Virtually anything we sense, think and do is uncertain. For instance, when driving a car, you often need to determine how close you are to the car in front of you. It is near impossible to estimate this distance with absolute certainty - but it is possible to guess and even to estimate the uncertainty associated with that guess. Accordingly, we reduce speed when driving at night, because we realize perceived distance is more uncertain in the dark than on a sunny, clear day. How do we infer that visual information is less reliable at night? How does the brain represent knowledge of sensory uncertainty? How do we decide to reduce speed? The overall aim of this proposal is to investigate the neural basis of perceptual decision-making under uncertainty. We will concentrate on two major research questions. First, we aim to establish the degree to which sensory uncertainty is represented in human visual cortex. Second, we will examine whether observers use knowledge of this uncertainty in their decisions. We will address these questions using functional magnetic resonance imaging (fMRI), in combination with a novel analytical method to analyzing fMRI data that we recently developed. This novel approach allows us to characterize, on a trial-by-trial basis, the uncertainty in cortical stimulus representations, and to address unresolved issues regarding the neural mechanisms of human decision-making. The results from this project will provide important new insights into the neural basis of visual choice under uncertainty, with profound implications for theories of cortical visual function.

In an increasingly multicultural society, many infants frequently hear foreign-accented speech alongside the native community accent. How does this impact on early language acquisition? During the first year infants learn the sound categories of their native language, knowledge that is crucial for further language development. The infants? environment plays a critical role in this development, yet previous research has assumed uniformity in infants? linguistic environments, ignoring the variation between sub-populations within the community. The proposed project focuses foreign-accented speech, which is characterised by transfer of acoustic elements from the native language into the target language, as a source of infants? linguistic input. Adults emphasise relevant, language-specific acoustic cues when talking to infants, and the acoustic properties emphasised in infant-directed, foreign-accented speech will be examined. This is the first investigation into the influence of foreign-accented speech on infant language acquisition. Combining insights from phonetics, psycholinguistics and language acquisition, it approaches the issue from the perspective of both adults and infants, by looking at acoustic characteristics of foreign-accented infant-directed speech and how infants respond to these cues. A longitudinal element addresses the role of variability by examining how infants? differential weighting of ?home? vs. ?community? accent cues develops over time.

Retinitis Pigmentosa (RP) refers to a group of hereditary eye diseases that causes photoreceptor degeneration which eventually leads to vision loss. Adequate therapies for these diseases are not yet available. In this project I will evaluate a new approach (optogenetics) to restore retinal function after photoreceptor degeneration.

According to the United Nations there is a need for the development of indicators for ecosystem services and for better predictions on how these are affected by environmental change. From a perspective of ecosystem functioning, not only species diversity is important, but also the functional diversity within communities, based on functional traits of species. A better understanding of how functional diversity is influenced by environmental change is a prerequisite for predicting changes in ecosystem functioning and for cost-efficient management strategies. In order to link environmental changes to ecosystem functions and associated ecosystem services, we will distinguish between two aspects: traits on the one hand determine the response of the plants to environmental change and on the other hand traits are instrumental for the effect that plants impose on ecosystem functions and ecosystem services (response-to-effect framework). By using traits of known importance to ecosystem functions, shifts in trait composition within communities can be used as indicators (proxies) for changes in ecosystem functions and associated ecosystem services. Our objectives are: 1. To develop a set of trait-based indicators of ecosystem functions and associated ecosystem services; 2. To link changes in habitat quality and connectivity to shifts in indicators of ecosystem functions and services; Especially the trait-based approach to ecosystem services is innovative. By combining recent trait databases with the Dutch National Vegetation Database, containing over 562.000 geo-referenced site descriptions of species composition and habitat characteristics, this can be done in a way that could not be achieved before.

The project aims to apply spatial dynamical modelling to reconstruct and understand the development of the cultural landscape in the Dutch part of the Roman limes zone. The Roman conquest and occupation of the Lower Rhine region resulted in a system of fortifications of the Rhine border (the limes). The garrisons needed provisions like food and building materials. Where these came from and how they were managed is only known in general terms. Great uncertainties exist on the organisation of the socio-economic system, its relation to the military presence in the area, the logistics involved, and its impact on land use. Spatial dynamical modelling can assist in interpreting past landscape development. It is a computer technique for building rule-based models that will simulate spatial processes - like the development of land use - through time. In this way, cause-and-effect chains will become more transparent. It can also tell us whether developments inevitably lead in a certain direction (path dependence), and if different scenarios produce similar outcomes (equifinality). The Dutch limes zone offers a rich set of archaeological and palaeo-environmental data. We want to use these data and spatial dynamical modelling to set up scenarios of resource management along the limes, and test these against the archaeological evidence. What was needed to maintain the border garrisons? How did the Romans organize production, transport and distribution of goods? How did the local population respond? How did it influence landscape development and settlement pattern? The modelling will result in scenarios of cultural landscape development using different theoretical perspectives and focusing on the interaction of natural, economic and socio-cultural factors. The plausibility of these scenarios can be assessed by comparing the modelling results to the archaeological record. We will also formulate best practices for spatial dynamical modelling in archaeology that will benefit other researchers.