6 research outputs found
Color-dependent changes in humans during a verbal fluency task under colored light exposure assessed by SPA-fNIRS.
Light evokes robust visual and nonvisual physiological and psychological effects in humans, such as emotional and behavioral responses, as well as changes in cognitive brain activity and performance. The aim of this study was to investigate how colored light exposure (CLE) and a verbal fluency task (VFT) interact and affect cerebral hemodynamics, oxygenation, and systemic physiology as determined by systemic physiology augmented functional near-infrared spectroscopy (SPA-fNIRS). 32 healthy adults (17 female, 15 male, age: 25.5 ± 4.3 years) were exposed to blue and red light for 9 min while performing a VFT. Before and after the CLE, subjects were in darkness. We found that this long-term CLE-VFT paradigm elicited distinct changes in the prefrontal cortex and in most systemic physiological parameters. The subjects' performance depended significantly on the type of VFT and the sex of the subject. Compared to red light, blue evoked stronger responses in cerebral hemodynamics and oxygenation in the visual cortex. Color-dependent changes were evident in the recovery phase of several systemic physiological parameters. This study showed that the CLE has effects that endure at least 15 min after cessation of the CLE. This underlines the importance of considering the persistent influence of colored light on brain function, cognition, and systemic physiology in everyday life
Managing Learner’s Affective States in Intelligent Tutoring Systems
Abstract. Recent works in Computer Science, Neurosciences, Education, and Psychology have shown that emotions play an important role in learning. Learner’s cognitive ability depends on his emotions. We will point out the role of emotions in learning, distinguishing the different types and models of emotions which have been considered until now. We will address an important issue con-cerning the different means to detect emotions and introduce recent approaches to measure brain activity using Electroencephalograms (EEG). Knowing the influ-ence of emotional events on learning it becomes important to induce specific emo-tions so that the learner can be in a more adequate state for better learning or memorization. To this end, we will introduce the main components of an emotion-ally intelligent tutoring system able to recognize, interpret and influence learner’s emotions. We will talk about specific virtual agents that can influence learner’s emotions to motivate and encourage him and involve a more cooperative work, particularly in narrative learning environments. Pushing further this paradigm, we will present the advantages and perspectives of subliminal learning which inter
Effects of exposure to colored light on cerebral and systemic physiology in humans
Humans in industrialized societies have become independent of the natural
day and night cycle due to the invention and use of artificial light. Colored light is
an element of everyday life, which affects various human functions. The main aim
of this PhD thesis is to comprehensively investigate the effects of exposure to
colored light on cerebral and human physiology. To achieve this goal, 201 healthy
right-handed adults were recruited for 20 different colored light conditions. By
using systemic physiology augmented functional near-infrared spectroscopy (SPA-fNIRS)
neuroimaging, each subject was measured 2-4 times on different days
resulting in 676 single measurements. The SPA-fNIRS approach combines the
measurement of brain activity and systemic physiological changes. fNIRS is a non-invasive neuroimaging technique employed to measure changes in cerebral hemodynamics and oxygenation. There is an interaction between these and
changes in systemic physiology: consequently, the SPA-fNIRS generally enables
us to identify and understand these interactions. We simultaneously assessed the
effects of colored light exposure (CLE) in the visual cortex (VC), prefrontal cortex
(PFC) and systemic physiology. Such a comprehensive study has not been carried
out yet, and an integrative view of how the color of light affects the brain and systemic physiology is lacking. In general, CLE has relatively long-lasting effects
on cerebral and systemic physiology in humans, and yellow light leads to higher
brain activation in the PFC than the other colored lights. Yellow CLE is associated
with more active and positive emotions, including happiness, joy, hope, and cheerfulness. We also show that long-term colored light exposures induce
wavelength-dependent modulations of brain responses in the VC. Violet and blue
lights elicit higher changes in cerebral parameters compared to the other colored
lights during the CLE and recovery phase. Our results show that CLE affects
individual humans differently. In particular, blue light leads to eight different
hemodynamic response patterns, while the typical hemodynamic response pattern
(increase in oxygenated ([O2Hb]) and decrease in deoxygenated ([HHb])
hemoglobin) is still observed and valid at the group-level analysis. The SPA-fNIRS approach is able to show that systemic and cerebral physiology interact.
Experimental findings in most parts of this research display that inter-subject
variability of hemodynamic responses is partially explained by systemic
physiological changes. The finding of this research that blue light has an
activating effect in the VC should be taken into consideration when assessing the
impact of modern light sources such as screens and light-emitting diodes (LEDs)
on the human body. Our findings that yellow light leads to higher PFC activation
be tested as a potentially beneficial tool in chromotherapy, i.e., a complementary
medicine method, to balance “energy” lacking in physical, emotional, and mental
levels. Although yellow light, i.e., CLE in general term, influences humans in
several positive ways, it should be noted that each individual reacts differently to
the CLE, implying that colored light therapy has to be also adjusted to each
individual. Therefore, further research should clarify which color in CLE benefits
whom. In a civilization that is rapidly exposed to new and increasing lighting, the
findings of this research are relevant for the scientific community, medical
professionals, and society