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P 39. Functional causality of the dorsal stream in sensorimotor integration of speech repetition
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Society Proceedings / Clinical Neurophysiology 124 (2013) e39–e187
P 37. Hemispheric asymmetries in language processing: Evidence from false memories for lists, texts, and ambiguous words—E. BenArtzi a, M. Faust b (a Center for Academic Studies, Psychology, Or Yehuda, Israel, b Bar Ilan University, Psychology, Bar Ilan, Israel) Previous research suggests that, whereas the left cerebral hemisphere (LH) is dominant for language processing, the right hemisphere (RH) may play a unique role in the comprehension of natural language, i.e. in processing language in contexts that extend beyond the meanings of individual words or sentences such as stories, conversations, or texts, and thus may contribute uniquely to the processing of lexical ambiguity by activating and maintaining a wide range of meanings, including subordinate. A series of studies used the word-lists false memory paradigm (Roediger and McDermott, 1995) to examine the difference between the two cerebral hemispheres in language processing. Specifically, we tested the susceptibility of the LH and RH to unpresented target words following the presentation of semantically related words appearing in either word lists or short texts (Study 1) and whether these differences between the two cerebral hemispheres in semantic processing also affect memory representations for different meanings of ambiguous words (Study 2). Specifically, we tested the differences between the LH and RH in recollecting unpresented, semantically related, ambiguous words following the presentation of lists of words all related to either the dominant or the subordinate meanings of these ambiguous words. Findings of Study 1 showed that the RH produced more false alarms than the LH for unpresented target words following either word lists or texts. These findings reveal hemispheric differences in memory for semantically related information and suggest that RH advantage in long-term maintenance of a wide range of textrelated word meanings may be one aspect of its unique contribution to the construction of a discourse model. Findings of Study 2 indicated that for the unpresented ambiguous words, the LH made more false alarms than the RH for the dominant lists, whereas the opposite pattern emerged for subordinate lists. These results support the RH coarse semantic coding theory (Beeman, 1998) indicating that during word recognition, the RH activates and maintains a broader and less differentiated range of related meanings than the LH, including both dominant and subordinate meanings of ambiguous words. Furthermore, the findings suggest that hemispheric differences in ambiguity resolution during language processing extend also to verbal memory.
The task required adaptation to occasional tempo changes (i.e., accelerations or decelerations of large or small magnitude). In order to interfere with motor simulation processes, dTMS (two pulses, with an inter-onset-interval of 100 ms and intensity at 110% of the individual’s resting motor threshold) or sham was delivered over the right primary motor cortex prior to each tempo change. Tempo adaptation accuracy was quantified on the basis of the ratio between produced keystroke inter-onset intervals and target inter-onset intervals in recorded bassline parts (cf. Repp, 2005). Participant’s “perspective taking” tendencies (i.e., how spontaneously they adopt others’ perspectives) were assessed at the end of the experiment via an empathy questionnaire based on the Interpersonal Reactivity Index (Davis, 1980). Results: Results indicated that dTMS impaired tempo adaptation accuracy only when pianists had practiced the left-hand bassline part beforehand, i.e., when motor simulation was presumably enhanced. This impairment, which was associated with a deceleration in the performance with respect to the audible bassline, occurred irrespective of tempo change direction (acceleration or deceleration) and magnitude (small or large). Finally, the decelerating effect of dTMS on performance tempo was greater in empathic individuals who possessed a stronger tendency to adopt others’ perspectives (cf. Novembre, 2012). Conclusion: These findings indicate that motor simulation provides a functional resource for the temporal coordination of one’s own behaviour with others in dynamic social contexts.
