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Amsterdam-Zuidoost, Netherlands

Piwek L.,University of Glasgow | McKay L.S.,Netherlands Institute for Neuroscience | Pollick F.E.,University of Glasgow
Cognition | Year: 2014

The uncanny valley hypothesis states that the acceptability of an artificial character will not increase linearly in relation to its likeness to human form. Instead, after an initial rise in acceptability there will be a pronounced decrease when the character is similar, but not identical to human form (Mori, 1970/2012). Moreover, it has been claimed but never directly tested that movement would accentuate this dip and make moving characters less acceptable. We used a number of full-body animated computer characters along with a parametrically defined motion set to examine the effect of motion quality on the uncanny valley. We found that improving the motion quality systematically improved the acceptability of the characters. In particular, the character classified in the deepest location of the uncanny valley became more acceptable when it was animated. Our results showed that although an uncanny valley was found for static characters, the deepening of the valley with motion, originally predicted by Mori (1970/2012), was not obtained. © 2013 Elsevier B.V. Source

Nieuwenhuys R.,Netherlands Institute for Neuroscience
Frontiers in Neuroanatomy | Year: 2011

According to His (1891, 1893) the brainstem consists of two longitudinal zones, the dorsal alar plate (sensory in nature) and the ventral basal plate (motor in nature). Johnston and Herrick indicated that both plates can be subdivided into separate somatic and visceral zones, distinguishing somatosensory and viscerosensory zones within the alar plate, and visceromotor and somatomotor zones within the basal plate. To test the validity of this "four-functional-zones" concept, I developed a topological procedure, surveying the spatial relationships of the various cell masses in the brainstem in a single figure. Brainstems of 16 different anamniote species were analyzed, and revealed that the brainstems are clearly divisible into four morphological zones, which correspond largely with the functional zones of Johnston and Herrick. Exceptions include (1) the magnocellular vestibular nucleus situated in the viscerosensory zone; (2) the basal plate containing a number of evidently non-motor centers (superior and inferior olives). Nevertheless the functional zonal model has explanatory value. Thus, it is possible to interpret certain brain specializations related to particular behavioral profiles, as "local hypertrophies" of one or two functional columns. Recent developmental molecular studies on brains of birds and mammals confirmed the presence of longitudinal zones, and also showed molecularly defined transverse bands or neuromeres throughout development. The intersecting boundaries of the longitudinal zones and the transverse bands appeared to delimit radially arranged histogenetic domains. Because neuromeres have been observed in embryonic and larval stages of numerous anamniote species, it may be hypothesized that the brainstems of all vertebrates share a basic organizational plan, in which intersecting longitudinal and transverse zones form fundamental histogenetic and genoarchitectonic units. © 2011 Nieuwenhuys. Source

Self M.W.,Netherlands Institute for Neuroscience
Current biology : CB | Year: 2013

What roles do the different cortical layers play in visual processing? We recorded simultaneously from all layers of the primary visual cortex while monkeys performed a figure-ground segregation task. This task can be divided into different subprocesses that are thought to engage feedforward, horizontal, and feedback processes at different time points. These different connection types have different patterns of laminar terminations in V1 and can therefore be distinguished with laminar recordings. We found that the visual response started 40 ms after stimulus presentation in layers 4 and 6, which are targets of feedforward connections from the lateral geniculate nucleus and distribute activity to the other layers. Boundary detection started shortly after the visual response. In this phase, boundaries of the figure induced synaptic currents and stronger neuronal responses in upper layer 4 and the superficial layers ~70 ms after stimulus onset, consistent with the hypothesis that they are detected by horizontal connections. In the next phase, ~30 ms later, synaptic inputs arrived in layers 1, 2, and 5 that receive feedback from higher visual areas, which caused the filling in of the representation of the entire figure with enhanced neuronal activity. The present results reveal unique contributions of the different cortical layers to the formation of a visual percept. This new blueprint of laminar processing may generalize to other tasks and to other areas of the cerebral cortex, where the layers are likely to have roles similar to those in area V1. Copyright © 2013 Elsevier Ltd. All rights reserved. Source

Nieuwenhuys R.,Netherlands Institute for Neuroscience
Brain Structure and Function | Year: 2011

