Adrien Chopin, Ph.D
Research Scientist in Cognitive Sciences
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Two new stereotests valid for measuring binocular 3D-vision

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We have created two new tests designed to measure a person's ability to perceive binocular depth: eRDS and the Vivid Vision Stereo Test. eRDS is reliable and precise but shows initial learning effects, so we recommend discarding the first measures. The Vivid Vision Stereo Test has poorer precision but is easy and fast to complete, and does not show learning effects. Additionally, eRDS cannot be cheated and both tests have negligibly low probabilities of being passed by chance. These tests can be used to evaluate if treatments improve a person's ability to see 3D depth.

Article: Denkinger, S., Antoniou, M.P., Tarello, D., Levi, D.M., Backus, B.T., Bavelier, D., & Chopin, A. (2023) The eRDS v6 Stereotest and the Vivid Vision Stereo Test: Two New Tests of Stereoscopic Vision. Translation Vision Science & Technology, 12(3):1. [Link] [PDF]


Screens can be good for the very young child's cognition

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We have carefully reviewed the scientific literature of the last two decades and we argue that the effects of screen viewing depend mostly on contextual aspects of the viewing. Children below 3 years old can in fact benefit from screen viewing if the adult caregiver interacts during viewing and if the watched content has specific characteristics (slow pace, breaks for the child to answer...). In other words, it is the quality of the viewing, not its quantity that determines the effects.

Article: Guellai, B., Somogyi, E., Esseily, R., & Chopin, A. (2022). Effects of screen exposure on young children’s cognitive development: A review. Frontiers in Psychology, 13. [Link] [PDF]


Birds can learn as well from robots as from live tutors

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We exposed young zebra finch birds to robots or live bird tutors and measured how well they could learn their songs from them. We did not find overall differences in learning and if anything, robots allowed the birds to reach their learning peaks quicker. Bird behaviors were not predictive of the results.

Article: Araguas, A., Guellaï, B., Gauthier, P., Richer, F., Montone, G., Chopin, A., & Derégnaucourt, S. (2022). Design of a robotic zebra finch for experimental studies on developmental song learning. Journal of Experimental Biology, 225(3), jeb242949. [Link] [PDF]


Action video games increase learning speed

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After we trained 77 young adults on action video games, they exhibited faster learning in perception and working memory. We used stratified randomization, pre-registration, demonstrated the causal aspect and controlled for several confounds, like expectations. 
  • Article: Zhang, R.-Y., Chopin, A., Shibata, K., Lu, Z.-L., Jaeggi, S. M., Buschkuehl, M., … Bavelier, D. (2021). Action video game play facilitates “learning to learn.” Communications Biology, 4(1), 1154.  [Link and PDF] [RTS interview]

Amblyopia: A treatment for global stereoblindness using local stereo-training

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We demonstrated on 5 adults with amblyopia who were completely blind to global stereopsis, that it is possible to recover fine global stereovision after training local stereopsis only. This transfer of learning from local to global stereopsis is compatible with an interacting two-stage model for stereopsis.
  • Article: Chopin, A., Silver, M.A., Sheynin, Y., Ding, J. & Levi, D.M. (2021) Transfer of perceptual learning from local stereopsis to global stereopsis in adults with amblyopia: a preliminary study. Frontiers in Neurosciences 15:1244.  [Link and PDF]

Newborns know when you look at them

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We familiarized two groups of newborns with videos of different talking faces that were presented with either a direct or a faraway gaze. Newborns looked longer at the familiar face, but only in the direct gaze condition. These results suggest that just-born infants can perceive slight differences of gazes when someone is addressing to them.
  • Article: Guellaï, B., Hausberger, M., Chopin, A. et al. Premises of social cognition: Newborns are sensitive to a direct versus a faraway gaze. Sci. Rep. 10, 9796 (2020). [Link] / [PDF]

Action video gaming changes your visual perception

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After reviewing this topic, we conclude that gaming improves mostly the perception of motion and contrast, and visual processing in periphery. We established a dose-response relationship for intervention studies that demonstrates a causal role of action video games.

