基于互信息的功能磁共振图像配准

互信息作为衡量两幅图像配准的相似性测度函数,当两幅图像配准时,互信息达到最大值。该文提出了基于互信息脑功能磁共振图像配准新方法,采用了无需计算梯度的Powell直接搜索算法,并通过多分辨的方式加快了图像配准速度。磁共振的配准实验证明,互信息法能准确地实现多模态医学图像的配准,并且能达到亚像素的精度。     

不同性质汉语隐喻句认知加工的fMRI研究

有关隐喻认知研究的一个核心问题是:隐喻加工机制与一般言语理解相比是否具有独特性以及隐喻理解伴随的神经生理机制是否有其独特的模式? 对此问题的回答需要对隐喻性质进行区分。常见的熟悉隐喻可进一步区分为词源性隐喻与引发性隐喻,其中词源性隐喻的隐喻义属于词语多个词义中的一个延伸义,而引发性隐喻则是将两个分属于不同概念领域的概念进行非字面的语义联结。词源性隐喻句和引发性隐喻句的理解包含了与一般语义句理解不同的加工内容。相比一般句,词源性隐喻句特异性地激活了与语义竞争相关的左侧颞中回、颞上回以及与加工深度有关的额下回,而引发性隐喻句则在左侧额下回有更多激活。隐喻的内在加工过程和神经机制并不单一,探讨隐喻理解与一般语义理解的异同需要考虑具体的隐喻性质。     

It’s about the process,not the result: An fMRI approach to explore the encoding of explicit and implicit price information

This research examines the neurophysiological correlates of consumers’ price memory processes. We focus on the explicit and implicit dimensions of consumers’ price knowledge and use an experimental functional Magnetic Resonance Imaging (fMRI) study to assess how the encoding of task-dependent price memory affects the choice process and neural activation. The findings of our study add to the field of consumer neuroscience by demonstrating how neural correlates of explicit and implicit task-dependent price memory can shed light on processes that guide consumer decision-making. Over the course of our experiment we found that consumers did not always make consistent decisions, but that their decisions were influenced by explicit components of price memory. Implicit price memory components seem to have a more supportive role in the decision-making process. In summary, we found that price memory is a dynamic construct that is influenced by unconscious and neurophysiological processes, and we conclude that a neurophysiological perspective can add value for consumer and marketing research.     

Does Elicitation Method Matter? Behavioral and Neuroimaging Evidence from Capacity Allocation Game

To date, it has not been elucidated whether the strategy method and the direct‐response method lead to different behaviors in experiments of economic games. In this study, we investigate this issue under a multi‐round setting of the capacity allocation game with both of the elicitation methods. In the first experiment (regular behavioral experiment), subjects are paired to make decisions in a laboratory through a computer network platform. In the second experiment (neuroimaging experiment), the functional magnetic resonance imaging (fMRI) technique is applied to observe similarities and differences in brain activities between the two elicitation methods. The results show that no significant difference is observed in the ordering behaviors between the two methods. Meanwhile, the neuroimaging data reveal that the strategy method induces comparable activations in similar brain regions, as does the direct‐response method. Additionally, it is more likely that subjects adjust their decisions during the feedback phase, rather than during the decision phase. Our results indicate that, in multi‐round game experiments without features such as emotion, the effect of the elicitation method is not likely to be exhibited.     

Ethical and Regulatory Challenges in Psychophysiology and Neuroscience-Based Technology for Determining Behavior

In the past three decades, there has been an explosion in research to understand the mechanisms of brain function. Recent advances in psychophysiology and neuroscience, while still limited, have sparked great interest in developing technologies that could peer into the brain and be used to identify or indicate certain behaviors. The polygraph (lie detector) represents an old technology used for discerning clues to the human brain; functional magnetic resonance imaging (fMRI) represents one of the newest efforts. The use of these technologies in intelligence and counterintelligence in the field without validation represents a major concern about its usefulness. Both research on this new technology and subsequent use on public raise ethical challenges. This article will address the overall ethical issues associated with these new technologies. The report identifies the ethical and cultural challenges in conducting research on these new tools, explores the possibility of using current U.S. regulatory requirements regarding drugs and devices as a model for regulating these new technologies, and suggests approaches for the future.     

Undercoverage of Wavelet-Based Resampling Confidence Intervals

The decorrelating property of the discrete wavelet transformation (DWT) appears valuable because one can avoid estimating the correlation structure in the original data space by bootstrap resampling of the DWT. Several authors have shown that the wavestrap approximately retains the correlation structure of observations. However, simply retaining the same correlation structure of original observations does not guarantee enough variation for regression parameter estimators. Our simulation studies show that these wavestraps yield undercoverage of parameters for a simple linear regression for time series data of the type that arise in functional MRI experiments. It is disappointing that the wavestrap does not even provide valid resamples for both white noise sequences and fractional Brownian noise sequences. Thus, the wavestrap method is not completely valid in obtaining resamples related to linear regression analysis and should be used with caution for hypothesis testing as well. The reasons for these undercoverages are also discussed. A parametric bootstrap resampling in the wavelet domain is introduced to offer insight into these previously undiscovered defects in wavestrapping.     

国内基于ERP和fMRI技术的语言研究综述

ERP技术和IMRI技术是目前最先进的研究大脑的思维、记忆、语言等高级认知活动的实验方法，被研究者称为“观察脑的高级功能的窗口”。本文通过CNKI中国期刊网和人工筛选，搜集到基于ERP和fMRI技术的语言研究论文54篇，通过比较、归纳，将这些论文从语言学的角度进行主题分类，以展示国内认知神经科学研究在语言领域的成果，提高语言学界对语言的认知神经研究的关注。     

fMRI、ERPs技术框架下的双语认知研究

fMRI、ERPs等是认知神经科学的最新技术,这些技术可帮助人们更直观地了解大脑加工语言的机制.目前,在fMRI、ERPs技术框架下的双语认知研究,在双语词汇研究、加工语言的脑机制研究等方面已取得不少成果,这些技术与成果对汉语作为第二语言研究具有积极的启示意义.对外汉语作为一个语言学、教育学、心理学等多学科的交叉学科,有必要突破现有的研究框架,引入亲属学科的研究范式和技术手段,拓宽研究领域.     

An investigation of a quadratic design criterion for estimation of the hemodynamic response function

Optimal experimental design for estimation of the hemodynamic response function (HRF) is investigated using a nonlinear model with a quadratic mean squared error design criterion. This criterion is used, along with a genetic algorithm, to select locally optimal designs that are shown to be, in most cases, more efficient than designs selected with the more commonly used linear expansion criterion. These designs are also shown to result in lower overall asymptotic estimator variance and bias. The investigation focuses on a single stimulus type, but the criterion can also be used with multiple stimulus types.