The Actinopterygii or ray-finned fishes comprise, in addition to the large superorder of teleosts, four other superorders, namely the cladistians, the chondrosteans, the ginglymodes, and the halecomorphs, each with a limited number of species. The telencephalon of actinopterygian fishes differs from that in all other vertebrates in that it consists of a pair of solid lobes. Lateral ventricles surrounded by nervous tissue are entirely lacking. At the end of the nineteenth century, the theory was advanced that the unusual configuration of the forebrain in actinopterygians results from an outward bending or eversion of its lateral walls. This theory was accepted by some authors, rejected or neglected by others, and modified by some other authors. The present paper is based on the data derived from the literature, complemented by new observations on a large collection of histological material comprising specimens of all five actinopterygian superorders. The paper consists of three parts. In the first, a survey of the development of the telencephalon in actinopterygian fishes is presented. The data collected show clearly that an outward bending or eversion of the pallial parts of the solid hemispheres is the principal morphogenetic event in all five actinopterygian superorders. In all of these superorders, except for the cladistians, eversion is coupled with a marked thickening of the pallial walls. In the second part, some aspects of the general morphology of the telencephalon in mature actinopterygians are highlighted. It is pointed out that (1) the degree of eversion varies considerably among the various actinopterygian groups; (2) eversion leads to the transformation of the telencephalic roof plate into a wide membrane or tela choroidea, which is bilaterally attached to the lateral or ventrolateral aspect of the solid hemispheres; (3) the lines of attachment or taeniae of the tela choroidea form the most important landmarks in the telencephalon of actinopterygians, indicating the sites where the greatly enlarged ventricular surface of the hemispheres ends and its reduced meningeal surface begins; (4) the meningeal surface of the telencephalon shows in most actinopterygians bilaterally a longitudinally oriented sulcus externus, the depth of which is generally positively correlated with the degree of eversion; (5) a distinct lateral olfactory tract, occupying a constant topological position close to the taenia, is present in all actinopterygians studied; and (6) this tract is not homologous to the tract of the same name in the evaginated and inverted forebrains of other groups of vertebrates. In the third and final section, the concept that the structural organization of the pallium in actinopterygians can be fully explained by a simple eversion of its walls, and the various theories, according to which the eversion is complicated by extensive shifts of its constituent cell groups, are discussed and evaluated. It is concluded that there are no reasons to doubt that the pallium of actinopterygian fishes is the product of a simple and complete eversion. © The Author(s) 2010. Source

Marcotte L.,University of Pennsylvania | Aronica E.,Netherlands Institute for Neuroscience | Aronica E.,University of Amsterdam | Baybis M.,University of Pennsylvania | Crino P.B.,University of Pennsylvania
Acta Neuropathologica | Year: 2012

Tubers are cerebral cortical developmental malformations associated with epilepsy and autism in tuberous sclerosis complex (TSC). The disparity between tuber number and severity of neurological impairment often observed in TSC led us to hypothesize that microscopic structural abnormalities distinct from tubers may occur in TSC. Serial frontal to occipital lobe sections were prepared from five postmortem TSC brain specimens. Sections were probed with cresyl violet stain or NeuN antibodies to define cytoarchitectural abnormalities and phospho-S6 (Ser235/236) antibodies to define mammalian target of rapamycin complex 1 (mTORC1) pathway activation. Tubers identified in all specimens (mean, 5 tubers per brain specimen) were defined by abnormal cortical lamination, dysmorphic neurons, and giant cells (GCs) and exhibited robust phospho-S6 immunolabeling. Histopathological analysis of non-tuber cortices demonstrated that 32% of the sections exhibited microscopic cytoarchitectural alterations, whereas 68% of the sections did not. Four types of morphological abnormalities were defined including: (1) focal dyslamination, (2) heterotopic neurons, (3) small collections of giant cells (GCs) and neurons we termed "microtubers", (4) isolated GCs we termed "sentinel" cells. When compared with control cortex, phospho-S6 labeling was enhanced in microtubers and sentinel cells and in some but not all areas of dyslamination. There are microscopic cytoarchitectural abnormalities identified in postmortem TSC brain specimens that are distinct from tubers. mTORC1 cascade activation in these areas supports a widespread effect of TSC1 or TSC2 mutations on brain development. Tubers may represent the most dramatic developmental abnormality in TSC; however, more regionally pervasive yet subtle abnormalities may contribute to neurological disability in TSC. © Springer-Verlag 2012. Source

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