Ross Nicholas M, Kowler Eileen
Department of Psychology, Rutgers University, Piscataway, NJ, USA.
J Vis. 2013 Mar 1;13(4):1. doi: 10.1167/13.4.1.
Videos are often accompanied by narration delivered either by an audio stream or by captions, yet little is known about saccadic patterns while viewing narrated video displays. Eye movements were recorded while viewing video clips with (a) audio narration, (b) captions, (c) no narration, or (d) concurrent captions and audio. A surprisingly large proportion of time (>40%) was spent reading captions even in the presence of a redundant audio stream. Redundant audio did not affect the saccadic reading patterns but did lead to skipping of some portions of the captions and to delays of saccades made into the caption region. In the absence of captions, fixations were drawn to regions with a high density of information, such as the central region of the display, and to regions with high levels of temporal change (actions and events), regardless of the presence of narration. The strong attraction to captions, with or without redundant audio, raises the question of what determines how time is apportioned between captions and video regions so as to minimize information loss. The strategies of apportioning time may be based on several factors, including the inherent attraction of the line of sight to any available text, the moment by moment impressions of the relative importance of the information in the caption and the video, and the drive to integrate visual text accompanied by audio into a single narrative stream.
视频通常配有由音频流或字幕提供的旁白,但对于观看有旁白的视频显示时的扫视模式却知之甚少。在观看视频片段时记录了眼动情况,这些视频片段分别有:(a) 音频旁白、(b) 字幕、(c) 无旁白或 (d) 同时有字幕和音频。即使存在冗余的音频流,仍有相当大比例的时间(>40%)用于阅读字幕。冗余音频并未影响扫视阅读模式,但确实导致跳过了部分字幕内容,并使进入字幕区域的扫视出现延迟。在没有字幕的情况下,注视点会被吸引到信息密度高的区域,如显示屏的中央区域,以及时间变化程度高的区域(动作和事件),无论是否有旁白。无论有无冗余音频,对字幕的强烈吸引力都引发了一个问题:是什么决定了如何在字幕和视频区域之间分配时间,以尽量减少信息损失。分配时间的策略可能基于几个因素,包括视线对任何可用文本的固有吸引力、对字幕和视频中信息相对重要性的即时印象,以及将伴有音频的视觉文本整合到单一叙事流中的驱动力。