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The antecedents of free will : The importance of concept heterogeneity inresearch interpretation and discussionJensen, Magnus J. C. January 2018 (has links)
Scientific research on free will was started by Libet et al. (1982). They detected that thereadiness potential (RP) proceeded urges with up to 350ms. One interpretation of the RP wasthat it represented motor planning. The research progress of antecedent brain activity inrelation to conscious urges is investigated by looking at contemporary studies. How differentassumptions and definitions of the free will concept influences interpretation of these studiesis also discussed. The evidence is in favor that the RP is not representing motor planning.Antecedent activity has been detected with numerous technologies, most notably fMRIclassifiers which have been used to predict decisions in advance. Scrutiny of these resultsreveals that the experimental setups are dependent on time-locking trials which may construethe results. It is shown that predictions based on probabilistic antecedents can be interpretedin numerous ways. The review shows that free will positions differ from each other onseveral factors, such as whether free will is either-or or exists on a spectrum. Some notablepositions are not dependent on antecedent activity at all. The notion of control is one of thepivotal factors deciding if a subject experience free will, not if they are the causer per se.Future discussion will be improved by systematizing the differences between the free willpositions and communicating them clearly. Convergent evidence points at the explanatorymodel of free will being a cognitive feeling – A feeling which reports ownership over actionsbut does not cause them.
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The Unconscious Formation of Motor and Abstract IntentionsSoon, Chun Siong 20 September 2017 (has links) (PDF)
Three separate fMRI studies were conducted to study the neural dynamics of free decision formation. In Study 1, we first searched across the brain for spatiotemporal patterns that could predict the specific outcome and timing of free motor decisions to make a left or right button press (Soon et al., 2008). In Study 2, we replicated Study 1 using ultra-high field fMRI for improved temporal and spatial resolution to more accurately characterize the evolution of decision-predictive information in prefrontal cortex (Bode et al., 2011). In Study 3, to unequivocally dissociate high-level intentions from motor preparation and execution, we investigated the neural precursors of abstract intentions as participants spontaneously decided to perform either of two mental arithmetic tasks: addition or subtraction (Soon et al., 2013). Across the three studies, we consistently found that upcoming decisions could be predicted with ~60% accuracy from fine-grained spatial activation patterns occurring a few seconds before the decisions reached awareness, with very similar profiles for both motor and abstract intentions. The content and timing of the decisions appeared to be encoded in two functionally dissociable sets of regions: frontopolar and posterior cingulate/ precuneus cortex encoded the content but not the timing of the decisions, while the pre-supplementary motor area encoded the timing but not the content of the decisions. The choice-predictive regions in both motor and abstract decision tasks overlapped partially with the default mode network. High-resolution imaging in Study 2 further revealed that as the time-point of conscious decision approached, activity patterns in frontopolar cortex became increasingly stable with respect to the final choice.
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Detection of Lateralized Readiness Potential using Emotiv EPOC / Detekce LRP pomocí Emotiv EPOCBártík, Radovan January 2013 (has links)
Emotiv EPOC is a low-cost consumer headset capable of acquiring a raw EEG signal. The thesis evaluates its usage for an acquisition of research event-related potentials. A controlled laboratory experiment was performed with an objective of isolating the Bereitschaftspotential (Readiness Potential) and other movement-related potentials and comparing the results with the results of the previous research. The possibility of measuring the potential with Emotiv EPOC was not confirmed, most probably due to procedural issues during the experiment, however, further analysis of the data suggests its presence. Other outcomes of the research include qualitative findings about the headset, mainly its hardware construction, and testing feedback of EEGLab, an open source toolbox for EEG processing and visualization.
