From Hate to Love: How Learning Can Change Affective Responses to Touched Materials

Müge Cavdan, Alexander Freund, Anna-Klara Trieschmann,
Katja Doerschner, and Knut Drewing

Justus Liebig University, 3539 Giessen, Germany
Bilkent University, 06800 Ankara, Turkey

Abstract. People display systematic affective reactions to specific properties of touched materials. For example, granular materials such as fine sand feel
pleasant, while rough materials feel unpleasant. We wondered how far such relationships between sensory material properties and affective responses can be changed by learning. Manipulations in the present experiment aimed at unlearning the previously observed negative relationship between roughness and valence and the positive one between granularity and valence. In the learning phase, participants haptically explored materials that are either very rough or very fine-grained while they simultaneously watched positive or negative stimuli, respectively, from the International Affective Picture System (IAPS). A control group did not interact with granular or rough materials during the learning phase. In the experimental phase, participants rated a representative diverse set of 28 materials according to twelve affective adjectives. We found a significantly weaker relationship between granularity and valence in the experimental group compared to the control group, whereas roughness-valence correlations did not differ between groups. That is, the valence of granular materials was unlearned (i.e., to modify the existing valence of granular materials) but not that of rough materials. These points to differences in the strength of perceptuo-affective relations, which we discuss in terms of hard-wired versus learned connections.

To conitnue reading, please click here.

ISBCS 2020 – Effect of expectations on perception of dynamic material properties

Authors – Amna Malik, Katja Doerschner, Hüseyin Boyaci

The current global situation that we are all facing has forced us to look to the virtual world in order to continue within academia and research. Amna Malik, hosted by the University of Bilkent, has done just, virtually narrating her video for ISBCS presentation.

In the abstract Amna says:

“Visual information plays a vital role in object and material recognition. Based on our daily life interaction with objects, our brain learns to make associations between how an object looks like, what material it is made of and its physical and functional properties. Hence, before even we touch an object, simply by looking at it, we have expectations about how it will behave under different forces. For example, we expect a wine glass to shatter if it falls and hits the ground. Upon viewing an object, incoming visual information is combined with prior knowledge to help us recognizing objects, accessing their properties and making efficient decisions regarding actions involving interaction with objects. In this study we aimed to investigate the role of expectations in perception of material properties in dynamic scenes and how they affect perceptual decisions. We used novel computer animations of objects falling on ground, which are manipulated to behave in an expected or unexpected manner. Observers were asked to answer whether the object broke or not upon hitting the ground. We measured reaction times and percent correct responses for each condition. We found out that observers take longer to respond in the surprising condition. Hence, we concluded that expectations influence perception of dynamic material properties and perceptual decision making is delayed when these expectations are violated, which implies that additional processing is required when incoming sensory information does not match the expectations.”

We would like to congratulate Amna on a terrific presentation and encourage everyone to watch the video!

Visual Science of Art Conference 2019

Written by Jacob Cheeseman

As someone who considers himself a scientist first, and an artist second, I came to the Visual Science of Art Conference (VSAC) 2019 with keen interest. The meeting aims to enhance our scientific understanding of how visual artists depict the world, and to further communication between fields that, while traditionally divided within academia, share a passion for seeing.
This year we were gathered in Leuven, Belgium, a city that could well have the perfect balance of culture and functionality. And the opening reception was held at the Stadhuis, an absolutely gorgeous example of 15th-century gothic architecture. Our group was welcomed in this grand hall by no less than the mayor of Leuven, Mohamed Ridouani, whose presence signified how this alliance of art and science has strengthened both communities.

Stadhuis van Leuven

The content of the meeting spanned a range of diverse topics, including the visual perception of material properties, empirical aesthetics, and historical studies of rendering techniques. There was also no shortage of visual art—the work of Maaike Schoorel being a notable example. Working from reference photographs of real scenes, she paints a kind of phantasmic representation of the original image, accentuating only the critical lines and shading that suggest the underlying forms. The effect is to break any photographic constraints on interpretation, and to allow each viewer to project their own imagery onto the canvas.

