Dr Nikos Gkekas' Outputs (6)

Speed Estimation for Visual Tracking Emerges Dynamically from Nonlinear Frequency Interactions (2022)
Journal Article
Meso, A. I., Gekas, N., Mamassian, P., & Masson, G. S. (2022). Speed Estimation for Visual Tracking Emerges Dynamically from Nonlinear Frequency Interactions. eNeuro, 9(3), https://doi.org/10.1523/ENEURO.0511-21.2022

Sensing the movement of fast objects within our visual environments is essential for controlling actions. It requires online estimation of motion direction and speed. We probed human speed representation using ocular tracking of stimuli of different... Read More about Speed Estimation for Visual Tracking Emerges Dynamically from Nonlinear Frequency Interactions.

Adaptation to one perceived motion direction can generate multiple velocity aftereffects (2021)
Journal Article
Gekas, N., & Mamassian, P. (2021). Adaptation to one perceived motion direction can generate multiple velocity aftereffects. Journal of Vision, 21(5), Article 17. https://doi.org/10.1167/jov.21.5.17

Sensory adaptation is a useful tool to identify the links between perceptual effects and neural mechanisms. Even though motion adaptation is one of the earliest and most documented aftereffects, few studies have investigated the perception of directi... Read More about Adaptation to one perceived motion direction can generate multiple velocity aftereffects.

Disambiguating serial effects of multiple timescales (2019)
Journal Article
Gekas, N., McDermott, K. C., & Mamassian, P. (2019). Disambiguating serial effects of multiple timescales. Journal of Vision, 19(6), Article 24. https://doi.org/10.1167/19.6.24

What has been previously experienced can systematically affect human perception in the present. We designed a novel psychophysical experiment to measure the perceptual effects of adapting to dynamically changing stimulus statistics. Observers are pre... Read More about Disambiguating serial effects of multiple timescales.

A Normalization Mechanism for Estimating Visual Motion across Speeds and Scales (2017)
Journal Article
Gekas, N., Meso, A. I., Masson, G. S., & Mamassian, P. (2017). A Normalization Mechanism for Estimating Visual Motion across Speeds and Scales. Current Biology, 27(10), 1514-1520.e3. https://doi.org/10.1016/j.cub.2017.04.022

Interacting with the natural environment leads to complex stimulations of our senses. Here we focus on the estimation of visual speed, a critical source of information for the survival of many animal species as they monitor moving prey or approaching... Read More about A Normalization Mechanism for Estimating Visual Motion across Speeds and Scales.

Expectations developed over multiple timescales facilitate visual search performance (2015)
Journal Article
Gekas, N., Seitz, A. R., & Seriès, P. (2015). Expectations developed over multiple timescales facilitate visual search performance. Journal of Vision, 15(9), Article 10. https://doi.org/10.1167/15.9.10

Our perception of the world is strongly influenced by our expectations, and a question of key importance is how the visual system develops and updates its expectations through interaction with the environment. We used a visual search task to investig... Read More about Expectations developed over multiple timescales facilitate visual search performance.

Complexity and specificity of experimentally-induced expectations in motion perception (2013)
Journal Article
Gekas, N., Chalk, M., Seitz, A., & Series, P. (2013). Complexity and specificity of experimentally-induced expectations in motion perception. Journal of Vision, 13(4), Article 8. https://doi.org/10.1167/13.4.8

Abstract Our perceptions are fundamentally altered by our expectations, i.e., priors about the world. In previous statistical learning experiments (Chalk, Seitz, & Seriès, 2010), we investigated how such priors are formed by presenting subjects with... Read More about Complexity and specificity of experimentally-induced expectations in motion perception.