  • Article: Chopin, A., Bediou, B. & Bavelier, D. Altering perception: the case of action video gaming. Curr. Opin. Psychol. 29, 168–173 (2019). https://doi.org/10.1016/j.copsyc.2019.03.004 [Link] / [PDF]

Another way by which people deceive clinical stereotests of 3D-vision

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We have found that several well-known clinical stereotests used to determine stereo-anomaly can be deceived using what we call "binocular non-stereoscopic cues". These are a new family of cues that only happen with the two eyes. Participants with amblyopia had more difficulty using non-stereoscopic cues than typical observers.
  • Article: Chopin, A., Chan, S. W., Guellai, B., Bavelier, D. & Levi, D. M. Binocular non-stereoscopic cues can deceive clinical tests of stereopsis. Sci. Rep. 9, 5789 (2019). http://doi.org/10.1038/s41598-019-42149-2 [Link] / [PDF]

The prevalence and diagnosis of stereoblindness is 7%

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We determined that 7% of the population below the age of 60 is totally stereoblind, meaning that they see no depth from the difference of viewpoints between eyes. We also show that this value strongly depends on the way it is measured and explain why. We demonstrate that the expected relationship to exposure duration does not exist. We propose the concept of ecological stereoblindness, that does not depend on the way it is measured. We also show what is the best way to measure stereoblindness and what to expect when using clinical stereotests that can clearly be deceived. Finally, we show how to improve clinical stereotests.
  • Article: Chopin, A., Bavelier, D., & Levi, D. M. (2019). The prevalence and diagnosis of ‘stereoblindness’ in adults less than 60 years of age: a best evidence synthesis. Ophthalmic and Physiological Optics, 39(2), 66–85. http://doi.org/10.1111/opo.12607 [Link] / [PDF]

an fMRI-analysis pipeline for pRF retinotopy

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This full pipeline helps with the transformation of anatomical, inplane and EPI data into population receptive-fields retinopy. It uses mrVista, freesurfer, and FSL. It includes nifti conversion, motion and slice timing correction, artefact removal, segmentation, alignment, pRF calculations and visualization of pRF model results on a mesh projection.
  • Code: Chopin A., Theiss, J., Popham S., Byrne K., Silver, M. (2016-2017) [On my Github profile]

Are screens good or bad for the young child?

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The quick answer from our review is that passive screens are very bad for the cognitive development, particularly before 3 years and even when in the background. The situation is alarming given the statistics for babies' screen time. However there are two exceptions: when adults supervise the screen time actively and when 5-6 years-old children watch a very specific educative TV show: Sesame Street.

  • Article (in French): Esseily, R., Guellai, B., Chopin, A., Somogyi, E. (2017) L’écran est-il bon ou mauvais pour le jeune enfant? Spirale, 3(83): 28-40. [Link] / [PDF]

Dressmakers have needle-sharp 3D vision

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They are 80% more accurate than non-dressmakers at calculating the distances between themselves and objects, and 43% better at estimating distances between objects. We are still determining whether dressmaking sharpens stereoscopic vision, or whether dressmakers are drawn to the trade because of their visual stereo-acuity
  • Article: Chopin, A., Levi, D.M., Bavelier, D. (2017) Dressmakers show enhanced stereoscopic vision. Scientific Reports. 7:3435 [Abstract] / [PDF] / [Altmetrics]

Newborns prefer speech that is synchronized with lips

With Bahia Guellai, we showed that newborns can make the difference between lip-synchronized and lip-unsynchronized speech. It suggests that they can use that information for lip-reading and learning to talk. It is very surprising when you think they are just born a few hours ago.
  • Article: Guellaï, B., Streri, A., Chopin, A., Rider, D., Kitamura, C. (2016) Newborns’ sensitivity to the visual aspects of infant-directed speech: Evidence from point-line displays of talking faces. Journal of Experimental Psychology: Human Perception and Performance, 42(9), 1275-1281. [Abstract] / [PDF]

Blindness to depth from absolute disparities and the mechanism of depth from relative disparities

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We discovered that observers are almost blind to absolute disparities and that it cannot be explained by memory-related or vergence-related explanations. Our results are only compatible with the idea that absolute disparities (depth between an object and fixation point) are transformed into relative disparities (depth between objects).
  • Article: Chopin, A., Knill, D.C, Levi, D.M., Bavelier, D. (2016) The absolute disparity anomaly and the mechanism of relative disparities. Journal of Vision, 16:8, 2  [Abstract] / [PDF]
  • Conference proceeding: Chopin, A., Knill, D.C, Levi, D.M., Bavelier, D. (2014). Stereoscopic depth from absolute and relative disparities [Abstract] Journal of Vision, 14:10, 969 [PDF]

