Local contrast and maintained generalization.

Pigeons received variable-interval reinforcement for key pecking during presentations of horizontal and vertical line-orientation stimuli, while pecks during five intermediate orientations were extinguished. Lowest peck rates were observed during presentations of negative stimuli adjacent to the positive orientations while peck rate during 45 degrees (the intermediate negative orientation) was relatively high, i.e., there were negative contrast shoulders. When peck rates were manipulated in the positive orientations, peck rate in neithboring orientations changed in the opposite direction. Contrast shoulders faded after prolonged training. A second type of contrast, local contrast, was correlated with similarity of preceding stimulus and different average peck rates during different stages of the discrimination process. The data suggest that sequential local contrast accompanying the formation of a discrimination contributes to the form of generalization gradients. Blough's model of stimulus control predicts the changes in gradient form described here, but may not accurately depict the underlying process responsible for gradient form.     

Stimulus control of Pavlovian facilitation

Two experiments were conducted using an autoshaping procedure with pigeons to examine whether dimensional stimulus control by a Pavlovian facilitator parallels the control established following operant discrimination training. Facilitation training consisted of the presentation of a black vertical line on a white background as the B stimulus in a feature-positive discrimination in which the A stimulus (white keylight) was followed by grain presentation only if preceded by B. In this way, B facilitates or sets the occasion for pecking at A. Subsequent testing for generalization along the line-orientation dimension produced decremental gradients when the facilitation paradigm incorporated an explicit feature-negative stimulus (B−). These results parallel the decremental control obtained following operant discrimination training and suggest that Pavlovian facilitators and instrumental discriminative stimuli are functionally equivalent.     

远、近空间内注意加工的分离

临床证据发现空间忽视症病人对于近处和远处空间内的注意加工存在差异,表现为空间忽视只发生于近处空间或只发生于远处空间,提示近处空间与远处空间在脑内可能是分别表征的。对健康成人的研究也发现了与之类似的近处空间和远处空间注意的分离现象,即在近处空间表现出左偏的伪忽视现象,在远处空间表现出左偏减弱或者右偏的趋势。本文综述了远、近空间内注意加工分离的实验证据以及采用线段二分任务这一主要的研究范式相关的实验结果,并且着重指出了远、近空间的划分不是绝对的,而是动态可变的研究证据。最后,指出了将来的研究需要深入考察空间参照系统在远、近空间知觉中的作用,以及关注社会交互情境下的远、近空间距离认知的动态变化。     

Spatial numerical associations in preschoolers

ABSTRACT

Three-to-five-year-old French children were asked to add or remove objects to or from linear displays. The hypothesis of a universal tendency to represent increasing number magnitudes from left to right led to predict a majority of manipulations at the right end of the rows, whatever children's hand laterality. Conversely, if numbers are not inherently associated with space, children were expected to favour laterality-consistent manipulations. The results showed a strong tendency to operate on the right end of the rows in right-handers, but no preference in left-handers. These findings suggest that the task elicited a left-to-right oriented representation of magnitudes that counteracted laterality-related responses in left-handed children. The young age of children and the lack of a developmental trend towards right preference weaken the hypothesis of a cultural origin of this oriented representation. The possibility that our results are due to weaker brain lateralisation in left-handers compared to right-handers is addressed in Discussion section.     

How do we convert a number into a finger trajectory?

How do we understand two-digit numbers such as 42? Models of multi-digit number comprehension differ widely. Some postulate that the decades and units digits are processed separately and possibly serially. Others hypothesize a holistic process which maps the entire 2-digit string onto a magnitude, represented as a position on a number line. In educated adults, the number line is thought to be linear, but the “number sense” hypothesis proposes that a logarithmic scale underlies our intuitions of number size, and that this compressive representation may still be dormant in the adult brain. We investigated these issues by asking adults to point to the location of two-digit numbers on a number line while their finger location was continuously monitored. Finger trajectories revealed a linear scale, yet with a transient logarithmic effect suggesting the activation of a compressive and holistic quantity representation. Units and decades digits were processed in parallel, without any difference in left-to-right vs. right-to-left readers. The late part of the trajectory was influenced by spatial reference points placed at the left end, middle, and right end of the line. Altogether, finger trajectory analysis provides a precise cognitive decomposition of the sequence of stages used in converting a number to a quantity and then a position.     

