My research interests lie within the field of visual search: how do people look for things in their environment? In our daily lives we perform numerous visual searches, often for mundane objects such as our mobile phones or our keys. Some might even conduct visual searches for a living - radiologists spend much of their time looking for tumours in X-ray images, and airport security officers scrutinze our luggage to look for threats such as bombs.
Even though we have the conscious experience that we can see everything within our visual field, search is oftentimes difficult (e.g. searching for your keys on a messy table). I am interested in how the limitations, structure, and organization of the visual system constrains processing, and how that consequently affects visual search. To answer this question, I examine the visual system in a holistic fashion: from the retina, to the visual areas of the brain, to the interaction between vision, perception, and attention. I employ a variety of methods, such as behavioural experiments (in-person and online), eye-tracking, and computational modeling. Ultimately, my goal is to understand the mechanisms of visual search, at both the basic and applied levels, in order to develop theories and models to explain and predict how we search for things in our environment.
Beyond that, I also have interests in the broad areas of vision science, human attention, and applied statistical methods. I am a supporter of open science and pre-registration. You can take a look at my pre-registered studies over at Open Science Framework.
Even though we have the conscious experience that we can see everything within our visual field, search is oftentimes difficult (e.g. searching for your keys on a messy table). I am interested in how the limitations, structure, and organization of the visual system constrains processing, and how that consequently affects visual search. To answer this question, I examine the visual system in a holistic fashion: from the retina, to the visual areas of the brain, to the interaction between vision, perception, and attention. I employ a variety of methods, such as behavioural experiments (in-person and online), eye-tracking, and computational modeling. Ultimately, my goal is to understand the mechanisms of visual search, at both the basic and applied levels, in order to develop theories and models to explain and predict how we search for things in our environment.
Beyond that, I also have interests in the broad areas of vision science, human attention, and applied statistical methods. I am a supporter of open science and pre-registration. You can take a look at my pre-registered studies over at Open Science Framework.
Projects
Variability in parallel search Recently our lab demonstrated that, contrary to previous theories of visual search, there exists variability in reaction times in parallel (i.e early visual processing in) visual search (Buetti, Cronin, Madison, Wang, & Lleras, 2016). As the number of items in the search display increases, reaction times increase in a logarithmic fashion. This suggests that early visual processing in visual search involves an accumulation of evidence towards a non-target threshold. In visual search tasks, locations that are unlikely to contain the target are excluded in early visual processing; attention is then allocated to the remaining unrejected locations. Allocation of attention in visual search How is attention to candidate locations that are likely to contain the target? Our model of visual search proposes that the output of early visual processing is a location map that arises from the rejection of regions that are unlikely to contain the target. I have utilized eye-tracking methodologies to show that attentional allocation is random and, in fact, not guided by target-distractor similarity. Biologically-plausible neural network Currently, I am also working on building a biologically-plausible neural network that accounts for the results from our lab. Please visit my Github repo for the code and more info! |
Publications
Ng, G.J.P., Patel, T.N., Buetti, S., & Lleras, A. (in press). Prioritization in visual attention does not work the way you think it does. Journal of Experimental Psychology: Human Perception and Performance.
Buetti, S., Xue, F., Liu, Q., Hur, J., Ng, G. J. P., & Heller, W. (2020). Perceived control in the lab and in daily life impact emotion-induced temporal distortions. Timing and Time Perception.
Lleras, A., Wang, Z., Ng, G.J.P., Ballew, K., Xu, J., & Buetti, S. (2020). A target contrast signal theory of parallel processing in goal-directed search. Attention, Perception, & Psychophysics, 82, 394-425.
Ng, G.J.P., Buetti, S., Dolcos, S., Dolcos, F., & Lleras, A. (2019). Distractor rejection in parallel search tasks takes time but does not benefit from context repetition. Visual Cognition, 27(5-8), 609-625.
Ng, G.J.P., Lleras, A., & Buetti, S. (2018). Fixed-target efficient search has logarithmic efficiency with and without eye movements. Attention, Perception, & Psychophysics, 80(7), 1752-1762.
Wong, S. S. H., Ng, G. J. P., Tempel, T., & Lim, S. W. H. (2017). Retrieval Practice Enhances Analogical Problem Solving. The Journal of Experimental Education.
Chong, J.S.X.*, Ng,G.J.P.*, Lee, S. C., & Zhou, J. (2016). Salience network connectivity in the insula is associated with individual differences in interoceptive accuracy. Brain Structure and Function, 222(4), 1635-1644. *Joint First-Authors
Hon, N., Ng,G.J.P., & Chan, G. (2016). Rare targets are less susceptible to attention capture once detection has begun. Psychonomic Bulletin and Review, 23, 445-450.