References Davis. A multidimensional approach to individual differences in empathy. JSAS Catalog of selected documents in psychology; 1980. D’Ausilio et al. Cross-modal plasticity of the motor cortex while listening to a rehearsed musical piece. Eur J Neurosci 2006. Haueisen J, Knösche TR. Involuntary motor activity in pianists evoked by music perception. J Cognitive Neurosci 2001. Novembre et al. Distinguishing Self and Other in Joint Action. Evidence from a Musical Paradigm. Cereb. Cortex 2012. Repp. Sensorimotor synchronization: a review of the tapping literature. Psychon B Rev 2005.
doi:10.1016/j.clinph.2013.04.115
doi:10.1016/j.clinph.2013.04.116
P 38. Motor simulation coordinates joint actions in real time: Music performance meets on-line double-pulse TMS—G. Novembre a, L. Ticini a, S. Schütz-Bosbach a, P. Keller b,a (a Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, b The MARCS Institute, Sydney, Germany)
P 39. Functional causality of the dorsal stream in sensorimotor integration of speech repetition—T. Murakami a, C. Kell b, J. Restle b, Y. Ugawa a, U. Ziemann c (a Fukushima Medical University, Neurology, Fukushima, Japan, b Goethe-University, Neurology, Frankfurt am Main, Germany, c Eberhard-Karls-University, Neurology, Tübingen, Germany)
Question: Joint action is grounded in the ability to integrate simultaneous self-and other-related behaviour in real time. We investigated whether this function is underpinned by motor simulation, i.e. the capacity to represent a perceived action in terms of the neural resources required to execute it (Jeannerod, 2000). This was tested in a music performance experiment wherein on-line brain stimulation (double-pulse Transcranial Magnetic Stimulation, dTMS) was employed to interfere with motor simulation. Methods: Ten pianists (13.81 ± 3.86 years of musical training) played the right-hand part of piano pieces in synchrony with a recording of the left-hand part, which had (Trained) or had not (Untrained) been practiced beforehand. Training was assumed to enhance motor simulation of the audible left-hand part (cf. Haueisen and Knösche, 2001; D’Ausilio, 2006; Novembre, 2012).
Introduction: Acquisition of language skills is necessary for social interactions in humans, and speech repetition plays a fundamental role in its acquisition by mapping auditory speech input onto matching speech output. At the level of neuronal networks in the brain, speech repetition occurs within the auditory dorsal stream, which is constituted by a temporo-parieto-frontal network formed by the posterior part of superior temporal sulcus (pSTS), the posterior inferior frontal gyrus (pIFG), and the temporo-parietal junction (Tpj). However, it is less known which component of the dorsal stream plays an essential role in the modulation of speech repetition. Objectives: To investigate the issue of causality of the dorsal stream in sensorimotor integration of speech repetition, we
Society Proceedings / Clinical Neurophysiology 124 (2013) e39–e187
employed continuous theta-burst transcranial magnetic stimulation (cTBS) in order to disrupt neuronal activity in the stimulated areas. Methods: Nineteen right-handed German volunteers performed four behavioral speech tasks. (1) Word-picture matching test: subjects listened to a German noun and were asked to choose a picture which fit to the word heard from four different pictures; the target picture, pictures implying a phonemic or semantic error, and an unrelated picture. (2) Syllable repetition test: subjects listened to one of six different syllables and repeated the perceived syllable immediately. (3) Pseudo-word repetition test: subjects listened to meaningless pseudo-words and immediately repeated it. (4) Sentence repetition test: subjects listened to German sentences and immediately repeated it. In all the tests, error rates (ER) and reaction time (RT) were calculated. Inhibitory cTBS was applied over the individual activated regions of the left pIFG, Tpj, pSTS by using an fMRI-guided TMS neuronavigation system. Left middle occipital gyrus (MOG) was also stimulated as a control region to clarify the topographical specificity of cTBS effects because it is assumed that the MOG is concerned with visual processing. The behavioral speech tests were performed after cTBS over four sites mentioned above, and they were compared by repeated measures ANOVAs. Results: (1) In word-picture matching test, cTBS of Tpj, pSTS and pIFG increased phonemic errors compared to cTBS of MOG. No other types of errors were affected by any sites of cTBS. (2) The syllable repetition ERs were significantly larger after cTBS of Tpj, pSTS and pIFG than after cTBS over MOG. (3) Pseudo-word repetition test demonstrated that