A Novel Method for Layover Detection in Mountainous Areas with SAR Images

It is well known that there are geometric distortions in synthetic aperture radar (SAR) images when the terrain undulates. Layover is the most common one, which brings challenges to the application of SAR remote sensing. This study proposes a novel detection method that is mainly aimed at the layover caused by mountains and can be performed with only medium-resolution SAR images and no other auxiliary data. The detection includes the following four stages: initial processing, difference image calculation and rough and fine layover detection. Initial processing mainly obtains the potential layover areas, which are mixed with the built-up areas after classification. Additionally, according to the analysis of the backscatter coefficient (BC) of various ground objects with different polarization images, the layover areas are detected step-by-step from the mixed areas, in which the region-based FCM segmentation algorithm and spatial relationship criteria are used. Taking the Danjiangkou Reservoir area as the study area, the relevant experiments with Sentinel-1A SAR images were conducted. The quantitative analysis of detection results adopted the figure of merit (FoM), and the highest accuracy was up to 87.6% of one selected validation region. Experiments in the South Taihang area also showed the satisfactory effect of layover detection, and the values of FoM were all above 85%. These results show that the proposed method can do well in the layover detection caused by mountains. Its simplicity and effectiveness are helpful in removing the influence of layover on SAR image applications to a certain extent and improving the development of SAR remote sensing technology.

Music to Your Ears

Listeners usually have no difficulties telling the difference between speech and song. Yet when a spoken phrase is repeated several times, they often report a perceptual transformation that turns speech into song. There is a great deal of variability in the perception of the speech-to-song illusion (STS). It may result partly from linguistic properties of spoken phrases and be partly due to the individual processing difference of listeners exposed to STS. To date, existing evidence is insufficient to predict who is most likely to experience the transformation, and which sentences may be more conducive to the transformation once spoken repeatedly. The present study investigates these questions with French and English listeners, testing the hypothesis that the transformation is achieved by means of functional re-evaluation of phrasal prosody during repetition. Such prosodic re-analysis places demands on the phonological structure of sentences and language proficiency of listeners. Two experiments show that STS is facilitated in high-sonority sentences and in listeners’ non-native languages and support the hypothesis that STS involves a switch between musical and linguistic perception modes.

Causality, subjectivity and mental spaces: Insights from on-line discourse processing

Research has shown that it requires less time to process information that is part of an objective causal relation describing states of affairs in the world (She was out of breath because she was running), than information that is part of a subjective relation (She must have been in a hurry because she was running) expressing a claim or conclusion and a supporting argument. Representing subjectivity seems to require extra cognitive operations.In Mental Spaces Theory (MST; Fauconnier, Gilles. 1994. Mental spaces: Aspects of meaning construction in natural language. Cambridge: MIT Press) the difference between these two relation types can be described in terms of an extra mental space in the discourse representation of subjective relations: representing the Subject of Consciousness (SoC). In processing terms, this might imply that the processing difference is not present if this SoC has already been established in the discourse. We tested this prediction in two eye tracking experiments. The results of Experiment 1 showed that signaling the subjectivity of the relation by introducing a subject of consciousness beforehand did not diminish the processing asymmetry compared to a neutral context. However, the relative complexity of subjective relations was diminished in the context of Free Indirect Speech (No! He was absolutely sure. There was no doubt about it. She was running so she was in hurry; Experiment 2).In terms of MST and the representation of subjectivity in general, this implies that not only creating a representation of a thinking subject, but also assigning a claim to this thinking subject requires extra processing effort.

Multivariate pattern analysis of fMRI data for imaginary and real colours in grapheme-colour synaesthesia

Grapheme-colour synaesthesia is a subjective phenomenon related to perception and imagination, in which some people involuntarily but systematically associate specific, idiosyncratic colours to achromatic letters or digits. Its investigation is relevant to unravel the neural correlates of colour perception in isolation from low-level neural processing of spectral components, as well as the neural correlates of imagination by being able to reliably trigger imaginary colour experiences. However, functional MRI studies using univariate analyses failed to provide univocal evidence of the activation of the ‘colour network’ by synaesthesia. Applying Multivariate (multivoxel) Pattern Analysis (MVPA) on 20 synaesthetes and 20 control participants, we tested whether the neural processing of real colours (concentric rings) and synaesthetic colours (black graphemes) shared patterns of activations. Region of interest analyses in retinotopically and anatomically defined visual regions revealed neither evidence of shared circuits for real and synaesthetic colour processing, nor processing difference between synaesthetes and controls. We also found no correlation with individual experiences, characterised by measuring the strength of synaesthetic associations. The whole brain, searchlight, analysis led to similar results. We conclude that identifying the neural correlates of the synaesthetic experience of colours may still be beyond the reach of present technology and data analysis techniques.

Age Differences in Information Use While Making Decisions

Recent research on the decision-making abilities of older adults has shown that they use less information than young adults. One explanation ascribes this age difference to reductions in cognitive abilities with age. The article includes three experimental studies that focused on determining the conditions in which older and young adults would display dissimilar information processing characteristics. Findings from Studies 1 and 2 demonstrated that older adults are not necessarily at greater disadvantage than young adults in decision contexts that demand more information processing resources. Findings from Study 3 indicated that older adults when faced with decisions that require greater processing are likely to use a strategy that reduces the amount of information needed, whereas younger adults rely on strategies that utilize more resources. Combined the findings indicate that older adults change their decision-making strategies based on the context and information provided. Furthermore, support is provided for processing difference.