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P8-25 Differential effects of spatial frequency on the processing of Japanese Kanji and Kana: An MEG analysis
29th International Congress of Clinical Neurophysiology effect, with longer reaction time when the subject should verify if a universal (All) conclusion contradicts a particular premise (Some). The Contradiction effect was not observed. The area involved in the reasoning tasks included the Temporo-polar cortex middle temporal gyrus BA 21 and the superior temporal gyri BA 38, the Orbitofrontal cortex BA 11 and 47 and the Anterior Cingulate BA 10 and 32. Conclusions: A consistent reasoning network was identified involving temporo-polar, orbito-frontal and anterior cingulated cortex. Simpler cerebral processing in heuristic figuring a single example instead of many or searching for the absence of a counterexample could be the reason why logical operator ‘Some’ induced smaller reasoning network activation than ‘All’. P8-24 The identification of contradiction by the reasoning brain: distinct neural structures manipulate attributes and the terms All and Some M.T. Medaglia1,2 , F. Tecchio3,5 , L. Tomasevic3 , P. Rotshtein1 , N.J. Thai2 , S. Seri2 , P.M. Rossini4,5 , C. Porcaro1,2 1 School of Psychology, University of Birmingham, Birmingham, UK, 2 Aston Brain Centre, School of Life and Health Sciences, Aston University, Birmingham, UK, 3 ISTC-CNR, Ospedale Fatebenefratelli, Isola Tiberina, Rome, Italy, 4 Dept. of Neurology, ‘Campus Bio-Medico’ University, Rome, Italy, 5 IRCCS San Raffaele, Tosinvest Sanita’, Cassino, Italy Objective: Contradiction is a cornerstone of human rationality and is often used in the context of a naturalistic debate as part of every day life and communication. We used an event-related fMRI study to investigate the brain activation patterns during the contradictory judgments process. Methods: Twelve volunteers took part in this experiment. A full 2×2 factorial design was used with the following factors: Logical Operator conclusion sentence (UNIVERSAL, PARTICULAR) and Contradiction (CONTRADICTORY, NOT CONTRADICTORY). The protocol contained 140 pairs of sentences, evenly divided in the following four forms: All Some Contradictory (AS-C), Some All Contradictory (SA-C) and All Some Noncontradictory (AS-nC), Some All Non-contradictory (SA-nC). An example of the AS-C case is: ‘All men are mortal’, ‘Some men are immortal’. The fMRI data were analyzed using SPM8. Results: Behavioral results for the number of errors indicated that volunteers performed PARTICULAR-UNIVERSAL and UNIVERSALPARTICULAR trials with comparable accuracy, both for the contradictory and not-contradictory conditions. Reaction Times showed a strong Logical Operator effect, with longer reaction times to identify the contradiction when a UNIVERSAL conclusion occurred, than a PARTICULAR one. In line with the behavioural findings, we observed a significantly greater BOLD signal change for propositions ending with a UNIVERSAL (SA) than for those ending with a PARTICULAR statement (AS) in the right superior frontal gyrus (BA 8), medial frontal gyrus (BA 10) and the right inferior parietal lobule (BA 40, angular gyrus). Right inferior frontal gyrus (BA 47), showed an increase activation during contradictory compared to notcontradictory trials. Conclusions: Our study provides neural evidence of a structural dissociation between areas that mediate the logical operator inversion medial and superior frontal gyri (BA 8, BA 10/32) and the inferior parietal lobule (BA 40) and those assessing contradictions inferior frontal gyrus (BA 47). P8-25 Differential effects of spatial frequency on the processing of Japanese Kanji and Kana: An MEG analysis S. Horie1 , T. Yamasaki1 , N. Hironaga1 , T. Okamoto2 , K. Ogata1 , S. Tobimatsu1 1 Department of Clinical Neurophysiology, Neurological Institute, Faculty of Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, 2 Division of Digital Organ, Digital Medicine Initiative, Kyushu University, Fukuoka, Japan Objective: Our recent ERP and fMRI studies have demonstrated the important roles of spatial frequency (SF) information on reading Japanese scripts; high-SF (HSF) for Kanji (morphogram) and low-SF (LSF) for Kana (phonogram). Based on the behaviors of the N400 component of ERPs, HSF information can differentiate the age of acquisition (AoA) between Kanji while semantics for Kana can be distinguished by LSF information.
