Jorge A. Santos’s research while affiliated with University of Minho and other places

To perceive, identify and understand the action of others, it is essential to perceptually organize individual and local moving body parts (such as limbs) into the whole configuration of a human body in action. Configural processing—processing the relations among features or parts of a stimulus—is a fundamental ability in the perception of several important social stimuli, such as faces or biological motion. Despite this, we know very little about how human infants develop the ability to perceive and prefer configural relations in biological motion. We present two preferential looking experiments (one cross-sectional and one longitudinal) measuring infants’ preferential attention between a coherent motion configuration of a person walking vs. a scrambled point-light walker (i.e., a stimulus in which all configural relations were removed, thus, in which the perception of a person is impossible). We found that three-month-old infants prefer a coherent point-light walker in relation to a scrambled display, but both five- and seven-month-old infants do not show any preference. We discuss our findings in terms of the different perceptual, attentional, motor, and brain processes available at each age group, and how they dynamically interact with selective attention toward the coherent and socially relevant motion of a person walking during our first year of life.

An online sound categorization study was carried out to assess the association of everyday sounds with regard to medical equipment audio alarms. There were seven clinical alarm risk categories as described in IEC 6060-1-1-8 as well as an additional alarm category for 'Blood Pressure'. After a headphone screening test, participants categorized all sounds into one of the categories, a methodology adapted from a classic usability methodology called Card Sorting [1]. They were asked to indicate the quality of fit of their evaluation (Poor, Fair, Perfect) after sorting each sound. From the eight categories tested, a consensus was achieved for the categories of Blood Pressure, Cardiac, Power Down and Ventilation. For the other categories of Drug Administration, Temperature, Perfusion and Oxygen, lower consistency was observed, highlighting the difficulty of sound design for specific contexts. Having evidence of agreement among participants is an important output for the general goal of designing a library of informative sounds for medical devices.

Nowadays, interoperable decision support systems play a crucial role to improve production activity control in industrial Companies, and enable them to face the growing exigencies imposed by the arising Industry 4.0 era. In this paper an interoperable decision support system based on multivariate time series for setup data processing and visualization is put forward. The proposed system is described, in the context of a general architecture presented, and its application through an illustrative example from a stamping factory is analysed. Through the case study it is possible to realize about the importance of the proposed system, and its suitability of application to other companies, for instance in other industrial sectors and manufacturing environments.

Biological motion perception—our capacity to perceive the intrinsic motion of humans and animals—has been implicated as a precursor of social development in infancy. In the adult brain, several biological motion neural correlates have been identified; of particular importance, the right posterior superior temporal sulcus (rpSTS). We present a study, conducted with fNIRS, which measured brain activations in infants’ right posterior temporal region to point-light walkers, a standard stimulus category of biological motion perception studies. Seven-month-old infants (n = 23) participated in a within-subject blocked design with three experimental conditions and one baseline. Infants viewed: an intact upright point-light walker of a person approaching the observer; the same point-light walker stimulus but inverted; and a selected frame from the point-light walker stimulus, approaching the viewer at constant velocity with no articulated motion, close to object motion. We found activations for both the upright and the inverted point-light walkers. The rigid moving point-light walker frame did not elicit any response consistent with a functional activation in this region. Our results suggest that biological motion is processed differently in the right middle posterior temporal cortex in infancy, and that articulated motion is a critical feature in biological motion processing at this early age.

Biological motion perception is a key component of action perception contributing to social cognition in crucial ways. Contemporary neuroimaging studies show that biological motion is processed differently in the human brain from other types of motion. In particular, the right posterior Superior Temporal Sulcus (rpSTS), an area known for its central role in social perception, has been consistently associated with the perception of biological motion in the mature brain. By contrast, most findings investigating the development of biological motion perception in infancy come from behavioral studies, and far less is known regarding the right STS’ role in processing biological motion. The current study used fNIRS to measure brain activation to biological motion in the rSTS region of 7–8-month-old infants. Infants were presented with two conditions: an approaching coherent motion of a person walking (coherent point-light-walker, PLW); and a spatially scrambled version of this display, where the global configuration of a person walking was disrupted (scrambled PLW). We found a functional activation, i.e., a significant increase in HbO2 concentration in relation to baseline, in the right middle-posterior temporal cortex only when infants viewed the coherent point-light-walker. This activation statistically differed from the scrambled point-light-walker, and no significant activations were found for viewing the scrambled motion. Our study adds evidence pointing to rSTS’ sensitivity to the global human configuration in biological motion processing during infancy. The rSTS seems thus to become functionally specialized in biological motion configuration as early as at 7–8 months of age.

