Carmel David, Saker Pascal, Rees Geraint, Lavie Nilli
Institute of Cognitive Neuroscience, University College London, London, UK.
J Vis. 2007 Dec 17;7(14):14.1-13. doi: 10.1167/7.14.14.
Subjective visual experience depends not only on the spatial arrangement of the environment, but also on the temporal pattern of stimulation. For example, flickering and steady light presented in the same location evoke a very different perceptual experience due to their different temporal patterns. Here, we examined whether the availability of processing resources affected the temporal resolution of conscious flicker perception--the ability to distinguish rapid changes in light intensity, detecting visual temporal patterns. Participants detected flicker in a fixated LED that flickered at or around the individually adjusted critical flicker fusion (CFF) threshold while searching for a target letter presented in the periphery either on its own (low perceptual load) or among other letters (high load). Physically identical flickering stimuli were more likely to be perceived as "fused" under high (compared to low) load in the peripheral letter search. Furthermore, psychophysical measures showed a reduction in flicker detection sensitivity under high perceptual load. These results could not be due to criterion or stimulus prioritization differences or to differential likelihood of forgetting the correct response under different load conditions. These findings demonstrate that perceptual load influences conscious perception of temporal patterns.
主观视觉体验不仅取决于环境的空间布局，还取决于刺激的时间模式。例如，由于时间模式不同，同一位置呈现的闪烁光和稳定光会引发截然不同的感知体验。在此，我们研究了处理资源的可用性是否会影响有意识闪烁感知的时间分辨率——即区分光强度快速变化、检测视觉时间模式的能力。参与者在注视一个以个体调整后的临界闪烁融合（CFF）阈值或其附近频率闪烁的发光二极管（LED）时检测闪烁，同时在周边单独呈现（低感知负荷）或与其他字母一起呈现（高负荷）的情况下搜索目标字母。在周边字母搜索中，与低负荷相比，高负荷下物理上相同的闪烁刺激更有可能被感知为“融合”。此外，心理物理学测量表明，在高感知负荷下闪烁检测灵敏度降低。这些结果并非由于标准或刺激优先级差异，也不是由于在不同负荷条件下忘记正确反应的可能性不同。这些发现表明，感知负荷会影响对时间模式的有意识感知。
