Perception & Mind Lab Presentations @ VSS 2023
Saturday, May 20
Event-based warping: An illusory distortion of time within events
Rui Zhe Goh, Hanbei Zhou, Chaz Firestone, Ian Phillips
rgoh1@jhu.edu
Objects are fundamental units of perception which structure our experience of space. A striking finding about object representation is that objecthood warps our perception of spatial distance, such that two dots perceived within an object appear farther apart than two dots perceived in empty space — an illusion known as “Object-based Warping” (Vickery & Chun, 2010). However, just as objects are fundamental to our experience of space, events are fundamental to our experience of time. Does spatial object-based warping have a temporal event-based counterpart? Here, we show that it does: Just as two dots in an *object* are perceived as farther apart in *space*, we show that two probes within an *event* are perceived as further apart in *time* — introducing “Event-based Warping” to the literature. In our first experiment, subjects judged the duration between two auditory probes (i.e., two tones) with respect to a standard reference duration. There were two types of trials: In event trials, probes were presented during an auditory event (a brief period of noise during an otherwise-silent soundtrack). In non-event trials, probes were not presented during any auditory event but simply played in silence. Subjects judged probes within an event to be further apart than probes not within an event, showing that event representations warp perceived duration. Crucially, we further demonstrate that this temporal warping phenomenon also arises in vision. In a second, cross-modal experiment, observers judged the duration between two visual probes (i.e., two flashes) presented either within or not within an auditory event. Again, subjects judged probes on event trials as further apart in time than probes on non-event trials, showing that event-based warping occurs cross-modally. We suggest that object-based warping and event-based warping are instances of a more general phenomenon in which structural representations give rise to perceptual distortions.
Talk: Saturday, May 20, 5:15pm ET, Talk Room 2, Temporal Processing
[VSS Link]
What does learning look like? Inferring epistemic intent from observed actions
Sholei Croom, Hanbei Zhou, Chaz Firestone
scroom1@jhu.edu
Beyond recognizing objects, faces, and scenes, we can also recognize the actions of other people. Accordingly, a large literature explores how we make inferences about behaviors such as walking, reaching, pushing, lifting, and chasing. However, in addition to actions with physical goals (i.e., trying to *do* something), we also perform actions with epistemic goals (i.e., trying to *learn* something). For example, someone might press on a door to figure out whether it is locked, or shake a box to determine its contents (e.g., a child wondering if a wrapped-up present contains Lego blocks or a teddy bear). Such ‘epistemic actions’ raise an intriguing question: Can observers tell, just by looking, what another person is trying to learn? And if so, how fine-grained is this ability? We filmed volunteers playing two rounds of a ‘physics game’ in which they shook an opaque box to determine either (a) the number of objects hidden inside, or (b) the shape of the objects hidden inside. Then, an independent group of participants watched these videos (without audio) and were instructed to identify which videos showed someone shaking for number and which videos showed someone shaking for shape. Across multiple task variations and hundreds of observers, participants succeeded at this discrimination, accurately determining which actors were trying to learn what, purely by observing the box-shaking dynamics. This result held both for easy discriminations (e.g., 5-vs-15) and hard discriminations (e.g., 2-vs-3), and both for actors who correctly guessed the contents of the box and actors who failed to do so — isolating the role of epistemic *intent* per se. We conclude that observers can visually recognize not only what someone wants to do, but also what someone wants to know, introducing a new dimension to research on visual action understanding.
Talk: Saturday, May 20, 5:45pm ET, Talk Room 1, Intuitive Physics and Event Perception
[VSS Link]
Sunday, May 21
What do the inattentionally blind see? Evidence from 10,000 subjects
Makaela Nartker, Chaz Firestone, Howard Egeth, Ian Phillips
makaela@jhu.edu
Inattentional blindness (IB) – the failure to notice perfectly visible stimuli when attention is otherwise engaged – has fascinated vision scientists for nearly half a century. A key reason is that IB is thought to illuminate the relationship between attention and awareness, seemingly revealing that visual consciousness requires attention. In drawing such conclusions, a crucial assumption is that subjects who report not noticing an unexpected stimulus are truly unaware of it. In four experiments, involving >10,000 participants, we found that subjects who report not noticing an unexpected stimulus can still answer questions about it at above-chance levels, casting doubt on this assumption. Exps.1-3 tested brief-duration IB: On trials 1-3, a cross briefly appeared, and subjects reported which arm was longer. On trial 4, some subjects were shown an unexpected colored line on one side of the display; others were shown nothing additional. Exp.4 tested sustained IB: Subjects counted how often squares of one color bounced off the display’s perimeter, while ignoring squares of another color. During this task, some subjects were shown either a circle or triangle traversing the display for 5s. In all experiments, regardless of whether something unexpected appeared, each subject answered the traditional IB question (“Did you notice anything unusual?” yes/no), followed by other discrimination questions (e.g., “Was the extra line red or blue?”). Exps.1-4 revealed significant sensitivity to location (Exps.1&3), color (Exps.2&4) and shape (Exps.2&4), even amongst non-noticing subjects. Moreover, subjects were biased to report not noticing, suggesting greater awareness than is revealed by yes/no questioning. Indeed, Exp.3 found (a) that even highly confident non-noticers performed above chance on location discrimination, and (b) that yes/no confidence predicted discrimination accuracy, suggesting that subjects have graded access to information about unexpected stimuli. Together, these data are consistent with the hypothesis that inattention degrades but does not abolish awareness.
