Begoña Mateo Martínez1; José Francisco Serrano Ortiz1; Carlos Planells Palop; José Laparra Hernández1; Laura Martínez Gómez1; Ignacio Bermejo Bosch1y2; Jorge LLopis Verdú3; Juan Serra Lluch3
(1) Instituto de Biomecánica (IBV) Universitat Politècnica de València (Edificio 9C) Camino de Vera s/n (46022) Valencia (Spain)
(2) IBV’s Healhcare Technology Group. CIBER in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN)
(3) Universitat Politècnica de València (UPV)
Departamento de Expresión Gráfica Arquitectónica -ETSA. Grupo de Investigación del Color en Arquitectura y Diseño
The Instituto de Biomecánica (IBV) has determined the influence of the room color on the emotional state of the elderly in a retirement home, as well as on the improvement of their sense of direction and ambulation. Techniques based on the analysis of physiological response and eye tracking were used, which made it possible to obtain information about users in an objective and quantitative manner without interfering with their activities. The results showed the impact of color on the emotional response of the elderly, as well as the usefulness of the IBV techniques to obtain detailed information about emotional and cognitive responses, such as relaxation, stress or sense of direction.
ELDERLY PEOPLE
Elderly people account for 17% of the population, and they are expected to reach 30% by 2060. Elderly people are a heterogeneous group that ranges from people without any limitations to people with severe disabilities. However, as people get older, their abilities may change on a physical, sensory, cognitive and emotional level.
Aging can cause an increase in the demand for retirement homes, senior centers and sheltered housing. However, we must bear in mind that older people are an increasingly active group that participates in social life, enjoy leisure, and who are becoming more active consumers. It is therefore important to adapt products and services to these new demands and lifestyles of the new generations of elderly people.
In this context, there is a need to act on their environments to promote well-being and to help keep the personal development and the lifestyles of the elderly. Current products and services not only have to be functional, safe and easy to use, but also consider the emotional response they generate in older people.
EMOTIONS
Emotions may seem like an abstract or ethereal concept, but they "color and define" essential cognitive processes such as memory, preferences, motivation or decision-making. In addition, various studies highlight their impact not only on the person's well-being but also on their health.
In fact, humans can show a wide variety of emotions associated with their interaction with the objects that surround them, and these emotions can influence both the general well-being and the decisions related to these objects.
Although emotions can be categorically described, assigning labels such as joy or sadness, they can also be represented in a continuous manner through the Activity, which determines the intensity of the emotion, and the Valence, which indicates whether the emotion is positive or negative (Figure 1).
Figure 1. Two-dimensional model, activation and valence, based on Russell (1980). In square brackets, images/situations that generate this emotion.
Most assessments of the user's emotional response are based on questionnaires that turn subjective information (the user’s opinion) into objective information. However, users may feel awkward or unable to decide when the differences among the products are very subtle. Furthermore, it is well known that the emotional response is partially processed unconsciously.
The analysis of the physiological response helps to better understand the unconscious response of people, in an objective and quantitative way, without influencing the user. It is combined with techniques such as eye tracking to help understand the conscious cognitive processes in decision-making.
How both techniques were used by the IBV in order to take up the challenge is described as “Identifying the most appropriate colors to induce different moods and determine the best color combinations to improve the sense of direction, location and ambulation in retirement homes.”
ANALYSIS OF THE PHYSIOLOGICAL RESPONSE
During the past 15 years, different body signals have been used to assess the emotional response, such as facial electromyography (EMG), heart rate, blood pressure, electroencephalography (EEG), temperature, respiratory rate and skin conductivity (GSR). The following signals should be noted:
• Heart rate variability (HRV) is associated with the balance between the sympathetic and parasympathetic nervous systems. HRV is inversely related to the intensity or emotional activation. When there is a high cognitive or emotional demand, the heart shows a steady rhythm to optimize performance, reducing heart variability. In contrast, when the person is in a state of relaxation or low activity, the heart rhythm is more variable, since it does not need to optimize the body's performance, thus increasing variability.
• Galvanic skin response (GSR) reflects the activity of the sweat glands, which respond to changes in the sympathetic nervous system. An increase in the level of emotional activation causes an increase in the level of GSR. The GSR signal has two components, a tonic component, which changes slowly, and a phasic component that is responsible for rapid variations, such as the response to a stimulus.
The physiological variables were recorded with the Biosignalplux® by Plux wireless Biosignals S.A., using GSR (galvanic skin response) sensors placed on the subjects' hands and ECG (electrocardiogram) sensors on the chest.
GAZE ANALYSIS
Visual exploration consists of fixations and saccadic movements. Fixations involve maintaining the gaze on a point, and are associated with cognitive processes, such as processing a complex image. Saccadic movements are fast movements (30ms-120ms) related to information search processes. In fact, during the saccadic movements, "visual agnosia" occurs, which means that we stop seeing, even if we are not aware of it.
