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Many sequences are acquired in the hippocampus. Sequences are represented by a series of events which are associative representations of information and they are linked with each other by common representations. The sequences must, however, be recalled individually, even if the sequences are overlapped at some representations: otherwise we couldn’t retrieve own precious memory correctly. Therefore,...
What a human’s eye tells a human’s brain? In this paper, we analyze the information capacity of visual attention. Our hypothesis is that the limit of perceptible spatial frequency is related to observing time. Given more time, one can obtain higher resolution – that is, higher spatial frequency information, of the presented visual stimuli. We designed an experiment to simulate natural viewing conditions,...
Learning with adaptivity is a key issue in many nowadays applications. The most important aspect of such an issue is incremental learning (IL). This latter seeks to equip learning algorithms with the ability to deal with data arriving over long periods of time. Once used during the learning process, old data is never used in subsequent learning stages. This paper suggests a new IL algorithm which...
Memory consolidation is an increasingly important cortical process in which a new memory is transferred to a stable state over time. Memory is said to be labile when certain cognitive and/or pharmacological processes lead to its partial or total destruction. Classical theory held that once consolidated, memory is not susceptible to disruption. However, recent experiments have suggested that when a...
The CMAC neural network is a well-established computational model of the human cerebellum. A major advantage is its localized generalization property which allows for efficient computations. However, there are also two major problems associated with this localized associative property. Firstly, it is difficult to fully-train a CMAC network as the training data has to fully cover the entire set of...
The disparity energy model can explain physiological properties of binocular neurons in early visual cortex quantitatively. Therefore, many physiologically-plausible models for binocular stereopsis employed the disparity energy model as a model neuron. These models can explain a variety of psychological data. However, most of them cannot handle with stereo transparency. Here, we develop a simple model...
The functional connectivity of the resting state, or default mode, of the human brain has been a research focus, because it is reportedly altered in many neurological and psychiatric disorders. Among the methods to assess the functional connectivity of the resting brain, independent component analysis (ICA) has been very useful. But how to choose the optimal number of separated components and the...
This paper presents an automatic acquisition process to acquire the semantic meaning for the words. This process obtains the representation vectors for stemmed words by iteratively improving the vectors, using a trained Elman network [4]. Experiments performed on a corpus composed of Shakespeare’s writings show its linguistic analysis and categorization abilities. Index Terms: word...
Existing attention models concentrate on bottom-up attention guidance, and lack of effective definition of top-down attention information. In this paper we define a new holistic scene representation and use it as top-down attention information which works in three ways. The first is to discriminate between close-up and open scene categories. The second and the third are to provide reliable priors...
To investigate the accuracy for absolute quantification of brain creatine (Cr) concentration using in vivo long echo time PRESS sequence performed with an external standard. Ten swine and an external standard phantom were investigated by 1.5T GE Signa scanner and the standard head coil. 1H-MRS data were acquired from the two VOI (2x2x2cm3) placed in swine brain and external standard solution by using...
Most researchers focused on particular result ignore intermediate stages of learning process of neural networks. The unstable and transitory phenomena, discovered in neural networks during the learning process, long time after the initial stage of learning, when the network knows nothing because of random values of all weights, and long time before final stage of learning process, when the network...
We propose a computational model consisting of mutually connected V1, V2, and PP modules, to realize the effect of attention to the determination of border-ownership (BO) that tells on which side of a contour owns the border. The V2 module determines BO from surrounding contrast extracted by the V1 module that could be affected by top-down spatial attention from the PP module. The simulation results...
Identification tasks are experimented on multi-layered self-organizing maps with feedback, using strings of category symbols of English sentences. Training is carried out in a setting that approximates language acquisition by human infants as closely as possible. Novel strings that are not used in training are tested whether they can be identified as grammatical or not. Test strings can be longer...
Traditional document indexing methods, although useful, do not take into account some important aspects of language, such as syntax and semantics. Unlikely, semantic hyperspaces are mathematical and statistical-based techniques that do it. However, although they are an improvement on traditional methods, the output representation is still vector like. This paper proposes a computational model of text...
The purpose of this study is to investigate the cortical areas involved in comprehending Korean regular and irregular verb Eojeols. Eojeols is the specific spacing unit of a sentence which is bigger than a word but smaller than phrase. This study showed that there is a distinction between the process and representation of regularly and irregularly inflected verbs in Korean using neuroimaging and hehavioral...
Barn owls perform sound localization based on analyses of interaural differences in arrival time and intensity of sound. Two kinds of neural signals representing the interaural time difference (ITD) and interaural intensity difference (IID) are processed in parallel in anatomically separate pathway. The values of ITD and IID are largely changed depending on frequency components of sound. The neural...
Most species of bats making echolocation use Doppler-shifted frequency of ultrasonic echo pulse to measure the velocity of target. The neural circuits for detecting the target velocity are specialized for fine-frequency analysis of the second harmonic constant frequency (CF2) component of Doppler-shifted echoes. To perform the fine-frequency analysis, the feedback signals from cortex to subcortical...
The speech recognition ability of most CI users in noisy environment remains quite poor, especially for those who speak tonal language, such as Mandarin. Based on the results of the acoustic research on Mandarin, a novel algorithm using fundamental frequency was proposed, adding the principle of frequency bands selection. Using this principle F0 was encoded only in the selected frequency bands, which...
Identifying gene function has many useful applications especially in Gene Therapy. Identifying gene function based on gene expression data is much easier in prokaryotes than eukaryotes due to the relatively simple structure of prokaryotes. That is why tissue-specific expression is the primary tool for identifying gene function in eukaryotes. However, recent studies have shown that there is a strong...
The main goal of the present study was to examine the cerebral regions associated with the lexical and idiomatic ambiguity resolution. In our experimentation by fMRI, we specially refer to two goals. The first goal was to show the difference between the activation areas related to several kinds of ambiguities. The second goal was to reveal the difference of the activation areas related to ambiguity...
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