Investigating the influence of meditation style and practitioner experience on change blindness using a flicker-paradigm.

Change blindness engenders an inability to detect changes made to a visual scene and has negative implications for areas such as road safety and eye-witness memory. Therefore, it’s important to find ways of reducing change blindness to create a safer society. One way this might be achieved is through the practice of meditation. Regular practice of meditation may reduce the effects of change blindness by expanding a practitioner’s consciousness and brain potential over time. This study compared the influence of practitioner experience and medi- tation style- Transcendental Meditation (TM) or Mindfulness-based Meditation (MBM), on change blindness susceptibility. Forty-six participants (30 female and 16 male) with a com- bined mean age of 42 years old, were assigned to two experimental groups depending on the pre-existing meditation style they practiced. Both groups completed an identical experimen- tal task known as a flicker-paradigm where they had to identify changes made to various images. A two-way independent ANOVA revealed a significant effect of meditation style and experience on change-detection reaction times- (F(1,42) =7.22, p < 0.05, = .147), with long-term transcendental meditation practitioners recording faster reaction times (mean = 5927.73, SD = 606.92) on average than long-term mindfulness-based practitioners (mean = 10949.92 SD = 984.72). These results support the contention that long-term practice of transcendental meditation is more effective at reducing change blindness than long-term practice of mindfulness-based meditation.

Neurally-constrained modeling of human gaze strategies in a change blindness task

Despite possessing the capacity for selective attention, we often fail to notice the obvious. We investigated participants’ (n = 39) failures to detect salient changes in a change blindness experiment. Surprisingly, change detection success varied by over two-fold across participants. These variations could not be readily explained by differences in scan paths or fixated visual features. Yet, two simple gaze metrics–mean duration of fixations and the variance of saccade amplitudes–systematically predicted change detection success. We explored the mechanistic underpinnings of these results with a neurally-constrained model based on the Bayesian framework of sequential probability ratio testing, with a posterior odds-ratio rule for shifting gaze. The model’s gaze strategies and success rates closely mimicked human data. Moreover, the model outperformed a state-of-the-art deep neural network (DeepGaze II) with predicting human gaze patterns in this change blindness task. Our mechanistic model reveals putative rational observer search strategies for change detection during change blindness, with critical real-world implications.

Metacognitive judgements of change detection predict change blindness

People tend to think they are not susceptible to change blindness and overestimate their ability to detect salient changes in scenes. Here, we investigated whether participants’ metacognitive judgements of change detection ability predict change blindness. In Experiment 1, participants completed a change blindness task in which participants viewed alternating versions of a scene until they detected what changed between them and 6-7 months later, provided their metacognitive judgements. We found that changes rated as more likely to be spotted were detected faster than changes rated as more unlikely to be spotted. Metacognitive judgements continued to predict change blindness when accounting for low-level image properties (i.e., change size and eccentricity). In Experiment 2, metacognitive judgements from a new group of participants were compared to those collected in Experiment 1 to determine whether people are better predicting their own change blindness or if the predictions from others are equally effective. There was no effect of participant group on the relationship between metacognitive judgements and change blindness. Finally, in Experiment 3, we investigated whether metacognitive judgements are based on a high-level image property – semantic similarity. An independent group of participants provided descriptions of the two versions of the scenes and another group rated the similarity between the descriptions. We found that changes rated as more similar were judged as being more difficult to detect than changes rated as less similar; however, semantic similarity was not predictive of change blindness. These findings reveal that (1) people can accurately rate the relative difficulty of different changes and predict change blindness for different images and (2) metacognitive judgements of change detection likelihood are not fully explained by low-level and semantic image properties.

Binocular fusion enhances the efficiency of spot-the-difference gameplay

Spot-the-difference, the popular childhood game and a prototypical change blindness task, involves identification of differences in local features of two otherwise identical scenes using an eye scanning and matching strategy. Through binocular fusion of the companion scenes, the game becomes a visual search task, wherein players can simply scan the cyclopean percept for local features that may distinctly stand-out due to binocular rivalry/lustre. Here, we had a total of 100 visually normal adult (18–28 years of age) volunteers play this game in the traditional non-fusion mode and after cross-fusion of the companion images using a hand-held mirror stereoscope. The results demonstrate that the fusion mode significantly speeds up gameplay and reduces errors, relative to the non-fusion mode, for a range of target sizes, contrasts, and chromaticity tested (all, p<0.001). Amongst the three types of local feature differences available in these images (polarity difference, presence/absence of a local feature difference and shape difference in a local feature difference), features containing polarity difference was identified as first in ~60–70% of instances in both modes of gameplay (p<0.01), with this proportion being larger in the fusion than in the non-fusion mode. The binocular fusion advantage is lost when the lustre cue is purposefully weakened through alterations in target luminance polarity. The spot-the-difference game may thus be cheated using binocular fusion and the differences readily identified through a vivid experience of binocular rivalry/lustre.