117 research outputs found
Neurophysiological correlates of embodiment and motivational factors during the perception of virtual architectural environments
The recent efforts aimed at providing neuroscientific explanations of how people perceive and experience architectural environments have largely justified the initial belief in the value of neuroscience for architecture. However, a systematic development of a coherent theoretical and experimental framework is missing. To investigate the neurophysiological reactions related to the appreciation of ambiances, we recorded the electroencephalographic (EEG) signals in an immersive virtual reality during the appreciation of interior designs. Such data have been analyzed according to the working hypothesis that appreciated environments involve embodied simulation mechanisms and circuits mediating approaching stimuli. EEG recordings of 12 healthy subjects have been performed during the perception of three-dimensional interiors that have been simulated in a CAVE system and judged according to dimensions of familiarity, novelty, comfort, pleasantness, arousal and presence. A correlation analysis on personal judgments returned that scores of novelty, pleasantness and comfort are positively correlated, while familiarity and novelty are in negative way. Statistical spectral maps reveal that pleasant, novel and comfortable interiors produce a de-synchronization of the mu rhythm over left sensorimotor areas. Interiors judged more pleasant and less familiar generate an activation of left frontal areas (theta and alpha bands), along an involvement of areas devoted to spatial navigation. An increase in comfort returns an enhancement of the theta frontal midline activity. Cerebral activations underlying appreciation of architecture could involve different mechanisms regulating corporeal, emotional and cognitive reactions. Therefore, it might be suggested that people's experience of architectural environments is intrinsically structured by the possibilities for action
Nonsymmetric Interactions Trigger Collective Swings in Globally Ordered Systems
Many systems in nature, from ferromagnets to flocks of birds, exhibit ordering phenomena on the large scale. In condensed matter systems, order is statistically robust for large enough dimensions, with relative fluctuations due to noise vanishing with system size. Several biological systems, however, are less stable and spontaneously change their global state on relatively short time scales. Here we show that there are two crucial ingredients in these systems that enhance the effect of noise, leading to collective changes of state on finite time scales and off-equilibrium behavior: the nonsymmetric nature of interactions between individuals, and the presence of local heterogeneities in the topology of the network. Our results might explain what is observed in several living systems and are consistent with recent experimental data on bird flocks and other animal groups
Silent Flocks
Experiments find coherent information transfer through biological groups on
length and time scales distinctly below those on which asymptotically correct
hydrodynamic theories apply. We present here a new continuum theory of
collective motion coupling the velocity and density fields of Toner and Tu to
the inertial spin field recently introduced to describe information propagation
in natural flocks of birds. The long-wavelength limit of the new equations
reproduces Toner-Tu theory, while at shorter wavelengths (or, equivalently,
smaller damping), spin fluctuations dominate over density fluctuations and
second sound propagation of the kind observed in real flocks emerges. We study
the dispersion relation of the new theory and find that when the speed of
second sound is large, a gap sharply separates first from second sound modes.
This gap implies the existence of `silent' flocks, namely medium-sized systems
across which neither first nor second sound can propagate
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The impact of the built environment on health behaviours and disease transmission in social systems
The environment plays an important role in disease dynamics and in determining the health of individuals. Specifically, the built environment has a large impact on the prevention and containment of both chronic and infectious disease in humans and in non-human animals. The effects of the built environment on health can be direct, for example, by influencing environmental quality, or indirect by influencing behaviours that impact disease transmission and health. Furthermore, these impacts can happen at many scales, from the individual to the society, and from the design of the plates we eat from to the design of cities. In this paper, we review the ways that the built environment affects both the prevention and the containment of chronic and infectious disease. We bring examples from both human and animal societies and attempt to identify parallels and gaps between the study of humans and animals that can be capitalized on to advance the scope and perspective of research in each respective field. By consolidating this literature, we hope to highlight the importance of built structures in determining the complex dynamics of disease and in impacting the health behaviours of both humans and animals.This article is part of the theme issue 'Interdisciplinary approaches for uncovering the impacts of architecture on collective behaviour'
The enactive approach to architectural experience: A neurophysiological perspective on embodiment, motivation, and affordances
From the enactivist perspective, the way people perceptually experience the world, including architectural spaces, is governed by the dynamic sensorimotor activity of the human organism as a whole and is thereby influenced by the particular conditions of man’s embodiment