ERs significantly increased after cTBS of Tpj and pSTS than after cTBS of MOG and pIFG. (4) In the sentence repetition test, no differences were observed in ERs between sites of cTBS. Throughout all the behavioral tests, RTs were not significantly different between sites of cTBS. Conclusion: Disruption of the dorsal stream led to increases of phonemic errors in word-picture matching test and to increases of errors of syllable and pseudo-word repetitions, demonstrating that the dorsal stream plays a crucial role in sensorimotor integration of phonological processing. The lack of cTBS effects on native sentences may be explained by the idea that the lexical/semantic material processing is done by the ventral auditory stream. The sensory phonological system performs critical modulation of subsequent articulation in the motor system via a sensorimotor interface, supporting evidence that the sensory system is situated hierarchically at higher level to modulate the motor articulation. doi:10.1016/j.clinph.2013.04.117
P 40. Representation of the incorrect use of an object is supported by the DLPFC: The tDCS effect on ERP N400 for visual and linguistic stimuli—M. Balconi, S. Vitaloni (Catholic University of Milan, Milan, Italy) In the present study, we explored the representation of an incongruent action (instrumentally incorrect use of an object) in comparison with sentences ending with an incongruent action word, taking into account the role of left dorsolateral prefrontal cortex (DLPFC) activation (Balconi and Caldiroli, 2011; Balconi and Vitaloni, 2012). This activity was appositely modulated by tDCS (transcranial direct current stimulation). First, we sought to analyse the direct effect of tDCS on the ERP profile in response to the semantic task. Two different tasks were examined: a first objectrelated action representation induced by an action sequence (Experiment 1) and a second object-related action representation induced by a sentence (Experiment 2). The effect of tDCS when subjects processed congruent/incongruent object-related actions
e83
or sentences was verified by measuring changes in the ERP (event-related potential) N400, ERs (Error Rates) and RTs (Response Times). In Experiment 1, thirty subjects performed the detection task within a dynamic context (video tapes representing a sequence of four action frames). In Experiment 2, 28 subjects read sentences that represented object-related actions. The stimulation effect (a cathode applied to the DLPFC and an anode to the right supraorbital region) was analysed by comparing the ER, RT and ERP profiles before and after stimulation (or sham treatment). A significant reduction of the N400 was observed for incongruent stimuli in the case of cathodal (inhibitory) stimulation of the DLPFC compared with pre-stimulation conditions for Experiment 1 and Experiment 2. Moreover, ERs were increased, and RTs were reduced in response to incongruent conditions after tDCS, but not after sham stimulation in Experiments 1 and 2. It was suggested that perturbation of the DLPFC may limit the ability to analyse a semantically anomalous action sequence, with a reduced N400 ERP effect and increased random responses being observed. Finally, the contribution of the frontal area to the semantic processing of action was discussed (Balconi et al., 2012). References Balconi M, Caldiroli C. Semantic violation effect on object-related action comprehension. N400-like event-related potentials for unusual and incorrect use. Neuroscience 2011;197:191–9. Balconi M, Vitaloni S. The tDCS effect on alpha brain oscillation for correct vs. incorrect object use. The contribution of the left DLPFC. Neurosci Lett 2012;517:25–9. Balconi M, Caldiroli C, Vitaloni S. tDCS effect on EEG profile in response to semantic motor anomaly detection. Neurorehab Neural Repair 2012;26:33–4. doi:10.1016/j.clinph.2013.04.118
P 41. Motor evoked potentials as biomarker for sexual urge—M. Schecklmann a, J. Konzog b, T.B. Poeppl a, M. Greenlee b, B. Langguth a (a University of Regensburg, Department of Psychiatry, Regensburg, Germany, b University of Regensburg, Department of Experimental Psychology, Regensburg, Germany) Introduction: Previous work documents that motor cortex excitability is modulated by emotional states-induced by music for example. Recently, motivation and reward anticipation-operationalized by the viewing of food or money stimuli and by the use of a slot machine respectively-increased motor evoked potentials (MEPs). Motivational besides emotional, cognitive, and physiological processing is one component of a four component model of sexual arousal. Activity in limbic (emotional) areas is considered to spill over to motor cortex via the basal ganglia (motivation) with top-down control of frontal (cognitive) areas. Objectives: Here, we aim to investigate the influence of sexual urge on motor evoked potentials. Materials and methods: 24 heterosexual healthy men viewed single stimuli of naked women or men genitals covered with black bars. Control stimuli were generated by Fourier transformation of these stimuli. Each stimulus category was shown 60 times without repeti-
