Kenichi Ueno

Cells in the animal early visual cortex are sensitive to contour orientations and form repeated structures known as orientation columns. At the behavioral level, there exist 2 well-known global biases in orientation perception (oblique effect and radial bias) in both animals and humans. However, their neural bases are still under debate. To unveil how these behavioral biases are achieved in the early visual cortex, we conducted high-resolution functional magnetic resonance imaging experiments with a novel continuous and periodic stimulation paradigm. By inserting resting recovery periods between successive stimulation periods and introducing a pair of orthogonal stimulation conditions that differed by 90 ° con-tinuously, we focused on analyzing a blood oxygenation level-dependent response modulated by the change in stimulus orientation and reliably extracted orientation preferences of single voxels. We found that there are more voxels preferring horizontal and vertical orientations,...

Neuroscientists have traditionally relied on physiological and anatomical studies on experimental animals and clinicopathological studies on patients with localized brain damages to reveal the brain mechanisms of mental functions. Modern imaging techniques, however, permit us to observe non-invasively the neural activity of normal human brain. Among noninvasive measurement techniques, functional magnetic resonance imaging (fMRI) is growing rapidly because of its superior spatial resolution and complete non-invasiveness. We have set up an fMRI system with the static magnetic field of 4Tesla at RIKEN.

The variability of color-selective neurons in human visual cortex is considered more diverse than cone-opponent mechanisms. We addressed this issue by deriving histograms of hue-selective voxels measured using fMRI with a novel stimulation paradigm, where the stimulus hue changed continuously. Despite the large between-subject difference in hue-selective histograms, individual voxels exhibited selectivity for intermediate hues, such as purple, cyan, and orange, in addition to those along cone-opponent axes. In order to rule the possibility out that the selectivity for intermediate hues emerged through spatial summation of activities of neurons selectively responding to cone-opponent signals, we further tested hue-selective adaptations in intermediate directions of cone-opponent axes, by measuring responses to 4 diagonal hues during concurrent adaptation to 1 of the 4 hues. The selective and unidirectional reduction in response to the adapted hue lends supports to our argument that c...

Although the neural correlates that underlie abdominal pain have been investigated, so-called brain processes involved in modulating "gut feelings" remain unclear. In the current study, we used electrointestinography (EIG) to measure intestinal activity of healthy humans at rest. EIG measured myoelectrical activity of intestinal smooth muscles from the abdominal surface and was simultaneously conducted along with brain activity measurement using functional magnetic resonance imaging (fMRI). Correlations between the frequency powers of EIG and fMRI signals during 30min of rest were then examined to elucidate gut-brain interactions. Neural activity correlating with 0.14- to 0.21-Hz EIG (suggested to reflect intestinal activity) was observed in the right anterior and middle insula. Moreover, this EIG frequency band correlated with anxiety scores along with resting-state functional connectivity between the insula and dorsal anterior cingulate cortex. These findings suggest tha...

OUR UNDERSTANDING OF FACIAL EMOTION PERCEPTION HAS BEEN DOMINATED BY TWO SEEMINGLY OPPOSING THEORIES: the categorical and dimensional theories. However, we have recently demonstrated that hybrid processing involving both categorical and dimensional perception can be induced in an implicit manner (Fujimura etal., 2012). The underlying neural mechanisms of this hybrid processing remain unknown. In this study, we tested the hypothesis that separate neural loci might intrinsically encode categorical and dimensional processing functions that serve as a basis for hybrid processing. We used functional magnetic resonance imaging to measure neural correlates while subjects passively viewed emotional faces and performed tasks that were unrelated to facial emotion processing. Activity in the right fusiform face area (FFA) increased in response to psychologically obvious emotions and decreased in response to ambiguous expressions, demonstrating the role of the FFA in categorical processing. The...

