Scientific rigor typically demands externally checkable measurement: instruments, behavior, or recordings that other people can verify. In that scientific sense, introspection is not "direct measurement" of brain activity. Still, some authors argue that introspection may be our least sensory-mediated access to experience because it does not rely on external sensory transduction. At the same time, introspective reports can be unreliable, especially for higher-order explanations of why we acted or chose as we did, as discussed in classic work on limits of verbal reports about mental processes and in overviews like the Stanford Encyclopedia of Philosophy entry on introspection.
The point of this article is narrower: compared with seeing an external object, introspection does not require sensory transduction (like retina to thalamus to visual cortex). But awareness of thoughts still depends on brain processes that interpret and reconstruct what we think we are experiencing. Any claim that awareness is identical to a thought's neural activity goes beyond what is directly established and should be treated as philosophical framing.
The mediation problem in external observation
When you observe anything external to yourself, information undergoes extensive transformation. Light reflects off an object, travels through space, enters your eye, and triggers photoreceptor cells. These generate neural signals that journey through multiple processing stages in your visual cortex, integrate with other sensory information and memory, and finally produce the conscious experience of "seeing."
Along the way, signals pass from retina through the optic nerve to the thalamus (lateral geniculate nucleus) and then to primary visual cortex (V1), with multiple cortical stages shaping what we perceive, as summarized in vision central processing descriptions. This process involves multiple processing steps where information is filtered, integrated, interpreted, and reconstructed. By the time you "see" something, you are experiencing a processed neural representation of the object.
In contrast, introspection does not require the same sensory pipeline. But it still relies on interpretive brain processing, and people can be wrong about what drove a decision or what they were attending to. The best framing is modest: introspection may remove some sensory steps, yet it does not remove reconstruction, inference, or error.
Thoughts obey physics in a deeper sense
Thoughts are not just physical because brains are physical objects. In a more constraining sense, whatever you can think, feel, or imagine corresponds to a physically possible configuration of neural activity.
Yet we imagine things that violate physical laws constantly. We envision flying without wings, traveling faster than light, or time running backward. These do not violate brain physics – they only violate external-world physics. The neural networks representing "flying" and "self" can activate together because your reality-monitoring system allows it, or is temporarily offline.
Dreams of flight obey neural network physics even while depicting events that violate gravitational physics. The internal world follows different rules than the external world, but remains firmly constrained by physics – just a different manifestation of it.
Thoughts can represent physically impossible scenarios while remaining physically possible brain states. A clearer way to say it is: any thought corresponds to some physically possible brain state, even if the scenario being imagined would be impossible in the external world.
For waking imagination, it is safer to say that internal simulation can decouple from external constraints. For dreaming, Brenner uses the example that reflective self-monitoring can differ from wakefulness, but this remains a general illustration rather than a settled mechanism.
Why imagination works in reality despite different physics
This creates a puzzle: if internal simulation is not the same as the external world, why does imagination work at all in the real world? Why can engineers mentally design bridges that actually stand? Why can mathematics discovered through contemplation sometimes predict physical reality?
The proposed answer is evolutionary: neural dynamics were shaped by the needs of prediction and action in a world governed by stable constraints. As a result, some internal models can be useful approximations for parts of reality, even when they are simplified or wrong in important ways.
Like a map that uses different materials than the territory but preserves relevant structural relationships, imagination generates things that work in reality because its physics, while different, systematically relates to reality's physics. The constraints on what we can imagine reflect constraints imposed by the physical world, iterated through evolution.
The unreasonable effectiveness of mathematics
Eugene Wigner famously described "the unreasonable effectiveness of mathematics in the natural sciences." It seems remarkable that pure thought, conducted entirely within the brain, should unlock nature's deepest laws. Our brains evolved for survival tasks – tracking prey, avoiding predators, coordinating groups. Yet the same neural substrate discovers prime numbers, proves mathematical theorems, and develops quantum mechanics.
This makes sense, the argument suggests, if internal reasoning can sometimes track external structure well enough to produce reliable predictions. That does not require claiming that introspection is "direct access" to physical law. It only requires that internal models can be aligned with external constraints often enough to be useful.
When a theoretical physicist works through equations, the work is still happening inside a brain. The result can translate into testable theories and eventually into technology. Modern electronics depend on quantum mechanics (for example, band structure in semiconductors). In very small transistors, quantum tunneling can also become an important effect, often showing up as leakage that engineers must manage.
Toward a third state of consciousness
We may be approaching what could be called a "third state of consciousness" – neither awake nor asleep, but always active. This is hard speculation, not an established near-term trajectory. Some research discusses "local sleep" phenomena during wakefulness under sleep pressure, but this is usually framed as a failure mode that can impair performance, not as a stable upgrade. Extending local sleep into an always-on hybrid human-AI consciousness is speculative.
