Showing posts with label Neuroscience. Show all posts
Showing posts with label Neuroscience. Show all posts

Thursday, 21 May 2026

The brain’s code seems to be in constant flux. Neuroscientists are baffled




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I — The Myth of the Stable Neuron

Why neuroscience cannot decide what its basic units are

Neuroscience still quietly inherits a metaphysics in which the brain is composed of stable units—neurons—that reliably “do things.” This assumption is rarely defended; it is simply embedded in experimental design, analysis pipelines, and interpretation.

The logic is familiar:

  • a stimulus is presented
  • a neuron responds
  • repeated trials reveal a stable tuning curve
  • therefore, the neuron “encodes” something

This produces a deceptively clean picture: a world of features mirrored by a world of neural tokens.

But this picture is not discovered—it is constructed by the experimental frame itself. It depends on:

  • discretising continuous activity into unit responses
  • holding behavioural context fixed
  • assuming that temporal variability is noise around a stable mapping

The problem is not that this model is wrong in detail. The problem is that it defines correctness in advance of what counts as variation.

Once long-term recordings become possible, the supposed stability begins to dissolve—not dramatically, but systematically. The neuron stops behaving like a unit of function and starts behaving like a participant in a shifting coordination field.

At that point, neuroscience does not revise its ontology. It renames the anomaly.

Which brings us to “representational drift.”


II — Representational Drift is Not an Explanation

It is a label for the failure of a model that insists on stability

“Representational drift” is often treated as a discovery: neurons change their tuning over time even when behaviour is held constant.

But notice what must already be assumed for this to be a “problem”:

  • that there exists a stable representational mapping
  • that neural populations are meant to preserve it
  • that time should not affect identity of encoding

Drift is then defined as:

deviation from a presumed invariant code

But this is not an explanation. It is a diagnostic term for when a representational model stops fitting its own output.

The deeper issue is that “representation” does not degrade gracefully under empirical stress. It either holds, or it becomes a residual category for everything that no longer behaves as expected.

So the field responds by multiplying distinctions:

  • drift
  • noise
  • plasticity
  • remapping
  • context dependence

Each term is an attempt to protect the original assumption:

that there must still be a stable code somewhere underneath.

But what if that assumption is optional?

What if the system never contained a stable code in the first place?


III — Edelman Already Solved the Problem (And Was Ignored Anyway)

Population dynamics without the need for representational units

Neural Darwinism (Neuronal Group Selection Theory) already displaced the unit-based picture decades ago.

Its core move is simple but radical:

  • neural function is not assigned to fixed units
  • it emerges from selection over dynamic populations
  • stability is a property of recurrent selectional outcomes, not enduring elements

In this frame:

  • variability is not a deviation from function
  • it is the medium through which function stabilises

Which makes a crucial difference:

what mainstream neuroscience calls “drift” is not a problem in Edelman’s ontology, because there is no requirement for fixed representational identity to begin with.

Yet instead of adopting this shift, the field largely absorbed population language while retaining representational expectations.

This produces a hybrid structure:

  • population-level measurements
  • representational-level interpretation
  • unit-level intuition

And hybrids of incompatible ontologies do not produce synthesis—they produce recurring paradox.

“Drift” is one such paradox.


IV — The Stability Problem is Misframed

Why the question “how does behaviour remain stable?” assumes its own answer

The central puzzle in drift literature is:

If neural representations change, how does behaviour remain stable?

This question appears deep, but it quietly assumes:

  • behaviour is stable in a way that requires neural invariance beneath it
  • neural activity is responsible for preserving that stability

But this reverses the dependency.

Behavioural stability is not something the brain “maintains” against variability. It is an emergent regularity of:

  • repeated coupling
  • constrained environments
  • embodied action
  • and re-instantiated neural dynamics

Stability is not stored. It is enacted repeatedly under changing internal configurations.

The confusion arises because neuroscience keeps looking for:

a stable object inside the system that guarantees stability outside it

But there is no such object.