Poster: Sunday, May 21, 8:30am - 12:30pm ET, Banyan Breezeway, Attention: Cueing, Inattention
[VSS Link]
Monday, May 22
How to build a scene: Relational representations are constructed in a canonical order
Zekun Sun, Chaz Firestone, Alon Hafri
zekun@jhu.edu, alon@udel.edu
The world contains not only objects and features (e.g., glass vases, wooden tables), but also relations holding between them (e.g., glass vases *on* wooden tables). How does the mind combine discrete elements when constructing relational representations from visual scenes? Here, four experiments test the intriguing possibility that the mind builds relational representations according to the ‘roles’ of the participating objects. We take inspiration from psycholinguistics in hypothesizing that ‘reference’ objects (those that are large, stable, and/or physically ‘control’ other objects; e.g., tables) — rather than ‘figure’ objects (e.g., vases) — serve as the scaffold for relational representations. Using a ‘drag-and-drop’ task, we found that when participants had to position items to compose scenes from linguistic descriptions (e.g., “the vase is on the table”), they consistently placed the reference object first (i.e., first fixing the table, then placing the vase on top of it). We next explored whether this pattern goes beyond such preferences and drives visual processing itself. In a recognition task, participants quickly verified whether a description of a subsequently presented visual scene (e.g., “the vase is on the table”) was correct. Crucially, sometimes the reference object (e.g., the table) appeared right before the figure object (the vase), or vice-versa. We found a ‘reference-object advantage’: participants were faster to correctly respond when the reference object appeared before the figure object than vice-versa. Notably, the effect arose no matter the order of elements mentioned in the linguistic descriptions, and it was not explained by size or shape differences, since the same effects arose in an experiment using identical objects differing only in color (e.g., red book on blue book). We suggest that the mind employs a sequential routine for building relational representations from visual scenes, respecting the role that each element plays in the relation.
Poster: Monday, May 22, 8:30am – 12:30pm ET, Banyan Breezeway, Scene Perception: Spatiotemporal Factors
[VSS Link]
Caricaturing shapes in visual memory
Subin Han, Zekun Sun, Chaz Firestone
shan6@uoregon.edu, zekun@jhu.edu
When representing high-level stimuli such as faces or animals, we tend to emphasize their most salient features — such as a face's prominent cheekbones or a bird's pointed beak. Such ‘mental caricaturing' leaves traces in visual memory, which exaggerates these distinctive qualities when recalling and recognizing the stimulus at another time. How broadly does this phenomenon extend? In particular, might it also apply to more basic units of visual processing? Here, six experiments (N=700 Adults) explored how visual working memory exaggerates the features of even simple geometric shapes, automatically and without any task-related demand to do so. We generated a library of novel shapes, and gradually smoothed their contours — essentially altering the amount of information borne by the visible boundaries. In Experiment 1, participants saw a novel shape at the beginning of each trial; after a brief delay, they adjusted a copy of that shape to match the one they had just seen. Surprisingly, participants consistently reconstructed the shapes in “exaggerated” form — amplifying the curvature of the shapes' contours, enlarging their salient parts, and so on. Experiment 2 generalized this bias to new parameters, showing that the results were not specific to particular ranges of complexity values. Experiment 3 replicated the results with two-alternative forced choice; Experiment 4 ruled out response biases by comparing an online perception condition to a memory condition; and Experiment 5 ruled out strategic responding based on intuitive expectations about the reliability of memory. Finally, Experiment 6 amplified the effects in a serial reproduction experiment ending with a dramatically altered shape. Together, this work demonstrates a new memory distortion, whereby even the most basic units of visual processing are remembered as caricatured versions of themselves.
