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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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What is TMS?

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Dr. Rishabh Pathak


 

Transcranial Magnetic Stimulation (TMS) is a non-invasive neuromodulation technique that involves the use of magnetic fields to stimulate specific regions of the brain. Here are some key points about TMS:

 1. Mechanism of Action:

   - TMS works by generating a magnetic field that induces electrical currents in targeted areas of the brain, leading to the depolarization of neurons and the modulation of neural activity.

   - The stimulation can either increase or decrease the excitability of neurons, depending on the frequency and intensity of the magnetic pulses applied.

 2. Therapeutic Application:

   - TMS is commonly used in the treatment of various neuropsychiatric conditions, including depression, anxiety disorders, and certain neurological disorders.

   - In the context of depression, repetitive TMS (rTMS) is often used to target specific brain regions implicated in mood regulation, such as the left dorsolateral prefrontal cortex (dlPFC) and the subgenual anterior cingulate cortex (sgACC).

 3. Treatment for Depression:

   - TMS has been approved by regulatory agencies, such as the FDA in the United States, as a treatment for medication-resistant depression.

   - The therapeutic effects of TMS in depression are thought to involve both short-term changes in neural excitability and long-term neuroplastic changes that may contribute to symptom improvement.

 4. Administration:

   - TMS is typically administered in multiple sessions over a period of weeks, with each session lasting around 20-30 minutes.

   - The treatment schedule and parameters (e.g., frequency, intensity) of TMS sessions are tailored to individual patient needs and treatment protocols.

 5. Efficacy:

   - Clinical studies have shown that TMS can be effective in reducing depressive symptoms in a subset of patients who do not respond to traditional antidepressant medications.

   - Response rates to TMS treatment for depression typically range from 29% to 46%, with remission rates in the range of 18% to 31%.

 6. Safety:

   - TMS is considered a safe and well-tolerated treatment option for depression, with minimal side effects compared to other interventions like electroconvulsive therapy (ECT).

   - Common side effects of TMS may include mild headache, scalp discomfort, or muscle twitching during stimulation.

 

In summary, TMS is a non-invasive neuromodulation technique that has shown promise as a treatment option for depression, particularly in cases where traditional therapies have been ineffective. By targeting specific brain regions involved in mood regulation, TMS can help alleviate depressive symptoms and improve overall well-being in some individuals.

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