Adaptation and serial choice bias are unaltered in autism

Autism Spectrum Disorder (ASD) or autism is characterized by social and non-social symptoms, including sensory hyper- and hyposensitivities. A suggestion has been put forward that some of these symptoms could be explained by differences in how sensory information is integrated with its context, including a lower tendency to leverage the past in the processing of new perceptual input. At least two history-dependent effects of opposite directions have been described in the visual perception literature: a repulsive adaptation effect, where perception of a stimulus is biased away from an adaptor stimulus, and an attractive serial choice bias, where perceptual choices are biased towards the previous choice. In this study, we investigated whether autistic participants differed in either bias from typically developing controls (TD). Sixty-four adolescent participants (31 with ASD, 33 TD) were asked to categorize oriented line stimuli in two tasks which were designed so that we would induce either adaptation or serial choice bias. Although our tasks successfully induced both biases, in comparing the two groups, we found no differences in the magnitude of adaptation nor in the modulation of perceptual choices by the previous choice. In conclusion, we find no evidence of a decreased integration of the past in visual perception of autistic individuals.

The categorical use of a continuous time representation

The abstract concept of time is mentally represented as a spatially oriented line, with the past associated with the left space and the future associated with the right. Although the line is supposed to be continuous, most available evidence is also consistent with a categorical representation that only discriminates between past and future. The aim of the present study was to test the continuous or categorical nature of the mental timeline. Italian participants judged the temporal reference of 20 temporal expressions by pressing keys on either the left or the right. In Experiment 1 (N = 32), all words were presented at the center of the screen. In Experiment 2 (N = 32), each word was presented on the screen in a central, left, or right position. In Experiment 3 (N = 32), all text was mirror-reversed. In all experiments, participants were asked to place the 20 temporal expressions on a 10-cm line. The results showed a clear Spatial–TEmporal Association of Response Codes (STEARC) effect which did not vary in strength depending on the location of the temporal expressions on the line. However, there was also a clear Distance effect: latencies were slower for words that were closer to the present than further away. We conclude that the mental timeline is a continuous representation that can be used in a categorical way when an explicit past vs. future discrimination is required by the task.

De-stereotyping informal sector gendered division of work: a case of Magaba Home Industry, Harare, Zimbabwe

The informal sector is gradually becoming the sole source of income for millions of people around the world. Yet, there exists grossly asymmetric relationships between men and women in accessing functional prerequisites to operate and survive in the industry. Cultural and socially constructed consciousness within the industry, has created gendered division of work. Therefore, this study explored how to de-stereotype gendered division of work in the informal sector, focusing on Magaba Home Industries in Harare, Zimbabwe. This qualitative study concludes that human capital development accompanied with social and financial capital is significant in improving capacities of both women and men in productive informal work. The study recommends an ideological shift from perceived oriented line of work based on gender to mainstreaming equality of achievement based on mobile societies that foster upward social mobility thus bridging the gendered skills gap.

You see what you look for: perceptual biases induced by targets and distractors in visual search

Visual perception is, at any given moment, strongly influenced by its temporal context – what stimuli have recently been perceived and in what surroundings. We have previously shown that to-be-ignored items produce a bias upon subsequent perception that acts in parallel with other biases induced by attended items. However, our previous investigations were confined to biases upon a visual search target's perceived orientation, and it is unclear whether these biases influence perception in a more general sense. Canonical paradigms investigating so-called serial dependence have revealed biases in the perception of items not associated with any particular task. Therefore, we test here whether the biases from visual search targets and distractors affect the perceived orientation of a neutral test line, which is neither a target nor a distractor. To do so, we asked participants to search for an oddly oriented line among distractors and report its location for a few trials and then presented a task-irrelevant test line. Next, participants were asked to report the orientation of the test line. Our results indicate that in tasks involving visual search, targets induce a positive bias upon a neutral test line if their orientations are similar, and distractors also produce a repulsive bias if the test line's orientations and the distractors' average orientation are far apart in feature space. Additionally, our results show that proximity in feature space between previous and current stimuli plays a large role in determining the direction of the perceptual biases.

Determining and Evaluating Alternative Line Plans in Out-of-Control Situations

From time to time, large disruptions cause heavily utilized railway networks to get into a state of out-of-control, in which hardly any trains are able to run as the result of a lack of accurate and up-to-date information available to dispatchers. In this paper, we develop and test disruption management strategies for dealing with these situations. First, we propose an algorithm that finds an alternative line plan that can be operated in the affected part of the railway network. As the line plan should be feasible with respect to infrastructural and resource restrictions, we integrate these aspects in the algorithm in a Benders-like fashion. Second, to operate the railway system within the disrupted region, we propose several local train dispatching strategies requiring varying degrees of flexibility and coordination. Computational experiments based on disruptions in the Dutch railway network indicate that the algorithm performs well, finding workable and passenger-oriented line plans within a couple of minutes. Moreover, we also demonstrate in a simulation study that the produced line plans can be operated smoothly without depending on central coordination.

