Huberman Lab

How Your Thoughts Are Built & How You Can Shape Them | Dr. Jennifer Groh

November 10, 2025

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  • Thoughts are theorized to be mental instantiations that involve running simulations using the brain's sensory-motor infrastructure, which explains why shifting attention between sensory tasks (like driving and talking) requires resource reallocation. 
  • The brain constantly integrates visual and auditory information, dynamically mapping sound location relative to eye position, a complex computational feat learned throughout development to account for changing body size. 
  • Sound localization relies on incredibly precise processing of interaural time differences (as small as half a millisecond) and intensity differences, supplemented by frequency filtering from the ear's physical structure and the integration of reverberant sounds to perceive distance. 
  • Neurons in the auditory pathway, even those outside the superior colliculus, are affected by eye position, suggesting visual information about eye movements is incorporated early in sound processing, potentially for localization. 
  • A leading theory suggests that thinking involves running internal simulations using the brain's sensory and motor infrastructure, which explains why sensory input (like speech) can interfere with complex tasks. 
  • Attention and focus can be managed using principles analogous to physical interval training, where effortful cognitive work should be followed by mental rest, and changing one's immediate environment can help break out of cognitive ruts or attractor states. 
  • Activities with a seamless on-ramp to full attention and no inherent endpoint (like endless social media scrolling) are the most dangerous for attention and time management due to their slot machine-like dopamine engagement. 
  • Creating friction or 'exit paths' is crucial for managing technology use, such as segregating social media onto a separate, difficult-to-access device to break the cycle of mindless engagement. 
  • The physical environment (like a lab setting) provides strong external cues that can override internal distractions, highlighting how context shapes focus and attention, which relates to the multi-sensory integration discussed in the *Huberman Lab* episode. 

