A multidimensional examination of affective and cognitive empathy in anorexia nervosa

Socio-emotional features are crucial in the development and maintenance of anorexia nervosa (AN). The present study investigates the patterns of altered and preserved empathic abilities in AN. Empathy is an umbrella term that comprises the ability to recognise another's emotional state, take another's perspective, and fantasise (cognitive empathy), as well as the ability to experience vicarious emotions and signal them (affective empathy). These empathic abilities were measured in 43 AN patients and 33 healthy women through a multi-method approach comprising self-report measures, behavioural tasks and bodily correlates. Further, we assessed self-reported approach-avoidance attitudes towards suffering others. Results showed that, within the domain of cognitive empathy, AN patients reported impairment in recognising emotional expressions of anger and fantasising. Concerning affective empathy, they manifested lower sharing of others' positive emotions, higher self-reported distress, and higher facial expressiveness during a video depicting a suffering person. Finally, AN patients reported lower motivation to approach suffering others. Our results draw a complex picture of preserved and altered empathic abilities in AN and capture which are the deficits mediated by the higher levels of anxiety and depression reported by the AN population and those that seem to persist independently from these co-morbid conditions.

Heart rate variability analysis as an index of emotion regulation processes: interest of the Analgesia Nociception Index (ANI)

Autonomic Nervous System (ANS) variations are strongly influence by emotion regulation processes. Indeed, emotional stimuli are at the origin of an activation of the ANS and the way an individual pass from a state of alert in the case of emotional situation to a state of calm is closely coupled with the ANS flexibility. We have previously described and developed an Analgesia Nociception Index (ANI) for real time pain measurement during surgical procedure under general anesthesia. This index, based on heart rate variability analysis, constitutes a measure of parasympathetic tone and can be used in several other environments. In this paper, we hypothesized that such an index could be used as a tool to investigate the processes of emotional regulation of a human subject. To test this hypothesis, we analyzed ANI's response to a negative emotional stimulus. This analysis showed that the index decreases during the emotion induction phase and returns to its baseline after 2 minutes. This result confirms that ANI could be a good indicator of parasympathetic changes in emotional situation.

Categorical and dimensional study of the predictive factors of the development of a psychotrauma in victims of car accidents

OBJECTIVE

This study aimed to evaluate the predictive factors of the emergence of complete PTSD and subsyndromal PTSD (defined as individuals exposed to a traumatic event with at least one psychopathological impact, such as hyperarousal, avoidance or persistent re-experiencing) following a motor vehicle accident (MVA).

METHODS

We recruited 155 adult MVA patients, physically injured and admitted to trauma service, over two years. In the week following the accident, patients were asked to complete questionnaires assessing their social situation (sex, age, marital and employment status, prior MVA or trauma), comorbidity (MINI), distress (PDI) and dissociation (PDEQ) experienced during and immediately after the trauma. An evaluation using the CAPS was conducted six months after the trauma to assess a possible PTSD.

RESULTS

At six months, 25.8% of the participants developed subsyndromal symptoms and 7.74% developed complete PTSD. The three symptoms that best discriminated the groups were dysphoric emotion, perceived life threat and dissociation. Logistic regression results showed that the strongest predictor of PTSD was the perceived life threat. In addition, a dimensional approach to the results revealed significant correlations between (1) peritraumatic distress and persistent re-experiencing or hyperarousal and (2) dissociation score and avoidance strategy. The presence of a prior traumatic event reinforces avoidance strategies.

CONCLUSIONS

Our results stress that peritraumatic factors (especially the perception of a life threat) are good predictors of PTSD development. A dimensional perspective allows better identification of psychological complications following an MVA.

