Walking through Architectural Spaces: The Impact of Interior Forms on Human Brain Dynamics

Abstract

Neuroarchitecture uses neuroscientific tools to better understand architectural design and its impact on human perception and subjective experience. The form or shape of the built environment is fundamental to architectural design, but not many studies have shown the impact of different forms on the inhabitants' emotions. This study investigated the neurophysiological correlates of different interior forms on the perceivers' affective state and the accompanying brain activity. To understand the impact of naturalistic three-dimensional (3D) architectural forms, it is essential to perceive forms from different perspectives. We computed clusters of form features extracted from pictures of residential interiors and constructed exemplary 3D room models based on and representing different formal clusters. To investigate human brain activity during 3D perception of architectural spaces, we used a mobile brain/body imaging (MoBI) approach recording the electroencephalogram (EEG) of participants while they naturally walk through different interior forms in virtual reality (VR). The results revealed a strong impact of curvature geometries on activity in the anterior cingulate cortex (ACC). Theta band activity in ACC correlated with specific feature types (r_s (14) = 0.525, p = 0.037) and geometry (r_s (14) = -0.579, p = 0.019), providing evidence for a role of this structure in processing architectural features beyond their emotional impact. The posterior cingulate cortex and the occipital lobe were involved in the perception of different room perspectives during the stroll through the rooms. This study sheds new light on the use of mobile EEG and VR in architectural studies and provides the opportunity to study human brain dynamics in participants that actively explore and realistically experience architectural spaces.

Keywords: EEG; HMD; architectural interior form; mobile brain/body imaging (MoBI); neuroarchitecture; virtual reality.

Figure 1

Experimental setup. (A) Displays a participant while walking inside the laboratory wearing a head-mounted VR display (HTC Vive), the virtual room, and an electroencephalogram (EEG) cap. The participant provided written consent that the video recordings may be used in scientific publications. The blue box displays the borders of the walking space and the yellow box indicates the dimensions of the virtual room. The instructed walking paths are marked in red and all the walls and the door of virtual room are displayed in yellow. (B) Left: displays a participant wearing the head-mounted display (HMD; HTC Vive) and holding a controller in his hand. The EEG transmission systems were located in a backpack. The HMD cable was connected to the rendering PC and was extended to allow free movement of participants, Right: close view on the HMD place on an electrode cap with 128 actively amplified electrodes.

Figure 2

Block diagram of the experiment. Bottom middle: the onset of the different rooms. Top: example of rooms’ perspectives as participants perceived them while walking. First and then second row from left to right, after showing the Basic room for 5000 ms with a “Do Not Move” sign, the trial started and participants walked inside the virtual room. They then turned 90 degrees to their right and faced the right wall. Subsequently they turned 90 degrees to their left and faced the front wall, followed by an additional turn of 90 degrees to their left to face the left wall. After one additional turn of 90 degrees to their left, participants faced the entrance door. Then, participants walked back to the starting point (entrance door) and turned 180 degrees to face the room. At the end of each trial, the virtual self-assessment manikin (SAM) test and the Stroop test were shown. Defined markers describe events in the experimental protocol that were controlled and appeared at predefined time points during the experiment. These included, e.g., the onset of the basic room, the onset of the SAM test, etc. Undefined markers denote events that were not determined by the experimental protocol, i.e., the time point of some of the turnings depended on the individual preferred movement speed and viewing time. Sample room was created from Banaei et al. (2017).

Figure 3

The quaternion number changes as a function of time for one participant (A) w value for 34 rooms in about 1200 s. (B) Left: w changes in one room while participant is walking and turning, the turning points are marked, Right: turns marker description.

Figure 4

(A) Samples of virtual rooms created by form features, 1st row: two rooms belong to low pleasure and arousal group, 2nd row: two rooms belong to high pleasure and arousal group. (B) Geometry differences between two emotion rating groups. Virtual rooms were created from Banaei et al. (2017).

Figure 5

(A) Equivalent-dipole locations of main clusters’ independent components (ICs; small spheres) and their centroids (larger spheres), projected to the horizontal, sagittal and coronal views of the standard Montreal Neurological Institute (MNI) brain. (B) Clusters’ centroids and their scalp maps, marked with cluster number (Cls #), number of participants (# Ss) and number of ICs (# ICs) for each cluster in the corresponding color.

Figure 6

Event-related spectral perturbation (ERSP) results for the main effect of visual sequences (Top) and emotion rating (Bottom). The Y-axis shows frequency (Hz) from 3 Hz to 41 Hz and the X-axis shows time (ms) from −500 ms to 1200 ms. Significant results displayed for ERSPs in or near the anterior cingulate cortex (ACC; Cls 24), the left precentral gyrus (Cls 18), the posterior cingulate cortex (Cls 16) and the occipital lobe (Cls 8). Top row displays differences in ERSP dependent on the emotional ratings for the lower pleasure and arousal group compared to the higher pleasure and arousal group. The room perspectives are displayed in the order starting with room onset, followed by onset of the right wall and the front wall. Significant differences are marked with exact p values with FDR correction in the most right columns.