This article reviews evidence for the special inhibitory mechanisms required to keep response activation related to affordances of a non-target object from evoking responses. This evidence presents that response activation triggered by affordances of a non-target are automatically inhibited resulting, for example, in decelerated response speed when the response is compatible with the affordance. The article also highlights the neural processes that differentiate these non-target-related affordance effects from other non-target-related effects such as the Eriksen flanker effect that-contrary to these affordance effects-present decelerated response speed when there is incompatibility between the non-target and the response. The article discusses the role of frontal executive mechanisms in controlling action planning processes in these non-target-related affordance effects. It is also proposed that overlapping inhibition mechanisms prevent executing impulsive actions relative to affordances of a target and exaggerate inhibition of response activation triggered by affordances of a non-target.

To reduce errors in portion size estimation, a number of aids have been developed and tested. This systematic review synthesizes what is known about error associated with use of different portion size estimation aids (PSEAs) within self-reported dietary recall studies in children (aged ≤18 years). Eight electronic databases were searched using relevant keywords. From 8184 records identified and screened, 327 full texts were retrieved, with 10 records representing 9 studies meeting inclusion criteria. Studies using proxy reporting were excluded. Thirteen PSEAs were identified. To facilitate comparisons between different types of aids they were categorized into \'physical 2-dimensional (2D)\', \'digital 2D\' and \'3-dimensional\' PSEAs. Seven were physical 2D (e.g. food atlas), two were digital 2D (i.e. computer-based), and four were 3D (e.g. modelling clay, household items). Comparisons of PSEAs within studies found the smallest estimation errors for digital 2D and largest for 3D aids. Errors in relation to food type were varied, with portions of amorphous foods overestimated in multiple studies. No effects for recall interval time or sex were identified. One study reported a significant improvement in estimation error with increasing age. Across studies, large variations in study design and reporting of estimation error hindered the synthesis of evidence regarding the influence of different types of PSEAs on accuracy. While a definitive conclusion about the most accurate PSEA could not be drawn, a check-list to guide future PSEA development and testing has been proposed in the current review. This will assist comparability with future studies of PSEAs for children facilitate development of more accurate PSEAs in the future.

It is tempting to describe human reach-to-grasp movements in terms of two, more or less independent visuomotor channels, one relating hand transport to the object\'s location and the other relating grip aperture to the object\'s size. Our review of experimental work questions this framework for reasons that go beyond noting the dependence between the two channels. Both the lack of effect of size illusions on grip aperture and the finding that the variability in grip aperture does not depend on the object\'s size indicate that size information is not used to control grip aperture. An alternative is to describe grip formation as emerging from controlling the movements of the digits in space. Each digit\'s trajectory when grasping an object is remarkably similar to its trajectory when moving to tap the same position on its own. The similarity is also evident in the fast responses when the object is displaced. This review develops a new description of the speed-accuracy trade-off for multiple effectors that is applied to grasping. The most direct support for the digit-in-space framework is that prism-induced adaptation of each digit\'s tapping movements transfers to that digit\'s movements when grasping, leading to changes in grip aperture for adaptation in opposite directions for the two digits. We conclude that although grip aperture and hand transport are convenient variables to describe grasping, treating grasping as movements of the digits in space is a more suitable basis for understanding the neural control of grasping.

The size-weight illusion (SWI) refers to the phenomenon that objects that are objectively equal in weight but different in size or volume are perceived to differ in weight, such that smaller objects feel heavier than larger ones. This article reviews studies trying to support three different viewpoints with respect to the role of expectancies in causing the SWI. The first viewpoint argues for a crucial role; the second admits a role, yet without seeing consequences for sensorimotor processes; and the third denies any causal role for expectancies at all. A new explanation of the SWI is proposed that can integrate the different arguments. A distinctive feature of the new explanation is that it recognizes the causal influence of expectancies, yet combines this with certain reactive and direct behavioral consequences of perceiving size differences that are independent of experience-based expectancies, and that normally result in the adaptive application of forces to lift or handle differently sized objects. The new account explains why the illusion is associated with the repeated generation of inappropriate lifting forces (which can, however, be modified through extensive training), as well as why it depends on continuous visual exposure to size cues, appears at an early age, and is cognitively impenetrable.

Weight illusions--where one object feels heavier than an identically weighted counterpart--have been the focus of many recent scientific investigations. The most famous of these illusions is the \'size-weight illusion\', where a small object feels heavier than an identically weighted, but otherwise similar-looking, larger object. There are, however, a variety of similar illusions which can be induced by varying other stimulus properties, such as surface material, temperature, colour, and even shape. Despite well over 100 years of research, there is little consensus about the mechanisms underpinning these illusions. In this review, I will first provide an overview of the weight illusions that have been described. I will then outline the dominant theories that have emerged over the past decade for why we consistently misperceive the weights of objects which vary in size, with a particular focus on the role of lifters\' expectations of heaviness. Finally, I will discuss the magnitude of the various weight illusions and suggest how this largely overlooked facet of the topic might resolve some of the debates surrounding the cause of these misperceptions of heaviness.

This tutorial provides a selective review of research on object-based deployment of attention. It focuses primarily on behavioral studies with human observers. The tutorial is divided into five sections. It starts with an introduction to object-based attention and a description of the three commonly used experimental paradigms in object-based attention research. These are followed by a review of a variety of manifestations of object effects and the factors that influence object segmentation. The final two sections are devoted to two key issues in object-based research: the mechanisms that give rise to the object effects and the role of space in object-based selection.

To systematically review the proportion of parents able to recognize overweight status in their children who were recorded as being overweight by internationally recognized standards. Two independent reviewers searched electronic databases including MEDLINE, EMBASE, PSYCHINFO, and CINAHL for studies from inception to August 2007 using search terms related to childhood overweight and parents. Twenty-three studies satisfied inclusion criteria, representing 3864 overweight children from 7 countries and 5 distinct standard definitions of overweight status. Seventeen of 23 studies employed either greater than 95th centile or the International Obesity Task Force criteria. Parental recognition of their child\'s overweight status ranged from 6.2% to 73%, but in 19 of 23 studies, it was less than 50%. More than half of parents cannot recognize when their child is overweight. Relying on parents to seek help for their overweight children is likely to be ineffective, and hence population-based screening may be justified.

The portion size of foods has been identified as an important environmental factor known to affect short-term energy intake. Experiments that were conducted both in the free-living environment and in laboratory-based settings to investigate the effects of portion size on energy intake unanimously showed that as the portion size of food increased, so did subjects\' energy intake. Despite the fact that the profound effects of portion size on energy intake are well documented, the mechanisms by which portion size affects energy intake are poorly understood. There is some evidence that sensory influences (e.g. visual and olfactory cues), cognitive factors (e.g. learning, social norms, monetary considerations), and post-ingestive consequences (e.g. sensations of hunger and fullness) related to the portion size of foods may interact to affect the amount of food that is consumed during a meal.

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