[Dynamic paradigm in psychopathology: "chaos theory", from physics to psychiatry]

For the last thirty years, progress in the field of physics, known as "Chaos theory"--or more precisely: non-linear dynamical systems theory--has increased our understanding of complex systems dynamics. This framework's formalism is general enough to be applied in other domains, such as biology or psychology, where complex systems are the rule rather than the exception. Our goal is to show here that this framework can become a valuable tool in scientific fields such as neuroscience and psychiatry where objects possess natural time dependency (i.e. dynamical properties) and non-linear characteristics. The application of non-linear dynamics concepts on these topics is more precise than a loose metaphor and can throw a new light on mental functioning and dysfunctioning. A class of neural networks (recurrent neural networks) constitutes an example of the implementation of the dynamical system concept and provides models of cognitive processes (15). The state of activity of the network is represented in its state space and the time evolution of this state is a trajectory in this space. After a period of time those networks settle on an equilibrium (a kind of attractor). The strength of connections between neurons define the number and relations between those attractors. The attractors of the network are usually interpreted as "mental representations". When an initial condition is imposed to the network, the evolution towards an attractor is considered as a model of information processing (27). This information processing is not defined in a symbolic manner but is a result of the interaction between distributed elements. Several properties of dynamical models can be used to define a way where the symbolic properties emerge from physical and dynamical properties (28) and thus they can be candidates for the definition of the emergence of mental properties on the basis of neuronal dynamics (42). Nevertheless, mental properties can also be considered as the result of an underlying dynamics without explicit mention of the neuronal one (47). In that case, dynamical tools can be used to elucidate the Freudian psychodynamics (34, 35). Recurrent neuronal networks have been used to propose interpretation of several mental dysfunctions (12). For example in the case of schizophrenia, it has been proposed that troubles in the cortical pruning during development (13) may cause a decrease in neural network storage ability and lead to the creation of spurious attractors. Those attractors do not correspond to stored memories and attract a large amount of initial conditions: they were thus associated to reality distorsion observed in schizophrenia (14). Nevertheless, the behavior of these models are too simple to be directly compared with real physiological data. In fact, equilibrium attractors are hardly met in biological dynamics. More complex behaviors (such as oscillations or chaos) should thus to be taken into account. The study of chaotic behavior have lead to the development of numerical methods devoted to the analysis of complex time series (17). These methods may be used to characterise the dynamical processes at the time-scales of both the cerebral dynamics and the clinical symptoms variations. The application of these methods to physiological signals have shown that complex behaviors are related to healthy states whereas simple dynamics are related to pathology (8). These studies have thus confirmed the notion of "dynamical disease" (20, 21) which denotes pathological conditions characterised by changes in physiological rhythms. Depression has been studied within this framework (25, 32) in order to define possible changes in brain electrical rhythms related to this trouble and its evolution. It has been shown that controls' brain dynamics is more complex than depressive one and that the recovery of a complex brain activity depends on the number of previous episodes. In the case of the symptoms time evolution, several studies have demonstrated that non-linear dynamical process may be involved in the recurrence of symptoms in troubles such as manic-depressive illness (9) or schizophrenia (51). These observations can contribute to more parcimonious interpretation of the time course of these illnesses than usual theories. In the search of a relationship between brain dynamics and mental troubles, it has been shown in three depressed patients an important correlation between the characteristics of brain dynamics and the intensity of depressive mood (49). This preliminary observation is in accordance with the emergence hypothesis according which changes in neuronal dynamics should be related to changes in mental processes. We reviewed here some theoretical and experimental results related to the use of "physical" dynamical theory in the field of psychopathology. It has been argued that these applications go beyond metaphor and that they are empirically founded. Nevertheless, these studies only constitute first steps on the way of a cautious development and definition of a "dynamical paradigm" in psychopathology. The introduction of concepts from dynamics such as complexity and dynamical changes (i.e. bifurcations) permits a new perspective on function and dysfunction of the mind/brain and the time evolution of symptoms. Moreover, it offers a ground for the hypothesis of the emergence of mental properties on the basis of neuronal dynamics (42). Since this theory can help to throw light on classical problems in psychopathology, we consider that a precise examination of both its theoretical and empirical consequences is requested to define its validity on this topic.