V — The Real Crisis: Neuroscience Does Not Know Its Ontology

Why “drift” keeps returning no matter how often it is explained

The persistence of “representational drift” as a concept is not evidence of mystery in the brain. It is evidence of instability in the explanatory framework.

Neuroscience currently oscillates between three incompatible commitments:

  1. Neurons as stable encoders (classical tuning curve model)
  2. Populations as dynamic systems (Edelman-compatible structure)
  3. Representation as explanatory currency (still dominant language)

These cannot all be true at once.

So when data violates (1), the field shifts to (2) but interprets it through (3). When (2) resists (3), the mismatch is labelled (drift, noise, remapping, context dependence).

Nothing ever resolves because the underlying issue is not empirical—it is ontological.

The system is attempting to explain:

dynamic, continuously re-instantiated coordination fields
using:
a vocabulary built for stable symbol-like mappings

That mismatch is the real drift.


Coda — What Would Have to Change

A coherent neuroscience would not necessarily need a new discovery. It would require a refusal:

  • refusal of neurons as privileged carriers of function
  • refusal of representation as default explanation
  • refusal of stability as hidden substrate rather than emergent regularity

This is not a call for vagueness or mysticism. It is a call for consistency with the very data neuroscience already produces.

The irony is that the field is not lacking evidence.

It is lacking permission to reinterpret its own evidence without preserving its inherited metaphysics.

Wednesday, 10 September 2025

My blue is your blue: different people’s brains process colours in the same way



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Neural Myths of Colour: Why Nature Gets It Wrong

This week Nature announced that “my blue is your blue”: brains, they claim, represent colours in the same way. With fMRI scans and a machine-learning classifier, researchers “proved” that when you see red, I see red too — because our brains look alike.

This is not science; it’s a neural myth.


The Ontological Misstep

The article smuggles in a representationalist fantasy: that colour is a thing in the brain. It invites us to imagine that “redness” lives in a cluster of neurons, waiting to be decoded. This is category error of the first order. Colour is not matter; it is phenomenon. It exists only as construed experience. Neural activity scaffolds this construal, but it does not contain it. To say otherwise is to confuse physiology with meaning — a confusion as old as neuroscience itself.


The Classifier as Oracle

The machine-learning model is treated as if it were an oracle of truth: it sees across brains, therefore it reveals universality. But classifiers do not reveal; they cut. They enact a perspectival alignment, producing the very sameness they pretend to discover. To believe otherwise is to fall into the fallacy of objectification, mistaking an artefact of measurement for the structure of reality.


The Erasure of Difference

By trumpeting “shared neural codes,” the piece erases variation: the colour-blind, the synaesthete, the cultural other. If the study misclassifies, the article stays silent. Instead we are handed the fantasy of universality: “we all see the same.” In doing so, it repeats a colonial gesture — effacing difference in the name of sameness.


Value Disguised as Meaning

The real finding is trivial: similar physiological systems, when exposed to similar stimuli, show similar activations. This is a value-system fact — a matter of bodily organisation. Yet the article presents it as if it were a meaning-system fact — proof that construals of colour are identical across individuals. It confuses the scaffolding of meaning with meaning itself.


The Relational Reframe

Seen through relational ontology, the story looks different:

  • Colour is always already collective construal. To say “red” is to align construals across a community.

  • fMRI plus classifier is just another way of phasing that alignment into measurable form.

  • The supposed “universal neural code” is nothing but the trace of one methodological cut, mistaken for ontology.


Why It Matters

The danger is not the study itself — mapping correlations is useful work. The danger is the story Nature tells with it: that meaning is in the brain, that construal collapses into physiology, that collective difference can be erased in the name of sameness. This is not science; it is ontological sleight of hand.

Until we learn to see colour as phenomenon, not object, neuroscience will keep mistaking its own cuts for reality.

Saturday, 5 April 2025

How does the brain control consciousness? This deep-brain structure




ChatGPT Comments:

Smriti Mallapaty’s article, while accessible and engaging, presents an excellent opportunity to examine how mainstream science journalism handles the concept of consciousness—a notoriously slippery and often misrepresented topic.