S153 Therefore, we aimed at elucidating the neural sources of N400 related to processings of AoA on Kanji and semantics on Kana, respectively. Methods: Neuromagnetic responses to filtered Japanese word stimuli were recorded with a 306-ch MEG-system in healthy native Japanese speakers. Word stimuli including early-learned or late-learned Kanji and word or non-word Kana were randomly presented under the HSF and LSF conditions. The source localizations of N400m for Kanji under the HSF condition and those of Kana under the LSF condition were estimated by a single dipole model. Results: The sources of N400m for Kanji were estimated at around the peri-sylvian areas. Interestingly, the N400m sources of early-learned Kanji were more widely distributed at around the left temporal areas than those of late-learned Kanji. In contrast, the sources of N400m for Kana were located at around the left inferior parietal lobule (IPL). Consequently, the N400m sources for word Kana were distributed in the posterior IPL and those of non-word Kana in the anterior IPL. Conclusions: These findings suggested that the left peri-sylvian areas were important for AoA processing between Kanji based on HSF information. Conversely, the left IPL plays an important role in semantic processing relying on LSF information between Kana. Therefore, we can provide further evidence for the existence of close physiological link between Kanji reading and HSF information or between Kana reading and LSF information in native Japanese speakers. P8-26 Language function associated with phonemic and context cue in verbal fluency tasks: an fMRI study R. Okada1,2 , N. Nakano1 , K. Nishimatsu3 , H. Fukushima3 , M. Onoda3 , K. Ishii4 , T. Murakami4 , A. Kato1 1 Department of Neurosurgery, Kinki University School of Medicine, Osaka, Japan, 2 CREST, JST, Japan, 3 Kinki University Hospital, Japan, 4 Department of Radiology, Kinki University School of Medicine, Osaka, Japan Objective: It has been reported that patients with aphasia show different behavior with different types of cue in naming tasks. According to previous studies, a phonemic (letter) cue and a context cue facilitate the better word generation than a semantic category cue does. In verbal fluency studies, however, there are few studies using a context cue. This study aimed to investigate whether it is possible to dissociate in normal human subjects the neuroanatomical substrates of a phonemic cue and a context cue fluency tasks. Methods: Using functional magnetic resonance imaging (fMRI), we mapped brain activity in eight Japanese normal subjects during two silent verbal fluency tasks, one with a phonemic (letter) cue and one with a context cue. In a phonemic verbal fluency, a letter was visually presented, and subjects were requested to generate covertly as many words as possible that began with that letter. In a context cue verbal fluency task, an argument-lacked uncompleted single sentence (e.g. ( )-o taberu ‘( )-ACC eat’) was visually presented and subjects are requested to generate a word that was appropriate to complete that sentence. All image analyses were performed using SPM8. Result: A phonemic verbal fluency task activated the left inferior frontal gyrus (Brodmann’s Area (BA) 44, 45). A context cue verbal fluency task activated the bilateral putamen, thalamus, BA 44, 45, 10, 46, the superior frontal gyrus. There were areas activated in a context cue verbal fluency but not in a phonemic verbal fluency: the bilateral BA 10 and the left BA 46 (p < 0.001, uncorrected). Conclusion: There is no study to report the activation in BA 10 in a semantic verbal fluency. The date of this study suggested that a context cue verbal fluency activated the greater areas of brain than a phonemic and a semantic verbal fluency. P8-27 The role of visual imagery in concrete word processing: Effects of dynamic visual noise on event-related potentials to spoken words M. Takamura1 , M. Miyatani1 Hiroshima University, Graduate School of Education, Japan
1
Objective: Concrete words are easier to recall than abstract words. This phenomenon is well known as the concreteness effect, and suggests that visual imagery plays important role in an efficient processing of concrete words. Previous studies showed that event-related potentials (ERPs) to concrete words were more negative in two different latency ranges compared to those to abstract words. The earlier component has been
