How is symmetry processed and how does that influence visual preference?

Lead Research Organisation: University of Liverpool
Department Name: Institute of Psychology Health & Society


Everyone has experienced the sensation of looking at something beautiful, or made judgments about what they like and what they don't find appealing. But what happens between the cells that respond to light hitting the eye, and the time when we state our preferences? Unlike other thinkers concerned with aesthetics, such as philosophers and art critics, researchers working on cognitive neuroscience aim to discover how the humans process input from the senses (such as visual or hearing) and produce the emotional responses (pleasure) and preferences (overt judgements or tendencies to act in a particular way).

In most experiments, we will present people with different types of visual symmetry on a computer screen. Symmetry is important because an infinite number of symmetrical patterns can be generated - so we never have to show the same image twice. It is also interesting because symmetry appears throughout all cultures in human art and architecture. Animals are also sensitive to visual symmetry - so this is unlikely to be a cultural whim. We are interested in the links between the parts of the brain that detect visual symmetry, and those that produce emotional responses or overtly reported preferences.

The project will be split into six work packages, which will be shared between our national and international partners. WP1 will look at the relationship between detection speed and preference. It could be that the patterns that are most rapidly detected are the ones we like most. When we look at the world, we move our eyes all the time, therefore, WP2 will use an specialized eye tracking camera to measure peoples eye movements when they look at different kinds of symmetry. It could be that particular pattern of eye movements, for example, left to right, enhance preference. WP3 will measure brain activity using electrodes placed on the scalp. Patterns that produce more activity in the visual parts of the brain might be preferred to those which produce less visual activity.

In WP4 we will pioneer the use of new equipment to explore visual beauty. For example, in one study, we will use a computer program that implements a 'genetic algorithm'. Over many trials, the program produces patterns based on those that are looked at for the most time. The technique may have industrial applications, for example when designing graphics which most people find appealing. WP5 also explores new techniques with potential, real-world applications. It involves the use of Virtual Reality (VR) to present a room with different visual properties. It could be that the choice of patterns on the virtual walls speed up, or slow down the mental processing of emotional words, such as 'Love' or 'Hate'. This experiment will be conducted in Germany with Professor Heiko Hecht, who has used VR before. The experiment could produce a new tool for future interior designers, who want to test the psychological impact of their creative decisions. Finally, for WP6 we will discuss our ideas with the local art community in order to create a science-art dialogue, which is often lacking. WP6 will span the entire duration of the project, involving three annual meetings and a specialized workshop with both artists and scientists in year three.

In summary, this work will explore the brain-basis of beauty. It will help us understand the links between visual systems which detect patterns and other systems which produce emotional responses or aesthetic judgements. It will also develop two new techniques for exploring aesthetic processing, both of which have potential uses beyond the academic world. We hope this work will take research on aesthetics to exciting new places.

Planned Impact

Given the range of techniques that we will use to investigate symmetry, there is a variety of potential impacts outside academia. These impacts range from arts to marketing and information technology.

Contributions to Culture and Society
In many aspects of human cultures, great emphasis is placed on the concept and experience of beauty. Understanding how the human mind converts patterns of sensory input into subjective aesthetic pleasure, and how this drives preference, is therefore of general interest beyond academia. We plan to actively interact with and disseminate our findings to artistic communities. For example, we will present our work in local galleries (Open Eye and FACT) thereby reaching out to arts practitioners and the public. We will engage scholars at these institutions both by discussing our work, and by asking them to make predictions about results of experiments based on their own intuitive understanding of what it means to be an artist (WP6). The aim is to engage artists and people working in creative industries with the scientific study of aesthetics. We have also provided the contact details of two artists (under Users), one in Liverpool (Carl Hunter) and one in New York (Anita Sto) who know about our work and can conform their interest.

