Alex S. Baldwin

Research Associate at the Research Institute of the McGill University Health Centre

Areas of Specialisation

Research Interests

  • Spatial vision, including summation and masking
  • The use of augmented reality to conduct experiments
  • Integration of spatial form, including contour integration
  • Binocular vision, including fusion and stereopsis
  • Clinical measurement of stereoacuity
  • Treatment of amblyopia with binocular therapies
  • Plasticity in the visual system, and its modulation by exercise and drugs

Research Skills

  • Using Matlab to program experiments (with Psychtoolbox) and analyse data
  • Using Python to analyse data, produce visualisations, and process video (with OpenCV)
  • Programming 3D augmented reality experiments with Unity and C#
  • Producing scientific documents, presentations, and posters with LaTeX and Beamer

Education

McGill University

Postdoctoral Fellow in Ophthalmology: 2013-2018

Aston University

PhD in Neurosciences: 2009-2013

Keele University

BSc in Music Technology & Neuroscience (first class honours): 2006-2009

Publications

PhD Thesis

  • Alex S. Baldwin (2013). Pattern Integration in the Normal and Abnormal Human Visual System. Life and Health Sciences, Aston University.

Journal Articles

  • Juliane Tittes, Alex S Baldwin, Robert F Hess, Licia Cirina, Yaroslava Wenner, Claudia Kuhli-Hattenbach, Hanns Ackermann, Thomas Kohnen, & Maria Fronius (in review). Precise assessment of stereovision with digital testing in adults and children with normal and impaired binocularity.
  • Seung Hyun Min, Alex S Baldwin, Alexandre Reynaud & Robert F Hess (in review). The shift in ocular dominance from short-term deprivation exhibits unusual dynamics: no dependence on duration of deprivation.
  • Yasha Sheynin, Mira Chamoun, Alex S Baldwin, Pedro-Rosa-Neto, Robert F Hess & Elvire Vaucher (in review). Cholinergic potentiation alters short-term ocular dominance plasticity in adults.
  • Yi Gao, Alex S. Baldwin & Robert F. Hess (in review). The amblyopic deficit in second-order modulation processing: the role of response nonlinearity for contrast and motion.
  • Yi Gao, Alex S. Baldwin & Robert F. Hess (in review). Different nonlinearity in the processing of contrast- vs motion-defined boundaries.
  • Yi Gao, Alex S. Baldwin & Robert F. Hess (in review). The response nonlinearity to second-order contrast and orientation modulation characterized using pedestal masking.
  • Alex S. Baldwin & Robert F. Hess (2018). The mechanism of short-term monocular deprivation is not simple: separate effects on parallel and cross-oriented dichoptic masking. Scientific Reports, 8(6191), pp. 1-8. [Nature]
  • Alex S. Baldwin, Minnie Fu, Reza Farivar & Robert F. Hess (2017). The equivalent internal orientation and position noise for contour integration. Scientific Reports, 7(13048), pp. 1-12. [Nature]
  • Daniel P. Spiegel, Alex S. Baldwin, & Robert F. Hess (2017). Ocular dominance plasticity; inhibitory interactions and contrast equivalence. Scientific Reports, 7(39913), pp. 1-9. [Nature]
  • Daniel P. Spiegel, Alex S. Baldwin, & Robert F. Hess (2016). The relationship between fusion, suppression and diplopia in normal and amblyopic vision. Investigative Ophthalmology and Visual Science, 57(13), pp. 5810-5817. [IOVS]
  • Alex S. Baldwin, Gunnar Schmidtmann, Frederick A. A. Kingdom & Robert F. Hess (2016). Rejecting probability summation for radial frequency patterns, not so Quick! Vision Research, 122, pp. 124-134. [ScienceDirect]
  • Alex S. Baldwin, Daniel H. Baker & Robert F. Hess (2016). What do contrast threshold equivalent noise experiments actually measure? Noise vs. nonlinearity in different masking paradigms. PLoS One, 11(3):e0150942, pp. 1-26. [PLoS]
  • Alex S. Baldwin & Tim S. Meese (2015). Fourth-root summation of contrast over area: no end in sight when spatially inhomogeneous sensitivity is compensated by a witch's hat. Journal of Vision, 15(15):4, pp. 1-12. [JoV]
  • Frederick A. A. Kingdom, Alex S. Baldwin & Gunnar Schmidtmann (2015). Modelling probability and additive summation for detection across multiple mechanisms under the assumptions of signal detection theory. Journal of Vision, 15(5):1, pp. 1-16. [JoV]
  • Alex S. Baldwin, Jesse S. Husk, Lauren Edwards, Robert F. Hess (2015). The efficiency of second order orientation coherence detection. Vision Research, 109, pp. 45-51[ScienceDirect]
  • Alex S. Baldwin, Jesse S. Husk, Tim S. Meese & Robert F. Hess (2014). A two-stage model of orientation integration for Battenberg-modulated micropatterns. Journal of Vision, 14(1):30, pp. 1-21. [JoV]
  • Alex S. Baldwin, Tim S. Meese & Daniel H. Baker (2012). The attenuation surface for contrast sensitivity has the form of a "witch's hat" within the central visual field. Journal of Vision, 12(11):23, pp. 1-17. [JoV]
  • Emily House, Matthew Mold, Joanna Collingwood, Alex Baldwin, Steven Goodwin & Christopher Exley (2009). Copper Abolishes the β-Sheet Secondary Structure of Preformed Amyloid Fibrils of Amyloid-β42. Journal of Alzheimer's Disease. 18:811-817 [PubMed]