Travel behavior changes and responses to advanced traveler information in prolonged and large-scale network disruptions: A case study of west LRT line construction in the city of Calgary

The objective of this study was the investigation of travel behavioral effects of the reduction in traffic capacity resulting from the construction of the West LRT (Light Rail Transit) line in the city of Calgary, Alberta, Canada. Travelers’ responses to real-time information providing traffic updates and advisory detours due to lane/road closures were also examined. The West LRT alignment extends approximately 8.2 km from downtown into the city’s southwest. Many road closures took place in the vicinity of the LRT line construction zones, inducing significant delays to traffic. Data on travelers’ behavioral responses and responses to real-time information were obtained by conducting a survey on a sample of users of the main road affected by the construction. The survey also investigated the effects of West LRT line construction on drivers’ daily commutes, including increases in travel times, mode choices, alternate route choices, and selection of sources of information on traffic conditions. A significant change in the selection of transportation mode was caused by West LRT construction. Throughout the construction period, there was a decrease in the percentage of respondents who reported private vehicles as their first choice and an increase in the percentage of respondents who preferred public transit as their first and second choices. Radio was found to be the most preferred source for traffic updates and detour advice, followed by variable message signs (VMS). The findings of the en-route information model showed that driving experience, employment status, travel time and purpose, and desire for pre-trip information had significant effects on traveler’s rerouting decisions after getting en-route information through VMS. The results from this study are of interest for understanding behavioral changes for the purposes of traffic management, mitigation schemes and design of advanced traveler information systems in response to network disruptions.     

Are there any Good Arguments Against Goal-Line Technology?

Despite frequent calls by players, managers and fans, FIFA's resistance to the implementation of goal-line technology (GLT) has been well documented in national print and online media as well as FIFA's own website. In 2010, FIFA president Sepp Blatter outlined eight reasons why GLT should not be used in football. The reasons given by FIFA can be broadly separated into three categories; those dealing with the nature and value of the game of football, those related to issues of justice, and those concerned with the practical implementation of GLT. This paper intends to evaluate these eight reasons in order to assess whether there are, indeed, any good arguments against GLT in football.     

The Point of Scientificity,the Fall of the Epistemological Dominos,and the End of the Field of Educational Administration

The point of scientificity, or pos,represents a place in history whereeducational administration was founded as ascience. A pos creates a field of memoryand a field of studies. A pos isepistemologically sustained in its claim forscientific status by a line of demarcation orlod. A lod is supported by truthclaims based on various forms ofcorrespondence. As these forms have beeninterrogated and abandoned, correspondence hasgiven way to coherentism and finally to testsof falsification. As falsification has shownto contain serious flaws when compared to theactual history of scientific discoveries, theentire project of a distinct and unitaryfield known as educational administration isseriously cast into doubt. Contemporaryexaminations in educational administrationdiscourse show that even when the lod hasbeen undermined by epistemological shifts, theinitial pos has remained to supportclaims regarding the project of a ``science ofleadership.' The analysis contained in thisarticle show, however, that when claims of thelod are demonstrably unsustainable, theinitial pos must be similarly abandoned. With that collapse the concept of a fieldis likewise effaced. The epistemologicalalternative is to envision fields ofstudy which do not require a lod, excepton a longitudinal basis to ascertain whether aresearch program shaped and sustained by it isprogressive or regressive. In short, there areno aprori meta-criteria to separate sciencefrom non-science in educationaladministration.     

A Challenge to Brink's Metaphysical Egoism

Those who subscribe to aprudential conception of practical reason do not believe that there is a conflict between other-regarding and self-regarding norms as the former are held to be founded on the latter. Moral conduct, they maintain, is always rationally justifiable. The reasons we should fulfil the demands of other-regarding norms are the same as those we have for fulfilling self-regarding norms. David Brink has put forth an interesting and novel account of this approach to practical reason which he calls‘metaphysical egoism’. Metaphysical egoism requires that we modify our pre-theoretical understandings of self-interest on metaphysical grounds. I critically assess Brink’s argument and claim that metaphysical egoism does not adequately function as a motive or guide for action. It is susceptible to many of the same problems which strategic egoism faces. This revised version was published online in July 2006 with corrections to the Cover Date.