Eyeblink entrainment at breakpoints of speech

s / Neuroscience Research 68S (2010) e55–e108 e103 their juvenile stage, songbirds have been used as good model animals for studying neural basis of vocal learning. Based on numerous anatomical and physiological studies have suggested so far that vocal learners have a neural network called ‘song system’ specialized for vocal learning and production in their brain. To investigate molecular basis of vocal learning process, we carried out in situ hybridization screening of candidate genes with song system-related expressions in a songbird, Bengalese finch. We found that several neural circuit formation genes such as cadherin, neuropilin, plexin and ephrin showed vocal control area related expressions. Interestingly, cadherin-7 showed transiently strong expression in the RA nucleus in the sensory learning stage but its expression was down-regulated during the sensorimotor learning stage, while cadherin-6B expression was up-regulated during the development. Furthermore, to examine cadherin functions in vocal learning, we overexpressed cadherin-7 in the RA nucleus of juvenile finches with lentivirus and analyzed effects on vocal learning with various acoustic characteristic. Although control EGFP-overexpressed birds normally learned their father’s song, cadherin-7-overexpressed birds showed defects in vocal learning. These results suggest the possibility that exchange of cadherin expression plays a pivotal role in vocal learning process. doi:10.1016/j.neures.2010.07.216 O2-9-2-2 Cerebral correlates of word segmentation in infants Yasuyo Minagawa-Kawai 1,2 , Ai Kobayashi 1 1 Department Human Relations, Keio University, Tokyo 2 Global COE program, Centre for Advanced Research on Logic and Sensibility, Keio University, Tokyo Unlike written language, conversational speech does not have a remarkable interval between words. Specifically, speech rarely has any salient acoustic cues to indicate word boundaries. This becomes an obstacle for infants when they identify spoken words. Although this issue of word segmentation is crucial for word learning in the course of language acquisition, cerebral correlates of this mechanism remained unclear. To identify brain regions and network engaging this mechanism and find out early neural marker of word segmentation ability, the present study tested two groups of infants using a behavioral method and near-infrared spectroscopy (NIRS). First, we conducted a behavioral study to determine when Japanese infants start to segment words from continuous speech. On the basis of this behavioral data, we set up two age groups of infants (i.e. 5-7 and 8-10 month-olds) and measured their brain responses during training session of a new word and test session of word segmentation. In general, our results showed differential pattern of brain activations between target and control word stimuli in both training and test sessions. During the training session of the targeted word, large responses in the area of posterior STG, supra-marginal gyrus and inferior frontal region were observed. In contrast, during the control training, infants showed significant responses around the auditory area to the control words (i.e. a series of various new words). The results seem to indicate that the brain network of phonological short-term memory (dorsal pathway) is involved in the word learning process. In the test session, the infants showed larger activations in perisylvian channels to the target sentences than to the control ones. This suggests that infants even at 5-7 months-old are able to pick up words from running speech. doi:10.1016/j.neures.2010.07.217 O2-9-2-3 Eyeblink entrainment at breakpoints of speech Tamami Nakano 1,2 , Shigeru Kitazawa 1,3 1 Neurophysiology, Juntendo University, Graduate school of medication 2 Japan Society for the Promotion of Science, Tokyo, Japan 3 CREST, Japan Science and Technology Agency, Saitama, Japan The eyes play an essential role in social communication. Gaze entrainment to the same location, for example, encourages the sharing of attention. Eyeblinks, on the other hand, have thus far received minor attention. We previously showed that subjects blink in synchrony while viewing the same video stories. We therefore hypothesized that eyeblinks are synchronized between interactants during conversation. To test this hypothesis, we examined the temporal relationship between the eyeblinks of a listener and a speaker in face-to-face communication. Here, we show that listeners blinked