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Context: Treeline-ecotone spatial patterns and their dynamics reflect underlying processes. Changes in ecotone pattern may reflect changes in natural drivers or land-use practices. However, characterizing these dynamics presents a major challenge, limiting our ability to map, understand and predict changes in the upper limits of mountain forests. Objective: This paper proposes a new method using multiple pattern dimensions to describe treeline-ecotone spatial pattern shifts. This standardized protocol should be able to (i) distinguish different types of treeline-ecotone patterns within a large study area, (ii) characterize temporal pattern shifts in spatial pattern between two or more dates. Method: We mapped alpine treeline ecotones (ATE) at 648 sites in the eastern French Pyrenees using aerial images from ~ 1955 and ~ 2015, identifying forest and non-forest areas at the hillslope scale. Extracted patch metrics were summarized using a Principle Component Analysis (PCA) and spatial pattern change was quantified from the shift in the PCA space and compared to elevational shifts. Results: Three clusters of patterns were distinguished: diffuse, discrete and island-forming ATEs. Between 1955 and 2015, about half of the sites changed from one pattern cluster to another. Shifts into discrete ATEs were associated with smaller and negative elevational shifts, while shifts into diffuse ATEs coincided with the highest positive elevational shifts. Conclusion: The proposed method allows a standardized and repeatable quantification of vegetation pattern change in alpine treeline ecotones based on historical aerial imagery. Seeing the importance of treeline-ecotone shifts for alpine biodiversity, we encourage the use of this protocol to better understand treeline dynamics at treelines globally. [ABSTRACT FROM AUTHOR]

Recent findings from event-related potentials (ERPs) studies provided strong evidence that cen- trally presented emotional pictures could be used to assess affective processing. Moreover, several studies showed that emotionally charged stimuli may automatically attract attention even if these are not consciously identified. Indeed, such perceptive conditions can be compared to those typical of the peripheral vision, particularly known to have low spatial resolution capacities. The aim of the present study was to characterize at behavioral and neural levels the impact of emotional visual scenes presented in peripheral vision. Eighteen participants were asked to categorize neutral and unpleasant pictures presented at central (0°) and peripheral eccentricities (−30 and +30°) while ERPs were recorded from 63 electrodes. ERPs were analysed by means of spatio-temporal principal component analyses (PCA) in order to evaluate influences of the emotional content on ERP components for each spatial position (central vs. peripheral). Main results highlight that affective modulation of early ERP components exists for both centrally and peripherally presented pictures. These findings suggest that, for far peripheral eccentricities as for central vision, the brain engages specific resources to process emotional information. [ABSTRACT FROM AUTHOR]

Abstract: This article examined neural time course differences in the processing of emotional pictures in European and Asian individuals. Event-related potentials (ERPs) were recorded in 15 French and 15 Japanese volunteers during the presentation of neutral and emotional pictures in their own country. ERPs were analyzed by means of spatio-temporal Principal Component Analysis (PCA) and allow to evaluate cultural influences on emotional processing along three temporal windows: 105 to 140 ms, 176 to 230 ms and 255 to 455 ms. Main results highlight that (1) early ERP components coded emotional charge but were not modulated by cultural background, (2) later components showed a significant decrease of amplitudes at parieto-occipital areas for Japanese participants compared to French ones in emotional condition. These findings suggest that, in both populations, similar neurocognitive processes are involved in the early stage of the emotional stimuli processing and effects observed on later components may reflect a poorer engagement of parietal areas, known to be involved in emotional arousal dimension. Considering that cognitive judgments were similar in both populations, electrophysiological findings suggest that cultural influences on later stage of emotional processing could be related to the known lower level of emotionally expressive behavior in Japanese than in Caucasians. [Copyright &y& Elsevier]