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

In this episode, Dr. Andrew Huberman speaks with Dr. Jennifer Groh from Duke University about the fundamental nature of thoughts and how the brain constructs them from sensory information. Dr. Groh explains that our brains don't simply passively record the world as it is. Instead, the brain actively creates dynamic neural maps that integrate multiple sensory streams, particularly vision and sound, to generate a coherent understanding of our environment. These maps are not static representations but fluid constructs that change based on context and attention. One fascinating aspect of this process is how the brain localizes sound in space. This involves comparing the timing differences and intensity differences of sounds arriving at each ear, a process called binaural hearing. The brain performs complex calculations to determine where a sound source is located, demonstrating the sophisticated integration of sensory information happening constantly in the background of our consciousness. Dr. Groh discusses how context and expectations dramatically influence what we perceive. She uses the example of ventriloquism to illustrate how the brain reconciles conflicting sensory information. When a ventriloquist speaks while a dummy's lips move, we perceive the sound as coming from the dummy's mouth, not from the ventriloquist, because our visual system dominates in determining the location of the sound source. This shows that perception is not a direct reflection of reality but rather a constructed experience shaped by what the brain expects. A crucial insight from Dr. Groh is that thoughts are not randomly generated but rather emerge from what we focus on. This has profound implications for how we can shape our thinking patterns. By directing our attention intentionally, we don't just change our thoughts in that moment, we actually influence the structure of our neural circuits over time. This means that the habits of attention we develop today literally rewire our brains and determine the patterns of thinking available to us in the future. The conversation explores practical implications for improving focus, enhancing happiness, and completing tasks more effectively. Dr. Groh explains that task-switching comes with a neural cost because our brains must reconfigure their dynamic maps and attention patterns for each new task. Understanding this helps explain why multitasking is generally less effective than focused work. Finally, they discuss how recognizing these mechanisms gives us agency to rewire our default patterns of thinking and attention. By consciously choosing where to direct our focus, we can gradually reshape the neural circuits that underlie our habitual ways of thinking. This perspective bridges neuroscience with practical self-improvement by showing that neural plasticity allows us to literally rebuild our minds through deliberate attention practices.