Impacts of urban green infrastructure on attentional functioning: insights from an fMRI study

Abstract

Multiple studies using various measures, technologies, and participant groups have found that exposure to urban green infrastructure can help alleviate the daily attentional fatigue that human experience. Although we have made significant progress in understanding the effects of exposure to urban green infrastructure on attention restoration, two important gaps in our knowledge remain. First, we do not fully understand the neural processes underlying attention restoration that exposure to urban green infrastructure elicits. Second, we are largely unaware of how typical patterns of urban green infrastructure, such as combinations of trees and bioswales, affect recovery from attentional fatigue. This knowledge is crucial to guide the design and management of urban landscapes that effectively facilitate attention restoration. To address these gaps in our knowledge, we conducted a controlled experiment in which 43 participants were randomly assigned to one of three video treatment categories: no green infrastructure (No GI), trees, or trees and bioswales. We assessed attentional functioning using functional Magnetic Resonance Imaging (fMRI) and the Sustained Attention Response Task (SART). Participants exposed to urban settings with trees exhibited improved top-down attentional functioning, as evidenced by both fMRI and SART results. Those exposed to urban settings with trees and bioswales demonstrated some attention-restorative neural activity, but without significant improvements in SART performance. Conversely, participants exposed to videos of urban environments without green infrastructure displayed increased neural vigilance, suggesting a lack of attention restoration, accompanied by reduced SART performance. These consistent findings offer empirical support for the Attention Restoration Theory, highlighting the effectiveness of tree exposure in enhancing attentional functioning. Future research should investigate the potential impact of bioswales on attention restoration.

Keywords: attention restoration; bioswales; fMRI; functional connectivity; green infrastructure; trees.

Figure 1

The highlighted areas are the Fronto-Parietal Control Network (FPCN), which includes the lateral prefrontal cortex (lPFC) and posterior parietal cortex in both hemispheres. The FPCN is involved in attentional control and regulates a variety of cognitive processes. Color should be used in print.

Figure 2

The Default Mode Network (DMN) consists of the medial Prefrontal Cortex (mPFC) and the Precuneus (Precun). DMN is often coupled with the FPCN during attentionally demanding tasks. Color should be used in print.

Figure 3

The Salience Network (SN) mainly consists of the Anterior Cingulate Cortex (ACC) and the bilateral insular cortex (Ins). SN is lifesaving by providing vigilance to external stimuli. Color should be used in print.

Figure 4

Example images from the NoGI, Trees, Trees & Bio categories (from left to right). Color should be used in print.

Figure 5

Experimental procedures.

Figure 6

Mean of accuracy change between the two SART tests across the three Groups (No GI, Trees, Trees & Bio). Color should be used in print.

Figure 7

dlPFC and Visual Connectivity during Video Watching. rlPFC-rMOG1 connectivity was significantly higher in the Trees group compared to the No GI group and Trees * Bio group. Color should be used in print.

Figure 8

ACC and Visual Connectivity during Video Watching. ACC-rMOG2 connectivity was significantly higher in the No GI group compared to the Trees group and Trees * Bio group. Color should be used in print.