What are the mechanisms that construct our experience of reality?

The role of frontoparietal networks in resolving sensory ambiguity.

Overview

Conscious perception depends on the brain’s ability to resolve ambiguity in sensory signals. Our research examines how frontoparietal brain region — especially the inferior frontal cortex (IFC) and anterior insula — detect and resolve perceptual conflicts. We used neuroimaging, computational modeling, lesion studies, and brain stimulation to investigate how these systems contribute to a coherent experience of reality.


Key Findings

1. IFC detects and resolves conflict

We showed that the inferior frontal cortex plays a causal role in resolving perceptual ambiguity1. Transient disruption of IFC activity via TMS slowed perceptual updates in bistable vision tasks, indicating that this region helps update conscious percepts in response to conflict.

2. Insula tracks context violations

We found that both temporal and spatial context violations activate a common network including the anterior insula and right IFC2. These findings suggest a generalized mechanism for detecting when predictions fail, across multiple perceptual domains.

3. IFC damage reduces perceptual switching

In stroke patients with IFC lesions, spontaneous perceptual switching during ambiguous visual tasks was reduced compared to controls3. This supports a causal role for IFC in generating perceptual updates and maintaining a dynamic conscious state.


Synthesis

Together, these studies suggest that conscious perception relies on frontoparietal systems that detect and resolve sensory conflicts. The IFC appears to be central to this process, in which it detects mismatches between input and expectation, and triggers perceptual updates that shape awareness.


Methods

We used a multi-method approach:


Implications

Our findings clarify how higher-order brain regions influence perception. They support predictive processing accounts of consciousness and highlight the IFC as a potential target for therapeutic interventions in disorders involving perceptual rigidity or instability.


Future Directions


Resources

Papers:

Presentation:


  1. Weilnhammer et al., Current Biology, 2021 

  2. Reichenbach et al., bioRxiv, 2024 

  3. Fritsch et al., bioRxiv, 2024