Segments

Thoughts as Sensory Simulations
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(00:00:00)
  • Key Takeaway: Thoughts are hypothesized to be mental instantiations that run simulations using sensory-motor infrastructure, such as visualizing a cat’s appearance or smelling associated scents.
  • Summary: The theory suggests that thinking about a concept, like a cat, involves activating the visual and auditory cortices to run a brief simulation of those sensory qualities. This integrated cognitive system explains why engaging in one sensory-motor task, like driving in traffic, necessitates quieting other inputs, such as conversation.
Auditory-Visual Integration Origin
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(00:03:41)
  • Key Takeaway: The superior colliculus is a brain structure where visual and auditory stimuli responses converge, with auditory response fields shifting based on eye position.
  • Summary: Dr. Groh’s interest began with research showing that neurons in the superior colliculus respond to sound, but their spatial responsiveness changes depending on where the eyes are looking. This demonstrates the brain’s need to create dynamic maps by integrating sensory inputs to accurately perceive space.
Contextual Sensory Remapping
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(00:07:34)
  • Key Takeaway: The brain rapidly remaps auditory and visual space in milliseconds to align perception with context, such as when shifting attention from a phone screen to an external sound source.
  • Summary: When viewing media on a screen, the sound source is often simulated and does not match the visual location, yet the brain merges the inputs seamlessly unless a temporal delay is introduced, which causes discomfort. This rapid remapping ability allows us to instantly switch our perceived auditory location when someone speaks to us in a different direction.
Sound Localization Cues
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(01:13:52)
  • Key Takeaway: Sound localization relies on the brain calculating minute timing differences (up to half a millisecond) and intensity differences caused by the sound arriving at one ear before the other.
  • Summary: The physical distance between the ears creates differential delays for sound arrival, which the brain processes to locate a sound source horizontally. This processing is incredibly precise, handling timing differences smaller than a single action potential, and is further refined by the frequency filtering properties of the ear’s folds.
Self-Voice Perception and Hearing
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(01:22:48)
  • Key Takeaway: The brain actively manipulates sound transduction, likely turning down the volume in anticipation of one’s own voice, and records sound differently due to the lack of bone conduction cues.
  • Summary: Hearing one’s own voice recorded sounds awkward because the recording lacks the full frequency spectrum and, crucially, misses the bone conduction component that normally reaches the inner ear directly from the vocal cords. This self-cancellation mechanism prevents the speaker from being overwhelmed by their own sound output.
3D Sound and Distance Cues
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(01:30:18)
  • Key Takeaway: Auditory distance perception relies on loudness cues (requiring knowledge of source volume, like thunder) and the integration of delayed, reflected sound copies bouncing off environmental surfaces.
  • Summary: Unlike vision, sound depth perception is challenging because sound waves bend around objects, eliminating occlusion cues; therefore, the brain uses the sound’s intensity relative to expected volume to judge distance. The brain also integrates multiple arrival times from direct sound paths and echoes off surfaces like tables and ceilings into one coherent perception.
Music, Rhythm, and Community
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(00:47:39)
  • Key Takeaway: Music, particularly rhythm, is a universal human trait possibly evolved to facilitate concerted action among groups, enhancing fitness by allowing coordinated, louder displays to deter competitors.
  • Summary: Rhythm is the most critical component of music across all cultures, suggesting a deep evolutionary function related to group synchronization, such as coordinated stomping or chanting during vigor displays like the Maori Haka. This collective action can amplify group presence, potentially aiding in resource competition or courtship rituals, similar to sexual selection seen in other species.
Auditory-Visual Integration in Ear
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(01:02:39)
  • Key Takeaway: Eye position influences auditory signals in the superior colliculus and even in the ear structures themselves, suggesting a fundamental integration of visual and auditory localization cues.
  • Summary: Neurons in the superior colliculus integrate hearing and vision, mapping them onto one another. Researchers found that eye movements affect auditory signals even in brain areas more closely connected to the ear. This led to the discovery that eye movements cause physical movement of the eardrum, generating measurable signals in the ear canal.
Evolutionary Layers of Sensation
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(01:10:14)
  • Key Takeaway: Sensory systems, like vision and audition, evolved in layers, with basic functions like light/dark detection and motion preceding more complex features like fine detail and color vision.
  • Summary: The visual system first evolved to detect light/dark cycles, followed by motion detection, with fine detail and color vision evolving later. Similarly, the auditory system likely evolved basic directional and frequency detection before adding complexity. This evolutionary layering is mirrored in the motor system, from trunk movement to fine finger control.
Physical Space and Sound Perception
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(01:16:45)
  • Key Takeaway: The acoustic properties of a physical space, such as high ceilings and reflective surfaces in cathedrals, create long sound delays that fundamentally alter sound perception, favoring slower, sustained musical notes.
  • Summary: The sounds experienced in a setting are a combination of all reflective surfaces; for example, carpet absorbs sound while hard, high ceilings cause reflections with long delays. These long delays can result in echoes, which is why music like Gregorian chants, with long, sustained notes, works well in such environments, whereas fast music would become jumbled.
Sound, Emotion, and Community
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(01:22:47)
  • Key Takeaway: Joining together in sound, such as an audience singing along at a concert, is a highly effective way to communicate and generate shared emotion, potentially linking to primitive communication needs.