S153 Therefore, we aimed at elucidating the neural sources of N400 related to processings of AoA on Kanji and semantics on Kana, respectively. Methods: Neuromagnetic responses to filtered Japanese word stimuli were recorded with a 306-ch MEG-system in healthy native Japanese speakers. Word stimuli including early-learned or late-learned Kanji and word or non-word Kana were randomly presented under the HSF and LSF conditions. The source localizations of N400m for Kanji under the HSF condition and those of Kana under the LSF condition were estimated by a single dipole model. Results: The sources of N400m for Kanji were estimated at around the peri-sylvian areas. Interestingly, the N400m sources of early-learned Kanji were more widely distributed at around the left temporal areas than those of late-learned Kanji. In contrast, the sources of N400m for Kana were located at around the left inferior parietal lobule (IPL). Consequently, the N400m sources for word Kana were distributed in the posterior IPL and those of non-word Kana in the anterior IPL. Conclusions: These findings suggested that the left peri-sylvian areas were important for AoA processing between Kanji based on HSF information. Conversely, the left IPL plays an important role in semantic processing relying on LSF information between Kana. Therefore, we can provide further evidence for the existence of close physiological link between Kanji reading and HSF information or between Kana reading and LSF information in native Japanese speakers. P8-26 Language function associated with phonemic and context cue in verbal fluency tasks: an fMRI study R. Okada1,2 , N. Nakano1 , K. Nishimatsu3 , H. Fukushima3 , M. Onoda3 , K. Ishii4 , T. Murakami4 , A. Kato1 1 Department of Neurosurgery, Kinki University School of Medicine, Osaka, Japan, 2 CREST, JST, Japan, 3 Kinki University Hospital, Japan, 4 Department of Radiology, Kinki University School of Medicine, Osaka, Japan Objective: It has been reported that patients with aphasia show different behavior with different types of cue in naming tasks. According to previous studies, a phonemic (letter) cue and a context cue facilitate the better word generation than a semantic category cue does. In verbal fluency studies, however, there are few studies using a context cue. This study aimed to investigate whether it is possible to dissociate in normal human subjects the neuroanatomical substrates of a phonemic cue and a context cue fluency tasks. Methods: Using functional magnetic resonance imaging (fMRI), we mapped brain activity in eight Japanese normal subjects during two silent verbal fluency tasks, one with a phonemic (letter) cue and one with a context cue. In a phonemic verbal fluency, a letter was visually presented, and subjects were requested to generate covertly as many words as possible that began with that letter. In a context cue verbal fluency task, an argument-lacked uncompleted single sentence (e.g. ( )-o taberu ‘( )-ACC eat’) was visually presented and subjects are requested to generate a word that was appropriate to complete that sentence. All image analyses were performed using SPM8. Result: A phonemic verbal fluency task activated the left inferior frontal gyrus (Brodmann’s Area (BA) 44, 45). A context cue verbal fluency task activated the bilateral putamen, thalamus, BA 44, 45, 10, 46, the superior frontal gyrus. There were areas activated in a context cue verbal fluency but not in a phonemic verbal fluency: the bilateral BA 10 and the left BA 46 (p < 0.001, uncorrected). Conclusion: There is no study to report the activation in BA 10 in a semantic verbal fluency. The date of this study suggested that a context cue verbal fluency activated the greater areas of brain than a phonemic and a semantic verbal fluency. P8-27 The role of visual imagery in concrete word processing: Effects of dynamic visual noise on event-related potentials to spoken words M. Takamura1 , M. Miyatani1 Hiroshima University, Graduate School of Education, Japan
1
Objective: Concrete words are easier to recall than abstract words. This phenomenon is well known as the concreteness effect, and suggests that visual imagery plays important role in an efficient processing of concrete words. Previous studies showed that event-related potentials (ERPs) to concrete words were more negative in two different latency ranges compared to those to abstract words. The earlier component has been