An Analysis of Visual Behavior Characteristics of Naturalistic Gardens Using Eye-Tracking

Article information

J. People Plants Environ. 2024;27(6):615-622
Publication date (electronic) : 2024 December 31
doi : https://doi.org/10.11628/ksppe.2024.27.6.615
1Professor, Department of Landscape Architecture, Kyungpook National University, Daegu 41566, Republic of Korea
2Ph.D. Candidate, Department of Landscape Architecture, Kyungpook National University, Daegu 41566, Republic of Korea
*Corresponding author: Qian Wang, qiany@knu.ac.kr
First authorHyung-Sook Lee, soolee@knu.ac.kr
Received 2024 October 28; Revised 2024 November 11; Accepted 2024 November 17.

Abstract

Background and objective

As the understanding of biodiversity and sustainable ecological landscapes has increased, public interest in naturalistic landscapes has grown. However, naturalistic landscapes are still often seen as messy or even unsafe, and research findings on public perceptions remain inconsistent. The purposes of this study were to analyze public’s perception of naturalistic landscapes in Korea and to explore the value of naturalistic landscapes. Research on naturalistic landscapes in Korea remains limited. Therefore, the purpose of this study was to analyze public’s perception of naturalistic landscapes in Korea, and explored the value of naturalistic landscapes.

Methods

This study explores the perceived value of naturalistic landscapes in Korea in terms of ecological value, aesthetics, and preference for naturalistic and formal landscapes. An eye-tracking experiment was conducted to investigate the visual patterns of participants and differences in their attention toward the landscape elements of naturalistic and formal landscapes. Forty participants evaluated six images (three naturalistic landscapes and three formal landscapes) containing six elements (trees, shrubs, flowers, water, buildings, and hardscapes).

Results

The results revealed significant differences in perception between naturalistic and formal landscapes. Although participants were more familiar with formal landscapes, they had a higher perception of the ecological value, aesthetics, and preference for naturalistic landscapes. The eye-tracking results showed that the visual patterns were relatively dispersed across the naturalistic landscapes, while they were more concentrated in the formal landscapes. Participants spent more time looking at shrubs and flowers in the naturalistic landscapes. In the formal landscapes, attention was drawn more to hardscapes, buildings, and water.

Conclusion

These findings suggest that naturalistic landscapes not only benefit biodiversity and ecological sustainability but also align with public aesthetics. There is thus a need to consider incorporating more naturalistic landscapes into urban landscape design and to explore natural planting methods and compositional schemes that highlight their value.

Introduction

With rapid urbanization and population growth, urban parks and gardens have become important places where people can establish a relationship with nature. The formal “high culture” landscape style has had a significant impact on urban landscape design (Surratt, 2010). These landscapes are usually characterized by a manicured look, neat grasslands, and exotic plant species (Twedt et al., 2016). While formal landscapes provide opportunities for the public to engage with the natural environment, the introduction of many exotic plants can also lead to a loss of ecological functions and the homogenization of landscapes (Quigley, 2013). And the excessive management also requires significant human and financial resources. Consequently, the naturalistic landscapes, with their greater ecological significance and biodiversity conservation (Paek and Lee, 2018), has been explored and gradually integrated into urban and surrounding environments.

Some studies have suggested that, although people’s understanding of natural environments within urban areas is evolving, they still perceive naturalistic environments to be messy, disorderly, or even dangerous (Forbes et al., 2013). However, in recent years, people hold positive attitudes towards the aesthetics and restorative effects of more natural planting structures (Hoyle et al., 2017). People’s preference for naturalistic woodland garden is higher than urban ones (Kim et al. 2023). As these studies suggest, there are no consistent findings regarding public perceptions of naturalistic landscapes. In addition, research on public perceptions of naturalistic landscapes has predominantly focused on Western countries, with limited attention given to Asian regions, particularly South Korea. It is thus important to understand public attitudes and perceptions towards naturalistic landscapes, which have gained in popularity in Korea.

Previous studies have widely used subjective assessment methods, such as photographs and self-reports or interviews to evaluate landscape perceptions (Berto, 2005). Recent researches have used electroencephalography (Reece et al., 2022) and eye-tracking technology to measure landscape perceptions objectively and quantitatively (Amati, et al., 2013). Eye-tracking technology is particularly convenient because it allows researchers to record eye movement responses and behaviors, providing insights into visual attention and engagement for specific landscape characteristics or elements (Batool et al., 2022). For example, Nordh et al. (2013) evaluated the pocket park using eye tracking and found that the components that the participants looked at most were trees, followed by benches and bushes. Similarly, Batool et al. (2022) measured the preference and its relationship with gaze behavior using eye tracking. They found that the more a participant preferred a scene, the more exploratory their gaze became, with a higher number of fixations and saccades.

