Active Binaural Auditory Perceptual System for a Socially Interactive Humanoid Robot

Sound Source Localization (SSL) and gaze shift to the sound source behavior is an integral part of a socially interactive humanoid robot perception system. In noisy and reverberant environments, it is non-trivial to estimate the location of a sound source and accurately shift gaze in its direction. Previous SSL algorithms are deficient in the optimum approximation of distance to audio sources and to accurately detect, interpret, and differentiate the actual sound from comparable sound sources due to challenging acoustic environments. In this article, a learning-based model is presented to achieve noiseless and reverberation-resistant sound source localization in the real-world scenarios. The proposed system utilizes a multi-layered Gaussian Cross-Correlation with Phase Transform (GCC-PHAT) signal processing technique as a baseline for a Generalized Cross Correlation Convolution Neural Network (GCC-CNN) model. The proposed model is integrated with an efficient rotation algorithm to predict and orient toward the sound source. The performance of the proposed method is compared with the state-of-art deep network-based sound source localization methods. The findings of the proposed method outperform the existing neural network-based approaches by achieving the highest accuracy of 96.21% for an active binaural auditory perceptual system.

Testosterone amplifies the negative valence of an agonistic gestural display by exploiting receiver perceptual bias

Many animals communicate by performing elaborate displays that are incredibly extravagant and wildly bizarre. So, how do these displays evolve? One idea is that innate sensory biases arbitrarily favour the emergence of certain display traits over others, leading to the design of an unusual display. Here, we study how physiological factors associated with signal production influence this process, a topic that has received almost no attention. We focus on a tropical frog, whose males compete for access to females by performing an elaborate waving display. Our results show that sex hormones like testosterone regulate specific display gestures that exploit a highly conserved perceptual system, evolved originally to detect ‘dangerous' stimuli in the environment. Accordingly, testosterone makes certain gestures likely to appear more perilous to rivals during combat. This suggests that hormone action can interact with effects of sensory bias to create an evolutionary optimum that guides how display exaggeration unfolds.

Visual perception of surface properties through manipulation

Vision is a component of a perceptual system whose function is to support purposeful behavior. In this project we studied the perceptual system that supports the visual perception of surface properties through manipulation. Observers were tasked with finding dents in simulated flat glossy surfaces. The surfaces were presented on a tangible display system implemented on an Apple iPad, that rendered the surfaces in real time and allowed observers to directly interact with them by tilting and rotating the device. On each trial we recorded the angular deviations indicated by the device's accelerometer and the images seen by the observer. The data reveal purposeful patterns of manipulation that serve the task by producing images that highlight the dent features. These investigations suggest the presence of an active visuo-motor perceptual system involved in the perception of surface properties, and provide a novel method for its study using tangible display systems

Subjective spheres of influence: A perceptual system beyond Mindsponge

I developed a framework regarding an individual’s subjective spheres of influence based on the Mindsponge mechanism and Mindsponge-related studies to illustrate how individuals perceive what they can influence and what can influence them. In fact, this idea has germinated in my mind since I asked the question: “what are beyond Mindsponge?” The framework is expected to help explain how people interact with the world around them, how groups are formed, and how societies operate, which can be valuable for studying political, economic, social-cultural issues across disciplines.

Feature distribution learning by passive exposure

Humans can rapidly estimate the statistical properties of groups of stimuli, including their average and variability. But recent studies of so-called Feature Distribution Learning (FDL) have shown that observers can quickly learn even more complex aspects of feature distributions. In FDL, observers learn the full shape of a distribution of features in a set of distractor stimuli and use this information to improve visual search: response times (RT) are slowed if the target feature lies inside the previous distractor distribution, and the RT patterns closely reflect the distribution shape. FDL requires only a few trials and is markedly sensitive to different distribution types. It is unknown, however, whether our perceptual system encodes feature distributions automatically and by passive exposure, or whether this learning requires active engagement with the stimuli. In two experiments, we sought to answer this question. During an initial exposure stage, participants passively viewed a display of 36 lines that included one orientation singleton or no singletons. In the following search display, they had to find an oddly oriented target. The orientations of the lines were determined either by a Gaussian or a uniform distribution. We found evidence for FDL only when the passive trials contained an orientation singleton. Under these conditions, RT decreased as a function of the orientation distance between the target and the exposed distractor distribution. These results suggest that FDL can occur by passive exposure, but only if an orientation singleton appears during exposure to the distribution.