Industrial applications
The proposed work involves developing new methods for measuring implicit preferences. Such measures could be very attractive in commercial settings. We will build on work investigating eye movement in relation to preference. Early work was sponsored by Proctor and Gamble, and is now under further development by Acuity Intelligence Ltd. A more advanced investigation along these lines, focusing on symmetry, will be at the centre of our Work Package 4 at RHUL, involving Tim Holmes as consultant. Together with Professor Johannes Zanker, he has developed a computer algorithm that presents an array of different stimuli, evaluates preference using an eye tracker, and adapts the stimulus set accordingly. Through a number of stimulus 'generations', a set of pattern is evolving that resembles the preferred design. We will use this genetic algorithm to measure the evolution of aesthetic preferences for visual regularity and symmetry. Once the system has been optimized and validated, it will have immediate commercial applications, and industrial partners already showed considerable interest to use such methods for packaging or the organization of shelf displays. As a proof of concept, the procedure has already been used to investigate optimal crisp package designs.

In WP5 we are going to use a virtual reality system in collaboration with Professor Heiko Hecht at the University of Mainz. We will test if the findings of from our laboratory in Liverpool generalize to a 3D environment by manipulating the patterns on the walls of a virtual room. If the environment affects emotional processing, interior designers may be keen to apply the methodology to test the psychological impact of their plans for user-friendly of public spaces. The advantage of implicit procedures compared to overt verbal reporting is clear: with overt reports, participants may just try to say what they believe the researcher wants to hear, or simply avoid giving honest answers. Implicit preference measures avoid this problem, and thus more accurately approximate emotional processing in the real world, where there is rarely any obligation to report every subtle aesthetic impression. This has immense potential to boost the validity of market research in general.

In sum, whilst the current project will be of interest to academics working in aesthetics, the outcomes will go beyond this group of immediate users. We have specifically tailored certain experiments to engage a wider audience including those working in creative industries, and to have an impact on non-academic/commercial applications.


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Description We have carried out a systematic series of experiments to investigate the link between visual detection of symmetry and emotional responses, in particular preference formation.

One series of studies has used behavioural experiments to map the relationship between detection speed for different visual symmetries, such as reflection, rotation and translation, and preference for these patterns. Later in the project we have also explored some other formal aspects of the image, in particular the smoothness of the contours of a shape.

Another series of studies explored when visual areas of the brain are activated. In particular whether seeing a symmetric pattern was enough to activate these regions, or whether attention was necessary. Another key question was whether the response was a response to symmetry in the image or symmetry in an object that may be seen in perspective or partly occluded.

Our findings are reported in a series of papers (21 in total). With respect to the first aspect we have concluded that emotion is not a simple reflex, that is positive valence does not emerge by mere presentation of symmetry. However, when engaged in looking for symmetry positive associations are present when the stimulus is symmetrical as opposed to random (asymmetrical).

With respect to smooth curvature, we have documented a very strong and robust effect of smooth curvature on preference. This phenomenon has been known for a long time, but it had never been studied systematically.

With respect to the second aspect, we have shown that an activation in visual areas is present always when symmetry is present in the image. This is a visual response to the information I the stimulus. This is not in itself enough to generate positive valence, as mention above. However, these visual areas are also activated by symmetry that is not in the image, like when a pattern is presented in a slanted plane. This is possible through directing the attention of the observers to this aspect of the stimulus.
Exploitation Route During the period of the Grant we have had exciting and productive exchanges with organisations outside academia, in particular artistic organisations (e.g. FACT Liverpool), and with colleagues that use neurophysiological measures for symmetry perception.
Sectors Creative Economy,Education,Healthcare,Leisure Activities, including Sports, Recreation and Tourism