Society Proceedings / Clinical Neurophysiology 124 (2013) e39–e187
P 37. Hemispheric asymmetries in language processing: Evidence from false memories for lists, texts, and ambiguous words—E. BenArtzi a, M. Faust b (a Center for Academic Studies, Psychology, Or Yehuda, Israel, b Bar Ilan University, Psychology, Bar Ilan, Israel) Previous research suggests that, whereas the left cerebral hemisphere (LH) is dominant for language processing, the right hemisphere (RH) may play a unique role in the comprehension of natural language, i.e. in processing language in contexts that extend beyond the meanings of individual words or sentences such as stories, conversations, or texts, and thus may contribute uniquely to the processing of lexical ambiguity by activating and maintaining a wide range of meanings, including subordinate. A series of studies used the word-lists false memory paradigm (Roediger and McDermott, 1995) to examine the difference between the two cerebral hemispheres in language processing. Specifically, we tested the susceptibility of the LH and RH to unpresented target words following the presentation of semantically related words appearing in either word lists or short texts (Study 1) and whether these differences between the two cerebral hemispheres in semantic processing also affect memory representations for different meanings of ambiguous words (Study 2). Specifically, we tested the differences between the LH and RH in recollecting unpresented, semantically related, ambiguous words following the presentation of lists of words all related to either the dominant or the subordinate meanings of these ambiguous words. Findings of Study 1 showed that the RH produced more false alarms than the LH for unpresented target words following either word lists or texts. These findings reveal hemispheric differences in memory for semantically related information and suggest that RH advantage in long-term maintenance of a wide range of textrelated word meanings may be one aspect of its unique contribution to the construction of a discourse model. Findings of Study 2 indicated that for the unpresented ambiguous words, the LH made more false alarms than the RH for the dominant lists, whereas the opposite pattern emerged for subordinate lists. These results support the RH coarse semantic coding theory (Beeman, 1998) indicating that during word recognition, the RH activates and maintains a broader and less differentiated range of related meanings than the LH, including both dominant and subordinate meanings of ambiguous words. Furthermore, the findings suggest that hemispheric differences in ambiguity resolution during language processing extend also to verbal memory.
The task required adaptation to occasional tempo changes (i.e., accelerations or decelerations of large or small magnitude). In order to interfere with motor simulation processes, dTMS (two pulses, with an inter-onset-interval of 100 ms and intensity at 110% of the individual’s resting motor threshold) or sham was delivered over the right primary motor cortex prior to each tempo change. Tempo adaptation accuracy was quantified on the basis of the ratio between produced keystroke inter-onset intervals and target inter-onset intervals in recorded bassline parts (cf. Repp, 2005). Participant’s “perspective taking” tendencies (i.e., how spontaneously they adopt others’ perspectives) were assessed at the end of the experiment via an empathy questionnaire based on the Interpersonal Reactivity Index (Davis, 1980). Results: Results indicated that dTMS impaired tempo adaptation accuracy only when pianists had practiced the left-hand bassline part beforehand, i.e., when motor simulation was presumably enhanced. This impairment, which was associated with a deceleration in the performance with respect to the audible bassline, occurred irrespective of tempo change direction (acceleration or deceleration) and magnitude (small or large). Finally, the decelerating effect of dTMS on performance tempo was greater in empathic individuals who possessed a stronger tendency to adopt others’ perspectives (cf. Novembre, 2012). Conclusion: These findings indicate that motor simulation provides a functional resource for the temporal coordination of one’s own behaviour with others in dynamic social contexts.