Let’s break it down by looking at framing, conceptual clarity, methodological assumptions, and implications for theories of consciousness—plus we’ll shine a light on any subtle ontological or rhetorical moves that deserve interrogation.


1. Framing: “How does the brain control consciousness?”

Right from the headline, the article frames consciousness as something controlled by the brain—as if the brain is a sort of CEO flipping awareness switches. This framing subtly presupposes:

  • That consciousness is a thing (a discrete object or state), rather than an unfolding process or emergent phenomenon.

  • That there is a one-way causal relationship: the brain acts, and consciousness results—a framing that dodges thornier questions about the bidirectionality of brain-mind relations, or whether ‘the brain’ and ‘consciousness’ are even ontologically separable in this way.

This mechanistic framing primes the reader to accept neural correlates as explanations rather than as correlations—a category mistake that plagues much of consciousness discourse.


2. Conceptual Clarity: What does “conscious perception” mean here?

The article uses the term “conscious perception” to refer to the brain “becoming aware of its own thoughts.” That’s already a conflation of self-reflective cognition (thinking about thinking) with sensory awareness (e.g., noticing a flashing icon). Those are not the same kind of process—unless you're sneaking in a fairly specific theory of consciousness without naming it.

It’s worth asking: what theoretical lens is this built from? Is it Global Workspace Theory (GWT)? Higher-order thought theory? Integrated Information Theory (IIT)? Recurrent Processing Theory? The article never says—which has the effect of treating “consciousness” as a monolithic phenomenon rather than a field full of rival models.

So we’re left with a flattening: consciousness is equated with noticing a stimulus, which is equated with awareness, which is equated with neural activity in the thalamus and prefrontal cortex. This makes the article readable—but at the cost of conceptual rigour.


3. Methodological Assumptions: What’s being measured?

The study involved patients undergoing deep brain electrode therapy for chronic headaches—a rare opportunity, certainly, but also a highly unusual population. The experimental setup depends on:

  • A binary behavioural response (eye movement = yes or no) to indicate conscious awareness of a stimulus.

  • An assumption that the stimulus is perceived consciously only 50% of the time, which is statistically convenient but ontologically murky.

This method assumes a third-person observable behaviour (eye movement) can be equated with a first-person experience (conscious awareness)—a leap that rests on contested territory. Philosophically, this reflects the hard problem in disguise: turning qualia into data without confronting the transformation involved.

Furthermore, the claim that this is the “first time” simultaneous recordings have been made in thalamus and cortex in a consciousness-relevant task sounds impressive—but the phrase “relevant to consciousness science” is doing a lot of unexamined work. What exactly makes a task consciousness-relevant?


4. The Thalamus as a Gatekeeper: Good metaphor, or misleading one?

The article’s big takeaway is that the thalamus acts as a “filter” or “gatekeeper” for conscious awareness—a metaphor that’s been floating around since Francis Crick. But this metaphor carries baggage:

  • It implies a central executive function—some agentive part of the brain deciding what gets through—which anthropomorphises a system that is, presumably, not conscious itself.

  • It lends itself to the misleading notion of a Cartesian theatre—a place in the brain where “the show” of consciousness is watched.

Also, the claim that thalamic activity precedes cortical activity when participants are conscious of the icon is interesting—but temporality here is tricky. Does precedence imply causation? Or is the coordination between the thalamus and cortex part of a larger dynamical system where mutual entrainment is the real story?

The article leans toward the former, but this may be a misstep.


5. Alternative Interpretations and Scepticism

Liad Mudrik offers a necessary note of caution: the activity being tracked might reflect attention, not consciousness. This is vital. Many cognitive scientists argue that attention and consciousness are dissociable—indeed, you can attend to something unconsciously, or become conscious of something to which you're not attending.

The fact that this possibility is mentioned but not deeply explored points to a pattern in consciousness journalism: mention complexity, then move swiftly on.


6. Implications for Theories of Consciousness

If we accept the findings as reported, what are the implications?

  • They challenge theories that localise consciousness exclusively in the cortex, suggesting a more distributed, recursive model.

