Ageing effects on the attention demands of walking

Attention demands of walking were determined in six male and six female young adults (mean 26.3 yr) and 12 gender-matched healthy, active older adults (mean 71.1 yr) using a dual task procedure with a reaction time (RT) secondary task. In three conditions an auditory stimulus, a visual stimulus and both stimuli (auditory/visual) were presented. Relative to no-walking baselines, increased RT was found in all conditions revealing an attentional cost of normal walking. When participants traversed the laboratory walkway and also positioned one of their feet within a target area on the ground, attention demands were greater than in unconstrained walking. In the targeting task, RTs to the visual stimulus were longer than for the auditory stimulus due to the interference associated with viewing both the stimulus monitor and the foot-target. Older participants' RTs in the visual and auditory/visual conditions, but not in the auditory condition, were significantly longer than for the young group in both walking tasks but RTs for young and older adults were not different in no-walking baseline trials. Inspection of mean RT functions at time intervals following gait initiation (0-3000 ms from the first step) suggested a fluctuating attentional cost of walking with increased demands associated with contingencies requiring step length regulation. The findings have applied significance in demonstrating the possibility of increased falls and pedestrian accident risk in older individuals in dual task situations such as road crossing.     

Integrating the Automatic and the Controlled: Strategies in Semantic Priming in an Attractor Network With Latching Dynamics

Semantic priming has long been recognized to reflect, along with automatic semantic mechanisms, the contribution of controlled strategies. However, previous theories of controlled priming were mostly qualitative, lacking common grounds with modern mathematical models of automatic priming based on neural networks. Recently, we introduced a novel attractor network model of automatic semantic priming with latching dynamics. Here, we extend this work to show how the same model can also account for important findings regarding controlled processes. Assuming the rate of semantic transitions in the network can be adapted using simple reinforcement learning, we show how basic findings attributed to controlled processes in priming can be achieved, including their dependency on stimulus onset asynchrony and relatedness proportion and their unique effect on associative, category‐exemplar, mediated and backward prime‐target relations. We discuss how our mechanism relates to the classic expectancy theory and how it can be further extended in future developments of the model.     

Training‐induced recovery of low‐level vision followed by mid‐level perceptual improvements in developmental object and face agnosia

Long‐term deprivation of normal visual inputs can cause perceptual impairments at various levels of visual function, from basic visual acuity deficits, through mid‐level deficits such as contour integration and motion coherence, to high‐level face and object agnosia. Yet it is unclear whether training during adulthood, at a post‐developmental stage of the adult visual system, can overcome such developmental impairments. Here, we visually trained LG, a developmental object and face agnosic individual. Prior to training, at the age of 20, LG's basic and mid‐level visual functions such as visual acuity, crowding effects, and contour integration were underdeveloped relative to normal adult vision, corresponding to or poorer than those of 5–6 year olds (Gilaie‐Dotan, Perry, Bonneh, Malach & Bentin, 2009). Intensive visual training, based on lateral interactions, was applied for a period of 9 months. LG's directly trained but also untrained visual functions such as visual acuity, crowding, binocular stereopsis and also mid‐level contour integration improved significantly and reached near‐age‐level performance, with long‐term (over 4 years) persistence. Moreover, mid‐level functions that were tested post‐training were found to be normal in LG. Some possible subtle improvement was observed in LG's higher‐order visual functions such as object recognition and part integration, while LG's face perception skills have not improved thus far. These results suggest that corrective training at a post‐developmental stage, even in the adult visual system, can prove effective, and its enduring effects are the basis for a revival of a developmental cascade that can lead to reduced perceptual impairments.     

Speech affordances: A structural take on how much we can do with our words

Individuals can do a broad variety of things with their words and enjoy different degrees of this capacity. What moderates this capacity? And in cases in which this capacity is unjustly disrupted, what is a good explanation for it? These are the questions I address here. I propose that speech capacity, understood as the capacity to do things with your words, is a structural property importantly dependent on individuals' position in a social structure. My account facilitates a non‐individualistic explanation of cases in which speech capacity is undermined due to speaker's perceived social identity, e.g. episodes of silencing. Instead of appealing to interlocutors' implicit bias against speaker's identity, a structural approach refers to the positions interlocutors occupy in the social structure and the discursive conventions operating upon those positions. I articulate my proposal drawing on the notion of affordances. Each position within a social structure is associated with its own range of speech affordances. Thus, speech capacity is a function of the probability distribution of speech affordances across positions in the structure.     

Foreigners and Inclusion in Academia

This article discusses the category of foreigner in the context of academia. In the first part I explore this category and its philosophical significance. A quick look at the literature reveals that this category needs more attention in analyses of dimensions of privilege and disadvantage. Foreignness has peculiarities that demarcate it from other categories of identity, and it intersects with them in complicated ways. Devoting more attention to it would enable addressing issues affecting foreigners in academia that go commonly unnoticed. In the second part of the article I argue that current efforts to make academia a more inclusive environment should address the disadvantages that many foreign academics face. I focus on two senses of foreigner: working and living in a country that is not your country of origin, and being a nonnative speaker of the language in which you work.     

The multiple-stimulus-without-replacement preference assessment tool and its predictive validity

This study demonstrates the use of two web-based programs, one to identify video preferences and the other to assess their reinforcing effects. We used the Multiple-Stimulus-Without-Replacement Preference Assessment Tool (MSWO PAT) to identify the video preference hierarchies of seven participants, ages 4–11 years old. We then used a customized reinforcer assessment program that arranged a concurrent-chains preparation with programmed conjugate schedules of reinforcement. Button presses emitted by participants modulated the quality (volume and opacity) of selected videos on a moment-to-moment basis, allowing us to identify the reinforcing effects of the videos in little time. The results showed that the preference assessment had predictive value for five of seven participants. We discuss the MSWO PAT, parameters that may affect the identification of preferences and the use of conjugate schedules to identify reinforcers.