Cardiac cycle phases affect auditory-evoked potentials, startle eye blink and pre-motor reaction times in response to acoustic startle stimuli

in International Journal of Psychophysiology (2020), 157(1), 70-81

Startle stimuli evoke lower responses when presented during the early as compared to the late cardiac cycle phase, an effect that has been called ‘cardiac modulation of startle’ (CMS). The CMS effect may ... [more ▼]

Startle stimuli evoke lower responses when presented during the early as compared to the late cardiac cycle phase, an effect that has been called ‘cardiac modulation of startle’ (CMS). The CMS effect may be associated with visceral-afferent neural traffic, as it is reduced in individuals with degeneration of afferent autonomic nerves. The aim of this study was to investigate whether the CMS effect is due a modulation of only early, automatic stages of stimulus processing by baro-afferent neural traffic, or if late stages are also affected. We, therefore, investigated early and late components of auditory-evoked potentials (AEPs) to acoustic startle stimuli (105, 100, 95 dB), which were presented during the early (R-wave +230 ms) or the late cardiac cycle phase (R +530 ms) in two studies. In Study 1, participants were requested to ignore (n=25) or to respond to the stimuli with button-presses (n=24). In Study 2 (n=23), participants were asked to rate the intensity of the stimuli. We found lower EMG startle response magnitudes (both studies) and slower pre-motor reaction times in the early as compared to the late cardiac cycle phase (Study 1). We also observed lower N1 negativity (both studies), but higher P2 (Study 1) and P3 positivity (both studies) in response to stimuli presented in the early cardiac cycle phase. This AEP modulation pattern appears to be specific to the CMS effect, suggesting that early stages of startle stimulus processing are attenuated, whereas late stages are enhanced by baro-afferent neural traffic [less ▲]

Effects of rejection intensity and rejection sensitivity on social approach behavior in women

in PLoS ONE (2020), 15(1), 0227799

Objective: Perceived rejection plays an important role for mental health and social integration. This study investigated the impact of rejection intensity and rejection sensitivity on social approach ... [more ▼]

Objective: Perceived rejection plays an important role for mental health and social integration. This study investigated the impact of rejection intensity and rejection sensitivity on social approach behavior. Method: 121 female participants were randomly assigned to one of three conditions differing in the degree of induced rejection (inclusion, medium rejection, severe rejection). Thereafter they were asked to interact with an unknown person during a touch-based cooperative task. Results: Participants high in rejection sensitivity sought significantly less physical contact than participants low in rejection sensitivity. Individuals in the medium rejection condition touched their partners more often than those in the included condition, while no difference between included and severely rejected participants could be observed. Conclusions: The results suggest that the intensity of rejection matters with regard to coping. While participants in the medium intensity rejection condition aimed to ‘repair’ their social self by seeking increased contact with others, severely rejected participants did not adapt their behavior compared to included participants. Implications for therapy are discussed. [less ▲]

Childhood trauma affects stress-related interoceptive accuracy

in Frontiers in Psychiatry (2019), 10(1), 750

Early life adversity (ELA) may cause permanent disturbances in brain-body signaling. These disturbances are thought to contribute to physical symptoms and emotional dysregulation in adulthood. The current ... [more ▼]

Early life adversity (ELA) may cause permanent disturbances in brain-body signaling. These disturbances are thought to contribute to physical symptoms and emotional dysregulation in adulthood. The current study investigated the effects of childhood trauma on young adults’ interoceptive accuracy as an indicator of brain-body communication that may be dysregulated by ELA. Sixty-six participants completed an online-questionnaire followed by a laboratory session including the socially-evaluated cold pressor stress test during which ECG, salivary cortisol and interoceptive accuracy were assessed. Childhood trauma was negatively related to interoceptive accuracy (IAc) after the stressor. This stress-effect could not be observed for heart rate and cortisol, which were unrelated to IAc. Participants reporting higher baseline unpleasantness exhibited lower IAc after the stressor, while increases in unpleasantness due to the stressor were associated with higher IAc. Unpleasantness at baseline mediated the effect of childhood trauma on IAc after the stressor. [less ▲]

Parental divorce is associated with an increased risk to develop mental disorders in women

in Journal of Affective Disorders (2019), 257(1), 91-99

Background: Parental divorce has been associated with reduced well-being in young adults. It is, however, unclear whether this finding is clinically relevant as studies using structural clinical ... [more ▼]

Background: Parental divorce has been associated with reduced well-being in young adults. It is, however, unclear whether this finding is clinically relevant as studies using structural clinical interviews are missing. This study, therefore, investigated if young adults with divorced parents are at risk to develop mental disorders. Furthermore, differences in parental care, social connectedness, chronic stress and traumatic experiences between children of divorced and non-divorced parents were investigated. Methods: 121 women (mean age: 23 years) were interviewed using the Structured Clinical Interview for DSMIV Axis I (i.e., major mental disorders) and II (i.e., personality disorders) Disorders and asked to complete questionnaires assessing parental care, social connectedness (loneliness, attachment anxiety and avoidance), chronic stress, childhood trauma and depression. Results: Young adults of divorced parents had a higher risk for Axis I but not Axis II disorders as compared to young adults of non-divorced parents. Participants from divorced families as compared to non-divorced families reported more depression, loneliness, childhood trauma, attachment avoidance, attachment anxiety, chronic stress and less parental care. Limitations: Due to the cross-sectional design of this study, conclusions about causality remain speculative. Conclusion: The increased vulnerability of children of divorced parents to develop mental disorders, and to experience more chronic stress, loneliness, attachment avoidance, attachment anxiety, and traumatic experiences during childhood is alarming and highlights the importance of prevention programs and psycho-education during the process of parental divorce. Parental support with regard to adequate caregiving is needed to help parents to better support their children during and after their divorce. [less ▲]