Description The project was a study of fundamental aspects of visual perception and emotion. In this sense the outcome were mainly scientific and the main beneficiaries were academic. However, we had planned and worked on the engagement of a wider community. In particular the original application mentioned interest in our work from two organisations based in Liverpool, FACT (foundation for art and creative technology) and Open Eye Gallery (a museum specialised in photography. The curator at Open Eye who wrote the letter left soon after and is not working in Liverpool any longer, but we have kept in contact with the museum. With FACT our collaboration has been stronger and very productive. In the summer of 2015 we organised the European Conference on Visual Perception on campus. Marco Bertamini was the main organiser. This is a scientific conference but we integrated in the event other aspects that involved the larger community and the city. The conference was attended by approximately 1000 delegates from many countries. Just before the conference we had an event in the Everyman Theatre. This is a well-known theatre in Liverpool located near the University. We screened the documentary "Tim's Vermeer" and we had a panel of experts including Tim Jenison (the protagonist of the documentary) Prof Sir Colin Blakemore, Prof Sir Colin Blakemore, Prof Christopher Tyler, Prof Philip Steadman. This event was publicised as open to the public and free. More information: Another event free and open to the public was called Illusions Parade. This took place in a venue called Camp and Furnace (Baltic triangle). It combined scientists who demonstrated some illusions with interactive demos, and artists that had prepared works inspired by visual illusions. More information: The conference included a satellite meeting on Visual Science of Art (VSAC) and a symposium on Neural Responses to Symmetry. Both of these events were relevant for the research project funded by the Grant. They provided a chance of discussion and collaboration with our international colleagues. The symposium in particular was followed-up by a special issue in the journal Symmetry, edited by Bertamini and Griffin. More info: During the same period, we facilitated a collaboration that included Johannes Zanker (one of the CI on the Grant) and the TATE Liverpool. This project involved data collected within the museum using a mobile eye tracker. Another event that is more directly linked to the Grant is a one-day workshop on "Visual properties driving Visual Preference". We organised the first such workshop in January 2015 and the second in March 2016. We already have plans to continue holding this as an annual event. Although most of the participants to the workshop were academics (but not just Psychology, for instance we invited colleagues from Archaeology), we have included other members of the public and in particular people working on cultural and artistic projects. For instance in 2015 we had an artist who had worked on a "fractal clock" and both in 2015 and 2016 we had the Research and innovation Manager from FACT who attended the workshop (Roger McKinley). In addition, in 2016 we had two invited participants at the workshop from Unilever. This workshop has now been established as an annual event, in 2019 it will be the 5th event. More information here:
Sector Culture, Heritage, Museums and Collections
Impact Types Cultural,Societal

Description Unilever 
Organisation Unilever
Department Unilever UK R&D Centre Port Sunlight
Country United Kingdom 
Sector Private 
PI Contribution We have begun a collaboration with Unilever to discuss ways to measure aesthetic preference. This is of interest to the consumer psychologists at Port Sunlight R&D plant on the Wirral
Collaborator Contribution We gave a set of talks at Unilever, and we are in continued contact with them about future collaborations. Unilever are now constructing a lab in the Psychology department at Liverpool, so we anticipate continued collaboration.
Impact Unilever were a collaborator on an ERC research grant submitted by Makin in 2015
Start Year 2015
Description Aesthetics Workshop 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact We held an workshop about 'visual properties driving visual aesthetics' in University of Liverpool. This involved academics, but also artists and students.
Year(s) Of Engagement Activity 2015
Description European Conference on Visual Perception 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact In August 2015 we held the ECVP conference in Liverpool. I was on the organizing committee. Although this was an academic conference about vision science, there were numerous spin offs and public engagement excercises around the city, including the illusions parade at Camp and Furnace, a screening of the Film 'Tim's Vermeer' at the Every man theater followed by a panel discussion with the director. This was also an economic contribution to the city of Liverpool. Various industrial sponsors were present
Year(s) Of Engagement Activity 2015
Description VSAC conference 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact This conference was not just for academics, there were also local artists and industrial partners present
Year(s) Of Engagement Activity 2015
Description Visual properties driving visual aesthetics workshop 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact This was a follow up to our previous Aesthetics workshop, help in 2015. This time we also invited delegates from Unilever, who are interested in aesthetics and its relationship to pack design. There were also high profile academics from across Europe. This boosts the Uk research profile.
Year(s) Of Engagement Activity 2016