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The Unconscious Formation of Motor and Abstract IntentionsSoon, Chun Siong 10 April 2017 (has links)
Three separate fMRI studies were conducted to study the neural dynamics of free decision formation. In Study 1, we first searched across the brain for spatiotemporal patterns that could predict the specific outcome and timing of free motor decisions to make a left or right button press (Soon et al., 2008). In Study 2, we replicated Study 1 using ultra-high field fMRI for improved temporal and spatial resolution to more accurately characterize the evolution of decision-predictive information in prefrontal cortex (Bode et al., 2011). In Study 3, to unequivocally dissociate high-level intentions from motor preparation and execution, we investigated the neural precursors of abstract intentions as participants spontaneously decided to perform either of two mental arithmetic tasks: addition or subtraction (Soon et al., 2013). Across the three studies, we consistently found that upcoming decisions could be predicted with ~60% accuracy from fine-grained spatial activation patterns occurring a few seconds before the decisions reached awareness, with very similar profiles for both motor and abstract intentions. The content and timing of the decisions appeared to be encoded in two functionally dissociable sets of regions: frontopolar and posterior cingulate/ precuneus cortex encoded the content but not the timing of the decisions, while the pre-supplementary motor area encoded the timing but not the content of the decisions. The choice-predictive regions in both motor and abstract decision tasks overlapped partially with the default mode network. High-resolution imaging in Study 2 further revealed that as the time-point of conscious decision approached, activity patterns in frontopolar cortex became increasingly stable with respect to the final choice.:Abstract 1
1. General Introduction 5
2. Study 1: Decoding the Unconscious Formation of Motor Intentions 21
3. Study 2: Temporal Stability of Neural Patterns Involved in Intention Formation 56
4. Study 3: Decoding the Unconscious Formation of Abstract Intentions 89
5. General Discussion 119
References 145
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The Lateralized Readiness Potential as a Neural Indicator of Response Competition in Binary Decision TasksFrame, Mary E. 19 June 2014 (has links)
No description available.
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Estudo eletroencefalográfico do planejamento motor / Electroencephalographic study of motor planningJorge Shiro Inamori Takashima 23 June 2017 (has links)
A execução de movimentos voluntários é precedida por processos preparatórios que manifestam-se eletrofisiologicamente como um potencial elétrico lento denominado Bereitschaftspotential. As investigações sobre o significado fisiológico desses potenciais mostram-se muitas vezes inconclusivas devido à dificuldade de isolamento dos fatores ambientais e endógenos que os influenciam. Dentre essas variáveis, a expressão consciente do ato motor tem sido negligenciada por grande parte dos pesquisadores. O presente trabalho consiste em uma série de estudos eletrofisiológicos que visam demonstrar a influência do controle consciente sobre os processos preparatórios motores. Parte-se do desenvolvimento de protocolos comportamentais que modulam o envolvimento consciente sobre processos motores. Desse modo, verificamos que grande parte do Bereitschaftspotential comumente observado durante a geração de movimentos espontâneos estão associados com a escolha deliberada de agir. Em seguida, são investigadas como a variável em questão pode afetar os processos relacionados com a livre escolha de movimentos. Nossos resultados indicam que processos relacionados ao controle consciente afetam nitidamente a expressão de livre escolha sobre os potenciais preparatórios motores. Por fim, nós demonstramos como a influência do controle consciente nos processos motores pode estar afetada em pacientes com transtorno obsessivo-compulsivo / The execution of voluntary movements is preceded by preparatory processes that electrophysiologically are manifested as a slow electric potential called Bereitschaftspotential. Investigations on the physiological significance of these potentials are often inconclusive due to the difficulty of isolating the environmental or endogenous factors that influence them. Among these factors, the conscious expression of the motor act has been neglected by most researchers. The present work consists of a series of electrophysiological studies aimed at demonstrating the influence of conscious control on preparatory motor processes. Firstly, behavioral protocols that modulate the conscious involvement in motor control are proposed. Using these methods, we found that great part of the Bereitschaftspotential commonly observed during the generation of spontaneous movements is associated with the deliberate choice to act. Next, we investigated how this factor variable affects the processes related to the free mode of movement selection. Our results indicate that processes related to conscious control clearly affect the manifestations of free choice in preparatory motor potentials. Finally, we here demonstrated how the influence of conscious control on the motor processes can be affected in the obsessive-compulsive disorder