References Davis. A multidimensional approach to individual differences in empathy. JSAS Catalog of selected documents in psychology; 1980. D’Ausilio et al. Cross-modal plasticity of the motor cortex while listening to a rehearsed musical piece. Eur J Neurosci 2006. Haueisen J, Knösche TR. Involuntary motor activity in pianists evoked by music perception. J Cognitive Neurosci 2001. Novembre et al. Distinguishing Self and Other in Joint Action. Evidence from a Musical Paradigm. Cereb. Cortex 2012. Repp. Sensorimotor synchronization: a review of the tapping literature. Psychon B Rev 2005.
doi:10.1016/j.clinph.2013.04.115
doi:10.1016/j.clinph.2013.04.116
P 38. Motor simulation coordinates joint actions in real time: Music performance meets on-line double-pulse TMS—G. Novembre a, L. Ticini a, S. Schütz-Bosbach a, P. Keller b,a (a Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, b The MARCS Institute, Sydney, Germany)
P 39. Functional causality of the dorsal stream in sensorimotor integration of speech repetition—T. Murakami a, C. Kell b, J. Restle b, Y. Ugawa a, U. Ziemann c (a Fukushima Medical University, Neurology, Fukushima, Japan, b Goethe-University, Neurology, Frankfurt am Main, Germany, c Eberhard-Karls-University, Neurology, Tübingen, Germany)
Question: Joint action is grounded in the ability to integrate simultaneous self-and other-related behaviour in real time. We investigated whether this function is underpinned by motor simulation, i.e. the capacity to represent a perceived action in terms of the neural resources required to execute it (Jeannerod, 2000). This was tested in a music performance experiment wherein on-line brain stimulation (double-pulse Transcranial Magnetic Stimulation, dTMS) was employed to interfere with motor simulation. Methods: Ten pianists (13.81 ± 3.86 years of musical training) played the right-hand part of piano pieces in synchrony with a recording of the left-hand part, which had (Trained) or had not (Untrained) been practiced beforehand. Training was assumed to enhance motor simulation of the audible left-hand part (cf. Haueisen and Knösche, 2001; D’Ausilio, 2006; Novembre, 2012).
Introduction: Acquisition of language skills is necessary for social interactions in humans, and speech repetition plays a fundamental role in its acquisition by mapping auditory speech input onto matching speech output. At the level of neuronal networks in the brain, speech repetition occurs within the auditory dorsal stream, which is constituted by a temporo-parieto-frontal network formed by the posterior part of superior temporal sulcus (pSTS), the posterior inferior frontal gyrus (pIFG), and the temporo-parietal junction (Tpj). However, it is less known which component of the dorsal stream plays an essential role in the modulation of speech repetition. Objectives: To investigate the issue of causality of the dorsal stream in sensorimotor integration of speech repetition, we
Society Proceedings / Clinical Neurophysiology 124 (2013) e39–e187
employed continuous theta-burst transcranial magnetic stimulation (cTBS) in order to disrupt neuronal activity in the stimulated areas. Methods: Nineteen right-handed German volunteers performed four behavioral speech tasks. (1) Word-picture matching test: subjects listened to a German noun and were asked to choose a picture which fit to the word heard from four different pictures; the target picture, pictures implying a phonemic or semantic error, and an unrelated picture. (2) Syllable repetition test: subjects listened to one of six different syllables and repeated the perceived syllable immediately. (3) Pseudo-word repetition test: subjects listened to meaningless pseudo-words and immediately repeated it. (4) Sentence repetition test: subjects listened to German sentences and immediately repeated it. In all the tests, error rates (ER) and reaction time (RT) were calculated. Inhibitory cTBS was applied over the individual activated regions of the left pIFG, Tpj, pSTS by using an fMRI-guided TMS neuronavigation system. Left middle occipital gyrus (MOG) was also stimulated as a control region to clarify the topographical specificity of cTBS effects because it is assumed that the MOG is concerned with visual processing. The behavioral speech tests were performed after cTBS over four sites mentioned above, and they were compared by repeated measures ANOVAs. Results: (1) In word-picture matching test, cTBS of Tpj, pSTS and pIFG increased phonemic errors compared to cTBS of MOG. No other types of errors were affected by any sites of cTBS. (2) The syllable repetition ERs were significantly larger after cTBS of Tpj, pSTS and pIFG than after cTBS over MOG. (3) Pseudo-word repetition test demonstrated that ERs significantly increased after cTBS of Tpj and pSTS than after cTBS of MOG and pIFG. (4) In the sentence repetition test, no differences were observed in ERs between sites of cTBS. Throughout all the behavioral