Anton van Boxtel

Verbal, Facial and Autonomic Responses to Empathy-Eliciting Film Clips by Disruptive Male Adolescents with High Versus Low Callous-Unemotional Traits

This study examined empathy-related responding in male adolescents with disruptive behavior disorder (DBD), high or low on callous-unemotional (CU) traits. Facial electromyographic (EMG) and heart rate (HR) responses were monitored during exposure to empathy-inducing film clips portraying sadness, anger or happiness. Self-reports were assessed afterward. In agreement with expectations, DBD adolescents with high CU traits showed significantly lower levels of empathic sadness than healthy controls across all response systems. Between DBD subgroups significant differences emerged at the level of autonomic (not verbal or facial) reactions to sadness, with high CU respondents showing less HR change from baseline than low CU respondents. The study also examined basal patterns of autonomic function. Resting HR was not different between groups, but resting respiratory sinus arrhythmia (RSA) was significantly lower in DBD adolescents with high CU traits compared to controls. Results support the notion that CU traits designate a distinct subgroup of DBD individuals.

Motor Unit Firing Rate During Static Contraction Indicated by the Surface EMG Power Spectrum

In this study, power spectral density functions (PSDFs) were computed of interference EMG of various facial and jaw-elevator muscles during nonfatiguing submaximal static contractions, recorded with surface electrodes. A distinct peak was found in the PSDFs in the frequency region below 40 Hz. It was shown that the peak was due to genuine EMG activity and that it could not be considered as an artifact, which was caused by electrode displacements during contraction. An increase of contraction strength resulted in a shift of the peak to higher frequencies and a decrease of peak amplitude relative to the power spectral estimates above 40 Hz, which were shown to be determined by the shape of the motor unit (MU) action potentials. In accordance with mathematical models of the EMG PSDF, it was demonstrated that the peak indicates the dominant firing rate of the sampled MUs. Our results suggest that this can be defined as the firing rate of the first recruited low-threshold MUs, which may be expected to dominate the interference EMG signal because of their preponderance in number. The data further suggest that the peak can be more readily observed in PSDFs of facial and jaw-elevator muscles than in PSDFs of limb muscles. This might be related to differences in MU firing statistics.

Facial EMG and heart rate responses to emotion‐inducing film clips in boys with disruptive behavior disorders

We examined aspects of emotional empathy across different physiological response systems in boys with disruptive behavior disorders (DBD) and normal controls. Heart rate (HR) and electromyographic (EMG) reactivity in zygomaticus major and corrugator supercilii muscles were monitored during sadness-, anger-, or happiness-inducing film clips. Relative to controls, DBD boys showed significantly less HR reduction during sadness, and a smaller increase in corrugator EMG activity both during sadness and anger. No significant group differences emerged in HR and zygomaticus EMG responsivity during happiness. We also examined cardiac activity at rest and found higher resting HR and lower respiratory sinus arrhythmia in DBD boys compared to controls. Findings give evidence for a selective impairment in empathy with sadness and anger (not happiness) among DBD boys who exhibit relatively high levels of anxiety and poor emotional control.

Empathy dysfunction in children and adolescents with disruptive behavior disorders

In this essay, we focus on empathy in children and adolescents with disruptive behavior disorders (DBD), based on the assumption that lack of empathy is a risk factor for the development of DBD. We reflect on the heterogeneity of DBD, the complex nature of the empathy construct, discuss empathys role in aggression, and review recent findings from studies on empathic skills in children and adolescents with DBD. Research suggests that the mechanisms underlying empathy problems may be different for DBD subtypes. Individuals with psychopathic tendencies may show a selective impairment in empathy with sadness and fear due to abnormalities in neural circuits connected with the amygdala. Individuals without these tendencies may show little empathy for a variety of reasons, such as hostile attributions, anxiety and/or poor regulatory skills. Understanding more about the nature and causes of empathy dysfunction in DBD could aid in identifying subtypes and help to improve prevention and intervention programs. Suggestions for future research are made.

Respiratory sinus arrhythmia responses to induced emotional states : Effects of RSA indices, emotion induction method, age, and sex

The literature shows large inconsistencies in respiratory sinus arrhythmia (RSA) responses to induced emotional states. This may be caused by differences in emotion induction methods, RSA quantification, and non-emotional demands of the situation. In 83 healthy subjects, we studied RSA responses to pictures and film fragments eliciting six different discrete emotions relative to neutral baseline stimuli. RSA responses were quantified in the time and frequency domain and were additionally corrected for differences in mean heart rate and respiration rate, resulting in eight different RSA response measures. Subjective ratings of emotional stimuli and facial electromyographic responses indicated that pictures and film fragments elicited the intended emotions. Although RSA measures showed various emotional effects, responses were quite heterogeneous and frequently nonsignificant. They were substantially influenced by methodological factors, in particular time vs. frequency domain response measures, correction for changes in respiration rate, use of pictures vs. film fragments, and sex of participants.