Research using eye-tracking technology has mostly focused on eye movements in urban green spaces and parks, with relatively few studies examining visual patterns and differences in attention to various elements within naturalistic landscapes. Therefore, this study explores the value of naturalistic landscapes in Korea by assessing the ecological value, aesthetic perceptions, and preference for naturalistic and formal landscapes. Additionally, it investigates differences in attention to landscape elements between these two types of landscape. Specifically, this study attempts to answer three questions:

1) What differences are there in the public perception of naturalistic and formal landscapes?

2) What differences are there in the visual patterns exhibited when viewing naturalistic and formal landscapes?

3) What differences are there in the attention paid to the landscape elements of naturalistic and formal landscapes?

Research Methods

Stimuli

Landscape photographs were used in this study as the stimuli (Palmer, and Hoffman, 2001). Previous studies were consulted to establish specific definitions, characteristics, and elements of formal and naturalistic landscapes (Twedt et al., 2016; van den Berg and van Winsum-Westra, 2010). In this study, formal landscapes were defined as those with a neat appearance, geometric or artificial elements, and flat terrain, while naturalistic landscapes had a more natural look with fewer architectural elements and less evidence of human intervention. Based on these criteria, suitable images were obtained through site visits in Korea and Google image searches. On-site photos were taken using an iPhone 13 at a fixed camera height of 1.6 m between 11 am and 4 pm on a sunny day. A total of 10–12 garden photos were screened by type. After being reviewed by three landscape experts, a total of six garden photos were selected (Fig. 1).

Fig. 1

Representative images of the naturalistic (a) and formal landscapes(b), and example of AOI classification(c).

To explore the differences in attention toward landscape elements of the two landscapes, Adobe Photoshop was used to mark and set the areas of interest (AOIs) (De Smet et al., 2014) while excluding non-landscape components like the sky (Nordh et al., 2013). Six AOIs were established for the six images: trees, shrubs, flowers, water, buildings, and hardscapes. The relative area of each AOI was calculated by dividing its area by the area of the entire image using Auto CAD (Fig. 1).

Questionnaire measures

In the landscape perception evaluation, familiarity was included to assess participants’ recognition with the landscape, as it can significantly influence their overall perception (Kaplan and Kaplan, 1989). Ecological value was measured to rate participants’ awareness and appreciation of the landscape’s sustainability (Nassauer, 1995). Aesthetics was selected to evaluate the visual appeal of the landscape, which plays a crucial role in shaping emotional responses and satisfaction (Gobster et al., 2007). Preference was measured to determine participants’ overall liking of the landscape (Ulrich, 1983). Under the item of familiarity, participants were asked to respond to the statement: “It’s a familiar scene to me.” For ecological value, the query was: “That is a place with ecological value.” The item of aesthetics was addressed with the question: “This place has an attractive landscape.” To determine preference, participants were asked with: “This is my preferred scene.” All of the items were measured on a 7-point Likert scale (1 = strongly disagree, 7 = strongly agree).

Procedure

The experiment was conducted in the Landscape Architecture Laboratory of Kyungpook National University from June to July 2022. Upon arrival at the laboratory, the participant filled out a research consent form and rested briefly for 5 min to familiarize themselves with the laboratory environment before providing their socio-demographic details. A GP3 HD eye tracker, from Gazepoint, was used to record the eye movements of the participants. A 5-dot calibration procedure was conducted firstly. Following this, participants were asked to view the images freely. Each image was presented for 15s (Dupont et al., 2014). After the eye-tracking experiment, the participant was asked to observe the images freely while completing the perception questionnaire. The entire experiment lasted approximately 20–25 min for each participant. This study was approved by the Institutional Review Board of University (KNU-2022-0141) and all participants provided informed consent.

Data collection and analysis

Statistical analysis of the data was conducted using SPSS 26.0. Because the data did not follow a normal distribution and the sample sizes were small, the Mann-Whitney U test and Pearson correlation analysis were used to compare the differences and relationship in perception between naturalistic and formal landscapes. Heat maps were constructed to analyze visual patterns, and the relative fixation duration for each AOI was calculated to analyze attention to the landscape elements. The statistical significance level in this study was at 0.05.