Young Ants Already Possess a Mental Number Line

The workers of the ant Myrmica sabuleti were previously shown to have a compressed left to right oriented mental number line. It remained to know if they detain this trait soon after their emergence, or if they have to acquire it in the course of their life. We worked on workers a few days to at most 5-6 weeks old, maintained in small artificial nests. We trained them either to a small number of dots versus a larger one, or to a large number versus a smaller one, and tested them in front of twice the small or the large number of dots presented on the left as well as on the right of respectively the larger or the smaller number. The young ants went preferentially to the small number located on the left of the larger one, and to the large number located on the right of the smaller one. Such a left or right preference occurred only in the presence of a larger or a smaller number set between the two small or large presented numbers. Young ants thus mentally locate the small amounts on their left and the larger ones on their right. Their representation of amounts on an oriented line could be native.

Optimizing perception: Attended and ignored stimuli create opposing perceptual biases.

Humans have remarkable abilities to construct a stable visual world from continuously changing input. There is increasing evidence that momentary visual input blends with previous input to preserve perceptual continuity. Most studies have shown that such influences can be traced to characteristics of the attended object at a given moment. Little is known about the role of ignored stimuli in creating this continuity. This is important since while some input is selected for processing, other input must be actively ignored for efficient selection of the task-relevant stimuli. We asked whether attended targets and actively ignored distractor stimuli in an odd-one-out search task would bias observers’ perception differently. Our observers searched for an oddly oriented line among distractors, and were occasionally asked to report the orientation of the last visual search target they saw in an adjustment task. Our results show that at least two opposite biases from past stimuli influence current perception: A positive bias caused by serial dependence pulls perception of the target toward the previous target features, while a negative bias induced by the to-be-ignored distractor features pushes perception of the target away from the distractor distribution. Our results suggest that to-be-ignored items produce a perceptual bias that acts in parallel with other biases induced by attended items to optimize perception. Our results are the first to demonstrate how actively ignored information facilitates continuity in visual perception.

Optimizing perception: Attended and ignored stimuli create opposing perceptual biases

Humans have remarkable abilities to construct a stable visual world from continuously changing input. There is increasing evidence that momentary visual input blends with previous input to preserve perceptual continuity. Most studies have shown that such influences can be traced to characteristics of the attended object at a given moment. Little is known about the role of ignored stimuli in creating this continuity. This is important since while some input is selected for processing, other input must be actively ignored for efficient selection of the task-relevant stimuli. We asked whether attended targets and actively ignored distractor stimuli in an odd-one-out search task would bias observers’ perception differently. Our observers searched for an oddly oriented line among distractors, and were occasionally asked to report the orientation of the last visual search target they saw in an adjustment task. Our results show that at least two opposite biases from past stimuli influence current perception: A positive bias caused by serial dependence pulls perception of the target toward the previous target features, while a negative bias induced by the to-be-ignored distractor features pushes perception of the target away from the distractor distribution. Our results suggest that to-be-ignored items produce a perceptual bias that acts in parallel with other biases induced by attended items to optimize perception. Our results are the first to demonstrate how actively ignored information facilitates continuity in visual perception.Keywords:

Approach Towards Localization of Public Spaces Development in Muscat

With a population that doubled in the past 10 years, in addition to the consumption of land through neighborhoods in the form of leapfrog sprawl, Muscat, the capital of Oman, faces a challenge of the management and provision of services within the existing neighborhoods. With limited infrastructure including street and electricity, these neighbourhoods have lack of public space as a common urban deficiency. Hence the research aims to understand the potential of localizing the urban deficiency solutions through practical means of participatory approach. Accordingly, initial outline of existing public space participatory engagements are considered, followed by analysis of the role and contributions of the community towards development projects, and finally assesment and guideline of lessons learned from the independent public spaces a series of negotiation initiatives are presented. The research builds on an earlier study where two neighborhoods were analyzed in terms of public spaces and communal qualities. From this point, we develop a framework outlining the research project, actions list, and funds. Through an incremental series of actions, progress of the project took a community-oriented line of development. Thus, we found a participatory approach for the localization of public spaces within neighborhoods in Muscat.

An Application of Yaglom's Geometric Algebra to Kinematic Synthesis of Linkages for Prescribed Planar Motion of Oriented Lines

Planar motion coordination of an unoriented line passing through a point or tangent to a conic is a well-known problem in kinematics. In Yaglom's algebraic geometry, oriented lines in a plane are represented with dual numbers. In the present paper, such algebraic geometry is applied in the kinematic synthesis of an inverted slider–crank for prescribed three and four finitely separated positions of the coupler. No previous application of Yaglom's algebraic geometry in the area of linkage kinematic synthesis is recorded. To describe the planar finite displacement of an oriented line about a given rotation pole, new dual operators are initially obtained. Then, the loci of moving oriented lines whose three and four homologous planar positions are tangent to a circle are deduced. The paper proposes the application of findings to the mentioned kinematic synthesis of the inverted slider–crank. Numerical examples show the reliability of the proposed approach. Finally, it is also demonstrated that, for a general planar motion, there is not any line whose five finitely separated positions share the same concurrency point. For the case of planar infinitesimal displacements, the same property was established in a paper authored by Soni et al. (1978, “Higher Order, Planar Tangent-Line Envelope Curvature Theory,” ASME J. Mech. Des., 101(4), pp. 563–568.)