Adults address infants with a special speech register known as infant-directed speech (IDS), which conveys both linguistic and emotional information through its characteristic lexicon and exaggerated prosody (e.g., higher pitched, slower, and hyperarticulated). Although caregivers are known to regulate the usage of IDS (linguistic and emotional components) depending on their child's development, the underlying neural substrates of this flexible modification are largely unknown. Here, using an auditory observation method and functional magnetic resonance imaging (fMRI) of four different groups of females, we revealed the experience-dependent influence of the emotional component on linguistic processing in the right caudate nucleus when mothers process IDS: (1) non-mothers, who do not use IDS regularly, showed no significant difference between IDS and adult-directed speech (ADS); (2) mothers with preverbal infants, who primarily use the emotional component of IDS, showed the main ...

Emotional events resulting from a choice influence an individual's subsequent decision-making. Although the relationship between emotion and decision-making has been widely discussed, previous studies have mainly investigated decision outcomes that can easily be mapped to reward and punishment, including monetary gain/loss, gustatory stimuli, and pain. These studies regard emotion as a modulator of decision-making that can be made rationally in the absence of emotions. In our daily lives, however, we often encounter various emotional events that affect decisions by themselves, and mapping the events to a reward or punishment is often not straightforward. In this study, we investigated the neural substrates of how such emotional decision outcomes affect subsequent decision-making. By using functional magnetic resonance imaging (fMRI), we measured brain activities of humans during a stochastic decision-making task in which various emotional pictures were presented as decision outc...

Although recent psychophysical studies indicate that visual awareness and top-down attention are two distinct processes, it is not clear how they are neurally dissociated in the visual system. Using a two-by-two factorial functional magnetic resonance imaging design with binocular suppression, we found that the visibility or invisibility of a visual target led to only nonsignificant blood oxygenation level-dependent (BOLD) effects in the human primary visual cortex (V1). Directing attention toward and away from the target had much larger and robust effects across all study participants. The difference in the lower-level limit of BOLD activation between attention and awareness illustrates dissociated neural correlates of the two processes. Our results agree with previously reported V1 BOLD effects on attention, while they invite a reconsideration of the functional role of V1 in visual awareness.

People have long speculated whether the evolution of bipedalism in early hominins triggered tool use (by freeing their hands) or whether the necessity of making and using tools encouraged the shift to upright gait. Either way, it is commonly thought that one led to the other. In this study, we sought to shed new light on the origins of manual dexterity and bipedalism by mapping the neural representations in the brain of the fingers and toes of living people and monkeys. Contrary to the ‘hand-in-glove’ notion outlined above, our results suggest that adaptations underlying tool use evolved independently of those required for human bipedality. In both humans and monkeys, we found that each finger was represented separately in the primary sensorimotor cortex just as they are physically separated in the hand. This reflects the ability to use each digit independently, as required for the complex manipulation involved in tool use. The neural mapping of the subjects’ toes differed, however....

