple RDoC domains in populations at-risk for depression are reviewed and discussed. Future directions for the application of psychophysiological research in reaching a more complete understanding of depression vulnerability and, ultimately, improving clinical utility, are presented.

EEG time-frequency analysis reveals blunted tendency to approach and increased processing of unpleasant stimuli in dysphoria

To date, affective and cognitive processing of emotional information in individuals with depressive symptoms have been examined through peripheral psychophysiological measures, event-related potentials, and time–frequency analysis of oscillatory activity. However, electrocortical correlates of emotional and cognitive processing of affective content in depression have not been fully understood. Time–frequency analysis of electroencephalographic activity allows disentangling the brain's parallel processing of information. The present study employed a time–frequency approach to simultaneously examine affective disposition and cognitive processing during the viewing of emotional stimuli in dysphoria. Time–frequency event-related changes were examined during the viewing of pleasant, neutral and unpleasant pictures in 24 individuals with dysphoria and 24 controls. Affective disposition was indexed by delta and alpha power, while theta power was employed as a correlate of cognitive elaboration of the stimuli. Cluster-based statistics revealed a centro-parietal reduction in delta power for pleasant stimuli in individuals with dysphoria relative to controls. Also, dysphoria was characterized by an early fronto-central increase in theta power for unpleasant stimuli relative to neutral and pleasant ones. Comparatively, controls were characterized by a late fronto-central and occipital reduction in theta power for unpleasant stimuli relative to neutral and pleasant. The present study granted novel insights on the interrelated facets of affective elaboration in dysphoria, mainly characterized by a hypoactivation of the approach-related motivational system and a sustained facilitated cognitive processing of unpleasant stimuli.

Emotional processing prospectively modulates the impact of anxiety on COVID-19 pandemic-related post-traumatic stress symptoms: an ERP study

BACKGROUND

Considering that the elevated distress caused by the COVID-19 pandemic, in some cases, led to post-traumatic stress symptoms (PTSS), it has been proposed as a specific traumatic event. The present longitudinal study investigated pre-pandemic motivated attention to emotional stimuli, as indexed by Late Positive Potential (LPP) amplitude, in relation with the potential differential role of anxiety and depressive symptoms in predicting PTSS severity related to the COVID-19 pandemic.

METHODS

A total of 79 university students initially completed self-report measures of depression and anxiety along with a passive viewing task of emotional (pleasant, unpleasant) and neutral pictures while electroencephaloghic activity was recorded. In December 2020, 57 participants completed a questionnaire assessing PTSS.

RESULTS

Significant interactions between anxiety and LPP emerged in predicting pandemic-related PTSS, where greater anxiety symptoms predicted PTSS only in individuals with greater LPP to unpleasant or with reduced LPP to pleasant stimuli.

LIMITATIONS

The prevalence of the female sex, the relatively young age of the participants, as well as the fact that they were all enrolled in a University course might not allow the generalization of the findings.

CONCLUSIONS

Taken together, the present longitudinal study provided novel evidence on EEG predictors of pandemic-related PTSS that might be useful for the prevention and treatment of PTSS. Indeed, assessing anxiety symptoms and pre-trauma LPP to emotional stimuli might be a useful target for identifying individuals that are more vulnerable to the development of PTSS during times of crisis.

Disentangling emotional processing in dysphoria: An ERP and cardiac deceleration study

The present study aimed to investigate emotional processing in dysphoria. To this end, the amplitude of the Late Positive Potential (LPP) and cardiac deceleration were assessed during the passive viewing of affective (pleasant, neutral, and unpleasant) pictures in 26 individuals with dysphoria and in 25 non-depressed controls. The group with dysphoria revealed a smaller LPP amplitude than the group without dysphoria in response to pleasant and neutral, but not unpleasant, stimuli at centro-parieto-occipital sites. Interestingly, whereas both groups showed cardiac deceleration when viewing pleasant compared to neutral pictures (3-6 s time window), only individuals with dysphoria showed a prolonged cardiac deceleration in response to unpleasant stimuli as compared with neutral ones. This study suggests that dysphoria is characterized by reduced motivated attentional allocation to positive information and by sustained intake of unpleasant information. Overall, the present findings provide novel insights into the characterization of valence-specific attentional processes in dysphoria as potential vulnerability factors for clinically significant depression.