Phase diagram investigation and characterization of alloys in Bi-Ga10Sb90 section of Ga-Bi-Sb system

The results of phase equilibria investigation and characterization of the alloys in the Bi-Ga10Sb90 section of Ga-Bi-Sb system are presented in this paper. Phase diagram of the mentioned section has been calculated according to CALPHAD model, using Pandat software. In the frame of alloys characterization, structural, mechanical and electrical characteristics were determined using SEM-EDX analysis, microhardness and electroconductivity measurements

Phase diagram investigation and characterization of alloys in Bi-Ga10Sb90 section of Ga-Bi-Sb system

The results of phase equilibria investigation and characterization of the alloys in the Bi-Ga10Sb90 section of Ga-Bi-Sb system are presented in this paper. Phase diagram of the mentioned section has been calculated according to CALPHAD model, using Pandat software. In the frame of alloys characterization, structural, mechanical and electrical characteristics were determined using SEM-EDX analysis, microhardness and electroconductivity measurements

Saliency maps for finding changes in visual scenes?

Sudden changes in the environment reliably summon attention. This rapid change detection appears to operate in a similar fashion as pop-out in visual search, the phenomenon that very salient stimuli are directly attended, independently of the number of distracting objects. Pop-out is usually explained by the workings of saliency maps, i.e., map-like representations that code for the conspicuity at each location of the visual field. While past research emphasized similarities between pop-out search and change detection, our study highlights differences between the saliency computations in the two tasks: in contrast to pop-out search, saliency computation in change detection (i) operates independently across different stimulus properties (e.g., color and orientation), and (ii) is little influenced by trial history. These deviations from pop-out search are not due to idiosyncrasies of the stimuli or task design, as evidenced by a replication of standard findings in a comparable visual-search design. To explain these results, we outline a model of change detection involving the computation of feature-difference maps, which explains the known similarities and differences with visual search

Types of geometrical transformations and perceptual similarity of figures

In this study it was investigated which of several types of geometrical transformations emerge as dominant principle in grouping forms. It was assumed that forms which have more similar features would be grouped together more often. The stimuli consisted of basic form (O) and it’s transformation: (T1) rotation; (T2) projection onto horizontal plane; (T3) projection onto vertical plane; (T4) stretching and (T5) twisting. There were two groups of stimuli: (G1) asymmetrical planes and (G2) linear patterns. Stimuli varied in complexity (i.e. number of lines they contain): (S1) four; (S2) five and (S3) six.The sets of stimuli were created given by formula O-Tm-Tn. Subjects were asked to choose which of the stimuli from the set doesn’t go along with others. Results showed that the stimuli would be grouped together more often if they had more common features. These results were obtained for both groups of stimuli and all levels of complexity

Item-based selection is in good shape in visual compound search: a view from electrophysiology

We argue that although the framework put forward by Hulleman & Olivers (H&O) can successfully explain much of visual search behaviour, it appears limited to tasks without precise target identification demands. In particular, we contend that the unit of selection may be larger than a single item in standard detection tasks, whereas the unit may mandatorily be item-based in compound tasks

Item-based selection is in good shape in visual compound search: a view from electrophysiology

We argue that although the framework put forward by Hulleman & Olivers (H&O) can successfully explain much of visual search behaviour, it appears limited to tasks without precise target identification demands. In particular, we contend that the unit of selection may be larger than a single item in standard detection tasks, whereas the unit may mandatorily be item-based in compound tasks

Distinct neural markers of evidence accumulation index metacognitive processing before and after simple visual decisions

Perceptual decision-making is the process of using sensory information to guide behaviour. This process is affected by uncertainty arising from the reliability of incoming sensory evidence (i.e., perceptual uncertainty), and the categorisation of that evidence relative to a choice boundary (i.e., categorical uncertainty). Here, we investigated how these factors impact the temporal dynamics of evidence processing during decision-making, including metacognitive judgements. Human participants (N=36, 26 females) performed a visual-motion discrimination task while electroencephalography (EEG) was recorded. We manipulated perceptual uncertainty by varying motion coherence, and categorical uncertainty by varying the angular offset of motion signals relative to a criterion. To assess metacognition, participants rated their desire to change their mind after each trial. High uncertainty impaired perceptual and metacognitive judgements and reduced the amplitude of the centro-parietal positivity (CPP), a neural marker of evidence accumulation. Importantly, the coherence and offset manipulations affected the CPP at different time points, suggesting that perceptual and categorical uncertainty affect decision making in sequential stages. Moreover, the CPP predicted behavioural outcomes, with greater amplitude associated with faster and more accurate responses. The CPP also predicted metacognitive judgments: larger pre-decisional CPP amplitude was associated with a lower tendency for participants to want to change their mind, whereas larger post-decisional CPP amplitude predicted a higher tendency for participants to want to change their mind. These findings reveal a dissociation between pre- and post-decisional processes and suggest that the CPP is a common neural signature of evidence accumulation that tracks distinct sources of evidence before and after decisions

Behavioral and electroencephalography recordings of human observers during a decision-making task with varying levels of task difficulty

Using computational modelling of human behavior together with concurrent recording of brain activity by means of electroencephalography, this project aims to characterize neural and cognitive mechanisms of human decision making

RemapAttMap

Dataset of the Peripheral Remapping and Foveal Remapping of attention task