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Estudo eletroencefalográfico do planejamento motor / Electroencephalographic study of motor planningTakashima, Jorge Shiro Inamori 23 June 2017 (has links)
A execução de movimentos voluntários é precedida por processos preparatórios que manifestam-se eletrofisiologicamente como um potencial elétrico lento denominado Bereitschaftspotential. As investigações sobre o significado fisiológico desses potenciais mostram-se muitas vezes inconclusivas devido à dificuldade de isolamento dos fatores ambientais e endógenos que os influenciam. Dentre essas variáveis, a expressão consciente do ato motor tem sido negligenciada por grande parte dos pesquisadores. O presente trabalho consiste em uma série de estudos eletrofisiológicos que visam demonstrar a influência do controle consciente sobre os processos preparatórios motores. Parte-se do desenvolvimento de protocolos comportamentais que modulam o envolvimento consciente sobre processos motores. Desse modo, verificamos que grande parte do Bereitschaftspotential comumente observado durante a geração de movimentos espontâneos estão associados com a escolha deliberada de agir. Em seguida, são investigadas como a variável em questão pode afetar os processos relacionados com a livre escolha de movimentos. Nossos resultados indicam que processos relacionados ao controle consciente afetam nitidamente a expressão de livre escolha sobre os potenciais preparatórios motores. Por fim, nós demonstramos como a influência do controle consciente nos processos motores pode estar afetada em pacientes com transtorno obsessivo-compulsivo / The execution of voluntary movements is preceded by preparatory processes that electrophysiologically are manifested as a slow electric potential called Bereitschaftspotential. Investigations on the physiological significance of these potentials are often inconclusive due to the difficulty of isolating the environmental or endogenous factors that influence them. Among these factors, the conscious expression of the motor act has been neglected by most researchers. The present work consists of a series of electrophysiological studies aimed at demonstrating the influence of conscious control on preparatory motor processes. Firstly, behavioral protocols that modulate the conscious involvement in motor control are proposed. Using these methods, we found that great part of the Bereitschaftspotential commonly observed during the generation of spontaneous movements is associated with the deliberate choice to act. Next, we investigated how this factor variable affects the processes related to the free mode of movement selection. Our results indicate that processes related to conscious control clearly affect the manifestations of free choice in preparatory motor potentials. Finally, we here demonstrated how the influence of conscious control on the motor processes can be affected in the obsessive-compulsive disorder
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中文言語產製中語意及語音處理的電生理訊號 / Electrophysiological signatures of semantic and phonological processing in mandarin Chinese speech production張惠娟, Chang, Hui Chuan Unknown Date (has links)
習得年齡對語言處理有相當影響,但其成因及作用階段至今仍無定案,根據以知的行為研究成果及假說,結合事件相關電位技術,及雙重選擇按鍵與否典範,我們將嘗試找出習得年齡在言語產出中的作用階段。假定不欲按鍵則無側化動作準備電位,且側化準備電位起始時間取決於,何時取得用以決定反應手的訊息,我們請受試者根據圖片刺激的兩種語言屬性做出正確反應。
在實驗一中,語意屬性(人造或非人造)決定反應手,圖片名稱第一音節的語音屬性(一、三聲或二、四聲)決定按鍵與否。若習得年齡影響語意處理,我們預期在按鍵情形下,習得年齡早晚兩組的側化準備電位起始時間將有所不同;而不按鍵情形下的側化準備電位持續時間,將反映習得年齡對語音處理的影響。實驗二中,圖片經更嚴格挑選,以控制所有變項,且語言屬性與反應類別間的兩種對應都被測試。
實驗一和實驗二都發現不按鍵時,若反應手非由語意屬性決定,則側化準備電位不會出現。這個結果符合文獻記載,並暗示語意處理早於語音處理。實驗一中,早習得圖片的唸名反應時間、圖片分類反應時間、及側化準備電位起始時間都較短,支持習得年齡越早,語意提取速度越快。但實驗二中,習得年齡對側化準備電位起始時間沒有顯著影響,儘管前測顯示早習得圖片的唸名反應時間較短,其分類反應時間卻較長,。實驗三進一步肯定,習得年齡對唸名及圖片分類作業有相反效果,以及習得年齡對圖片分類作業的效果不因重複練習而喪失。
根據完整語音理論 (Brown & Watson, 1987),我們認為當作業要求完整的語音訊息,則習得年齡越早,提取速度越快,唸名作業如是;當作業要求片段的語音訊息,則習得年齡越早,提取速度越慢,額外時間用於解構完整語音訊息,我們的圖片判斷作業如是。實驗二中因少數圖片重複出現,習得年齡對語意處理的正面作用減少,習得年齡對片段語音處理的負面作用卻維持,使得習得年齡組別間,側化準備電位沒有顯著差異,且早習得組圖片分類反應時間反而較長。
總而言之,本研究支持概念/詞目競爭理論的說法,亦即習得年齡越早,語意提取速度越快。我們的資料也間接反映,習得年齡越早,語音提取速度越慢,但此推論仍需未來研究進一步支持。 / Age-of-acquisition (AoA) is one of the most robust variables for language processing. But its cause and locus during the processing are still under debate. Based on previous behavioral studies and established hypotheses, this study aims to find electrophysiological evidence for the locus of AoA effect during speech production. The continuous measure of speech production is approached by event-related potential (ERP) in conjunction with a manual, dual choice Go/Nogo paradigm. In this paradigm, participants need to choose the correct response according to two linguistic attributes of the target picture. The presumption of this paradigm is that the lateralized readiness potential (LRP), a motor preparation related component, would be absent once the Nogo decision has been made, and its onset marks the time point at which critical information for hand selection is available.