tests, RTs were not significantly different between sites of cTBS. Conclusion: Disruption of the dorsal stream led to increases of phonemic errors in word-picture matching test and to increases of errors of syllable and pseudo-word repetitions, demonstrating that the dorsal stream plays a crucial role in sensorimotor integration of phonological processing. The lack of cTBS effects on native sentences may be explained by the idea that the lexical/semantic material processing is done by the ventral auditory stream. The sensory phonological system performs critical modulation of subsequent articulation in the motor system via a sensorimotor interface, supporting evidence that the sensory system is situated hierarchically at higher level to modulate the motor articulation. doi:10.1016/j.clinph.2013.04.117
P 40. Representation of the incorrect use of an object is supported by the DLPFC: The tDCS effect on ERP N400 for visual and linguistic stimuli—M. Balconi, S. Vitaloni (Catholic University of Milan, Milan, Italy) In the present study, we explored the representation of an incongruent action (instrumentally incorrect use of an object) in comparison with sentences ending with an incongruent action word, taking into account the role of left dorsolateral prefrontal cortex (DLPFC) activation (Balconi and Caldiroli, 2011; Balconi and Vitaloni, 2012). This activity was appositely modulated by tDCS (transcranial direct current stimulation). First, we sought to analyse the direct effect of tDCS on the ERP profile in response to the semantic task. Two different tasks were examined: a first objectrelated action representation induced by an action sequence (Experiment 1) and a second object-related action representation induced by a sentence (Experiment 2). The effect of tDCS when subjects processed congruent/incongruent object-related actions
e83
or sentences was verified by measuring changes in the ERP (event-related potential) N400, ERs (Error Rates) and RTs (Response Times). In Experiment 1, thirty subjects performed the detection task within a dynamic context (video tapes representing a sequence of four action frames). In Experiment 2, 28 subjects read sentences that represented object-related actions. The stimulation effect (a cathode applied to the DLPFC and an anode to the right supraorbital region) was analysed by comparing the ER, RT and ERP profiles before and after stimulation (or sham treatment). A significant reduction of the N400 was observed for incongruent stimuli in the case of cathodal (inhibitory) stimulation of the DLPFC compared with pre-stimulation conditions for Experiment 1 and Experiment 2. Moreover, ERs were increased, and RTs were reduced in response to incongruent conditions after tDCS, but not after sham stimulation in Experiments 1 and 2. It was suggested that perturbation of the DLPFC may limit the ability to analyse a semantically anomalous action sequence, with a reduced N400 ERP effect and increased random responses being observed. Finally, the contribution of the frontal area to the semantic processing of action was discussed (Balconi et al., 2012). References Balconi M, Caldiroli C. Semantic violation effect on object-related action comprehension. N400-like event-related potentials for unusual and incorrect use. Neuroscience 2011;197:191–9. Balconi M, Vitaloni S. The tDCS effect on alpha brain oscillation for correct vs. incorrect object use. The contribution of the left DLPFC. Neurosci Lett 2012;517:25–9. Balconi M, Caldiroli C, Vitaloni S. tDCS effect on EEG profile in response to semantic motor anomaly detection. Neurorehab Neural Repair 2012;26:33–4. doi:10.1016/j.clinph.2013.04.118
P 41. Motor evoked potentials as biomarker for sexual urge—M. Schecklmann a, J. Konzog b, T.B. Poeppl a, M. Greenlee b, B. Langguth a (a University of Regensburg, Department of Psychiatry, Regensburg, Germany, b University of Regensburg, Department of Experimental Psychology, Regensburg, Germany) Introduction: Previous work documents that motor cortex excitability is modulated by emotional states-induced by music for example. Recently, motivation and reward anticipation-operationalized by the viewing of food or money stimuli and by the use of a slot machine respectively-increased motor evoked potentials (MEPs). Motivational besides emotional, cognitive, and physiological processing is one component of a four component model of sexual arousal. Activity in limbic (emotional) areas is considered to spill over to motor cortex via the basal ganglia (motivation) with top-down control of frontal (cognitive) areas. Objectives: Here, we aim to investigate the influence of sexual urge on motor evoked potentials. Materials and methods: 24 heterosexual healthy men viewed single stimuli of naked women or men genitals covered with black bars. Control stimuli were generated by Fourier transformation of these stimuli. Each stimulus category was shown 60 times without repeti-