s / Neuroscience Research 71S (2011) e108–e415 e259 from different feature dimensions, we made a reaction-time visual search task in which a singleton target differed from distractors in either color, shape, or both dimensions was presented and monkey subjects (Macaca fusucata) were required to make a saccade to a singleton target. In this study, we evaluated the easiness of the target detection by measuring the saccade reaction times (time from stimulus presentation to saccade initiation) for each stimulus condition. We found that the median saccade latency was reduced when the target-defining dimension was changed from a single feature to multiple features. Importantly, the reduction of reaction times tended to be large when two stimulus conditions (color and shape singletons) that elicited similar reaction times were combined. On the other hand, it tended to be small when those that elicited quite different reaction times were combined. These results suggest that visual salience signals from each feature dimension inhibit each other according to the relative difference in their signal strengths. doi:10.1016/j.neures.2011.07.1127 P3-k07 Mechanisms underlying selective responses to a combination of color and motion direction of neurons in V2 of macaque monkeys Hiroshi Tamura , Kousuke Aratono, Hisashi Takada Lab for Cog. Neuro., Grad. Sch. Front. Bio., Osaka Univ, Toyonaka, Japan In the earlier part of the visual processing of primates, neurons are sensitive to single visual submodality, such as color, shape, or motion direction. At the level of V2, however, there are neurons selectively responsive to a combination of color and motion direction (Aratono and Tamura, Neuro 2010). To elucidate mechanisms that generate the combination-selective responses, we analyzed visual responses of 1047 neurons in V2 of analgesized macaque monkeys. First, we investigated the possibility that luminance-contour responsive neurons provide inputs to combination-selective neurons by presenting stimuli on the equiluminant background. We found that the incidence of neurons selective to the combination was lower in the equiluminant condition than otherwise. The results indicate that mechanisms that utilize luminance contrast border, such as inputs from neurons sensitive to motion of luminance contour, contribute to the generation of the combination-selective responses. However, small but a significant fraction of neurons were responsive to the combinations even under the equiluminant condition. A mechanism that generates the combination-selective responses under the equiluminant condition is an integration of non-directional colorselective inputs based on the motion-energy model. The motion-energy model requires time delay between inputs to generate an oblique profile on the x–t plane of the space-time receptive field. Therefore, next, we investigated distribution of onset latency of V2 neurons to color stimuli presented on the equiluminant background, and found that the latency distributed in a wide range (61-93 ms, 25-75% quantiles). Thus, an appropriate integration of these color inputs also can confer selectivity to a combination of stimulus color and direction on V2 neurons. From these results, we conclude that diverse mechanisms contribute to the generation of selective responses to a combination of color and motion direction. Research fund: KAKENHI (23135521). doi:10.1016/j.neures.2011.07.1128 P3-k08 Dynamic perceptual changes of joint angles in a phantom arm Nobuyuki Inui Grad. Sch. Edu. Naruto Univ. Edu., Naruto, Japan Contorted phantom limbs often form when sensory inputs are removed, but the brain mechanisms underlying their formation are poorly understood. We tracked the evolution of an experimental phantom arm as well as a phantom hand during ischemic anesthesia of the right upper arm. Here we show that if a limb is fully extended or flexed at a joint before and during anesthesia, the phantom limb is flexed or extended in the opposite direction. In the first study subjects showed perceived posture of their right arm and hand using the left arm and hand. If the arm and hand were fully extended before and during anesthesia, the final phantom was bent at the wrist and elbow, but if the arm and hand were fully flexed before and during anesthesia, the final phantom was extended at wrist and elbow. The final perceived position of the wrist was more changed than that of the elbow. In the second study, however, when the hand and arm were held straight before and during anesthesia, the final phantom was not changed at the wrist although the final phantom was bent at the elbow. Hence, no default posture existed for the phantom arm and hand. The final perceived posture may depend on the initial and evolving sensory input during the block rather than the final sensory input. Sensory changes were monitored. In all subjects, impairment of largefiber cutaneous sensation began distally with von Frey thresholds increasing. These…

