Brain-mediated Transfer Learning of Convolutional Neural Networks

The human brain can effectively learn a new task from a small number of samples, which indicate that the brain can transfer its prior knowledge to solve tasks in different domains. This function is analogous to transfer learning (TL) in the field of machine learning. TL uses a well-trained feature space in a specific task domain to improve performance in new tasks with insufficient training data. TL with rich feature representations, such as features of convolutional neural networks (CNNs), shows high generalization ability across different task domains. However, such TL is still insufficient in making machine learning attain generalization ability comparable to that of the human brain. To examine if the internal representation of the brain could be used to achieve more efficient TL, we introduce a method for TL mediated by human brains. Our method transforms feature representations of audiovisual inputs in CNNs into those in activation patterns of individual brains via their association learned ahead using measured brain responses. Then, to estimate labels reflecting human cognition and behavior induced by the audiovisual inputs, the transformed representations are used for TL. We demonstrate that our brain-mediated TL (BTL) shows higher performance in the label estimation than the standard TL. In addition, we illustrate that the estimations mediated by different brains vary from brain to brain, and the variability reflects the individual variability in perception. Thus, our BTL provides a framework to improve the generalization ability of machine-learning feature representations and enable machine learning to estimate human-like cognition and behavior, including individual variability

Relational Network of People Constructed on the Basis of Similarity of Brain Activities.

The relational network of people (RNP) model has been attracting the interest of not only researchers but also industrial engineers. RNP can be constructed from friend lists in online social networking services (SNSs) and from inter-contact logs between individuals. One of the killer applications of RNP is the prediction of user demands, which is key to maximizing user satisfaction in content delivery services such as video streaming and video advertising. It is well known that an RNP representing social closeness between individuals (a so-called social network) can estimate user preferences simply, as we expect that people close to each other will have similar preferences. However, although there are many metrics that enable the social closeness between individuals to be measured, it is unclear which metric is best suited for individual services. Therefore, this paper introduces a new approach based on brain imaging. Brain imaging using functional Magnetic Resonance Imaging (fMRI) is powerful because it enables us to directly observe how a video content stimulates the brains of individual people. We propose a brain imaging-based RNP that represents the similarity of video-evoked brain activities between people as a network graph. We show an application scenario featuring predictive content delivery using the proposed RNP in which, when a user shows interest in a video content in some way, other users close to him or her can be expected to also be interested in it because their brain activities are correlated. Through numerical evaluation using multiple real datasets obtained by fMRI, we demonstrate that the proposed RNP is generalizable across brain imaging results for different sets of video content, thus suggesting that brain imaging data can be used to robustly generate RNP for utilization as a powerful tool for estimating user preferences

Psychological Stress-Induced Oxidative Stress as a Model of Sub-Healthy Condition and the Effect of TCM

Distress-mediated tissue oxidative stress was examined as a model of sub-healthy condition defined in traditional Chinese medicine theory. Mice were subjected to psychologically stressful conditions by whiskers removal. Under this condition, spontaneous locomotive activity was significantly enhanced in the dark (P < 0.05 versus the control mice in three different movements), and granulocytes/lymphocytes balance shifted to granulocytes. At the same time, peroxynitrite level in blood plasma increased to ∼180% from that of the control mice at 6 h after removal of the whiskers (P < 0.01), and was maintained even after 12 h. Both protein carbonyl formation and lipid peroxidation were significantly increased under this condition in brain, heart, liver and spleen at 6 h after removal of whiskers (P < 0.05 or P < 0.01), and these levels were maximized after 12 h (increased to 120–160%, P < 0.05 or P < 0.01). The oxidative tissue injuries observed at 12 h after the removal of the whiskers were effectively prevented by two traditional Chinese medicine formula: Shengmai San (SMS) and Ling Gui Zhu Gan Tang (LGZGT), when administered for 5 days before the removal of the whiskers. Therefore, this stress model is considered useful in assessing the preventive potential of antioxidants and antioxidant-based herbal mixtures in treating the pathophysiology associated with psychological or emotional distress

Characteristics of nucleosomes and linker DNA regions on the genome of the basidiomycete Mixia osmundae revealed by mono- and dinucleosome mapping