Poster: Monday, May 22, 8:30am – 12:30pm ET, Banyan Breezeway, Scene Perception: Spatiotemporal Factors
[VSS Link]
Visual guessing relies on metacognitive reasoning
Caroline Myers, Chaz Firestone, Justin Halberda
cmyers60@jhu.edu
If you were shown a color but weren't sure what it was, you'd guess. But what if you weren't shown a color and only believed you were? Traditional models of visual processing assume that observers unsure of what they’ve seen either 1) generate guesses by randomly selecting from a uniform distribution of all possible values, or in extreme cases 2) never guess. Yet, to date, no study has systematically measured whether and how human observers generate guesses. In the present study, adult observers performed a visual working memory task in which they were asked to report the color of a target stimulus presented for a brief (16, 33, 66, or 132 ms) duration before being masked. Critically, we were able to assess observers’ guess responses via the inclusion of 0-ms trials, in which no stimulus appeared. Responses on 0-ms trials were systematically non-uniform and characterized by distinct individual- and group-level preferences for regions of color space, suggesting that rather than responding randomly, guessing observers weight specific feature dimensions strategically, in a way that might reflect prior knowledge about the visual world or one’s own perceptual capacities. To test these possibilities, we measured guess responses in an equivalent orientation task. If guesses reflect a bias toward high-precision values, guesses should favor high-prevalence, high-precision regions of orientation space (horizontals and verticals). However, responses on 0-ms trials were instead characterized by the inverse pattern: observers were more likely to guess inter-cardinal compared to cardinal orientations, reflecting a bias away from high-precision regions. This pattern is consistent with a self-representing strategy in which observers take into account the precision of their own visual processing. Together, our findings suggest that rather than being uniform or nonexistent, guesses are informed by observers’ knowledge of their own perceptual capacity under perceptual uncertainty.
Poster: Monday, May 22, 8:30am - 12:30pm ET, Pavilion, Visual Working Memory: Space, Features, Objects
[VSS Link]
Tuesday, May 23
phiVis: Philosophy of Vision Science
A VSS satellite event, organized by Kevin Lande, Jorge Morales, and Chaz Firestone
www.phivis.org
The past decade has seen a resurgence in conversation between vision science and philosophy of perception on questions of fundamental interest to both fields, such as: What do we see? What is seeing for? What is seeing? The phiVIS workshop is a forum for continuing and expanding this interdisciplinary conversation. Short talks by philosophers of perception that engage with the latest research in vision science will be followed by discussion with a slate of vision scientists.
Event: Tuesday, May 23, 12:30pm - 2:30pm ET, Jamine/Palm Room.
Register: in person; online.
[VSS Link]
Also from lab members | Friday, May 19
Symposium: Critical Perspectives On Vision Science: Towards Unbiasing Our Methods and Role in Knowledge Production
Organizers: Vassiki Chauhan, Sholei Croom, Kathryn Graves, Jasmine Kwasa, Eline Kupers, Kimele Persaud
Speakers: Sholei Croom, Pawan Sinha, Jasmine Kwasa, Joel E Martinez, Vassiki S Chauhan
https://cpovssymposium.github.io/
Reckoning with a global pandemic and widespread social inequality has resulted in increased consciousness around issues such as racism, sexism, ableism, and discrimination against the LGBTQ+ community. As scientists, academics and industry professionals, our work operates within the larger context of these societal issues. Therefore, we must consider how our science perpetuates or mitigates the systemic oppressions that those most marginalized among us struggle against. The failure to use a critical lens in understanding how these systems impoverish our science can pose the risk of our science reifying oppressive systems. This symposium, organized by a team of historically underrepresented researchers and their allies, brings together complementary perspectives to call attention to how racial, ethnic, gender, and other systemic biases are perpetuated in our current methods and practices, and discuss approaches to ameliorate them in the scientific cycle. Specifically, our theoretical frameworks, visual stimuli, and data collection—both behavioral and neuroimaging. Speakers will present recent empirical and theoretical work in service of important questions such as: What are the bottlenecks in making our human participant pool more inclusive? How do our visual stimuli—a critical component of our scientific hypotheses—reflect historic and structural imbalances in our society? How does the way we study human perception affect how we perceive people? And how may these representations reflect and justify social oppression, or motivate social change? We argue that addressing systematic biases in science and higher education institutions is not only a moral obligation, but an epistemic one: By critically examining our tools and frameworks, and making a conscious effort to promote equity, our science will become more effective, innovative, and impactful. By providing a platform to leaders in our field who are taking this challenge head-on, we hope that more researchers across the vision science community will feel empowered to enact much-needed change. This symposium will start with a brief overview of the history of vision science, delivered by one of the organizers, Sholei Croom. Four speakers will then present their work in 20-minute presentations, plus 5 minutes for audience questions. Speakers will engage in different aspects of our overarching theme, focusing on current disparities as well as suggesting specific solutions. A final talk will be given by Vassiki Chauhan (one of the organizers), to encourage the audience in ways they can promote diversity and inclusivity in their own research and scientific community.
Symposium: Friday, May 19, 12:00pm-2:00pm ET, Talk Room 1
[VSS Link]