s / Neuroscience Research 58S (2007) S1–S244 S233 P3-h31 Neural mechanisms for preference-based decision making Ayako Isoo1,2, Kenichi Ueno3, Keiji Tanaka1, Kang Cheng1 1 Lab for Cognitive Brain Mapping, RIKEN BSI, Saitama, Japan; 2 Department of Neurosurgery, University of Tokyo, Tokyo, Japan; 3 Research Resources Center, RIKEN BSI, Saitama, Japan We speculate that neural mechanisms for positive emotions overlap with those for preference-based decision making. Using fMRI, we attempted to uncover how this preference for certain things over other things, focusing on the commodity preference, is represented. Forty-four healthy female college students answered questionnaires, in which 560 commodity brands from 100 categories were given with their logos. Based on the results of them, 80 pairs of preferred and neutral brands were determined. Eighty pairs of positive and neutral pictures were also selected from the International Affective Picture System (IAPS). Eighteen subjects participated in the fMRI study. In test task, each subject chose her preferred brand. In control task, she chose the logo judged as visually more striking. In brand-logo sessions, parahippocamal gyrus, midbrain, dorsolateral prefrontal cortex and cerebellum were activated. In IAPS sessions, activated areas were similar to those in brand-logo sessions, but appeared more extensive and included amygdala. P3-h32 Ventrolateral prefrontal response to taste stimuli Masako Okamoto, Yuji Wada, Daisuke Tsuzuki, Archana Singh, Ippeita Dan National Food Research Institute, Japan The role of the lateral prefrontal cortex (LPFC) in taste processing is gradually drawing attention. In our previous taste studies using multi-channel functional near-infrared spectroscopy (fNIRS), we have noticed prefrontal activity in response to taste-related stimuli even when no cognitive task is performed. To examine the observed activity further, we conducted a meta-analysis of our previous fNIRS data from 32 subjects (of which, 15 participated in two experiments). We found significant activation centering at inferior prefrontal gyrus (IFG) in both hemispheres in both taste and flavor tasting conditions. The cortical response did not show any significant correlation with subjective rating scores to the stimuli (intensity, familiarity, and hedonisity) at group level, but at the subject level, some subjects showed strong correlation to some of these rating scores. Our study suggests that, in addition to dorso-LPFC reported by Kringelbach, et al. (2004), IFG plays certain role in taste-related intra-oral stimulus processing. Research fund: This work is supported by Grant-in-aid for young scientists (B) 18700625 from MEXT of Japan. P3-h33 An fMRI study: Processing of item-situation relationship Keisuke Wakusawa1,2, Motoaki Sugiura1,3, Yuko Sassa1,4, Hyeonjeong eong1,5, Kaoru Horie6, Shigeru Sato6, Hiroyuki Yokoyama2, Shigeru Tsuchiya2, Ryuta Kawashima1,4 1 IDAC, Tohoku University, Japan; 2 Department of Pediatrics, Tohoku University, Japan; 3 NIPS, Japan; 4 RISTEX, JST, Japan; 5 GSICS, Tohoku University, Japan; 6 LBC, RC, Tohoku University, Japan This study examines the cortical mechanism of monitoring item-situation relationship and detecting irrelevant items (Ir). Healthy subjects judged whether a presented item was relevant to a situation or not. As items, object or behavior pictures were presented in separate sessions (O or B sessions). Each control task (Co or Cb) was detection of inverted item pictures. Greater activation during O/B than Co/Cb was analyzed to identify the activation for monitoring item-situation relationship and neural responses to Ir were analyzed. Activation during O and B was observed in several frontal, temporal regions and the posterior cingulate cortex. The right lateral prefrontal cortex was activated during B only. Activation for Ir was observed in the left lateral orbitofrontal cortex during O, and in the medial prefrontal cortex, and the left prefrontal cortex during B. No common activation was identified between them. P3-h34 5-HT2A receptor gene polymorphism modulates activation for monetary reward in the human ventrolateral frontal lobe during Go/No-go task Michio Nomura1,2, Hirohito M. Kondo2, Makio Kashino2,3,4 1 Dept of Psychology, Tokaigakuin University, Kakamigahara, Japan; 2 NTT Communication Science Labs, NTT Corp, Atsugi, Japan; 3 ERATO Shimojo Implicit Brain Function Project, JST, Atsugi, Japan; 4 Interdisciplinary Grad Sch of Science and Engineering, Tokyo Institute of Technology, Yokohama, Japan We examined whether the serotonergic system plays an important role in human impulsive behavior formonetary reward by measuring how 5HT2A receptor gene polymorphism (A-1438G in the promoter region) affects inhibitory motor control in a Go/No-go task using fMRI. Twentyseven participants were instructed to learn to respond to Go stimuli and inhibit their response to No-go stimuli under both the reward-only (R) condition and the…