We present findings on the nucleosomal arrangement in the genome of the basidiomycete Mixia osmundae, focusing on nucleosomal linker DNA regions. We have assembled the genomic sequences of M. osmundae, annotated genes and transcription start sites (TSSs) on the genome, and created a detailed nucleosome map based on sequencing mono- and dinucleosomal DNA fragments. The nucleosomal DNA length distribution of M. osmundae is similar to that of the filamentous ascomycete Aspergillus fumigatus, but differs from that of ascomycetous yeasts, strongly suggesting that nucleosome positioning has evolved primarily through neutral drift in fungal species. We found clear association between dinucleotide frequencies and linker DNA regions mapped as the midpoints of dinucleosomes. We also describe a unique pattern found in the nucleosome-depleted region upstream of the TSS observed in the dinucleosome map and the precursor status of dinucleosomes prior to the digestion into mononucleosomes by comparing the mono- and dinucleosome maps. We demonstrate that observation of dinucleosomes as well as of mononucleosomes is valuable in investigating nucleosomal organization of the genome

Not only Body Weight Perception but also Body Mass Index is Relevant to Suicidal Ideation and Self-Harming Behavior in Japanese Adolescents

Whether a low body mass index (BMI) is directly associated with a high risk of suicidal ideation or self-harming behavior in adolescents is still inconclusive. This study has, therefore, evaluated the relevance of BMI to suicidal ideation and self-harming behavior after controlling for body weight perception (BWP) and other potential confounding factors. BMI, BWP, suicidal ideation, and self-harming behavior were all assessed using a self-report questionnaire administered to 18,104 Japanese adolescents. Potential confounding factors were also evaluated. The data were then analyzed using bi-variate and multivariate logistic regression. Low BMI was associated with suicidal ideation and deliberate self-harm when controlling for sex, age, drug use, emotional distress, and BWP. Low BMI may be an independent risk factor for suicidal ideation and deliberate self-harming behavior in Japanese adolescents.ArticleJOURNAL OF NERVOUS AND MENTAL DISEASE. 200(4):305-309 (2012)journal articl

Disorganization of Semantic Brain Networks in Schizophrenia Revealed by fMRI

OBJECTIVES: Schizophrenia is a mental illness that presents with thought disorders including delusions and disorganized speech. Thought disorders have been regarded as a consequence of the loosening of associations between semantic concepts since the term "schizophrenia" was first coined by Bleuler. However, a mechanistic account of this cardinal disturbance in terms of functional dysconnection has been lacking. To evaluate how aberrant semantic connections are expressed through brain activity, we characterized large-scale network structures of concept representations using functional magnetic resonance imaging (fMRI). STUDY DESIGN: We quantified various concept representations in patients' brains from fMRI activity evoked by movie scenes using encoding modeling. We then constructed semantic brain networks by evaluating the similarity of these semantic representations and conducted graph theory-based network analyses. STUDY RESULTS: Neurotypical networks had small-world properties similar to those of natural languages, suggesting small-worldness as a universal property in semantic knowledge networks. Conversely, small-worldness was significantly reduced in networks of schizophrenia patients and was correlated with psychological measures of delusions. Patients' semantic networks were partitioned into more distinct categories and had more random within-category structures than those of controls. CONCLUSIONS: The differences in conceptual representations manifest altered semantic clustering and associative intrusions that underlie thought disorders. This is the first study to provide pathophysiological evidence for the loosening of associations as reflected in randomization of semantic networks in schizophrenia. Our method provides a promising approach for understanding the neural basis of altered or creative inner experiences of individuals with mental illness or exceptional abilities, respectively

Proximal Vertebral Body Fracture after 4-Level Fusion Using L1 as the Upper Instrumented Vertebra for Lumbar Degenerative Disease: Report of 2 Cases with Literature Review

Some cases with lumbar degenerative diseases require multi-level fusion surgeries. At our institute, 27 and 4 procedures of 3- and 4-level fusion were performed out of a total 672 posterior lumbar interfusions (PLIFs) on patients with lumbar degenerative disease from 2005 to 2010. We present 2 osteoporotic patients who developed proximal vertebral body fracture after 4-level fusion. Both cases presented with gait disability for leg pain by degenerative lumbar scoliosis and canal stenosis at the levels of L1/2-4/5. After 4-level fusion using L1 as the upper instrumented vertebra, proximal vertebral body fractures were found along with the right pedicle fractures of L1 in both cases. One of these patients, aged 82 years, was treated as an outpatient using a hard corset for 24 months, but the fractures were exacerbated over time. In the other patient, posterolateral fusion was extended from Th10 to L5. Both patients can walk alone and have been thoroughly followed up. In both cases, the fracture of the right L1 pedicle might be related to the subsequent fractures and fusion failure. In consideration of multi-level fusion, L1 should be avoided as an upper instrumented vertebra to prevent junctional kyphosis, especially in cases with osteoporosis and flat back posture