Abstract
Purpose :
In Feb 2015 an image of a dress was posted on Tumblr1 which triggered an internet phenomenon debating the issue: Is the dress blue and black (BB) or white and gold (WG)? Many claim the dress is BB while others insist WG. Experts reported that it depends on how one perceives the dress to be illuminated, with WG due to bluish light and BB due to yellowish light. Yet convincing evidence to explain the perceptual dichotomy is lacking. Our purpose was to determine if differences in pre-retinal absorption of blue light and neural processing impact perception of the colors of “the dress.”
Methods :
Macular pigment optical density (MPOD) was measured from right and left eyes (QuantifEye MPS II) and visual evoked potentials (VEPs) were recorded binocularly from 36 visually normal subjects divided into two groups: BB (n=19) or WG (n=17) based on initial perception of the dress and verbal response to iPhone, iPad and LCD dress images. The VEP stimulus was a high resolution color transparency of the dress retro-illuminated by a flashing white background from a VEP monitor (Diagnosys, LLC; gold cup electrode 1 cm above inion referenced to earlobes, 70 pattern onsets repeated twice). MPOD and VEP amplitude and latency were compared between BB and WG groups.
Results :
MPOD was significantly greater in the WG group (median = 0.46) vs. the BB group (median = 0.36, Mann-Whitney U, p=0.034). Onset VEPs to the appearance of the dress showed a negative wave followed by a positive peak with no difference between amplitudes between groups (p>0.7) but latency to the positive peak was significantly greater in the WG group (130 msec.) compared to the BB group (107 msec., p=0.008).
Conclusions :
Since the true colors of the dress are BB, the tendency to see WG with higher MPOD may reflect greater absorption of blue light. Moreover, and consistent with a recent fMRI study (1), the longer latency VEP in WG subjects suggests increased processing time to perceive the blue and black dress as WG. Our results identify the importance of both optical (pre-retinal absorption by macular pigment) and neural factors in perception of ambiguous stimuli, which hopefully will elucidate anomalous perceptions in brain injury, stroke and Alzheimer’s disease paving the way for efficacious treatment.
(1) Schlaffke et al., Cortex. 2015 Sep 30;73:271-275.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.