Respiratory sinus arrhythmia responses to cognitive tasks: Effects of task factors and RSA indices

Many studies show that respiratory sinus arrhythmia (RSA) decreases while performing cognitive tasks. However, there is uncertainty about the role of contaminating factors such as physical activity and stress-inducing task variables. Different methods to quantify RSA may also contribute to variable results. In 83 healthy subjects, we studied RSA responses to a working memory task requiring varying levels of cognitive control and a perceptual attention task not requiring strong cognitive control. RSA responses were quantified in the time and frequency domain and were additionally corrected for differences in mean interbeat interval and respiration rate, resulting in eight different RSA indices. The two tasks were clearly differentiated by heart rate and facial EMG reference measures. Cognitive control induced inhibition of RSA whereas perceptual attention generally did not. However, the results show several differences between different RSA indices, emphasizing the importance of methodological variables. Age and sex did not influence the results.

Differences in autonomic physiological responses between good and poor inductive reasoners

We investigated individual- and task-related differences in autonomic physiological responses induced by time limited figural and verbal inductive reasoning tasks. In a group of 52 participants, the percentage of correctly responded task items was evaluated together with nine different autonomic physiological response measures and respiration rate (RR). Weighted multidimensional scaling analyses of the physiological responses revealed three underlying dimensions, primarily characterized by RR, parasympathetic, and sympathetic activity. RR and sympathetic activity appeared to be relatively more important response dimensions for poor reasoners, whereas parasympathetic responsivity was relatively more important for good reasoners. These results suggest that poor reasoners showed higher levels of cognitive processing intensity than good reasoners. Furthermore, for the good reasoners, the dimension of sympathetic activity was relatively more important during the figural than during the verbal reasoning task, which was explained in terms of hemispheric lateralization in autonomic function.

Filters for optimal smoothing of acoustic and electric blink reflex EMG responses to determine blink response magnitude

The functional (i.e., kinematic) aspects of the blink reflex depend on the size of the integrated orbicularis oculi EMG response. Peak amplitude of smoothed rectified EMG is often used as an approximation of integrated EMG. A comparison was made between the outputs of 24 different smoothing filters, correlating peak amplitude of acoustic or electric blink reflexes with integrated EMG. The coefficient of determination (R2) was largest (i.e., ≥.95 for acoustic and ≥.90 for electric blink reflexes) when using either (1) a first-order resistor-capacitor filter with a time constant of 50 or 100 ms, (2) a boxcar filter averaging 51 or 101 data points, or (3) an unequal-weight finite impulse response filter with a cutoff frequency of 5 or 10 Hz. These filters are thus recommended when determining peak amplitude. Applying a baseline correction on peak amplitude and integrated EMG produced slightly smaller values of R2 compared with uncorrected measures.

Respiratory Sinus Arrhythmia Moderates the Relation between Parent-Adolescent Relationship Quality and Adolescents’ Social Adjustment

This 2-wave longitudinal study aimed (1) to investigate whether high resting RSA predicted adolescents’ lower externalizing behavior and higher empathic concern, and (2) to address the potential moderating role of resting RSA in the association between parent-adolescent relationship quality and adolescents’ externalizing behavior and empathic concern. In a sample of 379 adolescents (212 boys, 167 girls), resting RSA was assessed during a laboratory session, and adolescents reported on parental support, negative interaction with parents, empathic concern and externalizing behavior during a home visit. We found no support for high resting RSA predicting low externalizing behavior or high empathic concern. However, in line with our hypotheses, we did find several instances of RSA functioning as a moderator, although the interaction patterns varied. First, negative interaction with parents was a negative predictor of externalizing behavior for girls low in resting RSA, whereas the association was non-significant for girls with high RSA. Second, higher negative interaction with parents predicted lower empathic concern for boys high in resting RSA, whereas the association was reversed for boys with low resting RSA. Third, parental support was a positive predictor of empathic concern for girls high in resting RSA, whereas the association was non-significant for girls low in resting RSA. The findings suggest that adolescents with different levels of resting RSA respond differentially to relationship quality with parents.

Generalizability of Component Processes in Intelligence as Revealed by Latency Measures.

Abstract In this study, we explored the relationships between the latencies of theoretically corresponding and noncorresponding component processes across a diverse task universe derived from Guilfords Structure of Intellect (SI) model. Seventy-two participants were presented a task universe that consisted of six componential tasks with a semantic or figural content and with an emphasis on either cognition, inductive reasoning, or evaluation operations. Latencies of 18 component processes were estimated from these componential tasks by means of multiple regression analysis and identified as encoding, searching, inference, mapping, application, comparison, and justification components. Canonical correlation analysis indicated that on a componential level the task universe showed to a certain extent diversity, suggesting that there was only a small bias in favor of finding convergent relationships. Multidimensional scaling and hierarchical cluster analyses revealed a three-cluster solution of component processes, which were tentatively interpreted as an encoding, a reasoning, and an evaluation cluster. These results provide initial evidence that theoretically corresponding component processes were generalizable (convergent validity) and theoretically noncorresponding component processes were not generalizable (discriminant validity) across the given task universe.