In Experiment 1, which hand to respond depends on the target picture’s semantic attribute (artifact or non-artifact), to respond or not relies on its phonological attribute (the tone value of its first syllable). It is expected that if AoA influences lexical/semantic processing, LRP onset latency would be different under early and late AoA condition. AoA effect on phonological stage would be reflected on the duration of Nogo LRP. In Experiment 2 the reverse mapping between linguistic attribute and response types was also tested and variables other than AoA were more strictly controlled.
Both experiments replicate previous finding in that Nogo LRP only occurs when response hand is contingent on semantic information, which indicates that semantic stage precedes phonological stage. In Experiment 1, naming latency, picture classification RT (reaction time), and LRP onset latency were shorter for the early AoA group, indicating accelerated lexical/semantic retrieval. However, in Experiment 2, AoA effect on LRP onset latency was not found. And for items with early AoA, picture classification RT is significantly longer, despite that their naming latency is shorter in the pretest. Experiment 3 further validates the coexistence of the positive AoA effect on naming and negative AoA effect on tone classification and the resistance of the negative AoA effect to repetition.
Following the phonological completeness hypothesis (Brown & Watson, 1987), we suggest that when the unitary phonological form is demanded, as in the naming task, the early learned words has advantage. When a fraction of the unitary form is demanded, as in the tone classification task, extra time is needed to decompose the retrieved unitary form. The positive AoA effect on semantic stage is larger in Experiment 1 due to material selection and number of repetition. Thus in Experiment 1, the positive AoA effect on semantic stage remains, but in Experiment 2, it is overpowered by the negative AoA effect on fractional phonological extraction, resulting in the absence of AoA effect on LRP pattern and longer picture classification RT under early AoA condition.
In sum, results of this study indicate that semantic feature can be retrieved faster under early AoA condition, which is in line with concept/lemma competition hypothesis. Our results also imply slower tone retrieval under early AoA condition, which need to be further testified by future studies.
