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Attentional shifts by gaze direction in voluntary orienting: evidence from a microsaccade study.

Yokoyama T, Noguchi Y, Kita S - Exp Brain Res (2012)

Bottom Line: We found that microsaccade direction followed cue direction between 200 and 400 ms after gaze cues were presented.The results in Experiment 2 were consistent with those from Experiment 1.Taken together, these results indicate that the shift in spatial attention elicited by gaze direction is voluntary orienting.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan. yokoyama@lit.kobe-u.ac.jp

ABSTRACT
Shifts in spatial attention can be induced by the gaze direction of another. However, it is unclear whether gaze direction influences the allocation of attention by reflexive or voluntary orienting. The present study was designed to examine which type of attentional orienting is elicited by gaze direction. We conducted two experiments to answer this question. In Experiment 1, we used a modified Posner paradigm with gaze cues and measured microsaccades to index the allocation of attention. We found that microsaccade direction followed cue direction between 200 and 400 ms after gaze cues were presented. This is consistent with the latencies observed in other microsaccade studies in which voluntary orienting is manipulated, suggesting that gaze direction elicits voluntary orienting. However, Experiment 1 did not separate voluntary and reflexive orienting directionally, so in Experiment 2, we used an anticue task in which cue direction (direction to allocate attention) was the opposite of gaze direction (direction of gaze in depicted face). The results in Experiment 2 were consistent with those from Experiment 1. Microsaccade direction followed the cue direction, not gaze direction. Taken together, these results indicate that the shift in spatial attention elicited by gaze direction is voluntary orienting.

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Peak velocities of microsaccades as a function of their amplitude. This plot has 5,970 microsaccades from 10 participants in Experiment 1
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Fig2: Peak velocities of microsaccades as a function of their amplitude. This plot has 5,970 microsaccades from 10 participants in Experiment 1

Mentions: We used a modified version of the algorithm reported in Engbert and Kliegl (2003) to detect binocular microsaccades, adapted to the 500-Hz sampling rate used here. First, we transformed eye position data to velocities using a moving average of five data samples (10 ms) for each eye. Second, we computed the median-based standard deviation estimator as the velocity threshold and multiplied it by the relative velocity threshold (6.0). If the average velocity exceeded the velocity threshold in at least three consequent samples, we defined it as monocular microsaccades. Third, we defined binocular microsaccades when microsaccades occurred in both right and left eyes with a temporal overlap. Thus, binocular microsaccades were defined as microsaccades in this study. The microsaccades we extracted from the algorithm showed a strong correlation between peak velocity and amplitude (r = 0.947, p < 0.001), and thus use of this algorithm to extract microsaccades is reliable and valid in this study (Fig. 2). Microsaccades with amplitudes exceeding 1° were excluded from further analysis.Fig. 2


Attentional shifts by gaze direction in voluntary orienting: evidence from a microsaccade study.

Yokoyama T, Noguchi Y, Kita S - Exp Brain Res (2012)

Peak velocities of microsaccades as a function of their amplitude. This plot has 5,970 microsaccades from 10 participants in Experiment 1
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3475970&req=5

Fig2: Peak velocities of microsaccades as a function of their amplitude. This plot has 5,970 microsaccades from 10 participants in Experiment 1
Mentions: We used a modified version of the algorithm reported in Engbert and Kliegl (2003) to detect binocular microsaccades, adapted to the 500-Hz sampling rate used here. First, we transformed eye position data to velocities using a moving average of five data samples (10 ms) for each eye. Second, we computed the median-based standard deviation estimator as the velocity threshold and multiplied it by the relative velocity threshold (6.0). If the average velocity exceeded the velocity threshold in at least three consequent samples, we defined it as monocular microsaccades. Third, we defined binocular microsaccades when microsaccades occurred in both right and left eyes with a temporal overlap. Thus, binocular microsaccades were defined as microsaccades in this study. The microsaccades we extracted from the algorithm showed a strong correlation between peak velocity and amplitude (r = 0.947, p < 0.001), and thus use of this algorithm to extract microsaccades is reliable and valid in this study (Fig. 2). Microsaccades with amplitudes exceeding 1° were excluded from further analysis.Fig. 2

Bottom Line: We found that microsaccade direction followed cue direction between 200 and 400 ms after gaze cues were presented.The results in Experiment 2 were consistent with those from Experiment 1.Taken together, these results indicate that the shift in spatial attention elicited by gaze direction is voluntary orienting.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan. yokoyama@lit.kobe-u.ac.jp

ABSTRACT
Shifts in spatial attention can be induced by the gaze direction of another. However, it is unclear whether gaze direction influences the allocation of attention by reflexive or voluntary orienting. The present study was designed to examine which type of attentional orienting is elicited by gaze direction. We conducted two experiments to answer this question. In Experiment 1, we used a modified Posner paradigm with gaze cues and measured microsaccades to index the allocation of attention. We found that microsaccade direction followed cue direction between 200 and 400 ms after gaze cues were presented. This is consistent with the latencies observed in other microsaccade studies in which voluntary orienting is manipulated, suggesting that gaze direction elicits voluntary orienting. However, Experiment 1 did not separate voluntary and reflexive orienting directionally, so in Experiment 2, we used an anticue task in which cue direction (direction to allocate attention) was the opposite of gaze direction (direction of gaze in depicted face). The results in Experiment 2 were consistent with those from Experiment 1. Microsaccade direction followed the cue direction, not gaze direction. Taken together, these results indicate that the shift in spatial attention elicited by gaze direction is voluntary orienting.

Show MeSH
Related in: MedlinePlus