Wearable Sensory Apparatus for Real-Time Feedback in Wearable Robotics

We describe the Wearable Sensory Apparatus (WSA) System, which has been implemented and verified in accordance with the relevant standards. It comprises the Inertial Measurement Units (IMUs), real-time wireless data transmission over Ultrawideband (UWB), a Master Unit and several IMU dongles forming the Wireless Body Area Network (WBAN). The WSA is designed for, but is not restricted to, wearable robots. The paper focuses on the topology of the communication network, the WSA hardware, and the organization of the WSA firmware. The experimental evaluation of the WSA incorporates the confirmation of the timing using the supply current WSA profile, measurements related to determining the less error prone position of the master device on the backpack, measurements of the quality of the data transfer in a real environment scenario, measurements in the presence of other microwave signals, and an example of raw IMU signals during human walking. Placement of the master device on the top of the backpack was found to be less error prone, with less than 0.02% packet loss for all the IMU devices placed on different body segments. The packet loss did not change significantly in public buildings or on the street. There was no impact of Wi-Fi bands on the WSA data transfer. The WSA hardware and firmware passed conformance testing in a certified lab. Most importantly, the WSA performed reliably in the laboratory and in clinical tests with exoskeletons and prostheses.

Blind-Spots in Aristotle’s Doctrine of the Perceptual Mean

This paper aims to identify several interpretive problems posed by the final part of DA II.11 (423b27–424 a10), where Aristotle intertwines the thesis that a sense is like a ‘mean’ and an explanation for the existence of a ‘blind spot’ related to the sense of touch, adding the further contention that we are capable of discriminating because the mean ‘becomes the other opposite’ in relation to the perceptible property being perceived. To solve those problems, the paper explores a novel interpretation of Aristotle’s claims, arguing that they describe a homeostatic physiological reaction by which the sensory apparatus responds to perceptible stimuli. According to the proposed interpretation, such homeostatic reaction constitutes a necessary condition for perceiving what Aristotle refers to as ‘proper’ perceptible features, which include properties like ‘hot’ and ‘cold’ as well as colors and sounds.

Formations

Concerned with formations, the second chapter is devoted to historical scenes in the development of behavioral biology around 1900. The latter discipline systematized knowledge about swarms by relying on physical instead of then popular social models of interaction, e.g. in mass psychology. It developed a genuinely ‘biological gaze’ that was determined to study animal collectives in terms of the ‘systemic’ nature of their inter-individual behavior. Techniques and media for gathering data thus gained a new degree of relevance, replacing the human sensory apparatus, which perceived little more than noise, and traditional systems for recording information (diaries, hand-written observations), which could not deal with the abundance of data.

The Psammetichus Syndrome and Beyond

Thanks to Bruno Galantucci, “experimental semiotics” is usually nowadays taken to mean the study of “novel forms of communication which people develop when they cannot use pre-established communication systems”. In spite of Galantucci’s claim to have picked the label because it was free, it has actually been used in different ways at least twice before: by Colin Ware, who takes it to be involved with “the elucidation of symbols that gain their meaning by being structured to take advantage of the human sensory apparatus”, as opposed to conventional meaning-making, and by Kashima and Haslam, who apply it to complex social situations. The label could also conveniently be used to describe the kind of experiment that we have realized at Centre for Cognitive Semiotics, which are classical psychological experiments which have been enriched with a focus on the particular semiotic resources involved, while also applying phenomenological analysis to both the experimental situation and its outcome. These are all reductive uses of the terms “experimental” and “semiotics”. In fact, although Galantucci himself refers to Psammetichus’s famous experiment as being roughly analogous to his understanding of experimental semiotics, there are important differences, the Psammetichus experiment, in spite of its intentions, being more unbiased, if it could really be accomplished. Pursuing the principle that I have called the dialects of phenomenology and experiment, and what Jordan Zlatev has termed the conceptual-empirical loop, I will suggest, in the present paper, that these different experimental approaches can be related to different varieties of semiosis, thus helping us to spell out the full task of the discipline termed cognitive semiotics. This, in turn, will help us determine the full scope of cognitive semiotics, while also highlighting the importance of the semiotic part, that is, the attention to meaning, revealed by phenomenology.

Bayes-Like Integration of a New Sensory Skill with Vision

ABSTRACTHumans are effective at dealing with noisy, probabilistic information in familiar settings. One hallmark of this is Bayesian Cue Combination: combining multiple noisy estimates to increase precision beyond the best single estimate, taking into account their reliabilities. Here we show that adults also combine a novel audio cue to distance, akin to human echolocation, with a visual cue. Following two hours of training, subjects were more precise given both cues together versus the best single cue. This persisted when we changed the novel cue’s auditory frequency. Reliability changes also led to a re-weighting of cues without feedback, showing that they learned something more flexible than a rote decision rule for specific stimuli. The main findings replicated with a vibrotactile cue. These results show that the mature sensory apparatus can learn to flexibly integrate new sensory skills. The findings are unexpected considering previous empirical results and current models of multisensory learning.