Results and Discussion

Landscape perception

The study included a sample of 40 participants, consisting of 21 males and 19 females. According to the results of the Mann-Whitney U test (Table 1), there was a significant difference in familiarity between naturalistic and formal landscapes (p < .001) with participants showing more familiarity with formal landscapes (M = 4.68) than naturalistic landscapes (M = 3.98). There were also significant differences in ecological value, aesthetics, and preference between two landscapes (p < .001). Participants preferred naturalistic landscapes to formal landscapes, believing naturalistic landscapes to have greater ecological value and to be more aesthetically pleasing. The results of the correlation analysis for the landscape perception items (Table 2) showed that familiarity had a negative correlation with ecological value (r = −0.245, p < .001), meaning that participants perceived unfamiliar landscapes as having higher ecological value. The relationship between ecological value and aesthetics (r = 0.573, p < .001), ecological value and preference, (r = 0.526, p < .001), and preference and aesthetics (r = 0.827, p < .001) were significant and positive. This means that higher ecological value is associated with greater aesthetic appeal and preference, while landscapes preferred by individuals tend to be perceived as more aesthetically pleasing.

Comparative evaluation of the perception of the two landscapes (Mann-Whitney U test)

Correlation between landscape perception items (Pearson analysis)

Visual patterns

Heatmaps that were generated by overlaying the fixation data from all of the participants (Fig. 2). Regions with longer fixation durations appear in red, followed by yellow and green, while areas with shorter fixation durations are depicted in blue. In the present study, when viewing the naturalistic landscapes, the participants’ visual patterns were relatively scattered, while they were more focused when viewing the formal landscapes. This suggests that the participants had a relaxed viewing experience when viewing the naturalistic landscapes, where attention is not focused on a particular area of the landscape. With the naturalistic landscapes, the fixations were more focused on shrubs (N1 and N2) and water (N3) while, with the formal landscapes, participants were more attracted to the sculptures (F1 and F2). In addition, brightly colored flowers attracted stronger gaze behavior among the participants.

Fig. 2

Heatmaps for the naturalistic (N1, N2, N3) and formal landscapes (F1, F2, F3).

AOI analysis

Because differences in the relative area of the AOIs affect the fixation duration time, the relative fixation duration time for the AOIs was calculated by dividing the fixation duration by the relative area of each AOI (Table 3, Fig. 3). With the naturalistic landscapes, participants spent the longest relative fixation duration on flowers (18.06) in N1, shrubs in N2 (15.25). In N3, participants spent the longest relative fixation duration on shrubs (20.45). Although hardscapes had the largest areas in N3, the relative gaze duration was the shortest for these. Overall, participants had higher relative fixation durations on shrubs, flowers, and trees, while water, buildings, and hardscapes received less attention. In formal landscapes, participants spent more time gazing at smaller areas like water, buildings, and hardscapes, despite their limited size in F1 and F2, while spending less time on larger shrubs and trees. In F3, flowers, which covered the smallest area, received the longest fixation. Overall, participants focused more on smaller areas (hardscapes, buildings, water, flowers) and less on larger areas like shrubs and trees.

AOI analysis of the six images

Fig. 3

Relative fixation duration for the naturalistic and formal landscapes. *p < .05, **p < .01, ***p < .001.

Conclusion

This study explored the value of naturalist landscapes by comparing public perceptions of ecological value, aesthetics, and preferences between naturalistic and formal landscapes. In this study, participants preferred naturalistic landscapes to formal landscapes, although they considered formal landscapes to be more familiar. This finding is inconsistent with previous studies, suggesting the public prefers manicured or formal gardens over naturalistic ones (Hitchmough and Woudstra, 1999; Khew et al., 2014). Additionally, as awareness of the increasing severity of climate change and environmental damage grows, Korea has intensified its focus on eco-cities, biodiversity, and environmental protection issues. This emphasis may have contributed to a greater public awareness of ecological conservation (Ha et al., 2023; Haddad, 2023). In addition, participants perceived naturalistic landscapes to have more ecological and aesthetic value than formal ones. This is consistent with previous research, indicating that minimal human intervention enhances both (Jankevica, 2012; Twedt et al., 2016). The results show that naturalistic landscapes are beneficial to biodiversity and ecological sustainability, while also being beneficial for psychological restoration (Young et al., 2020). Landscapes with species richness and colour diversity of plants are also perceived by the public as beautiful and engaging (Hao et al., 2024).

Previous research suggests that a longer fixation duration indicates greater attention and interest in an object (Franěk et al., 2018). This study found that participants focused more on shrubs and flowers in naturalistic landscapes, with less interest in hardscapes, likely due to the positive emotions induced by bright colors (Haviland-Jones et al., 2005; Huang and Lin, 2020). In formal landscapes, despite their smaller area, hardscapes and water drew longer gazes. This finding aligns with previous research, suggesting that hardscapes may draw more attention from participants due to their distinct edges, contrasting colors that differ from the landscape background (Amati et al., 2018). This is also consistent with previous research showing that people tend to focus on elements that can be used (Kim et al., 2013). Furthermore, hardscapes attract longer fixations possibly because they often represent concrete, functional elements that are familiar to participants (Svobodova et al., 2011). The perceptions of landscapes tend to differ between cultures and countries, with studies from the UK, the Netherlands, and Singapore showing a public preference for manicured landscapes over naturalistic ones (Khew et al., 2014; Özgüner and Kendle, 2006; van den Berg and van Winsum-Westra, 2010). Though there are many differences in the design of the landscapes between these countries, these studies in these countries may not be generalizable to Asian countries. Therefore, understanding the public perception of different landscapes in Asian countries is important. By comparing and analyzing the perception of naturalistic and formal landscapes among Korean citizens, this study helps the understanding of public attitudes toward landscape perception in Asian countries.

