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A population of individually marked skylarks was studied by Juan D. Delius over four breeding seasons in Ravenglass, Cumbria, England. The original publication of his findings on their behaviour was published in German (Delius, 1963). Here, the article is presented in English for the first time, with updates of the relevant literature. published

Choir singing is positively associated with well-being and quality of life, and requires the coordination of physiological systems within and across individuals. Informed by models of interpersonal action coordination, we delineate the network topography of choir singing by analyzing cross-frequency couplings and within-frequency couplings (WFCs) of respiratory, cardiac, vocalizing, and motor subsystems. We find that respiratory and cardiac subsystems synchronize with one another during singing and are coupled to oscillatory vocalizing patterns, and to the hand-movement oscillations of the choir's conductor. The choir's cross-frequency connections are particularly strong when singing a canon in parts, apparently supporting the interaction and coordination of the different canon entries. In contrast, WFCs are more pronounced when singing the same canon in unison. We conclude that the temporal coordination dynamics of the observed subsystems form part of the functional substrate for choir singing. During singing, the choir functions as a superordinate system, or superorganism, that imposes boundary conditions on the dynamic features of the individual singers.

The visual control of pecking by pigeons (Columba livia) has latterly been thought to be restricted to the fixation stops interrupting their downward head movements because these stops prevent interference by motion blur. Pigeons were also assumed to close their eyes during the final head thrust of the peck. Here we re-examine their pecking motions using high-speed video recordings and supplementary provisions that permitted a three-dimensional spatial analysis of the movement, including measurements of their pupil diameters and eyelid slit width. The results confirm that pigeons do not close their eyes completely during the presumed optically ballistic phase of pecking. Instead their eyelids are narrowed to a slit. The width of this slit is sensitive to both the ambient illumination levels and the visual backgrounds against which seed targets have to be detected and grasped. There is also evidence of some interaction between pupil diameter and eyelid slit width. We surmise that besides being an eye-protecting reflex, the partial covering of the pupil with the eyelids may increase the depth of focus, enabling pigeons to obtain sharp retinal images of peck target items at very close range and during the beak-gape ‘handling’ of food items and occasional grit particles.

Pigeons learned to discriminate two different patterns displayed with miniature light-emitting diode arrays. They were then tested with 84 interspersed, non-reinforced degraded pattern pairs. Choices ranged between 100% and 50% for one or other of the patterns. Stimuli consisting of few pixels yielded low choice scores whereas those consisting of many pixels yielded a broad range of scores. Those patterns with a high number of pixels coinciding with those of the rewarded training stimulus were preferred and those with a high number of pixels coinciding with the non-rewarded training pattern were avoided; a discrimination index based on this correlated 0.74 with the pattern choices. Pixels common to both training patterns had a minimal influence. A pixel-by-pixel analysis revealed that eight pixels of one pattern and six pixels of the other pattern played a prominent role in the pigeons’ choices. These pixels were disposed in four and two clusters of neighbouring locations. A summary index calculated on this basis still only yielded a weak 0.73 correlation. The individual pigeons’ data furthermore showed that these clusters were a mere averaging mirage. The pigeons’ performance depends on deep learning in a midbrain-based multimillion synapse neuronal network. Pixelated visual patterns should be helpful when simulating perception of patterns with artificial networks. published

Developmental psychologist Paul B. Baltes (1939–2006) was born in Saarlouis, Germany. After studying in Germany he moved to the United States, where he continued the conceptual and methodological quest of his doctoral dissertation to transform developmental psychology into a science that seeks to describe, explain, and modify individual differences in behavioral development across the entire life span. His work was pivotal in establishing life span psychology as a comprehensive and distinct theoretical orientation within contemporary developmental psychology. Paul Baltes' career was characterized by internationality, interdisciplinarity, generativity, societal concern, and institutional prudence and sagacity. One of his central research interests was to explore age-graded changes in the range of plasticity in individual development, with the goal to identify and promote personal and societal conditions that favor successful aging. At the same time, he was not negligent of the negative sides of very old age, and spoke of old age and aging as ‘hope with a mourning band.’

Introduction Our central goal in this concluding chapter is to make the presentation of BASE findings accessible to readers from different backgrounds and to elucidate some implications for social policy and application. To this end, a certain degree of overlap in the material presented is unavoidable. To begin, we address readers with a general interest in aging research. Our aim is to show discrepancies between social expectations of old age and the evidence obtained in the Berlin Aging Study. We employ a format developed by Palmore (1988) in the Facts on Aging Quiz that confronts readers with a list of assertions about old age and aging. Using new questions and BASE findings, we then reveal the “correct” response (see Section 2). In Section 3, we address specialists in the field of gerontology and summarize important results from each of the four BASE research units. In Section 4, we take a systemic perspective, combine these discipline-specific findings, and examine whether certain groups of older people or patterns of aging can be distinguished. In a sense, the observations offered in Section 4 are the closest we come to a wholistic view of aging, one of the stated primary objectives of BASE. Finally, in the light of BASE findings, we consider whether current images of old age are too positive or too negative. We also discuss the implications of BASE results in terms of the theoretical conceptions of differential aging, continuity versus discontinuity, and systemic aspects of aging.

The neural cell adhesion molecule (NCAM) consists of three major isoforms with differing extents of intracellular domains. The largest, NCAM 180, may play an important role in the development and stabilization of cell contacts because of its interaction with the cytoskeleton, its accumulation at contact sites between cells, and age-dependent modifications of the immunoreactivity of its intracellular domain. The developmental expression pattern of NCAM 180 was examined in the cat visual cortex to explore its relation with the age-dependent decline of synaptic malleability. Western blot and immunohistochemical analyses were carried out by using a monoclonal antibody (D3) directed against an epitope of the intracellular domain specific to NCAM 180 and antibodies against all NCAM isoforms. The latter revealed a similar time course of increased expression during development by both Western blot and immunohistochemical analysis. In contrast, the D3 antibody showed an age-dependent increase of immunoreactivity by Western blot analysis and a decrease of reactivity by immunohistochemistry. In addition, the D3 antibody revealed characteristic developmental changes of immunoreactivity in the neuropil and distribution of immunopositive neuronal cell bodies in the different cortical laminae. The observations from this and another study (Kramer et al., 1997) suggest that the D3 antibody-specific NCAM 180 epitope is masked during the stabilization of connectivity.

We describe a new technique for the morphological characterization of immunohistochemically labeled neuron populations. We demonstrate that it is possible to fill neurons iontophoretically with Lucifer Yellow (LY) in fixed slices of cat visual cortex after the respective cells have been identified by indirect immunofluorescence for the neural cell adhesion molecule N-CAM 180, with the VC1.1 antibody or with an antibody against glutamate dehydrogenase (GAD). Morphological analysis of the injected cells at the light and electron microscopic level revealed that the N-CAM 180-positive neurons share the features of neuropeptidergic cortical interneurons. Depending on the antibody applied, the immunohistochemical treatment had little or no noticeable effect on the quality of LY filling or on the preservation of morphological details of the pre-labeled cells. This makes the method described ideally suited for the light and electron microscopic examination of selected, immunologically characterized neuron subpopulations.