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Task-Irrelevant Expectation Violations in Sequential Manual Actions: Evidence for a “ Check-after-Surprise ” Mode of Visual Attention and Eye-Hand Decoupling

View Article: PubMed Central - PubMed

ABSTRACT

When performing sequential manual actions (e.g., cooking), visual information is prioritized according to the task determining where and when to attend, look, and act. In well-practiced sequential actions, long-term memory (LTM)-based expectations specify which action targets might be found where and when. We have previously demonstrated (Foerster and Schneider, 2015b) that violations of such expectations that are task-relevant (e.g., target location change) cause a regression from a memory-based mode of attentional selection to visual search. How might task-irrelevant expectation violations in such well-practiced sequential manual actions modify attentional selection? This question was investigated by a computerized version of the number-connection test. Participants clicked on nine spatially distributed numbered target circles in ascending order while eye movements were recorded as proxy for covert attention. Target’s visual features and locations stayed constant for 65 prechange-trials, allowing practicing the manual action sequence. Consecutively, a task-irrelevant expectation violation occurred and stayed for 20 change-trials. Specifically, action target number 4 appeared in a different font. In 15 reversion-trials, number 4 returned to the original font. During the first task-irrelevant change trial, manual clicking was slower and eye scanpaths were larger and contained more fixations. The additional fixations were mainly checking fixations on the changed target while acting on later targets. Whereas the eyes repeatedly revisited the task-irrelevant change, cursor-paths remained completely unaffected. Effects lasted for 2–3 change trials and did not reappear during reversion. In conclusion, an unexpected task-irrelevant change on a task-defining feature of a well-practiced manual sequence leads to eye-hand decoupling and a “check-after-surprise” mode of attentional selection.

No MeSH data available.


Performance and eye movement measures over the course of the five prechange blocks. Error bars represent standard error of the means. (A) Click completion time in seconds and number of fixations per trial. (B) Number of searching, guiding, and checking fixations per trial. (C) Cursor-path and scanpath length as well as eye-cursor distance in °v.a.
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Figure 2: Performance and eye movement measures over the course of the five prechange blocks. Error bars represent standard error of the means. (A) Click completion time in seconds and number of fixations per trial. (B) Number of searching, guiding, and checking fixations per trial. (C) Cursor-path and scanpath length as well as eye-cursor distance in °v.a.

Mentions: Did participants adopt an LTM-based mode of attentional selection within the prechange phase? Over the course of the first five prechange blocks, trial completion time, number of fixations, cursor-path and scanpath length, and eye-cursor distance decreased as is typical for sensorimotor learning [Figures 2A,B; time: F(4,76) = 48.38, p < 0.001; linear trend F(1,19) = 75.63, p < 0.001; fixations: F(4,76) = 41.99, 𝜀 = 0.56, p < 0.001; linear trend F(1,19) = 71.42, p < 0.001; cursor-path: F(4,76) = 23.28, 𝜀 = 0.53, p < 0.001; linear trend F(1,19) = 33.07, p < 0.001; scanpath: F(4,76) = 30.00, 𝜀 = 0.48, p < 0.001; linear trend F(1,19) = 48.60, p < 0.001; eye-cursor distance: F(4,76) = 6.60, 𝜀 = 0.53, p < 0.01; linear trend F(1,19) = 13.11, p < 0.01]. An ANOVA on the number of fixations with block and fixation type as within-subject variables revealed significant main effects of block and type as well as a significant interaction [block: F(4,76) = 29.15, 𝜀 = 0.54, p < 0.001; type: F(2,38) = 158.39, 𝜀 = 0.62, p < 0.001; block by type: F(8,152) = 4.92, 𝜀 = 0.27, p < 0.05]. All types of fixations decreased significantly in the course of the prechange phase [Figure 2C; searching fixations: F(4,76) = 4.10, 𝜀 = 0.64, p < 0.05, linear trend F(1,19) = 7.31, p < 0.05; guiding fixations: F(4,76) = 3.75, 𝜀 = 0.46, p < 0.05, linear trend F(1,19) = 4.90, p < 0.05; checking fixations: F(4,76) = 33.40, 𝜀 = 0.41, p < 0.001, linear trend F(1,19) = 45.14, p < 0.001]. On average, significantly more guiding fixations were performed than searching and checking fixations, and more checking than searching fixations (all ps < 0.001). During the fifth prechange block, participants performed on average 8.95 guiding, 0.87 checking, and 0.27 searching fixations per trial. Guiding the hand (here cursor) sequentially with approximately one fixation to each target on an effective path is a typical characteristic of LTM-based attentional selection for sensorimotor control (Foerster et al., 2011, 2012; Foerster and Schneider, 2015a,b). None of the dependent variables was significantly different across blocks 4 and 5. Thus, a first plateau of gaze and manual action performance seemed to be reached after the 4th block.