For urban planners and landscape architects, it is crucial to create balanced environments that incorporate a mix of natural and artificial elements to cater to diverse preferences and functional needs. It is necessary to consider promoting the value of naturalistic landscapes and to explore naturalistic planting methods and composition schemes that can highlight these benefits. Future research should explore how these elements interact to create ecologically and psychologically enriching urban landscapes. The current study has several limitations that need to be considered. Firstly, the use of undergraduate and graduate students as participants may have influenced the results of the experiment because they may have received education in landscape-related fields. Secondly, the use of images for landscape perception in this study only allows the visual perception of the landscape to be considered, whereas other factors such as smell, sound, or temperature can influence the perception of real landscapes. Therefore, future studies should consider using dynamic stimuli or real-world experiences to create an immersive environment to evaluate the perception of landscapes.

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Article information Continued

Fig. 1

Representative images of the naturalistic (a) and formal landscapes(b), and example of AOI classification(c).

Fig. 2

Heatmaps for the naturalistic (N1, N2, N3) and formal landscapes (F1, F2, F3).

Fig. 3

Relative fixation duration for the naturalistic and formal landscapes. *p < .05, **p < .01, ***p < .001.

Table 1

Comparative evaluation of the perception of the two landscapes (Mann-Whitney U test)

Variable Landscape Mean S.D. Mann-Whitney U p
Familiarity Naturalistic 3.98 1.39 5133.00 0.000***
Formal 4.68 1.38

Ecological value Naturalistic 4.97 1.27 758.50 0.000***
Formal 2.38 0.81

Aesthetics Naturalistic 5.46 1.14 3130.00 0.000***
Formal 4.18 1.15

Preference Naturalistic 5.27 1.35 3808.00 0.000***
Formal 4.09 1.28
*

p < .05,

**

p < .01,

***

p < .001

Table 2

Correlation between landscape perception items (Pearson analysis)

1 2 3 4
Familiarity 1
Ecological Value −0.245** 1
Aesthetics −0.109 0.573** 1
Preference 0.015 0.526** 0.827** 1
*

p < .05,

**

p < .01,

***

p < .001

Table 3

AOI analysis of the six images

Trees Shrubs Flowers Water Buildings Hardscapes Sky/Other Total
N1 FD a) 3.66 1.57 5.41 0.00 1.26 0.00 3.09 15
Area b) 0.30 0.24 0.30 0.00 0.16 0.00 0.00 1
RFD c) 12.20 6.50 18.00 0.00 7.88 0.00 - -
N2 FD 3.54 6.16 2.28 0.00 0.00 0.00 3.02 15
Area 0.40 0.40 0.20 0.00 0.00 0.00 0.00 1
RFD 8.85 16.65 11.40 0.00 0.00 0.00 - -
N3 FD 1.58 7.40 0.00 1.16 0.00 1.58 3.28 15
Area 0.17 0.36 0.00 0.13 0.00 0.28 0.06 1
RFD 9.29 20.56 0.00 8.92 0.00 5.64 - -

F1 FD 1.67 3.54 0.00 1.28 1.16 3.63 3.72 15
Area 0.20 0.42 0.00 0.04 0.11 0.06 0.17 1
RFD 8.35 8.43 0.00 32.00 10.55 56.00 - -
F2 FD 0.84 3.52 0.00 0.00 3.57 2.36 4.70 15
Area 0.12 0.43 0.00 0.00 0.14 0.08 0.22 1
RFD 7.00 8.19 0.00 0.00 25.50 29.50 - -
F3 FD 3.02 3.86 1.32 0.00 0.74 2.33 3.74 15
Area 0.28 0.28 0.05 0.00 0.08 0.15 0.16 1
RFD 10.79 13.79 26.40 0.00 9.25 15.53 - -
a)

FD: Fixation duration, measured in seconds, that the length of time the eye stays on an element

b)

Area: area of each element/area of the entire image, expressed as a unitless value or percentage. For example, a value of 0.3 would represent 30% of the total image area.

c)

RFD: Relative fixation duration; the fixation duration of an element/area of the element, resulting in a unitless ratio.