IBV has 3 devices to record visual gaze: 1) Eyetracker Tobii® T120, which is integrated into a 17-inch screen to assess images (used in this project); 2) Tobii Pro Fusion ®, a portable system that can be integrated into any screen or tablet for remote assessment; and 3) Eyetracker Tobii® T120, which evaluates real environments and objects.
The first analysis allows us to obtain the heat maps (Figure 2, left), that is, on which areas of the image the user has focused, or even analyze the scanning pattern that the user has followed (Figure 2, right).
Figure 2. Example of a heat map and scanning pattern of an older person who is looking for his room.
However, for a further analysis, on the basis of the fixations and saccadic movements, various parameters can be calculated, such as the number of fixations, associated with low search efficiency, or the distance between saccadic movements, associated with a greater number of clues in the image that help to quickly locate information. The IBV has specific algorithms to analyze in detail the visual exploration of a product, evaluate aesthetic stimuli or assess the complexity of a task.
The experimental design performed by the IBV to assess the emotional impact of color on the elderly is briefly described below.
TESTING
A sample of 20 people over 70 years old was evaluated. The color alternatives of the activity room and the bedroom included six images of the same room with different wall colors: three cool colors and three warm colors (Figure 3).
Figure 3. Examples of color variations in the rooms.
Finally, the chromatic stimuli of the activity room consisted of enveloping images shown in virtual reality glasses, whereas in the case of the bedroom, the stimulus was shown on a 50-inch screen (Figure 4).
Figure 4. Elderly person evaluating the room with the Virtual Reality system.
RESULTS
The analysis of the physiological response (HRV and GSR) of the elderly made it possible to detect differences in the impact of the different colors. More specifically, to determine which colors generate a greater emotional impact (the level of activation rises), and which reduce the emotional impact (they contribute to greater relaxation or a lower level of activation).
The blue activity room is the one that produces the least activation and is the most relaxing for both genders, whereas the room that produces the greatest activation is the yellow one in women and the red one in men Therefore, the blue color is recommended to promote relaxation in these rooms; and, depending on gender, yellow or red to breathe energy into the elderly.
Similarly, in the case men, the red/pink color causes the least activation in the bedroom; while the violet is the one that generates the most emotional activation. These two colors have a different effect in women, since for them the red bedroom causes activation, whereas the violet one, relaxation.
In the case of the hallway, users chose the orange-blue combination as the most appropriate for locating objects. This combination also showed the greatest distance between the fixations of the gaze, that is to say, a greater search efficiency than the rest of color combinations. Therefore, this indicates that the choice is based on the most appropriate contrast optimization for each user, which allows them to visually explore the room in a more efficient way.
CONCLUSIONS
The analysis of the physiological response, HRV and GSR, made it possible to obtain the emotional response of the elderly in an objective and quantitative way, which allowed us to know the emotional activation generated by each color. In addition, eye tracking assessed how the color combinations contribute to the sense of direction and ambulation through a hallway.
The results confirmed that the level of emotional activation that a room causes can be modified by varying only its color, which involves that relaxation can be induced in situations of anxiety, and states such as sadness or apathy can be reversed using colors that promote activation.
In addition, the results suggest different physiological responses in men and women. Therefore, these differences must be considered when designing proposals to improve the well-being and satisfaction of the elderly in retirement homes.
Finally, the improvement provided by virtual reality immersion should be highlighted, since it has been proved to increase the emotional reaction of the subjects to the different chromatic stimuli, which is reflected in the physiological variables (Figure 5). In addition, no negative effects have been detected when applied to elderly users, which opens the doors to new experiences that include virtual reality and a higher level of interaction, such as the use of an interface or the control panel of an electric car.
Figure 5. Differences in the mean values and the level of activity in the GSR depending on the type of stimulus and/or activity.
ACKNOWLEDGMENTS
This study is part of the project whose acronym MODIFICA and titled: "Modifications of Visual Comfort in Residential Centers for the Improvement of the Quality of Life of the Elderly", is led by Dr. Ana Torres Barchino of the Color Research Group in Architecture of the University Institute for Heritage Restoration of the Universitat Politècnica de València.
This call is co-financed by the State Research Agency (AEI) and the European Regional Development Fund (FEDER) as funding bodies. (AEI/FEDER, UE) 2016-2019.
The project MODIFICA, arises as a response to the progressive phenomenon of aging of the population, which, with the consequent demand for residential centers, becomes an architecture that cannot be ignored.
Aims to establish guidelines for the chromatic characterization of the different types of architectural spaces intended for the elderly, in order to achieve habitability specifically adapted to their needs in order to promote the well-being and facilitate the personal development and improvement of the individuals residing there.