Lim, S. W. H., Ng,G.J.P., & Wong, G. Q. H. (2015). Learning research and statistical concepts using retrieval-based practice. Frontiers in Psychology, 6, 1484.
Ng, G.J.P., Patel, T.N., Buetti, S., & Lleras, A. (in press). Prioritization in visual attention does not work the way you think it does. Journal of Experimental Psychology: Human Perception and Performance.
Buetti, S., Xue, F., Liu, Q., Hur, J., Ng, G. J. P., & Heller, W. (2020). Perceived control in the lab and in daily life impact emotion-induced temporal distortions. Timing and Time Perception.
Lleras, A., Wang, Z., Ng, G.J.P., Ballew, K., Xu, J., & Buetti, S. (2020). A target contrast signal theory of parallel processing in goal-directed search. Attention, Perception, & Psychophysics, 82, 394-425.
Ng, G.J.P., Buetti, S., Dolcos, S., Dolcos, F., & Lleras, A. (2019). Distractor rejection in parallel search tasks takes time but does not benefit from context repetition. Visual Cognition, 27(5-8), 609-625.
Ng, G.J.P., Lleras, A., & Buetti, S. (2018). Fixed-target efficient search has logarithmic efficiency with and without eye movements. Attention, Perception, & Psychophysics, 80(7), 1752-1762.
Wong, S. S. H., Ng, G. J. P., Tempel, T., & Lim, S. W. H. (2017). Retrieval Practice Enhances Analogical Problem Solving. The Journal of Experimental Education.
Chong, J.S.X.*, Ng,G.J.P.*, Lee, S. C., & Zhou, J. (2016). Salience network connectivity in the insula is associated with individual differences in interoceptive accuracy. Brain Structure and Function, 222(4), 1635-1644. *Joint First-Authors
Hon, N., Ng,G.J.P., & Chan, G. (2016). Rare targets are less susceptible to attention capture once detection has begun. Psychonomic Bulletin and Review, 23, 445-450.
Lim, S. W. H., Ng,G.J.P., & Wong, G. Q. H. (2015). Learning research and statistical concepts using retrieval-based practice. Frontiers in Psychology, 6, 1484.
Conference presentations
Ng, G.J.P., Ballew, K.M., Lleras, A., & Buetti, S. (2020). Background complexity decreases evidence accumulation rates during parallel processing in efficient search. Poster presented at the 2020 Vision Sciences Society Annual Meeting. St. Pete Beach, Florida.
Ng,G.J.P., Zhou, J, Lleras, A., & Buetti, S. (2019). Scene context does not necessarily limit processing to target-consistent regions in visual search. Talk presented at the 2019 Vision Sciences Society Annual Meeting. St. Pete Beach, Florida.
Lively, Z.A., Ng, G.J.P., Buetti, S., & Lleras, A (2019). Visual working memory representations are shifted toward irrelevant features of distractors in intervening visual search tasks. Poster to be presented t the 2019 Vision Sciences Society Annual Meeting. St Pete Beach, Florida.
Ng,G.J.P., Buetti, S., & Lleras, A. (2018). Display repetitions do not improve search efficiency in parallel search tasks. Poster presented at the 2018 Vision Sciences Society Annual Meeting. St. Pete Beach, Florida.
Ng,G.J.P., Lleras, A., Buetti, S. (May 2017). The width of the functional viewing field is sensitive to distractor-target similarity even in efficient singleton search. 2017 Vision Sciences Society Annual Meeting. St. Pete Beach, Florida.
Ng,G.J.P., Buetti, S., & Lleras, A. (2016). The role of eye movements in parallel search: eye movements are neither necessary nor sufficient for logarithmic search functions to emerge. Poster presented at the 57th Annual Meeting of the Psychonomic Society, Boston, Massachusetts.
Buetti, S., Ng,G.J.P., Sanders, K. L., Hur, J., & Heller, W. (2016). Relationship between desire for control over life events and subjective perception of control over experimental events. Poster presented at the 57th Annual Meeting of the Psychonomic Society, Boston, Massachusetts.
Ng,G.J.P., & Lim, S. W. H. (2015). Testing the testing effect beyond verbatim tests. Poster presented at the 1st APS International Convention of Psychological Science, Amsterdam, The Netherlands.