Decision support visualization tools provide insights for solving problems by displaying data in an interactive, graphical format. Such tools can be effective for supporting decision-makers in finding new opportunities and in measuring decision outcomes. In this study, was used a visualization tool capable of handling multivariate time series for studying a problem of operational control in a textile manufacturing plant; the main goal was to identify sources of inefficiency in the daily production data of three machines. A concise rule-based model of the inefficiency measures (i.e. quantitative measures were transformed into categorical variables) was developed and then performed an in-depth visual analysis using a particular technique, the categorical time series plots stacked vertically. With this approach were identified a wide array of production inefficiency patterns, which were difficult to identify using standard quantitative reporting - temporal pattern of best and worst performing machines - and critically, along with most important sources of inefficiency and some interactions between them were revealed. The case study underlying this work was further contextualized within the state of the art, and demonstrates the effectiveness of adequate visual analysis as a decision support tool for operational control in manufacturing.

The global medical safety standard IEC 60601-1-8 includes general requirements for the design of auditory alarms for medical equipment. This document was last amended in 2012 and is currently being updated to be released in the end of 2019. The update includes major changes in the auditory warning signals design guidelines. One of the most important is the fact that it will allow stakeholders to design different versions of the same sound. It is thus relevant to systematize the thorough and robust body of knowledge developed in recent years regarding the design of clinical auditory alarms. This paper identifies the reported problems with clinical auditory alarms; revisits early and current audio design guidelines; and systematizes recommendations or good-practices on healthcare noise, considering spectral, temporal and spatial characteristics of auditory alarms. All content is based on standards and/or experimental studies on detection, learning, subjective perception, or spatial localization. Its aim is to provide a practical tool for designers to design better clinical auditory alarms.

The relationship between physical acoustic parameters and the subjective responses they evoke is important to assess in audio alarm design. While the perception of urgency has been thoroughly investigated, the perception of other variables such as pleasantness, negativeness and irritability has not. To characterize the psychological correlates of variables such as frequency, speed, rhythm and onset, twenty-six participants evaluated fifty-four audio warning signals according to six different semantic differential scales. Regression analysis showed that speed predicted mostly the perception of urgency, preoccupation and negativity; frequency predicted the perception of pleasantness and irritability; and rhythm affected the perception of urgency. No correlation was found with onset and offset times. These findings are important to human-centred design recommendations for auditory warning signals .

Garments used in hospitals play an important role in user’s comfort and health. This paper presents the developments of a patented design technology for medical garments aimed at users, caregivers, and health care providers. Traditional gowns lacking comfort and protection affect the patient’s dignity. Similarly, patients often use their own garments, which are not designed to provide the best comfort and protection if sensing capacity is affected. Additionally, they can interfere with caregivers’ daily tasks. The proposed pajamas consider these needs and allow an effective interaction between patient and caregiver without compromising the person’s self-esteem. The selection of functional textile fibers and the use of seamless production processes allow the design of products advantageous in the prevention of wounds and pressure ulcers, as pressure points are reduced and the micro-climate of the skin is managed in a more effective way, enhancing the levels of sensorial, physiological and ergonomic comfort. KeywordsComfortProtectionMedical garments design

When people walk side-by-side, they often synchronize their steps. To achieve this, individuals might cross-modally match audiovisual signals from the movements of the partner and kinesthetic, cutaneous, visual and auditory signals from their own movements. Because signals from different sensory systems are processed with noise and asynchronously, the challenge of the CNS is to derive the best estimate based on this conflicting information. This is currently thought to be done by a mechanism operating as a Maximum Likelihood Estimator (MLE). The present work investigated whether audiovisual signals from the partner are integrated according to MLE in order to synchronize steps during walking. Three experiments were conducted in which the sensory cues from a walking partner were virtually simulated. In Experiment 1 seven participants were instructed to synchronize with human-sized Point Light Walkers and/or footstep sounds. Results revealed highest synchronization performance with auditory and audiovisual cues. This was quantified by the time to achieve synchronization and by synchronization variability. However, this auditory dominance effect might have been due to artifacts of the setup. Therefore, in Experiment 2 human-sized virtual mannequins were implemented. Also, audiovisual stimuli were rendered in real-time and thus were synchronous and co-localized. All four participants synchronized best with audiovisual cues. For three of the four participants results point toward their optimal integration consistent with the MLE model. Experiment 3 yielded performance decrements for all three participants when the cues were incongruent. Overall, these findings suggest that individuals might optimally integrate audiovisual cues to synchronize steps during side-by-side walking.