  • Summary: The shared experience of sound, especially when people join in, communicates important feelings effectively. This communal sound experience may be evolutionarily significant, similar to primitive vocalizations used for group cohesion or signaling intent. The ability to agree on facts and acknowledge weaknesses is contrasted with the difficulty in achieving consensus in other domains, like politics.
Thought as Sensory Simulation
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(01:27:01)
  • Key Takeaway: Thinking may fundamentally involve running internal simulations across various sensory cortices (visual, auditory, etc.) using the brain’s existing sensory-motor infrastructure.
  • Summary: When a person thinks a concept, like ‘cat,’ their brain might be running a simulation that includes what a cat looks like and sounds like. This theory suggests that the extra sensory areas in the human brain, compared to other primates, are utilized for generating these internal simulations, which constitutes thought itself. This explains why unrelated thoughts are difficult to generate spontaneously.
Attractor States and Focus Hacking
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(01:33:18)
  • Key Takeaway: Flow states are deep ‘attractor states’ where the brain is deeply engaged, and the inability to focus often stems from not creating a narrow enough sensory context to drop into this state, exacerbated by constant digital input.
  • Summary: Cognitive states can be modeled as a ball bearing sinking into a trench (flow state) on a surface representing mental stability. The constant bombardment of information from devices like phones makes achieving these deep focus trenches difficult by introducing too many competing spheres of attention. Changing one’s immediate physical environment, even by moving seats, can serve as a tool to reset attention and break out of a rut.
Mental Work as Interval Training
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(01:45:58)
  • Key Takeaway: Effortful cognition, like deep writing, functions like an endurance event, requiring mental rest and recovery periods, suggesting that interval training principles apply to mental work.
  • Summary: The attention span for deep cognitive work often maps onto the duration of an event, similar to athletes; for example, one might only be able to write one sentence before needing a break. Trusting the brain’s need for mental rest allows ideas to ‘marinate’ and emerge later, much like physical recovery is necessary after intense exercise.
Vision, Focus, and Chickens
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(01:54:15)
  • Key Takeaway: Visual attention drives brain states, as evidenced by the ability to induce a state of hyper-focus (akin to hypnosis) in chickens by physically constraining their visual field along a line.
  • Summary: Hypnosis is described as a state of hyper-focus, which can be induced in chickens by placing their beaks on a line, locking their eyes into a focused cone of attention necessary for pecking. This phenomenon suggests that restricting visual input can anchor attention, a principle also utilized in some Chinese classrooms to improve focus before lessons.
Managing Digital Overload
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(02:05:53)
  • Key Takeaway: Unfiltered digital communication rapidly destroys states of calm achieved through natural environments.
  • Summary: The constant influx of digital messages, even non-critical ones, quickly erodes mental calm. While complete disconnection is often infeasible for those with responsibilities, awareness of the unfiltered nature of digital input is key to managing challenges in getting real work done. The movement to remove phones from classrooms is supported as a positive step.
Mindful Phone Usage
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(02:07:39)
  • Key Takeaway: Awareness of the current purpose for using a phone allows for swapping out boredom-driven use for healthier alternatives.
  • Summary: It is useful to consciously assess the desired outcome when picking up a phone, distinguishing between necessary tasks (like transit navigation or booking) and aimless scrolling driven by boredom. When boredom is the driver, swapping phone use for listening to an audiobook or reading a physical book can serve as a healthier exit path. Activities that provide a sense of satiety or completion, like finishing a Duolingo lesson, help create a natural stopping point.
Designing Against Endless Scroll
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(02:09:58)
  • Key Takeaway: Activities with a seamless on-ramp to full attention and no endpoint are the most problematic for attention regulation.
  • Summary: The brain is highly susceptible to activities that require no effort to start and offer no natural conclusion, similar to a slot machine. The speaker implemented a system by using an old phone solely for social media, requiring manual installation and sign-in (creating friction) to access it, thus preventing mindless engagement.
Contextual Focus Cues
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(02:12:23)
  • Key Takeaway: Strong environmental cues, such as being physically present in a dedicated workspace like a lab, override personal digital distractions.
  • Summary: When interacting with people at work or being physically inside the lab environment, digital distractions tend to fall away because the cues to stay focused are very strong. This reinforces the idea that the physical context plays a major role in maintaining attention.
Multi-Sensory Integration Wrap-up
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(02:12:48)
  • Key Takeaway: True multi-sensory integration, the merge of vision and hearing, is the core mechanic underlying thinking and focus.
  • Summary: The conversation successfully covered auditory, visual, and their integration, moving into how the physical environment shapes brain function. The brain creates its own internal environment, which individuals have more control over than they might realize unless they default to external circumstances. Thinking and working involve the merge of sensory inputs, not just isolated sensory processing.
Podcast Conclusion and Support
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(02:13:58)
  • Key Takeaway: Listeners can support the Huberman Lab podcast by subscribing on YouTube, following on Spotify/Apple, and pre-ordering the new book, Protocols.
  • Summary: Dr. Jennifer Groh’s book, Making Space: How the Brain Knows Where Things Are, is linked in the show notes. Andrew Huberman’s new book, Protocols: An Operating Manual for the Human Body, is available for pre-sale at protocolsbook.com and covers topics from sleep to focus. The Neural Network newsletter offers free summaries and protocols, accessible via the hubermanlab.com website.