Electrophysiology in neuropsychiatric research: a network perspective

A growing number of anatomic and physiologic studies have shown that parallel sensory and motor information processing occurs in multiple cortical areas. These findings challenge the traditional model of brain processing, which states that the brain is a collection of physically discrete processing modules that pass information to each other by neuronal impulses in a stepwise manner. New concepts based on neural network models suggest that the brain is a dynamically shifting collection of interpenetrating, distributed, and transient neural networks. Neither of these models is necessarily mutually exclusive, but each gives different perspectives on the brain that might be complementary. Each model has its own research methodology, with functional magnetic resonance imaging supporting notions of modular processing, and electrophysiology (eg, electroencephalography) emphasizing the network model. These two technologies might be combined fruitfully in the near future to provide us with a better understanding of the brain. However, this common enterprise can succeed only when the inherent limitations and advantages of both models and technologies are known. After a general introduction about electrophysiology as a research tool and its relation to the network model, several practical examples are given on the generation of pathophysiologic models and disease classification, intermediate phenotyping for genetic investigations, and pharmacodynamic modeling. Finally, proposals are made about how to integrate electrophysiology and neuroimaging methods.     

Suffering and interpersonal meaning: commentary

I would like to suggest that to describe suffering as a psychological phenomenon is still too general. It leaves the door open to the belief that suffering is an individual phenomenon, experienced because of dynamics arising out of the individual psyche as the pain arises out of the individual body. Instead of describing suffering as a psychological phenomenon, we should describe it as an interpersonal, even communal phenomenon....If the task of reestablishing, continuing, and creating interpersonal meaning within the context of suffering is accepted, the problem often arises concerning how the health professional can accomplish this task with the patient under the extraordinary circumstances that pain and illness, as well as the health-care environment, provide. Beyond sensitive and thoughtful dialogue, we may have to return to a sense of ceremony within health care, especially since the rationalistic naiveté of nineteenth-century positivism did so much to encourage the belief that the best health care is the one that does things efficiently and "unceremoniously"....     

Post-traumatic stress reactions following the March 11, 2004 terrorist attacks in a Madrid community sample: a cautionary note about the measurement of psychological trauma

Posttraumatic stress reactions related to the Madrid March 11, 2004, terrorist attacks were examined in a sample of Madrid residents (N = 503) 18-25 days after the attacks, using multiple diagnostic criteria and different cut-off scores. Based on the symptoms covered by the Posttraumatic Stress Disorder Checklist-Civilian (PCL-C; Weathers, Litz, Herman, Huska, and Keane, 1993), rates of probable posttraumatic stress disorder (PTSD) ranged from 3.4% to 13.3%. Taking into account additional criteria from the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 200; i.e., the impact of initial reaction and problems in daily functioning as a consequence of the traumatic event), only 1.9% of respondents reported probable PTSD. These results suggest that inferences about the impact of traumatic events on the general population are strongly influenced by the definition of traumatic response. Our findings also revealed that the magnitude of posttraumatic reactions is associated with several risk factors, including living close to the attacked locations, physical proximity to the attacks when they occurred, perception of one's life being at risk, intensity of initial emotional reactions, and being a daily user of the attacked train lines. The use of different cut-off scores did not affect the pattern of risk to develop traumatic stress. The implications of these results for public health policies related to terrorist attacks are discussed.     

Brain dopamine and kinematics of graphomotor functions

Three experiments were performed in an attempt to achieve a better understanding of the effect of dopamine on handwriting. In the first experiment, kinematic aspects of handwriting movements were compared between healthy participants and patients with Parkinson's disease (PD) on their usual dopaminergic treatment and following withdrawal of dopaminergic medication. In the second experiment, the writing performance of healthy participants with a hyperechogenicity of the substantia nigra as detected by transcranial sonography (TCS) was compared with the performance of healthy participants with low echogenicity of the substantia nigra. The third experiment examined the effect of central dopamine reduction on kinematic aspects of handwriting movements in healthy adults using acute phenylalanine and tyrosine depletion (APTD). A digitising tablet was used for the assessment of handwriting movements. Participants were asked to perform a simple writing task. Movement time, distance, velocity, acceleration and measures of fluency of handwriting movements were measured. The kinematic analysis of handwriting movements revealed that alterations of central dopaminergic neurotransmission adversely affect movement execution during handwriting. In comparison to the automatic processing of handwriting movements displayed by control participants, participants with an altered dopaminergic neurotransmission shifted from an automatic to a controlled processing of movement execution. Central dopamine appears to be of particular importance with regard to the automatic execution of well-learned movements.     