Depression as a dynamical disease

Mathematical models are helpful in the understanding of diseases through the use of dynamical indicators. A previous study has shown that brain activity can be characterized by a decrease of dynamical complexity in depressive subjects. The present paper confirms and extends these conclusions through the use of recent methodological advances: first episode and recurrent patients strongly differ in their dynamical response to therapeutic interventions. These results emphasize the need for clinical follow-ups to avoid recurrence and the necessity of specific therapeutic intervention in the case of recurrent patients.

Temporal localization of the response selection processing stage

Response choice is one of the stages in the information processing model proposed by Sanders. It is influenced by stimulus-response (S-R) compatibility. Segmentation of the processing window in intervals between RT and peak latencies and between peak latencies, was used to test the assumption that the decisional processes would be concomitant with the N200 rather than the P300 component. ERPs were recorded in ten subjects during a spatial S-R compatibility auditory task. The S-R compatibility effect is observed on P300 latencies but is only a trend on the N200 component. An effect also observed on the interval between RT and N200 and especially between N200 and P300 while no effect is observed on the interval between RT and P300. These results support the idea that the selection processes ending with P300 occurrence could start as early as the N200 peak component.

[Study of the organization of sensorimotor stages in man using delayed evoked potentials]

The main aim of this study was to test the relative organization of three of the stages of Sanders' 1990 information processing model: "features extraction", "response choice", and "motor adjustment". The variables influencing these stages: stimulus degradation, stimulus-response (SR) compatibility and preparatory period have been manipulated. Event related potentials (N100, N200, P300) and reaction time were recorded from ten healthy subjects, in a dichotic listening task. Reaction times are lengthened for degraded stimuli, in the absence of a preparatory period and for SR non compatible conditions. However, the interaction between preparatory period and stimulus degradation variables, suggests an overlapping of the corresponding stages contrary to Sanders' postulate. The non compatible condition increases the latency of N200 and P300 components. The results suggest that the response choice processing would be contemporary to the N200 component. They are discussed within the framework of models of early communication between sensory and motor systems.

Decrease of complexity in EEG as a symptom of depression

Nonlinear dynamic analysis provides new methods for the processing of the electroencephalogram (EEG). We demonstrate here that the EEG dynamics of major depressive subjects is more predictable, that is less complex, than that of control subjects. Moreover, the consequence of treatment upon the EEG dynamics seems to be dependent on the appearance of the illness. Although the specificity of this dynamic signature for different stages of depression is to be confirmed, the assumption of a strong link between a healthy system and a high level of complexity in dynamics is further supported.

Time for reorienting of attention: a premotor hypothesis of the underlying mechanism

The paradigm of the covert orienting of attention (COA) has shown that the displacement of visual attention may be assessed even in the absence of eye movement. Stimuli correctly cued before their presentation are usually detected faster than uncued stimuli. However, miscued stimuli induce an increased detection time, which has been attributed to the time required for the reorientation of attention from the incorrect to the correct spatial location. Currently, the mechanism of such a displacement of visual attention remains unknown. Rizzolatti et al. Neuropsychologia 25, 31-40 (1987) have suggested a premotor hypothesis which suggests that an oculomotor disprogramming and reprogramming is necessary to reorient visual attention, even if the eye movement is inhibited. Since shifting of auditory attention from one ear to the other does not require any motor control, we further investigated the model of COA in 20 normal subjects who performed two tasks requiring a reorienting of auditory attention: (1) a choice RT task that requires a response readjustment during the auditory reorienting; (2) a simple RT task that does not require a response readjustment during the auditory reorienting; (2) a simple RT task that does not require a response readjustment during the auditory reorienting. Results indicate that correctly cued stimuli significantly reduce the RT in both tasks and that this reduction is greater in the choice than in the simple RT task. This suggests that a correct cue may produce a pre-programming of the response, in addition to the pre-engagement of the perceptual attention.(ABSTRACT TRUNCATED AT 250 WORDS)