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Sprache und DenkenKao, Chung-Shan 16 December 2010 (has links)
Die Studie hat zum Ziel, im Rahmen des Äußerungsproduktionsmodells die Annahme thinking for speaking (Slobin, 1996) experimentell zu überprüfen. Ansatzpunkt ist der Unterschied in der Stellung der Markierung einer Entscheidungsfrage zwischen drei Sprachen. Während der Fragemodus im Deutschen/Polnischen vor dem Frageinhalt markiert wird, geschieht die Modusmarkierung im Chinesischen nach dem Inhalt. Um die entsprechende Satzstruktur aufzubauen, sollte der Fragemodus beim syntaktischen Kodierungsprozess (speaking) im Deutschen/Polnischen vor, im Chinesischen nach dem Inhalt verarbeitet werden. Unter Zugrundelegung der inkrementellen Äußerungsproduktion gehen wir davon aus, dass die Verarbeitungsreihenfolge beim vorangehenden Konzeptualisierungsprozess (thinking) mit der syntaktischen Kodierungsabfolge übereinstimmt: Der Fragemodus wird im Deutschen/ Polnischen vor, im Chinesischen hingegen nach dem Inhalt konzeptualisiert. Um den zeitlichen Ablauf der zwei Konzeptualisierungsprozess zu ermitteln, bedienten wir uns des lateralisierten Bereitschaftspotenzials (lateralized readiness potential, LRP) im binären Wahlreaktions-Go/Nogo-Paradigma. Im Versuch reagierten deutsche, chinesische und polnische Muttersprachler auf dargebotene Bilder mit Tastendrücken und Sprechen. Zu beobachten war das Auftreten eines LRP bei Nogo, das signalisierte, in welcher Reihenfolge sich die Handwahl und die Nogo-Entscheidung realisierten Ein Nogo-LRP trat bei allen drei Sprechergruppen auf. Zudem wurde festgestellt, dass die Nogo-Entscheidung, die erwartungsgemäß mit der sprachlichen Verarbeitung des Fragemodus verbunden wurde, bei den drei Sprechergruppen ungefähr zeitgleich getroffen wurde. Die Befunde legen nahe, dass der Fragemodus in den drei Sprachen zeitlich nicht unterschiedlich, sondern einheitlich geplant wurde. Die Schlussfolgerung wird im Rahmen von thinking for speaking sowie dem Äußerungsproduktionsmodell diskutiert. / Languages differ in the marking of the sentence mood of a polar interrogative (yes/no question). For instance, the interrogative mood is marked at the beginning of the surface structure in Polish, whereas the marker appears at the end in Chinese. In order to generate the corresponding sentence frame, the syntactic specification of the interrogative mood is early in Polish and late in Chinese. In this respect, German belongs to an interesting intermediate class. The yes/no-question is expressed by a shift of the finite verb from its final position in the underlying structure into the utterance initial position, a move affecting, hence, both the sentence final and the sentence initial constituents. The present study aimed to investigate whether during generation of the semantic structure of a polar interrogative, i.e. the processing preceding the grammatical formulation, the interrogative mood is encoded according to its position in the syntactic structure at distinctive time points in Chinese, German, and Polish. In a two-choice go/nogo experimental design, native speakers of the three languages responded to pictures by pressing buttons and producing utterances in their native language while their brain potentials were recorded. The emergence and latency of lateralized readiness potentials (LRP) in nogo conditions, in which speakers asked a yes/no question, should indicate the time point of processing the interrogative mood. The results revealed that Chinese, German, and Polish native speakers did not differ from each other in the electrophysiological indicator. The findings suggest that the semantic encoding of the interrogative mood is temporally consistent across languages despite its disparate syntactic specification. The consistent encoding may be ascribed to economic processing of interrogative moods at various sentential positions of the syntactic structures in languages or, more generally, to the overarching status of sentence mood in the semantic structure.
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An electrophysiological examination of visuomotor activity elicited by visual object affordancesDixon, Thomas Oliver January 2016 (has links)
A wide literature of predominantly behavioural experiments that use Stimulus Response Compatibility (SRC) have suggested that visual action information such as object affordance yields rapid and concurrent activation of visual and motor brain areas, but has rarely provided direct evidence for this proposition. This thesis examines some of the key claims from the affordance literature by applying electrophysiological measures to well established SRC procedures to determine the verities of the behavioural claims of rapid and automatic visuomotor activation evoked by viewing affording objects. The temporal sensitivity offered by the Lateralised Readiness Potential and by visual evoked potentials P1 and N1 made ideal candidates to assess the behavioural claims of rapid visuomotor activation by seen objects by examining the timecourse of neural activation elicited by viewing affording objects under various conditions. The experimental work in this thesis broadly confirms the claims of the behavioural literature however it also found a series of novel results that are not predicted by the behavioural literature due to limitations in reaction time measures. For example, while different classes of affordance have been shown to exert the same behavioural facilitation, electrophysiological measures reveal very different patterns of cortical activation for grip-type and lateralised affordances. These novel findings question the applicability of the label ‘visuomotor’ to grip-type affordance processing and suggest considerable revision to models of affordance. This thesis also offers a series of novel and surprising insights into the ability to dissociate afforded motor activity from behavioural output, into the relationship between affordance and early visual evoked potentials, and into affordance in the absence of the intention to act. Overall, this thesis provides detailed suggestions for considerable changes to current models of the neural activity underpinning object affordance.
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