C. Schröder

Perception of emotional speech in Parkinson's disease.

Nonmotor symptoms in Parkinsons disease (PD) involving cognition and emotionality have progressively received attention. The objective of the present study was to investigate recognition of emotional prosody in patients with PD (n = 14) in comparison to healthy control subjects (HC, n = 14). Event‐related brain potentials (ERP) were recorded in a modified oddball paradigm under passive listening and active target detection instructions. Results showed a poorer performance of PD patients in classifying emotional prosody. ERP generated by emotional deviants (happy/sad) during passive listening revealed diminished amplitudes of the mismatch‐related negativity for sad deviants, indicating an impairment of early preattentive processing of emotional prosody in PD.

Emotional Speech in Parkinson's Disease

Patients with Parkinsons disease (PD) tend to speak monotonously with minor modulation of pitch and intensity. The goal of this study was to find out whether these speech changes can be explained mainly by motor impairment, i.e. akinesia and rigidity of the articulatory apparatus, or whether alterations of emotional processing play an additional role. Sixteen patients with mild PD and 16 healthy controls (HC) were compared. Fundamental frequencies (pitch) and intensities (loudness) were determined as (1) maximal upper and lower values achieved in nonemotional speech (phonation capacity), (2) upper and lower values used when speaking “Anna” in emotional intonation (neutral, sad, happy) as requested (production task), or (3) when imitating a professional speaker (imitation task). Although groups did not significantly differ in their phonation capacity, patients showed a significantly smaller pitch and intensity range than HC in the production task. In the imitation task, however, ranges were again similar. These results suggest that alterations of emotional processing contribute to speech changes in PD, especially regarding emotional prosody, in addition to motor impairment.

Functional lesions and human action monitoring: combining repetitive transcranial magnetic stimulation and event-related brain potentials

OBJECTIVE Electrophysiological recordings of the error-related negativity (ERN) and functional imaging data point to an involvement of medial frontal cortex (including the anterior cingulate cortex, ACC) and dorsolateral prefrontal cortex (DLPFC) in the detection and correction of performance errors. Here, we studied this network by applying trains of rapid transcranial magnetic stimulation (rTMS) prior to the recording of the ERN. METHODS Low-frequency (0.9 Hz) rTMS was applied to medial frontal or lateral frontal regions (different sessions) for 60 s immediately before each 3 min ERN recording in 11 healthy young subjects. The ERN was obtained by multichannel recordings in a typical Eriksen flanker task with instructions calling for immediate error correction in case a performance error was detected by the subject. Event-related potentials were quantified and statistically evaluated using standard methodology. RESULTS Compared to a no-stimulation control condition, medial frontal stimulation led to a small but reliable decrease in the number of corrected errors as well as to an attenuation of the ERN and an increase of the subsequent error-positivity (Pe). No effect on these components was seen after lateral frontal stimulation. No reliable effects on the lateralized readiness potential were observed. CONCLUSIONS Functional lesions by rTMS appear to interfere with the functions of the medial frontal cortex in error detection and correction.

Changes of emotional prosody in Parkinson's disease

Even though the mesocortical dopamine system is known to play an important role in affect control and reward related behaviour, only little is known about the impact of Parkinsons disease on emotional communication. The ability to perceive and express emotions via speech plays an essential role in every day social life. Here, studies investigating perception and production of emotional prosody in Parkinsons disease will be reviewed and own results will be presented. Evidence will be provided that patients with Parkinsons disease do have changes of emotional prosody processing and that they also show alterations of emotional speech production. Together, these studies highlight the importance of the basal ganglia and their connections for emotional communication.

Gender Differences in Processing Emotional Prosody

Introduction: A requirement of functional electrical stimulation (FES), which is used extensively in rehabilitation of paraplegics, is that the stimulation should elicit a sufficiently powerful muscle contraction with minimum discomfort and fatigue. Although low frequency rectangular pulsed current (LFRP) is usually used, information has been increasing, that middle frequency alternating current (MFAC) reduces the fatigue rate more than LFRP. Additionally could be expected that MFAC causes less pain, thus allowing stimulation of sensory incomplete paraplegics. Because such MFAC stimulation-induced lower fatigue rate is a tradeoff with force reduction, it is important to determine whether MFAC stimulation is a realistic option for FES of paraplegics. Objective: To compare the isometric force, power, and pain sensations during FES cycling of paraplegics during electrical stimulation using MFAC or standard LFRP. Methods: Eleven complete paraplegic subjects participated. Isometric torques of the leg muscles and the pedaling power generated in the first 20 min during ergometer cycling were collected during stimulation (Fig. 1) with 20 Hz LFRP or 4 KHz sinusoidal modulated with 50 Hz MFAC (a total of four sessions). Subjectively sensed pain was quantitatively recorded during ergometer cycling at maximal stimulation with the visual analogue scale (VAS) method. Results: Isometric torque elicited during MFAC stimulation was significantly lower (p < 0.02). Moreover, mean pedaling power generated during MFAC was highly and significantly lower (p < 0.001) than during standard LFRP stimulation (Fig. 2). While there were no complains registered during LFRP stimulation, four of 11 participants reported an abdominal, tugging discomfort during MFAC stimulation (mean VAS = 3.2). Conclusion: From a clinical viewpoint MFAC is not a viable option for enhancing functional output or for minimizing discomfort during FES of complete and incomplete paraplegics.

Perception and production of emotional speech in Parkinson's disease

not received. CS3.5 Functional connectivity of the mesial temporal lobe in humans: an electrical study

Auditory orienting to speech and environmental sounds

Introduction: Attentional effects in the timeframe of the eventrelated N1 potential have been described and addressed as ‘‘N1effect’’ more than thirty years ago. In the meantime, this effect has been widely used as a tool to investigate attentional processes. While there has been some debate whether about the character of this phenomenon, e.g. in the sense of an overlapping ‘‘processing negativity’’ on the basic and obligatory N1 potential, until recently no doubt has been formulated about the temporal lobe/auditory cortex origin of this effect. In the last years however, some hints exist for an additional contribution of the anterior cingulate cortex (ACC) to the N1 effect: Based on different source localization techniques like dipoles or LORETA, an ACC-generator of the N1 potential has been described. Very recently, an ACC-generator during the N1-timeframe has also been described using intracranial measurements. In the present study we used trial by trial coupling of simultameous EEG and fMRI to investigate the neural generators of the N1-potential in choice reaction tasks. Methods: We investigated ten healthy subjects. The task was a choice reaction paradigm: Two · 30 tones of different pitches (800 and 1300 Hz) were presented by earphones at 85 dB SPL with pseudo-randomized sequence and interstimulus intervals (ISI: 2.5– 7.5 s). The subjects had to press the correct button. FMRI-data: (1.5 T Sonata scanner (Siemens); gradient echo EPI sequence; 12 slices; matrix: 128 · 128; slice thickness: 8 mm; interslice-gap: 0.4 mm; interleaved slice acquisition) were acquired in temporal synchrony to the task. BrainVoyager was used to compare differences in task specific BOLD responses. EEG signals were recorded simultaneously (61 channels; Cz reference; 1000 Hz sampling). After artefact correction, single trial modulations of the N1-potential amplitudes were used for a convolution with a hemodynamic response function to calculate the corresponding BOLD-effects. Results and conclusion: Main fMRI activation patterns using this method were found in the auditory cortex. As expected, additional dorsal anterior cingulate cortex activations were found. These results suggest a contribution of the dorsal ACC to the N1-effect.