The role of the inferior frontal cortex in resolving sensory ambiguity.
Have you ever wondered how your brain makes sense of the world around you? Sensory information is often noisy, incomplete, and ambiguous. Yet, our brains usually construct a coherent experience of reality. My research investigates how specific brain regions — particularly the inferior frontal cortex (IFC) and the anterior insula — help resolve ambiguity in perception and beyond.
Our experiments show that the IFC plays a crucial role in managing conflicting sensory signals. When we temporarily disrupted IFC activity using Transcranial Magnetic Stimulation (TMS), participants experienced slower perceptual shifts in tasks where visual stimuli could be interpreted in multiple ways. This finding suggests the IFC is actively involved in updating our conscious perception when faced with ambiguity.
Another key region, the anterior insula, along with the IFC, responds strongly to unexpected changes in both spatial and temporal contexts. These findings indicate that the insula helps detect moments when our predictions about the world fail, prompting the brain to adjust and update its expectations.
In individuals who suffered strokes affecting the IFC, we found a significant reduction in their ability to spontaneously shift perceptions during ambiguous visual tasks. This supports the idea that a healthy IFC is essential for maintaining the flexibility in perception, ensuring our conscious experience remains dynamic and responsive.
To arrive at these conclusions, we used a diverse set of approaches:
Our findings provide valuable insights into how higher-order brain regions shape our perception. This research supports theories of predictive processing, which suggest that the brain continuously generates and updates internal predictions to interpret sensory information. The IFC, identified as a critical node in this network, could also be a promising target for therapeutic strategies aimed at addressing perceptual and cognitive disorders involving rigid or unstable perceptions.
Looking ahead, we plan to: