We introduce dynamic light scattering imaging (DLSI) to enable the wide-field measurement of the speckle temporal intensity autocorrelation function. DLSI uses the full temporal sampling of speckle fluctuations and a comprehensive model to identify the dynamic scattering regime and obtain a quantitative image of the scatterer dynamics. It reveals errors in the traditional theory of laser Doppler flowmetry and laser speckle contrast imaging and provides guidance on the best model to use in cerebral blood flow imaging.

Fluorescence microscopes are indispensable to biology and neuroscience. The need for recording in freely behaving animals has further driven the development in miniaturized microscopes (miniscopes). However, conventional microscopes/miniscopes are inherently constrained by their limited space-bandwidth product, shallow depth of field (DOF), and inability to resolve three-dimensional (3D) distributed emitters. Here, we present a Computational Miniature Mesoscope (CM2) that overcomes these bottlenecks and enables single-shot 3D imaging across an 8 mm by 7 mm field of view and 2.5-mm DOF, achieving 7-μm lateral resolution and better than 200-μm axial resolution. The CM2 features a compact lightweight design that integrates a microlens array for imaging and a light-emitting diode array for excitation. Its expanded imaging capability is enabled by computational imaging that augments the optics by algorithms. We experimentally validate the mesoscopic imaging capability on 3D fluorescent samples. We further quantify the effects of scattering and background fluorescence on phantom experiments.

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Recently, cortical areas with motor properties have attracted attention widely to their involvement in both action generation and perception. Inferior frontal gyrus (IFG), ventral premotor cortex (PMv) and inferior parietal lobule (IPL), presumably consisting of motor-related areas, are of particular interest, given that they respond to motor behaviors both when they are performed and observed. Converging neuroimaging evidence has shown the functional roles of IFG, PMv and IPL in action understanding. Most studies have focused on the effects of modulations in goals and kinematics of observed actions on the brain response, but little research has explored the effects of manipulations in motor complexity. To address this, we used fNIRS to examine the brain activity in the frontal, motor, parietal and occipital regions, aiming to better understand the brain correlates involved in encoding motor complexity. Twenty-one healthy adults executed and observed two hand actions that differed in motor complexity. We found that motor complexity sensitive brain regions were present in the pars opercularis IFG/PMv, primary motor cortex (M1), IPL/supramarginal gyrus and middle occipital gyrus (MOG) during action execution, and in pars opercularis IFG/PMv and M1 during action observation. Our findings suggest that the processing of motor complexity involves not only M1 but also pars opercularis IFG, PMv and IPL, each of which plays a critical role in action perception and execution. Recent advances in cognitive neuroscience have shown that individuals can access and understand others' actions and intentions not only through meta-cognitive processes, inferential and propositional reasoning, but also in a direct, pre-cognitive and motor-based way, thus linking motor cognition to social cognition 1,2. Here, motor cognition refers to the functional roles that motor-related cortical areas play in understanding one's own and others' actions. Those motor-related areas include pars opercularis of the inferior frontal gyrus (IFG), ventral premotor cortex (PMv) and the rostral part of inferior parietal lobule (IPL). Not surprisingly, a large number of functional neuroimaging studies have found overlapped activation between action observation and execution in these brain regions 3-11. These motor-related areas have been reported to show motor properties, while they are not constrained to motor processing given their engagement in multiple cognitive functions, e.g., language and spatial attention 12,13. Some studies further considered aforementioned brain regions to be part of the Mirror Neuron System (MNS), which is considered to be a neural mechanism that is involved in action understanding 14-18. So far, converging neuroimaging studies have unraveled the functional roles that these motor-related areas play in action goal and intention understanding. A series of fMRI studies provided strong evidence that pars opercularis IFG, PMv and IPL responded particularly to goal-directed actions, even when actions with the same motor goal were perfor...