Neocortical GABAergic interneurons are roughly classified into three subgroups and distinguished by chemical markers, such as parvalbumin (PV), somatostatin (SS) and the others. PV-expressing neurons, fast-spiking neurons, are a major component of GABAergic interneurons in the neocortex and have been implicated in higher order functions, such as learning and memory, by generating gamma frequency oscillations. We previously generated BAC transgenic mice expressing dendritic membrane-targeted GFP selectively in PV-expressing neurons, and succeeded in visualizing the somata and dendrites in a Golgi stain-like fashion. By combining the immunofluorescence labeling of GABAergic terminals with the antibody to vesicular GABA transporter, we revealed that GABAergic terminals preferentially apposed to the proximal dendrites and somata. It is, however, unclear which type of GABAergic interneurons innervates the proximal dendrites and somata of PV-expressing neurons. In the present study, we visualize the axon terminals of PVor SS-expressing neurons by immunofluorescence staining in the transgenic mice, observe the close appositions to PV-expressing neurons under confocal laser-scanning microscope, and analyze the synaptic inputs quantitatively. These experiments would provide new insights into the local circuits composed by neocortical interneurons.

The progressive diminution of frequency of the flicker fusion threshold was observed in the process of the development of the fatigue stage. Non-arbitrary detection of a flicker fusion threshold was investigated from differences in the responses of pupil diameter and the visual evoked magnetic field (VEF) for flickering visual stimulation with a frequency over or under the flicker fusion threshold. Pupil diameter in periods of omission, and VEF of ON and OFF responses were observed for flickering visual stimulus durations with a frequency under or over 2.5 Hz or 7.5 Hz from the threshold. The pupil diameter increment was larger and decrement was smaller in the over 7.5 Hz flickering condition than in the under 7.5 Hz condition. The amplitude of OFF responses increased with the increment of the frequency of flicker. Differences in pupil diameter and OFF responses for VEF could show the frequency of the flicker fusion threshold in a non-arbitrary way.

When one is asked to select a label for a novel object from a given group of labels that includes both novel and familiar labels, one tends to choose a novel label. In other words, people spontaneously assume that an unfamiliar label goes with an unfamiliar object, even though logically, familiar labels may also be valid choices. This may seem natural and even trivial, but the fact that nonhuman animals robustly fail to demonstrate this same tendency suggests that it is not. This tendency of choice, called "exclusion," can bias human behavior, and seems relevant to aspects of human language (e.g., word learning), although substantially more research is required to validate. In this functional magnetic resonance imaging study, we investigated the neural correlates of this bias using a matching-to-sample procedure. The subjects were first trained on two sample-to-comparison associations between abstract visual stimuli. Then, in a test of exclusion, they were shown a novel sample and were asked to choose between a trained but incorrect comparison and a novel comparison. The subjects readily chose the novel comparison and rejected the trained one, thus demonstrating exclusion. Significant activation was observed in the prefrontal cortex (PFC) and inferior parietal lobule (IPL) during exclusion. Medial frontal activation was also observed, which was related to the appearance of the novel stimuli. These results suggest that the medial frontal cortex is associated with novelty detection and that the PFC and IPL are involved in rejecting the defined comparison in favor of the novel one.

Adults typically address infants in a special speech mode called infant-directed speech (IDS). IDS is characterized by a special prosody (i.e., higher pitched, slower and hyperarticulated) and a special lexicon ("baby talk"). Here we investigated which areas of the adult brain are involved in processing IDS, which aspects of IDS (prosodic or lexical) are processed, to what extent the experience of being a parent affects the way adults process IDS, and the effects of gender and personality on IDS processing. Using functional magnetic resonance imaging, we found that mothers with preverbal infants showed enhanced activation in the auditory dorsal pathway of the language areas, regardless of whether they listened to the prosodic or lexical component of IDS. We also found that extroverted mothers showed higher cortical activation in speech-related motor areas than did mothers with lower extroverted personality scores. Increased cortical activation levels were not found for fathers, non-parents, or mothers with older children.

