Top-down and bottom-up processing are two distinct yet highly interactive modes of neuronal activity underlying normal and abnormal human cognition. Here we characterize the dynamic processes that contribute to these two modes of cognitive operation. We used a blind source separation algorithm called second-order blind identification (SOBI [1]) to extract from high-density scalp EEG (128 channe...

In this paper we present an efficient real-time implementation of a broadband algorithm for blind source separation (BSS) of convolutive mixtures. A recently introduced matrix formulation allows straightforward simultaneous exploitation of nonwhiteness and nonstationarity of the source signals using second-order statistics. We examine the efficient implementation of the resulting algorithm and ...

In this paper, we address the problem of speech source separation by relying on time-frequency binary masks to segregate binaural mixtures. We describe an algorithm which can tackle reverberant mixtures and can extract the original sources while preserving their original spatial locations. The performance of the proposed algorithm is evaluated objectively and subjectively, by assessing the esti...

This paper addresses the tracking capability of blind source separation algorithms for rapidly time-varying sensor or source positions. Based on a known algorithm for blind source separation, which also allows for simultaneous localization of multiple active sources in reverberant environments, the source separation performance will be investigated for abrupt microphone array rotations represen...

The Blind Source Separation (BSS) problem is often solved by maximizing objective functions reflecting the statistical dependency between outputs. Since global maximization may be difficult without exhaustive search, criteria for which it can be proved that all the local maxima correspond to an acceptable solution of the BSS problem have been developed. These criteria are used in a deflation pr...

Source separation evaluation is typically a top-down process, starting with perceptual measures which capture fitness-for-purpose and followed by attempts to find physical (objective) measures that are predictive of the perceptual measures. In this paper, we take a contrasting bottom-up approach. We begin with the physical measures provided by the Blind Source Separation Evaluation Toolkit (BSS...

The problem of blind source separation is usually solved by optimizing a contrast function that measures either the independence of several variables or the non-gaussianity of a single variable. If the problem involves bounded sources, this knowledge can be exploited and the solution can be found with a customized contrast that relies on a simple endpoint estimator. The minimization of the leas...

Blinde Quellentrennung (Blind Source Separation, BSS) ist ein Verfahren zur Rekonstruktion der Quellsignale aus beobachteten Mischungen, wobei weitere Informationen über die Quellen, Quellenkonstellation oder Mischungsart nicht vorliegen. Mögliche Einsatzgebiete der Blinden Quellentrennung könnten beispielsweise rauschrobuste Spracherkennung, sprachgesteuerte Telekommunikationssysteme und Hörhi...