Emergence of collective changes in travel direction of starling flocks from individual birds fluctuations
One of the most impressive features of moving animal groups is their ability
to perform sudden coherent changes in travel direction. While this collective
decision can be a response to an external perturbation, such as the presence of
a predator, recent studies show that such directional switching can also emerge
from the intrinsic fluctuations in the individual behaviour. However, the cause
and the mechanism by which such collective changes of direction occur are not
fully understood yet. Here, we present an experimental study of spontaneous
collective turns in natural flocks of starlings. We employ a recently developed
tracking algorithm to reconstruct three-dimensional trajectories of each
individual bird in the flock for the whole duration of a turning event. Our
approach enables us to analyze changes in the individual behavior of every
group member and reveal the emergent dynamics of turning. We show that
spontaneous turns start from individuals located at the elongated edges of the
flocks, and then propagate through the group. We find that birds on the edges
deviate from the mean direction of motion much more frequently than other
individuals, indicating that persistent localized fluctuations are the crucial
ingredient for triggering a collective directional change. Finally, we
quantitatively show that birds follow equal radius paths during turning
allowing the flock to change orientation and redistribute risky locations among
group members. The whole process of turning is a remarkable example of how a
self-organized system can sustain collective changes and reorganize, while
retaining coherence.Comment: 18 pages, 2 Videos adde
Flocking and turning: a new model for self-organized collective motion
Birds in a flock move in a correlated way, resulting in large polarization of
velocities. A good understanding of this collective behavior exists for linear
motion of the flock. Yet observing actual birds, the center of mass of the
group often turns giving rise to more complicated dynamics, still keeping
strong polarization of the flock. Here we propose novel dynamical equations for
the collective motion of polarized animal groups that account for correlated
turning including solely social forces. We exploit rotational symmetries and
conservation laws of the problem to formulate a theory in terms of generalized
coordinates of motion for the velocity directions akin to a Hamiltonian
formulation for rotations. We explicitly derive the correspondence between this
formulation and the dynamics of the individual velocities, thus obtaining a new
model of collective motion. In the appropriate overdamped limit we recover the
well-known Vicsek model, which dissipates rotational information and does not
allow for polarized turns. Although the new model has its most vivid success in
describing turning groups, its dynamics is intrinsically different from
previous ones in a wide dynamical regime, while reducing to the hydrodynamic
description of Toner and Tu at very large length-scales. The derived framework
is therefore general and it may describe the collective motion of any strongly
polarized active matter system.Comment: Accepted for the Special Issue of the Journal of Statistical Physics:
Collective Behavior in Biological Systems, 17 pages, 4 figures, 3 video
Electroencephalographic correlates of sensorimotor integration and embodiment during the appreciation of virtual architectural environments
Nowadays there is the hope that neuroscientific findings will contribute to the improvement of building design in order to create environments which satisfy man's demands. This can be achieved through the understanding of neurophysiological correlates of architectural perception. To this aim, the electroencephalographic (EEG) signals of 12 healthy subjects were recorded during the perception of three immersive virtual reality environments (VEs). Afterwards, participants were asked to describe their experience in terms of Familiarity, Novelty, Comfort, Pleasantness, Arousal, and Presence using a rating scale from 1 to 9. These perceptual dimensions are hypothesized to influence the pattern of cerebral spectral activity, while Presence is used to assess the realism of the virtual stimulation. Hence, the collected scores were used to analyze the Power Spectral Density (PSD) of the EEG for each behavioral dimension in the theta, alpha and mu bands by means of time-frequency analysis and topographic statistical maps. Analysis of Presence resulted in the activation of the frontal-midline theta, indicating the involvement of sensorimotor integration mechanisms when subjects expressed to feel more present in the VEs. Similar patterns also characterized the experience of familiar and comfortable VEs. In addition, pleasant VEs increased the theta power across visuomotor circuits and activated the alpha band in areas devoted to visuospatial exploration and processing of categorical spatial relations. Finally, the de-synchronization of the mu rhythm described the perception of pleasant and comfortable VEs, showing the involvement of left motor areas and embodied mechanisms for environment appreciation. Overall, these results show the possibility to measure EEG correlates of architectural perception involving the cerebral circuits of sensorimotor integration, spatial navigation, and embodiment. These observations can help testing architectural hypotheses in order to design environments matching the changing needs of humans
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