Task-Irrelevant Expectation Violations in Sequential Manual Actions: Evidence for a “ Check-after-Surprise ” Mode of Visual Attention and Eye-Hand Decoupling
Performance and eye movement measures over the course of the five prechange blocks. Error bars represent standard error of the means. (A) Click completion time in seconds and number of fixations per trial. (B) Number of searching, guiding, and checking fixations per trial. (C) Cursor-path and scanpath length as well as eye-cursor distance in °v.a.
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Figure 2: Performance and eye movement measures over the course of the five prechange blocks. Error bars represent standard error of the means. (A) Click completion time in seconds and number of fixations per trial. (B) Number of searching, guiding, and checking fixations per trial. (C) Cursor-path and scanpath length as well as eye-cursor distance in °v.a.
Mentions: Did participants adopt an LTM-based mode of attentional selection within the prechange phase? Over the course of the first five prechange blocks, trial completion time, number of fixations, cursor-path and scanpath length, and eye-cursor distance decreased as is typical for sensorimotor learning [Figures 2A,B; time: F(4,76) = 48.38, p < 0.001; linear trend F(1,19) = 75.63, p < 0.001; fixations: F(4,76) = 41.99, 𝜀 = 0.56, p < 0.001; linear trend F(1,19) = 71.42, p < 0.001; cursor-path: F(4,76) = 23.28, 𝜀 = 0.53, p < 0.001; linear trend F(1,19) = 33.07, p < 0.001; scanpath: F(4,76) = 30.00, 𝜀 = 0.48, p < 0.001; linear trend F(1,19) = 48.60, p < 0.001; eye-cursor distance: F(4,76) = 6.60, 𝜀 = 0.53, p < 0.01; linear trend F(1,19) = 13.11, p < 0.01]. An ANOVA on the number of fixations with block and fixation type as within-subject variables revealed significant main effects of block and type as well as a significant interaction [block: F(4,76) = 29.15, 𝜀 = 0.54, p < 0.001; type: F(2,38) = 158.39, 𝜀 = 0.62, p < 0.001; block by type: F(8,152) = 4.92, 𝜀 = 0.27, p < 0.05]. All types of fixations decreased significantly in the course of the prechange phase [Figure 2C; searching fixations: F(4,76) = 4.10, 𝜀 = 0.64, p < 0.05, linear trend F(1,19) = 7.31, p < 0.05; guiding fixations: F(4,76) = 3.75, 𝜀 = 0.46, p < 0.05, linear trend F(1,19) = 4.90, p < 0.05; checking fixations: F(4,76) = 33.40, 𝜀 = 0.41, p < 0.001, linear trend F(1,19) = 45.14, p < 0.001]. On average, significantly more guiding fixations were performed than searching and checking fixations, and more checking than searching fixations (all ps < 0.001). During the fifth prechange block, participants performed on average 8.95 guiding, 0.87 checking, and 0.27 searching fixations per trial. Guiding the hand (here cursor) sequentially with approximately one fixation to each target on an effective path is a typical characteristic of LTM-based attentional selection for sensorimotor control (Foerster et al., 2011, 2012; Foerster and Schneider, 2015a,b). None of the dependent variables was significantly different across blocks 4 and 5. Thus, a first plateau of gaze and manual action performance seemed to be reached after the 4th block.

View Article: PubMed Central - PubMed

ABSTRACT

When performing sequential manual actions (e.g., cooking), visual information is prioritized according to the task determining where and when to attend, look, and act. In well-practiced sequential actions, long-term memory (LTM)-based expectations specify which action targets might be found where and when. We have previously demonstrated (Foerster and Schneider, 2015b) that violations of such expectations that are task-relevant (e.g., target location change) cause a regression from a memory-based mode of attentional selection to visual search. How might task-irrelevant expectation violations in such well-practiced sequential manual actions modify attentional selection? This question was investigated by a computerized version of the number-connection test. Participants clicked on nine spatially distributed numbered target circles in ascending order while eye movements were recorded as proxy for covert attention. Target&rsquo;s visual features and locations stayed constant for 65 prechange-trials, allowing practicing the manual action sequence. Consecutively, a task-irrelevant expectation violation occurred and stayed for 20 change-trials. Specifically, action target number 4 appeared in a different font. In 15 reversion-trials, number 4 returned to the original font. During the first task-irrelevant change trial, manual clicking was slower and eye scanpaths were larger and contained more fixations. The additional fixations were mainly checking fixations on the changed target while acting on later targets. Whereas the eyes repeatedly revisited the task-irrelevant change, cursor-paths remained completely unaffected. Effects lasted for 2&ndash;3 change trials and did not reappear during reversion. In conclusion, an unexpected task-irrelevant change on a task-defining feature of a well-practiced manual sequence leads to eye-hand decoupling and a &ldquo;check-after-surprise&rdquo; mode of attentional selection.

No MeSH data available.