It also helps to separate concepts: brain-computer interfaces are typically discussed as reading and sometimes enabling control via brain signals, while noninvasive methods that modulate brain activity are usually described as brain stimulation (for example, TMS or tDCS). Combining AI with stimulation in closed-loop systems is an active research area, but it does not yet justify claims about a new stable state of consciousness.
If such hybrid systems ever exist, they would likely be better described in terms of neural dynamics, computation, and control, rather than "new physics." Metaphors like "cybercortex" can be useful as imagery, but they should not be read as literal claims about new physical laws.
Limitations and quality of evidence
This perspective represents a theoretical and philosophical argument rather than an empirically established fact. The claims about introspection providing uniquely "direct" contact with reality are philosophical positions that remain debated. While the description of external sensory processing stages is well described in neuroscience, any claim that introspection provides direct access to neural activity should be treated as commentary.
The discussion of neural physics and imagination draws on evolutionary reasoning but lacks direct empirical support. The effectiveness of mathematics is well-documented historically, but the explanation for why this occurs remains speculative. The discussion of future consciousness states through AI and brain-computer interfaces is entirely speculative and represents potential future developments rather than current reality.
The article presents an interesting perspective that challenges conventional views on introspection and empirical observation, but readers should understand that these are theoretical arguments requiring further scientific validation.
What you can do about it
This article presents a philosophical perspective on consciousness and introspection rather than actionable advice. If you are interested in exploring introspection, meditation practices and mindfulness techniques can help develop awareness of your own mental processes. However, these practices should not replace evidence-based approaches to understanding consciousness or mental health.
For those interested in consciousness research, some projects aim to decode limited information from brain signals under controlled conditions. For example, work on reconstructing mental images from brain activity is often discussed as a step toward better brain-computer interfaces, not general "mind reading."
Related lines of work study communication as measurable coupling in neural responses. Some studies report that during successful conversation, speaker and listener show neural coupling, which can be quantified in recordings rather than treated as a mystical synchronization.
The relationship between consciousness and physical reality remains an active area of research, with various theories proposing different explanations for how subjective experience relates to objective neural activity.
Sources and related information
Psychology Today – Why Introspection Is Our Most Direct Contact With Reality – 2025
Psychiatrist Grant Hilary Brenner argues that introspection is our least sensory-mediated access to experience (posted November 16, 2025), because external perception requires sensory transduction and multiple processing stages. In this article, Brenner is used as the proponent of the "direct contact" framing, and the limitations are explicitly stated.
Stanford Encyclopedia of Philosophy – Introspection – 2010
The introspection entry is used to frame introspection as a debated topic, clarify terminology, and emphasize why first-person reports do not automatically count as direct measurement of neural activity.
Journal of Verbal Learning and Verbal Behavior – Telling more than we can know – 1977
The classic paper commonly cited as evidence for limits of introspective access is used here to support the claim that people can misreport or confabulate explanations for their own mental processes, based on verbal reports on mental processes.
University of Oregon Open Text – Vision: Central Processing – 2024
The vision overview is used to ground the claim that external perception involves multiple processing stages, including thalamic relays and primary visual cortex, based on vision central processing descriptions.
PubMed Central – Dreaming and the brain (review) – 2010
This review is used only as context for the claim that dreaming can involve altered self-monitoring and reflective awareness, based on overviews of dreaming and brain activity.
PubMed Central – Local aspects of sleep and wakefulness (review) – 2017
This review is included as context for the mention of local sleep phenomena during wakefulness and why it is not evidence of a stable third consciousness state, based on local sleep and wakefulness discussions.
PubMed Central – Neuromodulation techniques (overview) – 2024
This overview is included as context to separate brain-computer interfaces from noninvasive stimulation methods (for example, TMS and tDCS), based on neuromodulation technique summaries.
Wikipedia – Electronic band structure – 2025
This background reference is used to keep the electronics example accurate at a high level by linking modern chips to quantum mechanics via band structure in semiconductors, without claiming that all chips "depend on tunneling" as the core mechanism.
PNAS – Speaker-listener neural coupling underlies successful communication – 2010
This underlying study is included as context for the internal discussion of measurable neural coupling during conversation, via speaker-listener neural coupling.
Medium – Context: The Brain Sensing Itself (author cross-post) – 2025
Brenner's Medium post is listed only as an author cross-post of the same argument, not as independent evidence, via The Brain Sensing Itself: Our Most Direct Contact with Reality.