Stereopsis and rivalry are under influence of orientation illusions

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We found that the illusory tilt produced from Zöllner illusion influences the orientation disparities defining stereoscopic slant or rivalry. Thus, rivalry and stereopsis rely on the illusory rather than the displayed orientations.
  • Article: Chopin, A., Mamassian, P., & Blake, R. (2012). Stereopsis and rivalry are based on perceived rather than physical orientations. Vision Research, 63: 63-68.  [Abstract] / [PDF]
  • Conference proceeding: Chopin, A., Mamassian, P., & Blake, R.,  (2011). Transition between stereopsis and binocular rivalry is based on perceived, rather than physical, orientation [Abstract]. Journal of Vision,11(11): 301. doi: 10.1167/11.11.301 [Abstract] /  [PDF]

Perceptual adaptation could be a mechanism of prediction

 

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We uncovered that the current percept is strongly influenced by a group of stimuli remotely presented in the past. We explain it with a new theory according to which adaptation is predictive.
  • Article 1: Chopin, A., & Mamassian, P. (2012). Predictive properties of adaptation. Current Biology, 22(7): 622-626. doi:10.1016/j.cub.2012.02.021. [Abstract] / [PDF]
  • Article 2: Chopin, A., & Mamassian, P. (2013). Response: Genuine long-term positive aftereffects. Current Biology, 23(10), R439-R440. [Abstract] / [PDF]
  • Dispatch by Pr. Colin Clifford [Abstract] / [PDF]
  • Conference proceeding: Chopin, A., Capps, M., & Mamassian, P. (2010). Expectation from temporal sequences influences binocular rivalry [Abstract]. Journal of Vision, 10(7): 347. [Abstract] / [PDF]

Implicit probabilistic processings in the human ambiguous perception

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This my Ph.D thesis. I studied:
(1) the influence of one interpretation’s usefulness on bistable perception
(2) the way of changing bistable preferences
(3) the specificity of the first bistable percepts
(4) the influence of orientation illusion on stereo-fusion and rivalry
(5) the influence of past stimuli on the bistable percept through predictions
  • Ph.D. thesis in French - Universite Paris Descartes [Corrected version]

Mysterious biases in the most simple stereoscopic perception

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In a very simple stereo configuration, we discovered that observers exhibit strong biases. When an upper dot is presented in front of a lower dot, the depth between the dots is perceived as completely different from the depth between an upper dot behind a lower dot. We have shown that the bias cannot be explained by cyclovergence biases or the tilt of the horopter.
  • Article: Harris, J., Chopin, A., Zeiner, K., & Hibbard, P. (2012). Perception of relative depth interval: systematic biases in perceived depth. Quarterly Journal of Experimental Psychology. 65(1): 73-91.  [Abstract] / [PDF]
  • Conference proceeding: Harris, J., Chopin, A., & Zeiner, K. (2008). Individual differences in depth perception : are biases correlated with eye position? [Abstract]. Journal of Vision, 8(6):93, 93a, doi:10.1167/8.6.93. [Abstract]

Bistable preferences are not random

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 People experience preferences on the first percept of bistable stimuli. These preferences are strong, stable and specific to them. They look random and meaningless but we found that they are actually learned to be useful in the current task using the bistable stimuli.
  • Article:  [Abstract] / [PDF]

Operant conditioning of binocular rivalry

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If the image presented to an eye in binocular rivalry is useful for the current task, that image is found to become dominant, even when the observer is not aware of the usefulness of the image. This happens mainly on the first percept, independently of attention.
  • Article: Chopin, A., & Mamassian, P. (2010). Task usefulness affects perception of rivalrous images. Psychological Science, 21(12): 1886-93. [Abstract] / [PDF]
  • Conference proceeding: Chopin, A., & Mamassian, P. (2009). Task demands can affect binocular rivalry dynamics [Abstract]. Journal of Vision, 9(8):299, 299a, http://journalofvision.org/9/8/299/, doi:10.1167/9.8.299. [Abstract] / [PDF]


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