A Leak Zone Location Approach in Water Distribution Networks Combining Data-Driven and Model-Based Methods

Model-based and data-driven methods are commonly used in leak location strategies in water distribution networks. This paper formulates a hybrid methodology in two stages that complements the advantages and disadvantages of data-driven and model-based strategies. In the first stage, a support vector machine multiclass classifier is used to reduce the search space for the leak location task. In the second stage, leak location task is formulated as an inverse problem, and solved using a variation of the differential evolution algorithm called topological differential evolution. The robustness of the method is tested considering measurement and varying demand uncertainty conditions ranging from 5 to 15% of node nominal demands. The performance of the hybrid method is compared to the support vector machine classifier and topological differential evolution approaches as standalone methods of leak location. The hybrid proposal shows higher performance in terms of location accuracy, zone size, and computational load.

Dogs follow human misleading suggestions more often when the informant has a false belief

We investigated whether dogs ( Canis familiaris ) distinguish between human true (TB) and false beliefs (FB). In three experiments with a pre-registered change of location task, dogs ( n = 260) could retrieve food from one of two opaque buckets after witnessing a misleading suggestion by a human informant (the ‘communicator’) who held either a TB or a FB about the location of food. Dogs in both the TB and FB group witnessed the initial hiding of food, its subsequent displacement by a second experimenter, and finally, the misleading suggestion to the empty bucket by the communicator. On average, dogs chose the suggested container significantly more often in the FB group than in the TB group and hence were sensitive to the experimental manipulation. Terriers were the only group of breeds that behaved like human infants and apes tested in previous studies with a similar paradigm, by following the communicator's suggestion more often in the TB than in the FB group. We discuss the results in terms of processing of goals and beliefs. Overall, we provide evidence that pet dogs distinguish between TB and FB scenarios, suggesting that the mechanisms underlying sensitivity to others' beliefs have not evolved uniquely in the primate lineage.

Neurogenesis-mediated forgetting of complex paired-associates memories

The hippocampus is a critical structure involved in many forms of learning and memory. It is also one of the only regions in the adult mammalian brain that continues to generate new neurons throughout adulthood. This process of adult neurogenesis may increase the plasticity of the hippocampus which could be beneficial for learning but has also been demonstrated to decrease the stability of previously acquired memories. Here we test whether increased production of new neurons following the formation of a gradually acquired paired-associates task will result in forgetting of this type of memory. We trained mice in a touchscreen-based object/location task and then increased neurogenesis using voluntary exercise. Our results indicate that mice with increased neurogenesis show poor recall of the previously established memory. When subsequently exposed to a reversal task we also show that mice with increased neurogenesis require fewer correction trials to acquire the new task contingencies. This suggests that prior forgetting reduces perseveration on the now outdated memory. Together our results add to a growing body of literature which indicates the important role of adult neurogenesis in destabilizing previously acquired memories to allow for flexible encoding of new memories.

Failure to Report the Identity of a Face that was Just Selected: Attribute Amnesia of Faces

Attribute amnesia (AA) describes a phenomenon in which participants are unable to report an attribute that was just attended to select a target. Most studies investigating this effect used simple stimuli like letters and digits. The few studies using meaningful stimuli, however, found AA only when the target stimuli were used repeatedly. We tested the robustness of this boundary condition with a set of artificially generated faces. Participants were instructed to find the young face among 3 older faces and performed this task for the first 27 trials. On the 28th trial, they were unexpectedly asked to report the identity of the young target face they just saw. The following 4 trials repeated this identity question and the target faces never repeated throughout the experiment. Contrary to the previous findings, we observed AA with the current set of meaningful and unique targets. I.e., The pre-surprise location task performance was at ceiling, but the surprise identity accuracy was significantly lower than the following trial. The current finding expands the boundary conditions of AA and suggests that AA is applicable to visual experience that resembles our day-to-day lives.

Effects of age on goal-dependent modulation of episodic memory retrieval

Retrieval gating refers to the ability to modulate the retrieval of features of a single memory episode according to behavioral goals. Recent findings demonstrate that younger adults engage retrieval gating by attenuating the representation of task-irrelevant features of an episode. Here, we examine whether retrieval gating varies with age. Younger and older adults incidentally encoded words superimposed over scenes or scrambled backgrounds that were displayed in one of three spatial locations. Participants subsequently underwent fMRI as they completed two memory tasks: the background task, which tested memory for the word’s background, and the location task, testing memory for the word’s location. Employing univariate and multivariate approaches, we demonstrated that younger, but not older adults, exhibited attenuated reinstatement of scene information when it was goal-irrelevant (during the location task). Additionally, in younger adults only, the strength of scene reinstatement in the parahippocampal place area during the background task was related to item and source memory performance. Together, these findings point to an age-related decline in the ability to engage retrieval gating.

Confidence Ratings for Location Memory Not Changed with Metacognitive Aid

The Dunning-Kruger overconfidence bias is found in many domains of cognitive performance. Prior studies have shown that people can accurately judge their ability to point to familiar locations relative to other cognitive tasks. This research attempted to investigate the existence of the overconfidence bias in a spatial location task. In doing so, we hope to shed light on the underlying theoretical explanation for the overall effect. It was found that giving participants a chance to use their spatial location memory before having to assess their ability did not affect their self-assessments. It was concluded that the dual-curse account of the Dunning-Kruger effect is a better explanatory position than the metacognitive view, as the dual-curse holds that those with lower performance in a domain have a diminished ability to assess their performance in that domain.

Calibration Zone for the Parameters of the Differential Evolution Algorithm and Its Application to a Real Burst Location Problem

Numerical problems are usually solved using heuristic algorithms, due to their simplicity and easy understanding. Nevertheless, most of these methods have calibration parameters that do not count with selection premises oriented to obtain the best performance for the algorithm. This paper introduces an iterative technique that deals with this problem, searching for the calibration parameters that improve the Differential Evolution (DE) algorithm. The application of the proposed technique is illustrated on a real burst location problem in a pipeline prototype. The obtained results show the good performance of the methodology proposed for the burst location task, including the mapping of the calibration parameters that ameliorate the searching process.