Maaike Schoorel, Oranje Boterbloemen (Orange Buttercups), oil on canvas, 2011

The work I presented at the conference also deals with visual ambiguity, specifically the kind that depends on how we estimate distances in photographs. In everyday circumstances, our ability to identify surface material properties is effortless and automatic, but occasionally this ability can be challenged, especially when the visual pattern impedes a reliable estimation of distance. This can be seen in aerial photographs of planted fields, which can appear strikingly similar to woven fabric or textile. The pattern of light does not specify which interpretation is correct, and so our interpretations reveal what distances we have learned to associate with such images.

Jacob R. Cheeseman, Hunting for Ambiguity, photograph, 2018

In Jan Koenderink’s latest book, The Way of The Eye, he frames visual perception as a process of continually questioning our interpretations of images. Our first impression of what we are looking at is usually quite convincing, but if we relax our focus, other impressions enter into view. Surrealist painters like Dali seem to possess a supernatural talent for imagining multiple interpretations simultaneously, but how to compose photographs with this property strikes me as a slightly different, and perhaps more difficult task. When I asked Dr. Koenderink how one could compose such images, he suggested that it was a matter of attentional training.

To this end, I once spent a sunny afternoon in Giessen wandering around with my camera, hunting for ambiguous scenes. Although my perception of each scene was stable, by meditating on the question, “What else could this be?”, I began to see hints of possibility. By the end of that day I had hundreds of images, but not a clue whether any of them had captured what I had seen, or whether others would agree with my interpretations. One of my basic goals at VSAC was therefore to discuss this way of seeing with visual artists who play with ambiguity.

My line of questioning went something like this: “How does one compose images with multiple interpretations? While creating visual art, are you trying to reduce disparity between a mental image and a perceived image? Does one interpretation serve as the foundation for subsequent layers?” The answers I received to these questions were also rather ambiguous, which could mean that these are not the right questions, or that I am not ready for the answers. Maybe by the time this discussion resumes at next year’s meeting, I will be.

International Colour Vision Society Meeting 2019

Written by Ruben Pastilha

The International Colour Vision Society (ICVS) is an international group of physiologists, psychologists, physicists, geneticists, optometrists, ophthalmologists and visual scientists who have a research interest in the many aspects of colour vision and colour vision deficiencies.

Ruben Pastilha presenting his paper at the ICVS 2019

This years meeting was held in Riga, Latvia and I have been fortunate enough to win the runner-up Talk Prize.

I presented my paper on The Temporal Dynamics of Daylight: Speed Limits on Perception. Relatively little is known about human sensitivity to changes in illumination spectra over time. We have been interested in the temporal dynamics and speed limits of illumination change perception, in particular, for daylight changes. People are aware that outdoor illumination varies in chromaticity throughout the day, yet we don’t seem to directly perceive these changes while they occur. Using psychophysical testing with daylight metamers in an immersive illumination setting we found that, for 21 participants, the minimum detectable speed of chromaticity change is on average about 20 times larger than the fastest changes usually occurring in natural daylight. In addition, we found that changes in illumination chromaticity towards a neutral reference are hardest to detect, for non-neutral adaptation lights. This supports the notion that the brain encodes a neutral-daylight illumination prior.

Ruben presenting at ICVS 2019

World Haptics Conference 2019

Written by Muge Cavdan

World Haptics Conference 2019 (WHC) was the first major conference that I attend to in haptics. I was super excited to see all other works in my field. Since it is not only research but also applied field-oriented conference, I saw a lot of applications of the pure research.

First day of WHC 2019’s schedule is only included workshops. A total of 5 workshops held on current topics in haptics. I had a chance to attend “Softness Perception” which is directly related to my work. My supervisor Prof. Dr. Knut Drewing also had a talk entitled “Different Dimensions of Softness and Their Associated Exploratory Procedures” in this session.

Prof. Knut Drewing giving his talk about Different Dimensions of Softness and Their Associated Exploratory Procedures.

On the other days, talks, demonstrations, posters, & discussion sessions took place. There was a great environment in which you could have the opportunity to get involve in demonstrations and talk to people from different companies and universities during breaks or discussion sessions.

Demonstration session from 3rd day

All in all, throughout my Tokyo visit I got involved in a very different culture, met a lot of people from both industry and research, and most importantly learned how limitless what I can do in research. I would like to thank my supervisors Prof. Dr. Knut Drewing & Dr. Katja Doerschner for their support during my WHC 2019 paper submission and talk preparation.