Conference Abstracts

  • Juliane Tittes, Alex S Baldwin, Peggy Feige, Licia Cirina, Yaroslava Wenner, Claudia Kuhli-Hattenbach, Hanns Ackermann, Robert Hess, Thomas Kohnen, Maria Fronius (2018). Digital or analogue? First assessment of a newly developed digital stereotest in adults and children with and without amblyopia. (European Conference on Visual Perception, Trieste)
  • Robert Hess, Benjamin Thompson, Alex S Baldwin, Simon Clavagnier (2018). Feature-based attention modulates fMRI BOLD response in areas MT and V4. (European Conference on Visual Perception, Trieste)
  • Seung Hyun Min, Alex S Baldwin, Robert F Hess (2018). Visual plasticity induced by short-term monocular deprivation recovers without visual input. (Vision Sciences Society, St Pete Beach)
  • Ann L Webber, Katrina L Schmid, Rory J Dowdall, Megan E Finlay, Rachael L Larner, Edward Lee, Beom Seok Oh, Kryton A Skokidis, Alex S Baldwin, Alexandre Reynaud & Robert F Hess (2018). Suppression rather than visual acuity loss limits threshold stereoacuity. (Association for Research in Vision and Ophthalmology, Honolulu).
  • Alex S Baldwin & Robert F Hess (2017). Psychophysical investigation of dichoptic blur suppression in human vision. (Annual Meeting of the FRQS Vision Health Research Network, Montreal)
  • Seung Hyun Min, Alex S Baldwin, Alexandre Reynaud & Robert F Hess (2017). Duration dependency of monocular deprivation induced visual plasticity. (Society for Neuroscience Annual Meeting 2017, Washington DC)
  • Robert F Hess, Hayden Green, Elizabeth Finn, Alex S Baldwin & Nicholas Gant (2017). Exercise affects human ocular dominance plasticity. (Society for Neuroscience Annual Meeting, Washington DC)
  • Alex S. Baldwin & Robert F. Hess (in press). Investigation of interocular blur suppression with natural images reveals significant individual differences. (ECVP 2017, Berlin)
  • Yasha Sheynin, Mira Chamoun, Alex S. Baldwin, Elvire Vaucher & Robert F. Hess (in press). Cholinergic enhancement of short-term patching in healthy adults. (ECVP 2017, Berlin)
  • E. Abigail Finn, Jiawei Zhou, Alex S. Baldwin, Alexandre Reynaud & Robert F. Hess (in press). Is there an effect of exercise on human adult ocular dominance plasticity? (ECVP 2017, Berlin)
  • Alex S. Baldwin, Minnie Fu, Reza Farivar & Robert F. Hess (2017). Equivalent internal noise for contour integration. Journal of Vision, 17(1364). (VSS 2017, St. Pete Beach).
  • Yushu Wang, Alex S. Baldwin, Robert Hess & Kathy Mullen (2017). Nonlinearity of contrast responses in human achromatic and color vision. Journal of Vision, 17(1183). (VSS 2017, St. Pete Beach).
  • Angela Zhang, Paul Khayat, Hassan Akhavein, Alex S. Baldwin, Robert F. Hess & Reza Farivar (2016). Monkeys see snakes like humans do: a comparative analysis of external noise and efficiency in contour integration. (Society for Neuroscience 2016, San Diego).
  • Tatiana Ruiz, Daniel Spiegel, Alex S. Baldwin, Robert F. Hess & Reza Farivar. (2016). Mild traumatic brain injury patients recruit compensatory mechanisms to integrate visual information. (Society for Neuroscience 2016, San Diego).
  • Alex S. Baldwin, Gunnar Schmidtmann, Frederick A. A. Kingdom & Robert. F. Hess (2015). Rejecting probability summation for RF patterns, not so Quick! Journal of Vision, 15(12), pp. 1031-1031. (VSS 2015, St. Pete Beach). [Poster]
