Publications by authors named "Hamoon Zohdi"

Creative music therapy (CMT) has been shown to promote the development of brain function and structure in preterm infants. We aimed to investigate the effect of CMT on cerebral oxygenation and perfusion to examine how the brain reacts to CMT. Absolute levels of cerebrovascular oxygen saturation (StO) were measured in clinically stable preterm-born neonates (n = 20, gestational age: ≥30 weeks and < 37 weeks) using two near-infrared spectroscopy (NIRS)-based tissue oximeters over the right prefrontal cortex and left auditory cortex.

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Background: In our previous studies, we investigated the right-left asymmetry (RLA) of cerebral tissue oxygenation (StO) at rest in humans and the influence of the individual chronotype (i.e. individual chronobiological disposition) on StO.

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Colored light has important implications for human health and well-being, as well as for the aesthetics and function of various environments. In addition to its effects on visual function, colored light has significant effects on cognitive performance, behavior and systemic physiology. The aim of the current study was to comprehensively investigate how colored light exposure (CLE) combined with a cognitive task (2-back) affects performance, cerebral hemodynamics, oxygenation, and systemic physiology as assessed by systemic physiology augmented functional near-infrared spectroscopy (SPA-fNIRS).

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Individuals have different performance levels for cognitive tasks. Are these performance levels reflected in physiological parameters? The aim of this study was to address this question by systemic physiology augmented functional near-infrared spectroscopy (SPA-fNIRS). We aimed to investigate whether different verbal fluency task (VFT) performances under blue light exposure were associated with different changes in cerebrovascular oxygenation and systemic physiological activity.

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Background: All parameters of human physiology show chronobiological variability. While circadian (cycle length ~ 24 h) rhythms of the neuronal, hemodynamic and metabolic aspects of human brain activity are increasingly being explored, infradian (cycle length > 24 h) rhythms are largely unexplored.

Aim: We investigated if cerebrovascular oxygen saturation (StO) and blood volume ([tHb]) values measured over many years in many subjects during resting show infradian rhythmicity.

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Background: Although several studies published reference values for frontal cerebral tissue oxygen saturation (StO) measured with near-infrared spectroscopy (NIRS) based cerebral oximetry, a detailed investigation, whether and which factors from systemic physiology are related to the individual StO values, is missing.

Aim: We investigated how the state of the cardiorespiratory system is linked to StO values at rest.

Subjects And Methods: Absolute StO values (median over a 5 min resting-phase while sitting) were obtained from 126 healthy subjects (age: 24.

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Background: Sex differences in behavioural performance of a cognitive task have been repeatedly reported in the literature. Whether such differences are also relevant for evoked cerebral haemodynamic and oxygenation responses as well as systemic physiological changes is a topic of ongoing investigations.

Aim: We investigated whether changes in cerebral oxygenation and systemic physiological activity are sex-dependent during a verbal fluency task (VFT).

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There is large intersubject variability in cerebrovascular hemodynamic and systemic physiological responses induced by a verbal fluency task (VFT) under colored light exposure (CLE). We hypothesized that machine learning would enable us to classify the response patterns and provide new insights into the common response patterns between subjects. In total, 32 healthy subjects (15 men and 17 women, age: 25.

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In our previous investigations using systemic physiology augmented functional near-infrared spectroscopy (SPA-fNIRS) neuroimaging, we found larger variability between subjects in changes of cerebral hemodynamics and oxygenation induced by an intricate experimental paradigm involving colored light exposure and a cognitive task. We aimed to investigate the role the activity of the systemic physiology has on individual variations in the fNIRS data. Thirty-two healthy subjects (17 female, 15 male and age: 25.

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Background: In modern society, we are increasingly exposed to numerous sources of blue light, including screens (e.g., TVs, computers, laptops, smartphones, tablets) and light from fluorescent and LED lamps.

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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.

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When brain activity is measured by neuroimaging, the canonical hemodynamic response (increase in oxygenated hemoglobin ([OHb]) and decrease in deoxygenated hemoglobin ([HHb]) is not always seen in every subject. The reason for this intersubject-variability of the responses is still not completely understood. This study is performed with 32 healthy subjects, using the systemic physiology augmented functional near-infrared spectroscopy (SPA-fNIRS) approach.

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Our study reveals that frontal cerebral oxygenation asymmetry (FCOA), i.e. a difference in the oxygenation between the right and left prefrontal cortex (PFC), is a real phenomenon in healthy human subjects at rest.

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In the literature, it is well established that regular physical exercise is a powerful strategy to promote brain health and to improve cognitive performance. However, exact knowledge about which exercise prescription would be optimal in the setting of exercise-cognition science is lacking. While there is a strong theoretical rationale for using indicators of internal load (e.

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Background: We have repeatedly observed a right-left asymmetry (RLA) of prefrontal cerebral oxygenation of subjects during the resting state.

Aim: To clarify if the RLA is a reliably observable phenomenon at the group level and whether it is associated with systemic physiology, absolute tissue oxygen saturation (StO) or total hemoglobin concentration ([tHb]).

Material And Methods: StO and [tHb] values at the right and left prefrontal cortex (PFC) were calculated for two 5- min resting phases based on data from 76 single measurements (24 healthy adults, aged 22.

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Frequency-domain near-infrared spectroscopy (FD-NIRS) enables to measure absolute optical properties (i.e. the absorption coefficient, μ, and the reduced scattering coefficient, [Formula: see text]) of the brain tissue.

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Background: Absolute optical properties (i.e., the absorption coefficient, μ, and the reduced scattering coefficient, [Formula: see text]) of head tissue can be measured with frequency-domain near-infrared spectroscopy (FD-NIRS).

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Measurements of cerebral and muscle oxygenation (StO) and perfusion ([tHb]) with functional near-infrared spectroscopy (fNIRS) and near infrared spectroscopy (NIRS), respectively, can be influenced by changes in systemic physiology. The aim of our study was to apply the oblique subspace projections signal decomposition (OSPSD) to find the contribution from systemic physiology, i.e.

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Unlabelled: Recently accumulating evidence has put into question the role of large multinucleated giant cells (MNGCs) around bone biomaterials. While cells derived from the monocyte/macrophage lineage are one of the first cell types in contact with implanted biomaterials, it was originally thought that specifically in bone tissues, all giant cells were bone-resorbing osteoclasts whereas foreign body giant cells (FBGCs) were found associated with a connective tissue foreign body reaction resulting in fibrous encapsulation and/or material rejection. Despite the great majority of bone grafting materials routinely found with large osteoclasts, a special subclass of bone biomaterials has more recently been found surrounded by large giant cells virtually incapable of resorbing bone grafts even years after their implantation.

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