BackgroundDespite the immense literature related to diverse human electroencephalographic (EEG) parameters, very few studies have focused on the reliability of these measures. Some of the most studied components (i.e., P3 or MMN) have received more attention regarding the stability of their main parameters, such as latency, amplitude or topography. However, spectral modulations have not been as extensively evaluated considering that different analysis methods are available.The main aim of the present study is to assess the reliability of the latency, amplitude and topography of event-related desynchronization (ERD) for the alpha band (10–14 Hz) observed in a cognitive task (visual oddball). Topography reliability was analysed at different levels (for the group, within-subjects individually and between-subjects individually).ResultsThe latency for alpha ERD showed stable behaviour between two sessions, and the amplitude exhibited an increment (more negative) in the second session.Alpha ERD topography exhibited a high correlation score between sessions at the group level (r = 0.903, p<0.001). The mean value for within-subject correlations was 0.750 (with a range from 0.391 to 0.954). Regarding between-subject topography comparisons, some subjects showed a highly specific topography, whereas other subjects showed topographies that were more similar to those of other subjects.ConclusionERD was mainly stable between the two sessions with the exception of amplitude, which exhibited an increment in the second session. Topography exhibits excellent reliability at the group level; however, it exhibits highly heterogeneous behaviour at the individual level. Considering that the P3 was previously evaluated for this group of subjects, a direct comparison of the correlation scores was possible, and it showed that the ERD component is less reliable in individual topography than in the ERP component (P3).

Many scholars have thought the Classic period Maya did not cultivate the root crop manioc, while others have suggested it may have been an occasional cultigen in kitchen gardens. For many decades there was no reliable evidence that the ancient Maya cultivated manioc, but in the 1990s manioc pollen from the late Archaic was found in Belize, and somewhat older pollen was found in Tabasco. At about the same time of those discoveries, research within the Ceren village, El Salvador, encountered occasional scattered manioc plants that had grown in mounded ridges in kitchen gardens. These finds adjacent to households indicated manioc was not a staple crop, and vastly inferior to maize and beans in food volume produced. However, 2007 research in an agricultural area 200 m south of the Ceren village encountered intensive formal manioc planting beds. If manioc was widely cultivated in ancient times, its impressive productivity, ease of cultivation even in poor soils, and drought resistance suggest it might have been a staple crop helping to support dense Maya populations in the southeast periphery and elsewhere.

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The relationship with families is a crucial topic in educational services for children aged 0-6 years. The participatory and inclusive approach that has traditionally characterized Italian early childhood education and care has come under serious pressure during the Covid-19 pandemic: the ongoing health, social, political, and economic emergency has radically modified timeframes, spaces, an modes of communicating and relating, both in early years/nursery school settings and more generally. This paper examines the relationship between early childhood education services and families, by reporting and analyzing data from an exploratory study on distance education in services for children aged 0-6 years, during the spring 2020 lockdown in Italy. Specifically, a questionnaire was used to collect the views of a sample of educators, teachers, and coordinators concerning the practices that had been implemented in support of the remote educational relationship (in Italian, “Legami Educativi A Distanza – LEAD” programme). Among the various themes investigated, the focus here is on problematizing the ways in which families’ participation changed during the distance education phase.