In functional magnetic resonance imaging (fMRI), even subvoxel motion dramatically corrupts the blood oxygenation level-dependent (BOLD) signal, invalidating the assumption that intensity variation in time is primarily due to neuronal activity. Thus, correction of the subject's head movements is a fundamental step to be performed prior to data analysis. Most motion correction techniques register a series of volumes assuming that rigid body motion, characterized by rotational and translational parameters, occurs. Unlike the most widely used applications for fMRI data processing, which correct motion in the image domain by numerically estimating rotational and translational components simultaneously, the algorithm presented here operates in a three-dimensional k-space, to decouple and correct rotations and translations independently, offering new ways and more flexible procedures to estimate the parameters of interest. We developed an implementation of this method in MATLAB, and tested it on both simulated and experimental data. Its performance was quantified in terms of square differences and center of mass stability across time. Our data show that the algorithm proposed here successfully corrects for rigid-body motion, and its employment in future fMRI studies is feasible and promising.

The ability to think logically is a hallmark of human intelligence, yet our innate inferential abilities are marked by implicit biases that often lead to illogical inference. For example, given AB (“if A then B”), people frequently but fallaciously infer the inverse, BA. This mode of inference, called symmetry, is logically invalid because, although it may be true, it is not necessarily true. Given pairs of conditional relations, such as AB and BC, humans reflexively perform two additional modes of inference: transitivity, whereby one (validly) infers AC; and equivalence, whereby one (invalidly) infers CA. In sharp contrast, nonhuman animals can handle transitivity but can rarely be made to acquire symmetry or equivalence. In the present study, human subjects performed logical and illogical inferences about the relations between abstract, visually presented figures while their brain activation was monitored with fMRI. The prefrontal, medial frontal, and intraparietal cortices were a...

Adults typically address infants in a special speech mode called infant-directed speech (IDS). IDS is characterized by a special prosody (i.e., higher pitched, slower and hyperarticulated) and a special lexicon ("baby talk"). Here we investigated which areas of the adult brain are involved in processing IDS, which aspects of IDS (prosodic or lexical) are processed, to what extent the experience of being a parent affects the way adults process IDS, and the effects of gender and personality on IDS processing. Using functional magnetic resonance imaging, we found that mothers with preverbal infants showed enhanced activation in the auditory dorsal pathway of the language areas, regardless of whether they listened to the prosodic or lexical component of IDS. We also found that extroverted mothers showed higher cortical activation in speech-related motor areas than did mothers with lower extroverted personality scores. Increased cortical activation levels were not found for fathers, non-parents, or mothers with older children.

The superior capability of cognitive experts largely depends on quick automatic processes. To reveal their neural bases, we used functional magnetic resonance imaging to study brain activity of professional and amateur players in a board game named shogi. We found two activations specific to professionals: one in the precuneus of the parietal lobe during perception of board patterns, and the other in the caudate nucleus of the basal ganglia during quick generation of the best next move. Activities at these two sites covaried in relevant tasks. These results suggest that the precuneus-caudate circuit implements the automatic, yet complicated, processes of board-pattern perception and next-move generation in board game experts.

The progressive diminution of frequency of the flicker fusion threshold was observed in the process of the development of the fatigue stage. Non-arbitrary detection of a flicker fusion threshold was investigated from differences in the responses of pupil diameter and the visual evoked magnetic field (VEF) for flickering visual stimulation with a frequency over or under the flicker fusion threshold. Pupil diameter in periods of omission, and VEF of ON and OFF responses were observed for flickering visual stimulus durations with a frequency under or over 2.5 Hz or 7.5 Hz from the threshold. The pupil diameter increment was larger and decrement was smaller in the over 7.5 Hz flickering condition than in the under 7.5 Hz condition. The amplitude of OFF responses increased with the increment of the frequency of flicker. Differences in pupil diameter and OFF responses for VEF could show the frequency of the flicker fusion threshold in a non-arbitrary way.