Autistic-like traits and Positive Schizotypy as Diametric Specializations of the Predictive Mind

The predictive processing (PP) framework suggests that the mind works by making and testing predictions. According to PP, only prediction errors (rather than all sensory inputs) are processed by an organism’s perceptual system. Prediction errors can be weighted such that some errors (usually those deemed more reliable) will be more influential in updating prior beliefs. It has recently been argued that autism spectrum disorders (ASD) result from an underlying predictive processing mechanism. The weight given to sensory prediction errors is thought to be inflexibly high in ASD, meaning that the perceptual system utilizes even relatively small prediction errors to update prior beliefs. Deficits in executive functioning, theory of mind, and central coherence are all argued to flow naturally from this core underlying mechanism. The diametric model of autism and psychosis suggests that these disorders result from opposite cognitive tendencies. Building on the diametric model, others have argued that autistic-like traits and positive schizotypy represent diametric cognitive-perceptual and behavioral traits that exist on a continuum in normal, non-clinical populations. In this paper I argue that positive schizotypy (which consists of magical thinking, unusual experiences, and ideas of reference) can be explained by the opposite mechanism to that of autism, namely an inflexibly low weight given to sensory prediction errors. This mechanism can potentially explain such disparate features of positive schizotypy as increased exploratory behavior, hyper-theory of mind, attentional differences, idiosyncratic worldviews, and a hyper-active imagination.

Bedeutung und Weltwissen in der Konstruktionsgrammatik. Holistik oder Modularität?

Empirical and theoretical arguments are presented against a framesemantic grounding of construction grammar and thus against a holistic unification of meaning and world knowledge. A modular conception is the basis of the interplay between construction and projection in Goldberg (1995). Goldberg’s attempt to include frame semantics is at odds with this foundation and must be considered a failure. The same is true for the continuation by Boas (2003). The argumentation is supplemented, among other things, by the reference to the contrast of a perceptual system and a linguistic system of cognition in cognitive psychology and by the necessity to take a modular concept as a basis in the area of syntactic-semantic ambiguity of sentences.

Cultures of Pattern Recognition in Particle Physics. Preliminary Remarks.

One of the central operations of science is finding patterns in data. Pattern Recognition, although based in capabilities of the human perceptual system, is a cultural and social process bases on assemblages of different technologies and practices. This will be shown by comparing two case studies from the history of particle physics.

Multiple spatial reference frames underpin perceptual recalibration to audio-visual discrepancies

In dynamic multisensory environments, the perceptual system corrects for discrepancies arising between modalities. For instance, in the ventriloquism aftereffect (VAE), spatial disparities introduced between visual and auditory stimuli lead to a perceptual recalibration of auditory space. Previous research has shown that the VAE is underpinned by multiple recalibration mechanisms tuned to different timescales, however it remains unclear whether these mechanisms use common or distinct spatial reference frames. Here we asked whether the VAE operates in eye- or head-centred reference frames across a range of adaptation timescales, from a few seconds to a few minutes. We developed a novel paradigm for selectively manipulating the contribution of eye- versus head-centred visual signals to the VAE by manipulating auditory locations relative to either the head orientation or the point of fixation. Consistent with previous research, we found both eye- and head-centred frames contributed to the VAE across all timescales. However, we found no evidence for an interaction between spatial reference frames and adaptation duration. Our results indicate that the VAE is underpinned by multiple spatial reference frames that are similarly leveraged by the underlying time-sensitive mechanisms.