Visual adaptation to goal-directed hand actions

Prolonged exposure to visual stimuli, or adaptation, often results in an adaptation “aftereffect” which can profoundly distort our perception of subsequent visual stimuli. This technique has been commonly used to investigate mechanisms underlying our perception of simple visual stimuli, and more recently, of static faces. We tested whether humans would adapt to movies of hands grasping and placing different weight objects. After adapting to hands grasping light or heavy objects, subsequently perceived objects appeared relatively heavier, or lighter, respectively. The aftereffects increased logarithmically with adaptation action repetition and decayed logarithmically with time. Adaptation aftereffects also indicated that perception of actions relies predominantly on view-dependent mechanisms. Adapting to one action significantly influenced the perception of the opposite action. These aftereffects can only be explained by adaptation of mechanisms that take into account the presence/absence of the object in the hand. We tested if evidence on action processing mechanisms obtained using visual adaptation techniques confirms underlying neural processing. We recorded monkey superior temporal sulcus (STS) single-cell responses to hand actions. Cells sensitive to grasping or placing typically responded well to the opposite action; cells also responded during different phases of the actions. Cell responses were sensitive to the view of the action and were dependent upon the presence of the object in the scene. We show here that action processing mechanisms established using visual adaptation parallel the neural mechanisms revealed during recording from monkey STS. Visual adaptation techniques can thus be usefully employed to investigate brain mechanisms underlying action perception.Publisher PDFPeer reviewe

From a property tax to a land tax – who wins, who loses?

Whilst the theoretical case in favour of a tax on the value of land (a land tax) is well established, examples of its implementation in practice are relatively few in number. Where a land tax is levied, it is often part of a suite of land and property taxes that includes transfer taxes, wealth taxes betterment and recurrent taxes on land and property. Rarely is a land tax the sole mechanism for taxing real estate. Yet there is no shortage of land tax supporters, even in countries where other forms of real estate tax have a long history. England is one such country, where real estate taxes have existed since the 17th century in one form or another. Despite coming close at the beginning of the 19th century, governments on the left, right and in the centre ground of political discourse have not implemented a land tax. In the land tax debate throughout this period, there was an absence of empirical research to underpin the positions adopted by either proponents of a land tax or defenders of the status quo. It was not until 1964 that a small pilot exercise was undertaken to investigate the implications of introducing a land tax in England. This seems odd given that frequently cited criticisms of a land tax centre on its practical difficulties. This paper, therefore, looks at some of the consequences of switching from recurrent real estate taxes that are based on the value of land and improvements to one that is based on the value of land only. Focusing on one local authority area in the south east of England, the paper answers the following questions: how might the valuation of land be undertaken in a developed economy where most transactional evidence relates to land together with improvements, and what are the revenue implications of switching from a tax where the liability falls on the land owner rather than the property occupier in first instance. In particular, who are the winners and losers and does expansion of the tax base to include agricultural land uses significantly increase tax revenue

Social security, retirement age and optimal income taxation

It is often argued that implicit taxation on continued activity of elderly workers is responsible for the widely observed trend towards early retirement. In a world of laissez-faire or of first-best efficiency, there would be no such implicit taxation. The point of this paper is that, when first-best redistributive instruments are not available, because some variables are not observable, the optimal policy does imply a distortion of the retirement decision. Consequently, the inducement of early retirement may be part of the optimal tax-transfer policy. We consider a model in which individuals differ in their productivity and their capacity to work long and choose both their weekly labor supply and their age of retirement. We characterize the optimal non-linear tax-transfer that maximizes a utilitarian welfare function when weekly earnings and the length of active life are observable while individuals' productivity and health status are not observable. (C) 2003 Elsevier B.V. All rights reserved

Predicting and Preventing The Theft Of Electronic Products

The research presented within this paper was conducted as part of a two-year project (Project MARC) to develop and render operational a mechanism to assess the risk of theft of electronic products. Clarke and Newman (2002) proposed the use of two checklists – one to measure vulnerability the other to measure security, as a means of categorising products according to their vulnerability to theft. Consultation with key stakeholders yielded the common view that such a mechanism was worth pursuing, but that it must reflect the language of those who would use it. An extensive consultation with stakeholders from ten European member states ensued. Participants were asked to rate a range of electronic products in terms of vulnerability and security and to explain their ratings. Their responses were used to develop two checklists which incorporate a variety of factors, weighted according to the frequency with which they were expressed. The crime vulnerability checklist developed within this paper is judged fit for purpose as a provisional measurement but urge caution in relation to the security checklist

Sustaining the crime reduction impact of designing out crime: Re-evaluating the Secured by Design scheme 10 years on

Secured by Design (SBD) is an award scheme that aims to encourage housing developers to design out crime at the planning or concept stage. The scheme is managed by the Association of Chief Police Officers Crime Reduction Initiatives (ACPO CPI) while the day-to-day delivery of the scheme is conducted by Architectural Liaison Officers (ALOs) or Crime Prevention Design Advisors (CPDAs) working for individual police forces throughout the United Kingdom. The scheme sets standards for compliance that developments must meet to be awarded SBD status. This article presents the findings of research conducted over a 10-year period (1999–2009) into the effectiveness of the SBD scheme as a crime reduction measure. Utilising a variety of methods, the research aims to establish whether residents living within SBD developments experience less crime and fear of crime than their non-SBD counterparts; whether SBD developments show less visual signs of crime and disorder than their non-SBD counterparts; and finally, whether properties built to the SBD standard are able to sustain any crime reduction benefits over a 10-year period

It Looks Good, but What is it Like to Live There? Exploring the Impact of Innovative Housing Design on Crime

This paper reports on the findings of a collaborative project (funded by the Home Office and managed by the Commission for Architecture and the Built Environment - CABE) which was conducted in late 2009 and early 2010. The project set out to strengthen and update the evidence base on the impact of design on a range of crime types – with a specific focus upon housing developments acclaimed for their innovative design and award winning architecture. This paper presents the findings of an in-depth assessment of the impact of housing design features on crime. Utilising a comprehensive data collection exercise, the specific design features of thousands of homes were collated and assessed against police recorded crime data. The design features were based upon the key elements of Crime Prevention Through Environmental Design (CPTED) including road layout, house design, surveillance, territoriality, car parking, communal space, management and maintenance and physical security. The unique and painstaking methodology not only provided an excellent dataset for analysis, but also highlighted the need both for greater conceptual clarity within CPTED and for crime-risk assessments to be based on the careful operationalisation and measurement of CPTED factors. As well as assessing the impact of specific (and combined) design features upon crime, the research also resulted in the production of a new data collection tool designed to address the weaknesses of existing checklists in assessing innovative contemporary developments, which are often unconventional in nature. The paper explores the degree of conflict and/or synergy between the traditional principles of CPTED and contemporary directions in architecture and design. Finally the paper considers the extent to which traditional CPTED principles remain relevant within contemporary residential developments and explores whether areas of revision are required