Jack Lee's Brain Blog

  That’s a really good observation—and it points to something fundamental about how the brain handles communication between hemispheres. The corpus callosum , the anterior commissure , and the posterior commissure all connect left and right sides of the brain—but they do so in different ways, for different functions . The fact that they’re distinct pathways rather than one giant “super-bridge” tells us something about specialization and evolution. 🧠 The Corpus Callosum Main role : Broad integration of information between hemispheres. It’s the largest white matter tract in the brain, with ~200 million fibers. Connects corresponding cortical areas (e.g., motor, sensory, prefrontal regions). Think of it as the general-purpose data highway between hemispheres. 🧠 The Anterior Commissure Older evolutionary structure than the corpus callosum. Connects temporal lobes across hemispheres (especially amygdala and olfactory areas). Strong role in emotion, memory, and s...

Jumping in with the first post, this is a question I asked of ChatGTP.    I've been talking to ChatGTP for some time now, and this is a question I asked as I'm interested in the role of the corpus callosum and the work done by Sperry and Gazzaniga. I wanted to know if any other parts of the brain were separated aside from the corpus callosum.     Good question. The hippocampal commissure (also called the commissure of the fornix ) is the thin sheet of fibers that cross the midline just behind the anterior corpus callosum, connecting the two hippocampi. It’s much smaller than the main commissures, but it matters because the hippocampi are central to memory, navigation, and contextual processing . ✂️ Effects of Cutting the Hippocampal Commissure 1. Memory Integration Across Hemispheres Each hippocampus can still form memories independently, but cross-hemispheric coordination is impaired . This means episodic memory (which depends on bilateral hippocampal inter...

 For some reason I became interested in the brain, and in particular the corpus callosum, as a result of my messing about with ambidexterity over the years. I've been writing with both hands, drumming, playing piano, using left handed scissors, mouse, and such for a few years, but only recently have I been bothered to actually write about it.  My coming book, Meeting Myself Halfway: An Adventure Across The Corpus Callosum, and how ambidexterity has changed my life, is in progress. The role of this blog is to keep notes of my finding, my conversations with ChatGTP, and the formation of the book from mid 2025 to its publication, most likely at some point in early 2026.  Aside from my interest in the corpus callosum, these entries will include anything else I consider interesting that's brain related. We have, after all, this amazing device that sits between our ears. Few of us really bother to explore its potential, and it's only in recent years that I have been myself....