Ng, G.J.P., Ballew, K.M., Lleras, A., & Buetti, S. (2020). Background complexity decreases evidence accumulation rates during parallel processing in efficient search. Poster presented at the 2020 Vision Sciences Society Annual Meeting. St. Pete Beach, Florida.
Ng,G.J.P., Zhou, J, Lleras, A., & Buetti, S. (2019). Scene context does not necessarily limit processing to target-consistent regions in visual search. Talk presented at the 2019 Vision Sciences Society Annual Meeting. St. Pete Beach, Florida.
Lively, Z.A., Ng, G.J.P., Buetti, S., & Lleras, A (2019). Visual working memory representations are shifted toward irrelevant features of distractors in intervening visual search tasks. Poster to be presented t the 2019 Vision Sciences Society Annual Meeting. St Pete Beach, Florida.
Ng,G.J.P., Buetti, S., & Lleras, A. (2018). Display repetitions do not improve search efficiency in parallel search tasks. Poster presented at the 2018 Vision Sciences Society Annual Meeting. St. Pete Beach, Florida.
Ng,G.J.P., Lleras, A., Buetti, S. (May 2017). The width of the functional viewing field is sensitive to distractor-target similarity even in efficient singleton search. 2017 Vision Sciences Society Annual Meeting. St. Pete Beach, Florida.
Ng,G.J.P., Buetti, S., & Lleras, A. (2016). The role of eye movements in parallel search: eye movements are neither necessary nor sufficient for logarithmic search functions to emerge. Poster presented at the 57th Annual Meeting of the Psychonomic Society, Boston, Massachusetts.
Buetti, S., Ng,G.J.P., Sanders, K. L., Hur, J., & Heller, W. (2016). Relationship between desire for control over life events and subjective perception of control over experimental events. Poster presented at the 57th Annual Meeting of the Psychonomic Society, Boston, Massachusetts.
Ng,G.J.P., & Lim, S. W. H. (2015). Testing the testing effect beyond verbatim tests. Poster presented at the 1st APS International Convention of Psychological Science, Amsterdam, The Netherlands.
Other talks
Ng,G.J.P. (September, 2019). Scene context does not necessarily limit processing to target-consistent regions in visual search. Attention & Perception Division Brown Bag, University of Illinois at Urbana-Champaign.
Ng, G. J. P. (December, 2018). Display repetitions do not improve search efficiency in parallel search tasks. Attention & Perception
Division Brown Bag, University of Illinois at Urbana-Champaign.
Ng, G. J. P. (December, 2018). Visual attention does not prioritize search items by target-distractor similarity. Cognitive Division
Brown Bag, University of Illinois at Urbana-Champaign
Ng, G. J. P. (August, 2018). Target-distractor similarity does not determine inspection priority in visual search. Invited talk by the
Department of Psychology, National University of Singapore.
Ng, G. J. P. (January, 2018). Alumni Conversations. Invited talk by the Psychology Society, National University of Singapore
Ng,G.J.P. (October 2017). Random instead of guided allocation of attention in visual search. Attention & Perception Division Brown Bag. University of Illinois at Urbana-Champaign.
Ng,G.J.P. (Novmber 2016). The role of eye movements in parallel search. Visual Cognition and Human Performance Division Brown Bag. University of Illinois at Urbana-Champaign.
Ng,G.J.P. (September, 2019). Scene context does not necessarily limit processing to target-consistent regions in visual search. Attention & Perception Division Brown Bag, University of Illinois at Urbana-Champaign.
Ng, G. J. P. (December, 2018). Display repetitions do not improve search efficiency in parallel search tasks. Attention & Perception
Division Brown Bag, University of Illinois at Urbana-Champaign.
Ng, G. J. P. (December, 2018). Visual attention does not prioritize search items by target-distractor similarity. Cognitive Division
Brown Bag, University of Illinois at Urbana-Champaign
Ng, G. J. P. (August, 2018). Target-distractor similarity does not determine inspection priority in visual search. Invited talk by the
Department of Psychology, National University of Singapore.
Ng, G. J. P. (January, 2018). Alumni Conversations. Invited talk by the Psychology Society, National University of Singapore
Ng,G.J.P. (October 2017). Random instead of guided allocation of attention in visual search. Attention & Perception Division Brown Bag. University of Illinois at Urbana-Champaign.
Ng,G.J.P. (Novmber 2016). The role of eye movements in parallel search. Visual Cognition and Human Performance Division Brown Bag. University of Illinois at Urbana-Champaign.