Halvorson Kimberly M, Hazeltine Eliot
Department of Psychology, Metropolitan State University, 1450 Energy Park Drive, St. Paul, MN, 55108-5218, USA.
Department of Psychology, University of Iowa, Iowa City, IA, USA.
Psychon Bull Rev. 2015 Oct;22(5):1403-9. doi: 10.3758/s13423-015-0813-8.
Dual-task costs can be greatly reduced or even eliminated when both tasks use highly-compatible S-R associations. According to Greenwald (Journal of Experimental Psychology: Human Perception and Performance, 30, 632-636, 2003), this occurs because the appropriate response can be accessed without engaging performance-limiting response selection processes, a proposal consistent with the embodied cognition framework in that it suggests that stimuli can automatically activate motor codes (e.g., Pezzulo et al., New Ideas in Psychology, 31(3), 270-290, 2013). To test this account, we reversed the stimulus-response mappings for one or both tasks so that some participants had to "do the opposite" of what they perceived. In these reversed conditions, stimuli resembled the environmental outcome of the alternative (incorrect) response. Nonetheless, reversed tasks were performed without costs even when paired with an unreversed task. This finding suggests that the separation of the central codes across tasks (e.g., Wickens, 1984) is more critical than the specific S-R relationships; dual-task costs can be avoided when the tasks engage distinct modality-based systems.
当两项任务都使用高度兼容的刺激-反应关联时，双任务成本可以大幅降低甚至消除。根据格林沃尔德（《实验心理学杂志：人类感知与表现》，第30卷，第632 - 636页，2003年）的观点，出现这种情况是因为可以在不涉及限制表现的反应选择过程的情况下获取适当的反应，这一观点与具身认知框架一致，因为它表明刺激可以自动激活运动代码（例如，佩祖洛等人，《心理学新思想》，第31卷第3期，第270 - 290页，2013年）。为了验证这一观点，我们对一项或两项任务的刺激-反应映射进行了反转，以便一些参与者不得不做出与他们所感知的相反的动作。在这些反转条件下，刺激类似于替代（错误）反应的环境结果。尽管如此，即使与未反转的任务配对，反转任务的执行也没有成本。这一发现表明，任务间中枢代码的分离（例如，威肯斯，1984年）比特定的刺激-反应关系更为关键；当任务涉及不同的基于模态的系统时，可以避免双任务成本。