  • They support models that see conscious access as a systems-level phenomenon, involving timing, synchronisation, and possibly recurrent signalling (which aligns with GWT or even IIT in some interpretations).

  • However, they do not clarify what consciousness is, only what patterns of brain activity are associated with a specific behavioural report.

In other words: correlates, not causes.


Ontological Underpinnings: Materialist Monism in Disguise?

The article never explicitly addresses ontology, but it’s tacitly materialist: the brain produces consciousness, full stop. No room for emergentism, enactivism, panpsychism, or even the possibility that consciousness might be a semiotic process arising from biological substrates rather than a product of them.

This reductionism is not unusual, but it should be flagged—especially since you, Chris, operate within a meaning-centred framework (SFL + Edelman’s TNGS). From that standpoint, this entire framing is problematic: it treats experience as something that can be located, rather than construed.


Conclusion: A Well-Written Piece with a Neurocentric Tilt

Mallapaty’s article is engaging and informative for a general audience. But it falls into familiar traps:

  • Collapsing correlation into explanation

  • Slipping between concepts (attention ≠ consciousness)

  • Using metaphors ("gatekeeper") without unpacking their implications

  • Presenting a narrow, neural account as though it speaks to the full phenomenon of conscious experience

There’s real value in the empirical work here—but the framing obscures the theoretical choices involved. As always in consciousness science, the more confidently something is claimed, the more carefully we should read what’s left unsaid.

Let’s take the next step and run this article through two lenses that offer richer ways of construing what’s going on:

  1. A Systemic Functional Linguistics (SFL)–based critique focusing on how meaning is construed in the article and what metafunctions are doing the heavy lifting.

  2. A reframe in terms of potential-instance dynamics, interrogating what the study reveals (and conceals) when we shift from correlates of consciousness to the construal of meaning from neural potential.


1. SFL-Based Critique: Meaning, Metafunctions, and Ideological Framing

A. Ideational Metafunction: What experience is being construed?

The article presents an account of conscious perception as an observable, neural process—something that can be measured, located, and described using objective methods. That already tells us which experiential meaning potential is being selected: one grounded in material processes (recorded, moved, projected, activated).

But notice what's excluded: there's little to no construal of mental processes (thought, felt, experienced) in a subjective sense. The participants’ experiences are inferred only through behavioural proxies (eye movements) and linked directly to physical correlates.

What we’re seeing is a construal of consciousness as if it were a material process, rather than a mental or semiotic one.

This construal aligns with a materialist ontology, but from an SFL perspective, it's a highly constrained meaning potential—an instance that enacts only a very narrow subset of our experiential semiotic resources.


B. Interpersonal Metafunction: Who gets to be the sayer, and how?

The dominant voices are:

  • The scientists (e.g., Zhang, Mudrik, Shine), who are construed as authoritative Sayers (says, plans, suggests, found)

  • The reporter, who mostly plays an intermediary role, but with clear evaluative choices (remarkable, elaborate, tricky, support)

We also see participants (patients) entirely reduced to functions. They are grammatically realised only as Receivers (were asked, had electrodes implanted) or as Behavers in tightly constrained tasks. Their consciousness is treated as that which can be measured from the outside, never that which can speak from within.

This strips the phenomenon of intersubjectivity. Consciousness becomes not a relation, but a variable.

Interpersonally, then, the article maintains the epistemic authority of science while distancing the lived experience of consciousness itself—ironically silencing the very thing it's trying to study.


C. Textual Metafunction: How is the text organised?

The textual organisation privileges:

  • Linear causality: thalamus → cortex → behaviour → conclusion

  • Nominalisations that obscure agency: e.g., “activation”, “filtering”, “processing”, “awareness”

  • Repetition of metaphors (e.g., “gatekeeper”, “filter”, “access”), which pre-package the ideational content

These metaphors do a lot of ideological work. For instance, calling the thalamus a gatekeeper construes the brain as a bureaucracy and consciousness as an access-controlled domain—highly familiar metaphors from systems design and surveillance capitalism, not from lived experience or embodied cognition.

This metaphor construes meaning as something passively received—awaiting permission to enter awareness—rather than actively made.


