Mindfulness Meditation Biases Visual Temporal Order Discrimination but Not Under Conditions of Temporal Ventriloquism

Abstract

This study examined how cognitive plasticity acquired from a long (8 weeks) course of mindfulness training can modulate the perceptual processing of temporal order judgment (TOJ) on a sub-second scale. Observers carried out a TOJ on two visual disks, with or without concurrent paired beeps. A temporal ventriloquism paradigm was used in which the sound beeps either were synchronized with the two disks or bracketed the visual stimuli by leading the first disk by 50 ms and lagging the other by 50 ms. A left-to-right bias in TOJ was found under the visual-only condition after mindfulness training. This bias was positively correlated with "acting with awareness," a factor in the Five Facet Mindfulness Questionnaire, showing that awareness of every moment and enhanced attention focus magnify the left-to-right bias. However, the effect of mindfulness training may be short-lived and was not present when attention was diverted by auditory events in the cross-modal temporal ventriloquism illusion.

Keywords: attention; audiovisual; mindfulness meditation; temporal order judgment; temporal ventriloquism.

FIGURE 1

Audiovisual configurations. (A) Visual-only stimuli (no beep). (B) Two disks with two synchronized beeps. (C) Two disks with a leading beep (50 ms ahead of the first disk) and a lagging beep (50 ms behind the second disk). There were seven levels of stimulus onset asynchrony (SOA): −150, −100, −50, 0, 50, 100, and 150 ms (minus sign indicates that the right disk appeared first). The disks randomly appeared on the left or right side, separated by the above SOAs.

FIGURE 2

Stimuli configuration and task procedure. A black fixation point was first displayed for 1 s in the center of the screen with a gray background. The fixation point then disappeared, and 500 ms later, the disks were successively shown and beeps presented according to the given settings of the current trial. The second disk was presented for 500 ms, and the two disks disappeared at the same time. The participants pressed the left or right key of the keyboard to report whether they thought the first disk was presented at the left or right side of the screen.

FIGURE 3

Averaged psychometric curves. (A) The psychometric curves for the pre- and post-training test in the mindfulness-trained group. (B) The psychometric curves for the “pre” and “post” results in the control group. For both graphs, the solid lines represent post-test results, and the dotted lines represent pre-test results. The black lines represent the purely visual (no beeps) condition, the green lines represent the synchronous beeps condition, and the red lines represent the 50 ms lag beep condition. Error bars represent standard error.

FIGURE 4

The interaction between test sessions and groups for points of subjective equality (PSEs). The error bars represent standard errors of the means.

FIGURE 5

Average PSEs and just-noticeable differences (JNDs). The error bars represent standard errors of the means. (A,C for training group; B,D for control group).