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In the blink of an eye: Reading mental states from briefly presented eye regions.
Faces provide not only cues to an individual's identity, age, gender, and ethnicity but also insight into their mental states. The aim was to investigate the temporal aspects of processing of facial expressions of complex mental states for very short presentation times ranging from 12.5 to 100 ms in a four-alternative forced choice paradigm based on Reading the Mind in the Eyes test. Results show that participants are able to recognise very subtle differences between facial expressions ; performance is better than chance, even for the shortest presentation time. Importantly, we show for the first time that observers can recognise these expressions based on information contained in the eye region only. These results support the hypothesis that the eye region plays a particularly important role in social interactions and that the expressions in the eyes are a rich source of information about other peoples’ mental states. When asked to what extent the observers guessed during the task, they significantly underestimated their ability to make correct decisions, yet perform better than chance, even for very brief presentation times. These results are particularly relevant in the light of the current COVID-19 pandemic and the associated wearing of face coverings.
Schmidtmann, G., Logan, A. J., Carbon, C. C., Loong, J. T., Gold, I. (2020). In the blink of an eye: Reading mental states from briefly presented eye regions. i-Perception, 11(5), 1–18. [PDF]
In the blink of an eye: Reading mental states from briefly presented eye regions.
Schmidtmann, G., Logan, A. J., Carbon, C. C., Loong, J. T., Gold, I. (2020). In the blink of an eye: Reading mental states from briefly presented eye regions. i-Perception, 11(5), 1–18. [PDF]
Faces provide not only cues to an individual's identity, age, gender, and ethnicity but also insight into their mental states. The aim was to investigate the temporal aspects of processing of facial expressions of complex mental states for very short presentation times ranging from 12.5 to 100 ms in a four-alternative forced choice paradigm based on Reading the Mind in the Eyes test. Results show that participants are able to recognise very subtle differences between facial expressions ; performance is better than chance, even for the shortest presentation time. Importantly, we show for the first time that observers can recognise these expressions based on information contained in the eye region only. These results support the hypothesis that the eye region plays a particularly important role in social interactions and that the expressions in the eyes are a rich source of information about other peoples’ mental states. When asked to what extent the observers guessed during the task, they significantly underestimated their ability to make correct decisions, yet perform better than chance, even for very brief presentation times. These results are particularly relevant in the light of the current COVID-19 pandemic and the associated wearing of face coverings.
Barhoom, H.S., Joshi, M.R., Schmidtmann G. (2020) The effect of response biases on resolution thresholds of Sloan letters in central and paracentral vision, BioRxiv, https://doi.org/10.1101/2020.09.04.283119
Clinical Vision Science - A Concise Guide to Numbers, Laws, and Formulas
This book provides a concise and user-friendly guide to the most common and important numbers, laws and formulas in clinical vision science. Clinicians and trainees in ophthalmology, optometry, orthoptics, and ophthalmic dispensing, who are seeking an easy-to-use lab coat pocket size resource, will find this book to be an essential reference in clinical practice.
Clinical Vision Science: A Concise Guide to Numbers, Laws, and Formulas is clearly structured into basics, physical optics, visual optics and ophthalmic lenses, optical instruments, photometry, visual perception, clinical procedures, and anatomy & binocular vision. Each chapter contains a range of tables, formulas, large illustrations and flow charts to allow readers to quickly and accurately find key facts for each type of examination procedure.
Vision Scientists!
With ARVO and VSS cancelled and most of us working from home and under strict social distancing guidelines, we would like to invite vision scientists worldwide to join us for a weekly vision science virtual coffee break.
Come and join us on Zoom next Wednesday, 25th March.
Topic: Vision Science in times of social distancing
Time: Mar 25, 2020 03:00 pm London
08:00 am Pacfic
11:00 am Eastern
03:00 pm UK
04:00 Central European
Join Zoom Meeting
https://unibas.zoom.us/j/661371046
Schmidtmann, G., Jennings, B. J., Sandra, D. A., Pollock, J., & Gold, I. (2020). The McGill Face Database: Validation and Insights Into the Recognition of Facial Expressions of Complex Mental States. Perception. https://doi.org/10.1177/0301006620901671
Schmidtmann, G., Maria Zawadyl, “Summation within and between shapes in central and peripheral vision.“ Applied Vision Association (AVA) Christmas Meeting, Cardiff University, 2019 [SLIDES]
The processing of compound radial frequency patterns
Gunnar Schmidtmann, Frederick Kingdom, Gunter Loffler
Radial frequency (RF) patterns can be combined to construct complex shapes. Previous studies have suggested that such complex shapes may be encoded by multiple, narrowly-tuned RF shape channels. To test this hypothesis, thresholds were measured for detection and discrimination of various combinations of two RF components. Results show evidence of summation: sensitivity for the compounds was better than that for the components, with little effect of the components’ relative phase. If both RF components are processed separately at the point of detection, they would combine by probability summation (PS), resulting in only a small increase in sensitivity for the compound compared to the components. Summation exceeding the prediction of PS suggests a form of additive summation (AS) by a common mechanism. Data were compared to predictions of winner-take-all, where only the strongest component contributes to detection, a single channel AS model, and multi-channel PS and AS models. The multi-channel PS and AS models were modelled under both Fixed and Matched Attention Window scenarios, the former assuming a single internal noise source for both components and compounds or different internal noise sources for components and compounds respectively. The winner-take-all and single channel models could be rejected. Of the remaining models, the best performing one was an AS model with a Fixed Attention Window, consistent with detection being mediated by channels that are efficiently combined and limited by a single source of noise for both components and compounds.
Schmidtmann, G., Kingdom, F. A. A., & Loffler, G. (2019). The processing of compound radial frequency patterns. Vision Research, 161, 63–74. [PDF] [PubMed]