A left cerebral hemisphere’s superiority in processing spatial-categorical information in a non-verbal semantic format

Effects of Changes to Architectural Elements on Human Relaxation-Arousal Responses: Based on VR and EEG

This study combines electroencephalogram (EEG) with virtual reality (VR) technologies to measure the EEG responses of users experiencing changes to architectural elements. We analyze the ratio of alpha to beta waves (RAB) indicators to determine the pre- and poststimulation changes. In our methodology, thirty-three females experience using private rooms in a postpartum care center participated in the experiment. Their brain waves are measured while they are experiencing the VR space of a private room in a postpartum care center. Three architectural elements (i.e., aspect ratio of space, ceiling height, and window ratio) are varied in the VR space. In addition, a self-report questionnaire is administered to examine whether the responses are consistent with the results of the EEG response analysis. As a result, statistically significant differences (p < 0.05) are observed in the changes in the RAB indicator values of the pre- and poststimulation EEG while the subjects are experiencing the VR space where the architectural elements are varied. That is, the effects of the changes to architectural elements on users’ relaxation-arousal responses are statistically verified. Notably, in all the RAB indicator values where significant differences are observed, the poststimulation RAB decreases in comparison to the prestimulus ratios, which is indicative of the arousal response. However, the arousal levels vary across the architectural elements, which implies it would be possible to find out the elements that could induce less arousal response using the proposed method. Moreover, following the experience in the VR space, certain lobes of the brain (F4 and P3 EEG channels) show statistically significant differences in the relaxation-arousal responses. Unlike previous studies, which measured users’ physiological responses to abstract and primordial spatial elements, this study extends the boundaries of the literature by applying the architectural elements applicable to design in practice.

Categorical Perception Beyond the Basic Level: The Case of Warm and Cool Colors

Categories can affect our perception of the world, rendering between-category differences more salient than within-category ones. Across many studies, such categorical perception (CP) has been observed for the basic-level categories of one's native language. Other research points to categorical distinctions beyond the basic level, but it does not demonstrate CP for such distinctions. Here we provide such a demonstration. Specifically, we show CP in English speakers for the non-basic distinction between "warm" and "cool" colors, claimed to represent the earliest stage of color lexicon evolution. Notably, the advantage for discriminating colors that straddle the warm-cool boundary was restricted to the right visual field-the same behavioral signature previously observed for basic-level categories. This pattern held in a replication experiment with increased power. Our findings show that categorical distinctions beyond the basic-level repertoire of one's native language are psychologically salient and may be spontaneously accessed during normal perceptual processing.

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.

Left dominance for language perception starts in the extrastriate cortex: An ERP and sLORETA study

While it is well known that the left hemisphere is more efficient than the right in most tasks involving perception of speech stimuli, the neurophysiological pathways leading to these lateralised performance differences are as yet rather unclear. In particular, the question whether language lateralisation depends on semantic processing or is already evident in early perceptual stimulus processing has not been answered unequivocally. In the present study, we therefore recorded event-related potentials (ERPs) during tachistoscopic presentation of horizontally or vertically presented verbal stimuli in the left (LVF) and the right visual field (RVF). Participants were asked to indicate, whether the presented stimulus was a word or a non-word. On the behavioural level, participants showed stronger hemispheric asymmetries for horizontal, than for vertical stimulus presentation. In addition, ERP asymmetries were also modulated by stimulus presentation format, as the electrode by visual field interactions for P1 and N1 were stronger after vertical, than after horizontal stimulus presentation. Moreover, sLORETA revealed that ERP left-right asymmetries were mainly driven by the extrastriate cortex and reading-associated areas in the parietal cortex. Taken together, the present study shows electrophysiological support for the assumption that language lateralisation during speech perception arises from a left dominance for the processing of early perceptual stimulus aspects.