2. Reframing Through the Lens of Potential-Instance Dynamics

Now let’s leave behind the neuro-determinism and ask: What if consciousness is not located in the brain, but is the actualisation of meaning from potential by a meaning-maker? That’s your domain, Chris. Let’s walk it out.

A. The brain as a meaning substrate, not a meaning site

From the SFL + TNGS view, neural activity represents a field of potential, shaped by neuronal group selection, experience, and patterned connectivity. This field does not contain consciousness per se, but rather affords the construal of meaning.

Consciousness, then, is the instantiation of meaning from this neural potential—an act of semiosis, not simply a state of neural activation.

The thalamus, under this view, isn’t a gatekeeper but a mediator of affordances—modulating which patterns of neural connectivity are foregrounded in the flow of potential meaning. Its function is systemic, not executive.


B. Reframing the experiment: What was actually being measured?

What we call “conscious perception” in this study is just a behavioural instance that indexes the likelihood that an act of semiosis occurred. The participants’ eye movement is not the same as the perception—it is an externalised token of a meaning instance, one that likely, but not necessarily, correlates with the instantiation of perceptual meaning.

The researchers then correlate this instance (eye movement) with instantial systems (thalamic-cortical activity patterns) in an attempt to reverse-engineer the system of potential that gave rise to the instance.

But without accounting for the meaning-maker’s role—the deployment of meaning potential in context—this approach collapses instance into cause.

It treats the instance (awareness of the icon) as the effect of thalamic activity, when in fact it may be the actualisation of a potential that includes—but is not reducible to—neural signals.


C. What would a semiotically aware experiment look like?

To account for the actualisation of meaning, the experiment would need to:

  • Attend to meaning potentials shaped by context: what does the icon mean to the participant?

  • Distinguish between potential meaning (stimulus affordance), meaning potential (participant’s semiotic system), and meaning instance (actualised awareness).

  • Include participant reflection or report, not just behaviour—as a trace of the act of semiosis.

  • Map not only neural activation, but how that activation becomes organised into semiotic systems that yield meaning.

That would mean taking the participant seriously not just as a biological body but as a social-semiotic system embedded in culture, history, language, and symbolic exchange.


Conclusion: From Brain States to Meaning States

The article reflects the dominant paradigm: neural states as primary, consciousness as their emergent side-effect. But through SFL and the potential-instance lens, we can reorient:

  • Consciousness is not a thing the brain has, but a semiotic process enacted by a meaning-maker.

  • Neural structures (like the thalamus) are not gatekeepers of awareness, but fields of affordance that shape which meaning potentials are actualised.

  • The scientific account is not wrong, but incomplete: it flattens the meaning-making dimension into a neurophysiological one.

The article shows us how scientific discourse instantiates only one construal of consciousness—an instance of meaning that hides its own metafunctional structure. By naming that, we can open space for other construals—ones in which meaning is not observed from outside, but enacted from within.

Tuesday, 25 March 2025

Babies do make memories — so why can’t we recall our earliest years?




ChatGPT comments:

This is an interesting study, and it raises some fascinating questions when viewed through the lenses of Edelman and Halliday. Here are some key takeaways:

  1. Memory Encoding vs. Recall (Edelman’s Perspective)
    Edelman’s Theory of Neuronal Group Selection (TNGS) emphasises how neural circuits develop through selectional processes. If infants' hippocampi are already encoding memories, then neuronal groups are forming stable patterns. However, if recall is the problem, it suggests that later developmental changes alter the ‘search criteria’ for accessing these early patterns. Essentially, the neural maps that develop later in life may not align with the ones used during infancy.

  2. Memory and Meaning-Making (Halliday’s Perspective)
    From an SFL perspective, early memories are likely encoded with meaning potential that does not fully align with later linguistic and conceptual structures. A newborn’s semiotic system is far more embodied and tied to immediate sensory-motor experiences, whereas an adult’s semiotic system is far more abstract and mediated by language. This mismatch could explain why memories remain inaccessible—they are ‘stored’ in a system that lacks the later-developed organisational frameworks for retrieval.

