Scientific
publications

The mass digitization of books is changing the way information is created, disseminated and displayed. Electronic book readers (e-readers) generally refer to two main display technologies: the electronic ink (E-ink) and the liquid crystal display (LCD). Both technologies have advantages and disadvantages, but the question whether one or the other triggers less visual fatigue is still open. The aim of the present research was to study the effects of the display technology on visual fatigue. To this end, participants performed a longitudinal study in which two last generation e-readers (LCD, E-ink) and paper book were tested in three different prolonged reading sessions separated by – on average – ten days. Results from both objective (Blinks per second) and subjective (Visual Fatigue Scale) measures suggested that reading on the LCD (Kindle Fire HD) triggers higher visual fatigue with respect to both the E-ink (Kindle Paperwhite) and the paper book. The absence of differences between E-ink and paper suggests that, concerning visual fatigue, the E-ink is indeed very similar to the paper.

With the aim of studying attentional leftward bias in a driving context, we combined recording of gaze behaviour with a simulated driving task (Lane Change Test – LCT) in spatial symmetry conditions. The LCT requires driving along a straight traffic-free three-lane road, changing lanes according to the information provided by two identical road signs displayed concurrently on both left and right sides of the road. Participants directed most of their attention to the left-hand signs. The prevalent visuospatial nature of the driving task – which is supposed to mostly activate the right cerebral hemisphere – could have caused a contralateral attention shift. The introduction of a secondary task – performed with the right hand, concurrently with the LCT – attenuated the leftward bias.

Authors: F Onorati, R Barbieri, M Mauri, V Russo, L Mainardi

Journal: Frontiers in Neuroengineering 

With the recent advent of new recording devices and an easier access to signal processing tools, researchers are increasingly exploring and studying the Pupil Dilation (PD) signal. Recently, numerous studies pointed out the relations between PD dynamics and psychophysiological states. Although it is well known that PD is controlled by the Autonomic Nervous System (ANS), and ANS responses are related to emotional events/stimuli, the relationship between emotional states and PD is still an open issue. The aim of this study is to define the statistical properties of the PD signal, to understand its relationship with ANS correlates such as Heart Rate Variability (HRV) and respiration (RESP), and to explore if PD could provide information for the evaluation of the psychophysiological response of ANS to affective triggering events. ECG, RESP, and PD data from 13 normal subjects were recorded during a memory recall paradigm, and processed with spectral and cross-spectral analysis. Our results demonstrate that variability indices extracted from fast PD oscillations, not observable through standard cardiorespiratory identification in the frequency domain, would be able to discern psychophysiological responses elicited by basic emotional stimuli. A strong linear coupling was found between the variables, due to the influence of RESP on both PD and HRV within the High Frequency (HF) band, from 0.15 to 0.45Hz. Most importantly, our results point at PD features as possible candidates for characterizing basic emotional stimuli.