Neuro research: questions, ideas, and motivations

This post summarizes my independent readings and research into psychology and neuroscience.

My initial interest in the mind

In the past few years I’ve embarked on a lifelong quest to understand the mind and brain. Starting in the pandemic, I spent the evenings after my day job reading textbooks and papers, and writing the occasional blog post (I wrote this overview of my learnings from reading Bear et al’s Neuroscience: Exploring the Brain). At the beginning of this year, I left my job and started focusing on these studies full-time, trying to narrow my research on a few specific research questions.

My interest in the mind was initially piqued by the problem of consciousness. How does nonsentient matter give rise to conscious experience? In the tradition of Nagel’s What is it like to be a bat?, I think any theory of consciousness must account for the subjective, qualitative nature of conscious experience, and it’s hard to imagine how a theory that explains the world in purely objective terms could do so. I agree with David Chalmers that there really is a “hard” problem of consciousness, which might require a revision of our traditional reductionist/materialist metaphysics.¹ I wrote an accessible explainer a few years ago on the problem of consciousness, as well as some technical notes on consciousness on my blog: solving the hard problem with metaphysics, and notes on Morsella et al’s 2015 paper on passive frame theory.

Given that I think consciousness is, as posed above, a hard problem—potentially even a strictly philosophical problem—I didn’t want to restrict my studies to just that question, given that there are so many other interesting (and important) problems to solve in neuroscience and psychology. This is what led me to the current focus of my research, which is about understanding how the brain heals from psychological problems, specifically in the context of psychotherapy. For the past few months I’ve been more narrowly focused on this question, and I wrote my initial thoughts on it in an appendix to a recent blog post.

Current focus: memory reconsolidation

I began with Lane et al’s 2015 overview paper on memory resonsolidation. I was interested in this paper for a few reasons:

1. I was curious to get a general sense of the current open questions in neuroscience and psychotherapy;
2. I’m especially excited about bridging ideas across the disciplines of psychology, psychotherapy, neuroscience, and Eastern contemplative practices;
3. I’m intrigued by the promise of memory reconsolidation as a unifying framework for understanding therapeutic change;
4. I wanted to use the commentaries as an opportunity to see how researchers from different disciplines would approach the question and to find the current sources of disagreement.

I list some of my questions and notes below. As I’ve gone further into these readings, I’ve identified a number of research areas I’d like to get more background on, specifically in the study of memory.

• How effective is psychotherapy?
  • Ecker and Vaz 2022 summarize the research on this as such: randomized controlled trials show that therapy is moderately effective, and that the variance in effectiveness is high, with some proportion of patients receiving no benefit. Also, the variance in effectiveness is not accounted for by varying modalities, or by therapist traits such as age, gender, years of experience and so on. Anecdotally however, there are many examples of profound and lasting change in patients, and this kind of change is what Ecker and his colleagues are trying to understand and increase through their work on Coherence Therapy.
• Is memory reconsolidation the core brain mechanism underlying psychotherapeutic change?
  • From my reading of the Lane et al’s 2015 paper, the commentaries, and much of Ecker et al’s research, I’m convinced that at a coarse level, thinking about therapy in terms of updating previous memories is the correct paradigm, but that there’s still progress to be made in making our model of therapeutic change more precise, especially in the context of complex emotional learnings in real human life that therapists encounter, as opposed to the more straightforward association memories that we’ve done experimental research on. I list some of these questions below.
• How exactly does the brain store memories, i.e. what is the engram?
  • From my readings of introductory neuroscience textbooks I have some rough intuitions (e.g. that the hippocampus is involved in consolidation of memories; that Hebbian theory can explain how patterns of neural activation lead to changes in wiring that ultimately constitute memory formation; and so on) but the concrete details still seem fuzzy to me. I’d next like to read Han et al’s 2021 paper on The Essence of the Engram and also Gallistel’s research on information storage in molecules within the neuron.
• What happens when an implicit mental model (in the sense described by Ecker) goes from subconscious to conscious and explicitly verbalized? To what extent is verbalization of implicit memory structures necessary for activating those structures and subsequently reconsolidating them?
• What is our molecular picture of what happens in memory (re)consolidation? My current mental model is very simplistic (“inhibiting synthesis of X protein blocks memory (re)consolidation”) and I’d like to get a more detail picture of the causal mechanism.
• What are the relationships between semantic memory, autobiographical memory, and procedural memory? Some specific research I’d like to delve into further includes:
  • Barsalou’s claims that semantic memory is “embedded within a network of autobiographical memories”
  • Stanley Klein’s argument that episodic and semantic memory are not necessarily stored in different systems in the brain, but that instead the key distinction is in operations that occur at retrieval of the memory (and operations that, in rare cases, can actually be disrupted, such what are traditionally considered episodic memories no longer have this character of “a memory of me in a specific situation”)
    • From the same paper, I’m interested in exploring Dalla Barba et al’s claim that what we call “semantic memory” is related to memories that are stable and overlearned, whereas episodic memories are more malleable.
• What does neuroscience, as a field, need most at the moment? (e.g. better instruments for studying the brain, better methods of analyzing data, or as Krakauer et al put it in Neuroscience Needs Behavior, better theory and experimental design?)
  • I wrote more general notes on my understanding of neuroscience as a whole in Current understanding of neuroscience and Are lesions a good proxy for brain function?.
  • I also wrote some speculations in this post on what a “robust, unified” theory of the mind might look lie.