Psychophysiological assessment during exposure in driving phobic patients

A comprehensive assessment of fear or anxiety requires measurement of both self-report and physiological responses. Respiratory abnormalities have been rarely examined during real-life exposure, although they are an integral part of fear. Twenty-one women with a specific driving phobia and 17 nonphobic women were psychophysiologically monitored during 2 highway-driving sessions; phobic women completed an additional session. Respiratory movements, end-tidal partial pressure of carbon dioxide, an electrocardiogram, skin conductance, and skin temperature were recorded. Phobic patients differed from control participants both physiologically and experientially before, during, and after exposure. Effect size during exposure was large for the authors' measure of hyperventilation. Discriminant analysis indicated that multiple physiological measures contributed nonredundant information and correctly classified 95% of phobic and control participants. Thus, selected respiratory and autonomic measures are valid diagnostic and therapeutic outcome criteria for this situational phobia.     

Qualia im Knotenpunkt zwischen Leib und Seele: „Argumentatives“ Dilemma in der gegenwärtigen Diskussion über die Subjektivität mentaler Zustände

Qualia in the node-point between mind and body: Dilemma of present discussion about the subjectivity of mental states. The present discussion about qualia shows a bewildering variety of different positions. We show implicit assumptions about brain, subject, and qualia of this complex discussion. By means of three assumptions we divide the discussion about qualia into three different positions (proposition, opposition, intermediate solutions). These positions and their exemplaric authors are briefly presented along the lines of the three assumptions. The next step shows how each position solves the dilemma which arises if one relates all three assumptions by eliminating at least one of the three assumptions. Finally, general problems in the discussion of qualia are shown by means of which the dilemma of the relation between brain, subject and qualia may be brought closer to a solution without eliminating one assumption.     

Experimentelle Untersuchungen über simultane und sukzessive Gesichtswahrnehmungen

Zusammenfassung A. Lehmann hat in seiner Psychophysiologie ein allgemeines Gesetz aufgestellt, wonach gleichzeitige Erregungen sich hemmen, sukzessive dagegen sich bahnen. Die Schwelle für einen Schallreiz ist z. B. h?her, wenn gleichzeitig ein elektrischer Reiz einwirkt, wogegen, im allgemeinen von zwei einander folgenden gleich starken Reizen der zweite für st?rker gehalten wird. Wir führen hier diesen Satz an, um die Vermutung ausdrücklich abzuweisen, als ob unsere Prinzipien diesen oder einen ?hnlichen Sachverhalt ausdrückten. Wir sprachen nicht von einwirkenden Reizen oder physiologischen Erregungen, sondern von psychischen Inhalten, bzw. von deren gleichzeitigem oder sukzessivem Gegebensein. Und es war das Ergebnis unserer Versuche nicht, da? gleichzeitig erscheinende psychische Inhalte sich hemmen bzw. sukzessive sich bahnen, sondern es ergab sich nur,da? stückhafte Teile in einer einheitlichen simultanen Wahrnehmung in minderwertigerer Weise zur Geltung kommen als in zwei sukzessiven Wahrnehmungen, wo sie eben keine stückhaften Teile mehr sind, sondern selbst?ndige Gegebenheiten. Die Umkehrung dieses Satzes trifft aber auch zu und ist z. B. ableitbar aus unseren Versuchen über den Entfernungsvergleich der Diagonalen eines Quadrates. In jeder simultanen Wahrnehmung ergibt sich ein einheitlicher Gesamteindruck, und die diesem entsprechende Wahrnehmungsart ist eben die simultane, in welcher er auch besser verwirklicht wird, als wenn er aus einigen sukzessiven Wahrnehmungen zu entstehen h?tte. Mit 10 Figuren im Text. über einen Teil der nachfolgenden Experimente hat der Verf. schon auf dem Münchener Psychologenkongre? (April 1925) berichtet.     

Everyday temptations: an experience sampling study of desire, conflict, and self-control

How often and how strongly do people experience desires, to what extent do their desires conflict with other goals, and how often and successfully do people exercise self-control to resist their desires? To investigate desire and attempts to control desire in everyday life, we conducted a large-scale experience sampling study based on a conceptual framework integrating desire strength, conflict, resistance (use of self-control), and behavior enactment. A sample of 205 adults wore beepers for a week. They furnished 7,827 reports of desire episodes and completed personality measures of behavioral inhibition system/behavior activation system (BIS/BAS) sensitivity, trait self-control, perfectionism, and narcissistic entitlement. Results suggest that desires are frequent, variable in intensity, and largely unproblematic. Those urges that do conflict with other goals tend to elicit resistance, with uneven success. Desire strength, conflict, resistance, and self-regulatory success were moderated in multiple ways by personality variables as well as by situational and interpersonal factors such as alcohol consumption, the mere presence of others, and the presence of others who already had enacted the desire in question. Whereas personality generally had a stronger impact on the dimensions of desire that emerged early in its course (desire strength and conflict), situational factors showed relatively more influence on components later in the process (resistance and behavior enactment). In total, these findings offer a novel and detailed perspective on the nature of everyday desires and associated self-regulatory successes and failures.