Astolfi Laura, De Vico Fallani F, Cincotti F, Mattia D, Bianchi L, Marciani M G, Salinari S, Colosimo A, Tocci A, Soranzo R, Babiloni F
Department of Physiology and Pharmacology, University of Rome La Sapienza, 00185 Rome, Italy.
IEEE Trans Neural Syst Rehabil Eng. 2008 Dec;16(6):522-31. doi: 10.1109/TNSRE.2008.2009784.
We investigated brain activity during the observation of TV commercials by tracking the cortical activity and the functional connectivity changes in normal subjects. The aim was to elucidate if the TV commercials that were remembered by the subjects several days after their first observation elicited particular brain activity and connectivity compared with those generated during the observation of TV commercials that were quickly forgotten. High-resolution electroencephalogram (EEG) recordings were performed in a group of healthy subjects and the cortical activity during the observation of TV commercials was evaluated in several regions of interest coincident with the Brodmann areas (BAs). The patterns of cortical connectivity were obtained in the four principal frequency bands, Theta (3-7 Hz), Alpha (8-12 Hz), Beta (13-30 Hz), Gamma (30-40 Hz) and the directed influences between any given pair of the estimated cortical signals were evaluated by use of a multivariate spectral technique known as partial directed coherence. The topology of the cortical networks has been identified with tools derived from graph theory. Results suggest that the cortical activity and connectivity elicited by the viewing of the TV commercials that were remembered by the experimental subjects are markedly different from the brain activity elicited during the observation of the TV commercials that were forgotten. In particular, during the observation of the TV commercials that were remembered, the amount of cortical spectral activity from the frontal areas (BA 8 and 9) and from the parietal areas (BA 5, 7, and 40) is higher compared with the activity elicited by the observation of TV commercials that were forgotten. In addition, network analysis suggests a clear role of the parietal areas as a target of the incoming flow of information from all the other parts of the cortex during the observation of TV commercials that have been remembered. The techniques presented here shed new light on all the cortical networks and their behavior during the memorization of TV commercials. Such techniques could also be relevant in neuroeconomics and neuromarketing for the investigation of the neural substrates subserving other decision-making and recognition tasks.
我们通过追踪正常受试者的皮层活动和功能连接变化，研究了观看电视广告期间的大脑活动。目的是阐明与那些很快被遗忘的电视广告观看期间所产生的大脑活动和连接相比，受试者在首次观看几天后仍能记住的电视广告是否会引发特定的大脑活动和连接。对一组健康受试者进行了高分辨率脑电图（EEG）记录，并在与布罗德曼区域（BAs）重合的几个感兴趣区域评估了观看电视广告期间的皮层活动。在四个主要频段，即θ波（3 - 7赫兹）、α波（8 - 12赫兹）、β波（13 - 30赫兹）、γ波（30 - 40赫兹）中获得了皮层连接模式，并使用一种称为偏定向相干的多元谱技术评估了任何给定的一对估计皮层信号之间的定向影响。皮层网络的拓扑结构已通过源自图论的工具得以识别。结果表明，实验受试者记住的电视广告观看所引发的皮层活动和连接与遗忘的电视广告观看期间所引发的大脑活动明显不同。特别是，在观看被记住的电视广告期间，额叶区域（BA 8和9）和顶叶区域（BA 5、7和40）的皮层频谱活动量比观看被遗忘的电视广告所引发的活动更高。此外，网络分析表明，在观看被记住的电视广告期间，顶叶区域作为来自皮层所有其他部分的传入信息流的目标具有明确作用。这里介绍的技术为电视广告记忆期间的所有皮层网络及其行为提供了新的见解。此类技术在神经经济学和神经营销学中对于研究支持其他决策和识别任务的神经基质也可能具有相关性。
