Palmer John, Moore Cathleen M, White Alex L, Boynton Geoffrey M
Department of Psychology, University of Washington, Seattle, WA, 98195, USA.
Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA, 52242, USA.
Atten Percept Psychophys. 2025 May;87(4):1107-1131. doi: 10.3758/s13414-025-03066-x. Epub 2025 Apr 11.
Humans are not perfect at selectively responding to one stimulus while ignoring others visible at the same time. In spatial filtering tasks, this imperfect selectivity is often measured by how the judgment of the relevant stimulus depends on whether an irrelevant stimulus is associated with the same response. Such congruency effects decline with increasing spatial separation between stimuli and are minimal for widely separated stimuli. However, there is evidence that divided attention can increase congruency effects even for widely separated stimuli. We investigated this possibility for a pair of widely separated stimuli and a simple yes/no detection task. Performance was measured for a single task (only one of the stimuli was task-relevant) and for a dual task (both of the stimuli were task-relevant). In the single task there were small congruency effects, whereas in the dual task larger congruency effects occurred despite the widely separated stimuli. Results from a second experiment with sequential and simultaneous presentations were consistent with the congruency effect being due to later processes such as memory or decision rather than immediate processes such as perception. Additional results comparing high and low performance levels were consistent with congruency effects being due to a graded process such as attenuation or crosstalk rather than an all-or-none process such as blocking or substitution. These results rule out many possible theories of spatial selectivity. Our working hypothesis is that spatial selection can protect against interactive processing of multiple stimuli for a single task but not for dual tasks.
人类在选择性地对一种刺激做出反应而忽略同时可见的其他刺激方面并非完美无缺。在空间过滤任务中，这种不完美的选择性通常通过相关刺激的判断如何取决于无关刺激是否与相同反应相关联来衡量。这种一致性效应会随着刺激之间空间距离的增加而下降，对于相距甚远的刺激来说则最小。然而，有证据表明，即使对于相距甚远的刺激，分散注意力也会增加一致性效应。我们针对一对相距甚远的刺激和一个简单的是/否检测任务研究了这种可能性。测量了单一任务（只有一种刺激与任务相关）和双重任务（两种刺激都与任务相关）的表现。在单一任务中，一致性效应较小，而在双重任务中，尽管刺激相距甚远，但一致性效应更大。第二个关于顺序呈现和同时呈现的实验结果与一致性效应是由记忆或决策等后期过程而非感知等即时过程导致的观点一致。比较高绩效水平和低绩效水平的其他结果与一致性效应是由衰减或串扰等渐变过程而非阻断或替代等全或无过程导致的观点一致。这些结果排除了许多可能的空间选择性理论。我们的工作假设是，空间选择可以防止单一任务中多种刺激的交互处理，但不能防止双重任务中的这种处理。