  • Frederick A. A. Kingdom, Alex S. Baldwin & Gunnar Schmidtmann (2015). Modelling probability summation for the detection of multiple stimuli under signal detection theory. Journal of Vision, 15(12), pp. 473-473. (VSS 2015, St. Pete Beach).
  • Yi Gao, Alex S. Baldwin & Robert. F. Hess (2015). Dipper functions for second-order modulation of contrast, orientation, and motion. Journal of Vision, 15(12), pp. 469-469. (VSS 2015, St. Pete Beach).
  • Daniel P. Spiegel, Alex S. Baldwin, Mark A. Georgeson, Reza P. Farivar & Robert. F. Hess (2015). The relationship between fusion, suppression, and diplopia in amblyopia. Investigative Ophthalmology & Visual Science, 56(7), pp. 2196-2196 (ARVO 2015, Denver).
  • Alex S. Baldwin & Robert F. Hess (2014). Investigating the shape of the contrast sensitivity function using white, bandpass, and contrast jitter noise. Journal of Vision, 14:10, 1421. (VSS 2014, St. Pete Beach).
  • Alex S. Baldwin, Jesse S. Husk, Tim S. Meese & Robert F. Hess (2012). Pooling strategies for the integration of orientation signals depend on their spatial configuration. Perception, 41(12), pp. 1512-1513. (AVA Christmas Meeting 2012, UCL).
  • Alex S. Baldwin, Tim S. Meese & Daniel H. Baker (2012). A reevaluation of area summation of contrast with compensation for retinal inhomogeneity. Perception, 41 (ECVP Abstract Supplement): 223. (ECVP 2012, Sardinia).
  • Tim S. Meese, Rob Summers, Alex S. Baldwin (2012). Theory and data for area summation of contrast with and without uncertainty: Evidence for a noisy integrator model. Journal of Vision, 12:9, 601. (VSS 2012, Naples, Florida).
  • Alex S. Baldwin, Tim S. Meese & Daniel H. Baker (2012). Extensive physiological summation of contrast signals over area revealed by Witch’s Hat compensation for retinal inhomogeneity. Perception 41(3): 366. (AVA Spring Meeting 2011, Cardiff University)
  • Alex S. Baldwin, Tim S. Meese & Daniel H. Baker (2011). Retinal inhomogeneity and the witch's hat: Contrast sensitivity declines as a bi-linear function of eccentricity in each direction. Perception, 40: 112. (AVA Christmas Meeting 2010, Paris)
  • Alex S. Baldwin & Tim S. Meese (2010). A new approach to investigating the contrast sensitivity to contour integration in the fovea. Perception, 39 (ECVP Abstract Supplement): 26. (ECVP 2010, Switzerland).
  • Alex S. Baldwin, Tim S. Meese & Daniel H. Baker (2010). Loss of contrast sensitivity at 4 c/deg depends on eccentricity and meridian but not grating orientation for the central 9 deg of the visual field. Perception, 39(8): 1151. (AVA Spring Meeting 2010, Liverpool)

Teaching

McGill University

Teaching assistant for Advances in Visual Perception: 2017

Aston University

Teaching assistant for Vision Science and Research Methods: 2009-2013

Keele University

Teaching assistant for Human Physiology and Pathology: 2008 - 2009
Teaching assistant for Introduction to Neuroscience: 2008 - 2009

Awards and Memberships

2017: Awarded $18k towards my postdoctoral funding by the RI MUHC Studentship and Fellowship Competition.
2016: Travel award to present at the Form and Function in Ocular Disease symposium at Dalhousie University.
2013 - Present: Member of the Vision Sciences Society.
2009 - Present: Member of the Applied Vision Association.
2006-2009: Awarded the Keele University Dean's Scholarship.

References available upon request