Steady-state responses to concurrent melodies: source distribution, top-down, and bottom-up attention

Humans can direct attentional resources to a single sound occurring simultaneously among others to extract the most behaviourally relevant information present. To investigate this cognitive phenomenon in a precise manner, we used frequency-tagging to separate neural auditory steady-state responses (ASSRs) that can be traced back to each auditory stimulus, from the neural mix elicited by multiple simultaneous sounds. Using a mixture of 2 frequency-tagged melody streams, we instructed participants to selectively attend to one stream or the other while following the development of the pitch contour. Bottom-up attention towards either stream was also manipulated with salient changes in pitch. Distributed source analyses of magnetoencephalography measurements showed that the effect of ASSR enhancement from top-down driven attention was strongest at the left frontal cortex, while that of bottom-up driven attention was dominant at the right temporal cortex. Furthermore, the degree of ASSR suppression from simultaneous stimuli varied across cortical lobes and hemisphere. The ASSR source distribution changes from temporal-dominance during single-stream perception, to proportionally more activity in the frontal and centro-parietal cortical regions when listening to simultaneous streams. These findings are a step forward to studying cognition in more complex and naturalistic soundscapes using frequency-tagging

The climate emergency across business, community and campaign groups: motivations and barriers to driving change for the common good

Initiatives to help tackle the climate emergency have tended to focus on large-scale actions that governments can take and smaller-scale actions for individuals, with relatively limited attention given to the mass of groups that form society between these two ends of the spectrum. The aim here is to help close that gap and the chosen areas of study are business, community, and campaign groups. The approach was to assess the existing literature and to conduct three focus groups to identify what motivates these groups to take actions on climate change, while also uncovering the barriers that may drive choices of inaction. The findings indicate that multiple factors motivate environmental engagements across business, community, and campaign groups, but personal ethics and concern for the future play the most vital roles. The most common barriers cited were difficulties in accessing support schemes, a lack of clear accessible information, and financial implications. Better networking and knowledge exchange are considered essential for meaningful progress. This research provides a new framework, upon which many organisations can be better motivated to take actions in helping deal with the global climate emergency facing humanity. Practical action guides may be developed from existing materials, and small taskforces could be trained to provide direct hands-on support to groups across society, especially those in SMEs and local communities. The energies of younger people and campaigners, combined with the experiences of other generations, would create a powerful force for good

Complete Break Up of Ortho Positronium (Ps)- Hydrogenic ion System

The dynamics of the complete breakup process in an Ortho Ps - He+ system including electron loss to the continuum (ELC) is studied where both the projectile and the target get ionized. The process is essentially a four body problem and the present model takes account of the two centre effect on the electron ejected from the Ps atom which is crucial for a proper description of the ELC phenomena. The calculations are performed in the framework of Coulomb Distorted Eikonal Approximation. The exchange effect between the target and the projectile electron is taken into account in a consistent manner. The proper asymptotic 3-body boundary condition for this ionization process is also satisfied in the present model. A distinct broad ELC peak is noted in the fully differential cross sections (5DCS) for the Ps electron corroborating qualitatively the experiment for the Ps - He system. Both the dynamics of the ELC from the Ps and the ejected electron from the target He+ in the FDCS are studied using coplanar geometry. Interesting features are noted in the FDCS for both the electrons belonging to the target and the projectile.Comment: 14 pages,7 figure

Management actions to address the climate emergency: Motivations and barriers for SMEs and other societal micro/meso-level groups

Initiatives to tackle the climate emergency have tended to focus on large-scale actions that governments and investors (societal macro-levels) can take and smaller-scale individual habits, with limited attention given to the groups that form society between those ends of the spectrum (societal micro/meso-levels). This research aims to traverse that gap by studying three societal micro/meso-level groups; from the private, public and voluntary sectors, as represented by business, community and campaign groups. Existing literature and focus groups are used to identify what motivates actions on climate change, while exposing barriers that may drive choices of inaction. The study shows that concerns for the future and personal ethics play vital roles across business, community and campaign groups, while the principal barriers include difficulties in accessing support schemes and changes in political priorities. Better networking and knowledge exchange are considered essential for meaningful progress. This provides a new framework for management education to support organisations in tackling climate-related issues. Action guides may be developed and task-forces trained to provide hands-on support, especially for SMEs and local communities. The enthusiasm of younger people and campaigners, combined with others’ experiences, would create a powerful platform for climate emergency actions

On a common circle: natural scenes and Gestalt rules

To understand how the human visual system analyzes images, it is essential to know the structure of the visual environment. In particular, natural images display consistent statistical properties that distinguish them from random luminance distributions. We have studied the geometric regularities of oriented elements (edges or line segments) present in an ensemble of visual scenes, asking how much information the presence of a segment in a particular location of the visual scene carries about the presence of a second segment at different relative positions and orientations. We observed strong long-range correlations in the distribution of oriented segments that extend over the whole visual field. We further show that a very simple geometric rule, cocircularity, predicts the arrangement of segments in natural scenes, and that different geometrical arrangements show relevant differences in their scaling properties. Our results show similarities to geometric features of previous physiological and psychophysical studies. We discuss the implications of these findings for theories of early vision.Comment: 3 figures, 2 large figures not include

Chia-Yang Chen, clarinet

Max RegerKrzysztof PendereckiPaul PierneRoberto SierraGeorge Gershwi