with a delay of 0.25 to 0.75 s after the speaker blinked when the listeners viewed close-up video clips (with sound) of the speaker’s face. Furthermore, this entrainment was selectively triggered by speaker’s eyeblinks occurring at the end and during pauses in vocalization. Eyeblink entrainment was not observed when viewing identical video clips without sound, indicating that blink entrainment was not an automatic imitation triggered by mere visual perception of the speaker’s behavior. We therefore suggest that eyeblink entrainment reflects smooth communication between interactants in face-to-face conversation. doi:10.1016/j.neures.2010.07.218 O2-9-2-4 Abnormal pattern of brain activation in developmental stuttering during Katakana word reading Chang Cai 1 , Koichi Mori 1, Shuntaro Okazaki 2, Minae Okada 1 1 Research Institute, National Rehabilitation Center for Persons with Disabilities 2 Division of Cerebral Integration, National Institute for Physiological Sciences A dual route model for speech production has been suggested based on the word familiarity effect [Coltheart M, et al., Psychol Rev. 2001 Jan;108(1):20456], and its neural substrates include Broca’s area for reading unfamiliar or pseudowords [Ischebeck A, et al., J Cogn Neurosci. 2004 Jun;16(5):72741]. A relatively smaller volume of Broca’s area has been found in stuttering speakers than in non-stuttering speakers [Chang SE, et al., Neuroimage. 2008 Feb 1;39(3):1333-44], which could result in its dysfunction. In the present study, we employed an overt reading task of low and high familiarity words and pseudowords, presented in Katakana, to investigate the word-familiarity effect on the activity of Broca’s area of adult stuttering speakers with fMRI. Unlike non-stuttering speakers, stuttering subjects failed to show activation in Broca’s area for low familiarity words and pseudowords, which suggests that there is no word-familiarity effect on this language area in the stuttering subjects as predicted by the dual-route model. Besides, they showed stronger activations in the left lower motor cortex for all word categories. Together with the abnormal anatomical findings in Broca’s area in previous studies, we postulate that the elevated motor cortex activation in stuttering speakers are compensatory to dysfunctional Broca’s area during speech production. doi:10.1016/j.neures.2010.07.219 O2-9-3-1 Belief level of the player’s decision in unfair conditon of ultimatum game Makoto Yoshida , Yoshihiro Miyake Tokyo Institute of Technology Economic decision making was investigated in neuroeconomics field. As an economic decision making, we conducted ultimatum game with controlled time length for making decision. The controlled time length is our original for ultimatum game study. This study verified result of previous study, and clarified typical features between the controlled time length and belief level of the player’s decision. This features considered to be correlated to brain activity imaged by imaging tool such as fMRI and NIRS. In this game, two players split a sum of money; one player proposes a division ratio and the other player accepts or rejects the proposed ratio. If the other player accepts, the player obtains the proposed ratio of money. If rejects, obtains no money. Based on the economical view point, the counterpart player should always accept the proposal. But actually the counterpart player rejects the unfair proposal due to emotional reason. In this study, accept /reject ratio was different according to the controlled time length. Besides, previous study clarified the unfair proposal elicits brain activity in areas related to both emotion and cognition. Brain activity of the areas is considered to be also different according to time length in the unfair condition. We suggested the brain activity in the unfair condition correlates to the belief level of the player’s decision. doi:10.1016/j.neures.2010.07.220 O2-9-3-2 Representation of self and other actions in the medial frontal cortex Masaki Isoda 1,2,3 , Kyoko Yoshida 1,4, Nobuhito Saito 4, Atsushi Iriki 1 1 Lab Symb Cogn Develop, RIKEN BSI, Wako 2 Neural Systems Behavior, OIST, Okinawa 3 PRESTO, JST, Kawaguchi 4 Dept Neurosurg, Univ of Tokyo, Tokyo What neuronal code allows social beings to distinguish between self and other?s action? Although the so-called mirror neuron system points to a plausible neural mechanism for grasping other?s actions and intentions, this system alone does not enable a clear-cut distinction between aspects of self