Effects of basal and acute cortisol on cognitive flexibility in an emotional task switching paradigm in men

in Hormones and Behavior (2016), 81

The stress hormone cortisol is assumed to influence cognitive functions. While cortisol-induced alterations of declarative memory in particular are well-investigated, considerably less is known about its ... [more ▼]

The stress hormone cortisol is assumed to influence cognitive functions. While cortisol-induced alterations of declarative memory in particular are well-investigated, considerably less is known about its influence on executive functions. Moreover, most research has been focused on slow effects, and rapid non-genomic effects have not been studied. The present study sought to investigate the impact of acute cortisol administration as well as basal cortisol levels on cognitive flexibility, a core executive function, within the non-genomic time frame. Thirty-eight healthy male participants were randomly assigned to intravenously receive either cortisol or a placebo before performing a task switching paradigm with happy and angry faces as stimuli. Cortisol levels were measured at six points during the experiment. Additionally, before the experiment, basal cortisol measures for the cortisol awakening response were collected on three consecutive weekdays immediately following awakening and 30, 45, and 60 min after. First and foremost, results showed a pronounced impact of acute and basal cortisol on reaction time switch costs, particularly for angry faces. In the placebo group, low basal cortisol was associated with minimal switch costs, whereas high basal cortisol was related to maximal switch costs. In contrast, after cortisol injection, basal cortisol levels showed no impact. These results show that cognitive flexibility-enhancing effects of acute cortisol administration are only seen in men with high basal cortisol levels. This result supports the context dependency of cortisol administration and shows the relevance of taking basal cortisol levels into account. [less ▲]

The Eletrophysiology of Prepulse Inhibition

Poster (2015, June)

The acoustic startle response is decreased by a prepulse occurring 30-500 ms earlier. This prepulse inhibition (PPI) is interpreted in terms of the Interruption and Protection hypotheses, in which startle ... [more ▼]

The acoustic startle response is decreased by a prepulse occurring 30-500 ms earlier. This prepulse inhibition (PPI) is interpreted in terms of the Interruption and Protection hypotheses, in which startle responding interrupts prepulse processing, and PPI indicates the degree to which prepulse processing is protected from that interruption. We evaluated this hypotheses by measuring startle responding and evoked potentials (N1, P2) to both prepulse and startle stimuli under different attentional conditions (Attend Startle, Attend Prepulse, Ignore Both). 192 trials were presented in randomized order: Startle Alone (105dB noise), Prepulse Alone (70dB noise), and prepulse+startle stimuli with a stimulus onset asynchrony (SOA) of 120 (PPI120) or 500 ms (PPI500). 36 participants, randomly assigned to the three attention conditions, pressed a key to the startle or to the pre-pulse or did not respond. A 32-channel EEG and eyeblink EMG were measured. Independent of the attentional conditions, the EMG startle response was decreased by a pre-pulse at both SOAs, illustrating PPI. Prepulse N1/P2 amplitude was identical for the Prepulse Alone, PPI120, and PPI500 stimuli independent of the attentional conditions, demonstrating protection of primary sensory prepulse processing. N1/P2 potentials to the startle stimulus were affected by the SOAs and the attentional conditions, suggesting a change in startle processing by both variables. The results suggest a complete protection of prepulse processing. The reduced N1/P2 amplitudes to the startle stimulus at both SOAs suggest that the eliciting properties of the startle stimulus are decreased by the prepulse. [less ▲]

Cold pressor stress induces opposite effects on cardioceptive accuracy dependent on assessment paradigm

in Biological Psychology (2013), 93(1), 167-174

Interoception depends on visceral afferent neurotraffic and central control processes. Physiological arousal and organ activation provide the biochemical and mechanical basis for visceral afferent ... [more ▼]

Interoception depends on visceral afferent neurotraffic and central control processes. Physiological arousal and organ activation provide the biochemical and mechanical basis for visceral afferent neurotraffic. Perception of visceral symptoms occurs when attention is directed toward body sensations. Clinical studies suggest that stress contributes to the generation of visceral symptoms. However, during stress exposure attention is normally shifted away from bodily signals. Therefore, the net effects of stress on interoception remain unclear. We, therefore, investigated the impact of the cold pressor test or a control intervention (each n = 21) on three established laboratory paradigms to assess cardioceptive accuracy (CA): for the Schandry-paradigm, participants were asked to count heartbeats, while during the Whitehead-tasks subjects were asked to rate whether a cardiac sensation appeared simultaneously with an auditory or visual stimulus. CA was increased by stress when attention was focused on visceral sensations (Schandry), while it decreased when attention was additionally directed toward external stimuli (visual Whitehead). Explanations for these results are offered in terms of internal versus external deployment of attention, as well as specific effects of the cold pressor on the cardiovascular system. [less ▲]