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Unveiling Hidden Neural Codes: SIMPL – A Scalable and Fast Approach for Optimizing Latent Variables and Tuning Curves in Neural Population Data

Dr. Rishabh Pathak
This research paper presents SIMPL (Scalable Iterative Maximization of Population-coded Latents), a novel, computationally efficient algorithm designed to refine the estimation of latent variables and tuning curves from neural population activity. Latent variables in neural data represent essential low-dimensional quantities encoding behavioral or cognitive states, which neuroscientists seek to identify to understand brain computations better. Background and Motivation Traditional approaches commonly assume the observed behavioral variable as the latent neural code. However, this assumption can lead to inaccuracies because neural activity sometimes encodes internal cognitive states differing subtly from observable behavior (e.g., anticipation, mental simulation). Existing latent variable models face challenges such as high computational cost, poor scalability to large datasets, limited expressiveness of tuning models, or difficulties interpreting complex neural network-based functio...
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Manifestation of blindness-induced Neuroplasticity at different scales

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Dr. Rishabh Pathak


 Blindness-induced neuroplasticity manifests at different scales within the brain, reflecting the adaptive changes that occur in response to the loss of vision. Here are some manifestations of blindness-induced neuroplasticity at different scales:

1. Neurotransmitter Level: At the neurotransmitter level, blindness can lead to alterations in the balance between inhibitory and excitatory neurotransmitters in the brain. These changes in neurotransmitter activity can influence the overall excitability and functioning of neural circuits, contributing to adaptive responses to vision loss.

2. Cortical Reorganization: Blindness can result in cortical reorganization, where areas of the brain that were originally dedicated to processing visual information undergo functional changes to accommodate non-visual functions. For example, the visual cortex may be repurposed for processing tactile or auditory information, reflecting the brain's ability to adapt to the absence of visual input.

3. Structural Changes: Blindness-induced neuroplasticity can also lead to structural changes in the brain, such as alterations in gray matter volume or cortical thickness. Studies have shown that the visual pathway and cortical areas may exhibit differences in structural organization in response to vision loss, with late blindness potentially inducing less structural changes compared to early blindness.

4. Cross-Modal Plasticity: One of the key manifestations of blindness-induced neuroplasticity is cross-modal plasticity, where the brain integrates information from different sensory modalities to compensate for the loss of vision. This adaptive reorganization can occur at the level of the primary sensory cortex (V1) and lead to enhanced processing of non-visual sensory inputs, such as tactile or auditory information.

5. Functional Connectivity: Changes in resting-state functional connectivity have been observed in blind individuals, reflecting alterations in how different brain regions communicate in the absence of vision. Studies have shown weakened connectivity within the visual cortex and between visual and other sensory regions following vision loss, with potential restoration of connectivity patterns after sight recovery interventions.

6. Experience-Dependent Plasticity: The manifestation of blindness-induced neuroplasticity can also be experience-dependent, with factors such as early exposure to tactile stimuli influencing the degree of cortical reorganization and sensory processing enhancements in blind individuals. For example, learning Braille at an early age has been associated with higher tactile-induced visual responses, highlighting the role of experience in shaping neuroplastic changes.

 

By examining blindness-induced neuroplasticity at different scales, researchers can gain insights into the adaptive mechanisms that underlie the brain's ability to reorganize and compensate for the loss of vision. Understanding these manifestations is essential for developing targeted interventions and rehabilitation strategies to optimize sensory processing and functional outcomes in individuals with visual impairments.

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