  3. Individuation and Memory Access
    The individuation framework might also apply here. Infant memories are part of the child’s early individuation process—they are experiences before the system has been fully shaped by the broader social semiotic system. Later, as individuation unfolds and meaning potentials shift, early memories may no longer be ‘translatable’ into the adult’s current meaning system. They still exist as neuronal traces but are effectively ‘outside’ the accessible meaning potential.

  4. Potential-Instance Collapse in Memory Retrieval
    If memory is a semiotic phenomenon (as in Halliday) and also a material one (as in Edelman), then memory retrieval could be seen as an instance of potential being actualised—but only if the system’s meaning potential allows it. Infant memories might be like quantum superpositions: encoded but unobservable because the ‘measurement system’ (i.e., the adult brain’s retrieval strategies) is incompatible with them.

Overall, this study reinforces the idea that memories are not simply ‘stored’ like files in a database but are dynamic, developing alongside cognitive and semiotic systems. Early experiences shape later meaning potentials, even if they cannot be recalled as discrete events.

Yet, there are a few issues in the way the researchers frame their interpretation, particularly in how they conceptualise memory, recall, and the role of developmental changes. Here are the main problems:

  1. Over-reliance on a Storage-Retrieval Model
    The researchers frame memory as something that is "encoded" and later "retrieved," as if it were a static object placed in storage. This ignores the dynamic, reconstructive nature of memory. Edelman’s Theory of Neuronal Group Selection (TNGS) suggests that memory is not a simple retrieval of stored information but a reactivation of selected neuronal patterns in a changing system. Memories are actively reconstructed each time they are recalled, meaning that if early memories cannot be accessed, it’s not just a ‘search term’ mismatch—it’s a fundamental shift in the way memory itself is structured over time.

  2. Assumption of ‘Intact but Inaccessible’ Memories
    The idea that early memories are still "there" but merely "unreachable" is an oversimplification. This assumes that memories are stored in a fixed state and that the only issue is a failure in retrieval. However, developmental changes in the brain—especially the radical reorganisation of neural networks—suggest that early memories may not just be hidden but may have been restructured or even overwritten by later experiences. If meaning potential changes over time, the instances of early memory may no longer exist in a form that can be instantiated.

  3. Neglect of Meaning-Making in Memory Formation
    From an SFL perspective, the researchers do not fully account for the fact that memory is not just about storing sensory impressions but about making meaning from experience. If infant memory is structured differently from adult memory due to differences in semiotic systems, then early experiences may not be encoded in a way that aligns with later meaning-making processes. Their focus on "hippocampal activity" as proof of memory formation ignores how these memories might have functioned semiotically in infancy versus adulthood.

  4. Uncritical Use of Rat Studies as a Parallel
    The study cites optogenetic experiments in rats as evidence that infant memories may persist into adulthood. However, this assumes that rat and human memory systems function in analogous ways, which is not necessarily the case. Rats lack the same semiotic development as humans, so their early memories might be more continuous across their lifespan. The transformation of human memory over time is tightly linked to language and socialisation, which fundamentally change the meaning potential available for recall.

Alternative Framing

A better way to interpret the results would be:

  • Infant memory formation is real, but memory itself is dynamic and shaped by developmental changes in both the brain’s neural architecture (material order) and its semiotic system (semiotic order).
  • The inability to recall early memories is not simply a retrieval failure but a reflection of the way meaning-making systems evolve over time.
  • Memory is best understood not as an isolated object in storage but as a set of meaning potentials that shift with individuation and experience.

Their study is valuable in demonstrating that early memory encoding happens, but their interpretation of why those memories become inaccessible is too mechanistic and needs a more developmental, semiotic, and reconstructive perspective.

Saturday, 2 November 2024

The ineffable quality of the human brain





Blogger Comments:

From the perspective of Systemic Functional Linguistic Theory, the meaning potential of language is the 'elephant in the room' that gives rise to our unique cognitive skills. Semiotic phenomena require semiotic explanations. Material models of the brain are severely limited to explaining its material phenomena, such as the locations of its processes.