DATA FOR PAPER: Repetition violating events do not enhance sensitivity to embedded content, but repeated events can reduce sensitivity - Superseded

Oddball paradigms involve the presentation of sequences of repeated events that are broken by a novel ‘oddball’. These have been used to examine the neural and perceptual consequences of predictive processes in the brain. Two intriguing perceptual findings are that people are more sensitive to visual content embedded in oddballs, and that people perceive oddballs as longer lasting – relative to repeated events. Recent investigations have looked at the possibility that fluctuations in attention during presentation sequences might impact perception though. Because the number of repeated ‘standards’ (that do not require a behavioural judgement) seen before a ‘test’ (which can require a behavioural judgement) is often circumscribed, as more standards are encountered, the probability of a further standard decreases, whereas the probability of a test increases. So, later tests can be anticipated, whereas early tests are improbable. It has been shown that when all tests can be anticipated, and all tests are equally likely to be a further repeated standard or an oddball, oddballs still seem longer lasting than repeats. Here we show that the same conditions undermine the visual acuity advantage for oddball content. Our experiment clarifies that this increase in acuity for oddballs results from a degradation of acuity to repeat tests that cannot be anticipated. We found that peoples pupils tended to dilate as they expected a test, consistent with top-down attention scaling with test probability. In a 2nd experiment, we replicated the time perception difference and the lack of visual acuity difference under the same experimental conditions.This data record is superseded by an updated record with more complete data and metadata.异常刺激范式（Oddball Paradigm）指呈现一系列重复事件，随后以新颖的“异常刺激（oddball）”打破该序列。此类范式曾被用于探究大脑预测加工过程的神经与知觉效应。 两项颇具研究价值的知觉发现为：人们对嵌入异常刺激中的视觉内容更为敏感，且相较于重复事件，人们会感知到异常刺激的持续时长更长。 不过近期研究指出，刺激呈现序列中注意力的波动可能会对知觉产生影响。由于在“测试试次（test）”前呈现的、无需做出行为判断的重复“标准刺激（standard）”数量通常受限，随着更多标准刺激被呈现，后续出现标准刺激的概率会逐渐降低，而测试试次出现的概率则逐步上升。因此，较晚出现的测试试次可被预期，而早期测试试次则概率极低。 已有研究表明，即便所有测试试次均可被预期，且测试试次为重复标准刺激或异常刺激的概率完全均等，异常刺激仍会被感知为比重复刺激持续更久。 本研究证实，相同实验条件同样会削弱异常刺激的视觉敏锐度优势。本实验进一步阐明，异常刺激相关的敏锐度提升，源于对无法被预期的重复测试试次的敏锐度下降。研究发现，当被试预期到测试试次出现时，其瞳孔会出现扩张，这与自上而下注意随测试试次概率进行调节的结论相一致。 在第二项实验中，我们在相同实验条件下重复验证了时间知觉差异，以及视觉敏锐度差异消失的现象。 本数据集已由包含更完整数据与元数据的更新版数据集替代。