Langleben Daniel D, Loughead James W, Ruparel Kosha, Hakun Jonathan G, Busch-Winokur Samantha, Holloway Matthew B, Strasser Andrew A, Cappella Joseph N, Lerman Caryn
Department of Psychiatry, University of Pennsylvania School of Medicine, 3900 Chestnut Street, Philadelphia, PA 19104, USA.
Neuroimage. 2009 May 15;46(1):219-25. doi: 10.1016/j.neuroimage.2008.12.062. Epub 2009 Jan 14.
Public service announcements (PSAs) are non-commercial broadcast ads that are an important part of televised public health campaigns. "Message sensation value" (MSV), a measure of sensory intensity of audio, visual, and content features of an ad, is an important factor in PSA impact. Some communication theories propose that higher message sensation value brings increased attention and cognitive processing, leading to higher ad impact. Others argue that the attention-intensive format could compete with ad's message for cognitive resources and result in reduced processing of PSA content and reduced overall effectiveness. Brain imaging during PSA viewing provides a quantitative surrogate measure of PSA impact and addresses questions of PSA evaluation and design not accessible with traditional subjective and epidemiological methods. We used Blood Oxygenation Level Dependent (BOLD) functional Magnetic Resonance Imaging (fMRI) and recognition memory measures to compare high and low MSV anti-tobacco PSAs and neutral videos. In a short-delay, forced-choice memory test, frames extracted from PSAs were recognized more accurately than frames extracted from the NV. Frames from the low MSV PSAs were better recognized than frames from the high MSV PSAs. The accuracy of recognition of PSA frames was positively correlated with the prefrontal and temporal, and negatively correlated with the occipital cortex activation. The low MSV PSAs were associated with greater prefrontal and temporal activation, than the high MSV PSAs. The high MSV PSAs produced greater activation primarily in the occipital cortex. These findings support the "dual processing" and "limited capacity" theories of communication that postulate a competition between ad's content and format for the viewers' cognitive resources and suggest that the "attention-grabbing" high MSV format could impede the learning and retention of an ad. These findings demonstrate the potential of using neuroimaging in the design and evaluation of mass media public health communications.
公益广告（PSAs）是非商业性广播广告，是电视公共卫生运动的重要组成部分。“信息感知价值”（MSV）是衡量广告音频、视觉和内容特征的感官强度的指标，是公益广告影响力的一个重要因素。一些传播理论认为，较高的信息感知价值会带来更多的关注和认知加工，从而提高广告影响力。另一些人则认为，注意力密集型的形式可能会与广告信息争夺认知资源，导致公益广告内容的加工减少，整体效果降低。观看公益广告时的脑成像提供了公益广告影响力的定量替代指标，并解决了传统主观和流行病学方法无法解决的公益广告评估和设计问题。我们使用血氧水平依赖（BOLD）功能磁共振成像（fMRI）和识别记忆测量方法，比较了高MSV和低MSV的反烟草公益广告以及中性视频。在短延迟强制选择记忆测试中，从公益广告中提取的帧比从中性视频中提取的帧识别得更准确。低MSV公益广告的帧比高MSV公益广告的帧识别得更好。公益广告帧的识别准确率与前额叶和颞叶呈正相关，与枕叶皮质激活呈负相关。与高MSV公益广告相比，低MSV公益广告与更大的前额叶和颞叶激活相关。高MSV公益广告主要在枕叶皮质产生更大的激活。这些发现支持了传播的“双重加工”和“有限容量”理论，该理论假定广告内容和形式在争夺观众的认知资源，并表明“引人注目的”高MSV形式可能会阻碍广告的学习和记忆。这些发现证明了在大众媒体公共卫生传播的设计和评估中使用神经成像的潜力。
