
The Jim Rutt Show
EP 178 Anil Seth on A New Science of Consciousness
Episode guests
Podcast summary created with Snipd AI
Quick takeaways
- Perception involves constructing best guesses about sensory signals for understanding the world.
- Brain actively constructs perceptual content through Bayesian inference using prior knowledge and sensory information.
- Brain updates predictions based on sensory signals, minimizing errors for aligned perception with input.
- Paying attention in ambiguous situations enhances sensory precision to adjust predictions rapidly.
Deep dives
The Brain as a Prediction Machine in Perception
Perception involves the brain constructing best guesses about the causes of sensory signals to make sense of the world. The brain combines sensory information with prior expectations through Bayesian inference to form perceptual content. This idea challenges the traditional view of passive sensory reception, highlighting a brain-generated controlled hallucination where sensory signals control and refine the brain's predictions.
Controlled Hallucination and Perception
Perception is described as a controlled hallucination, where the brain actively constructs the content of our experiences based on sensory information and prior knowledge. The brain makes inferences about the causes of sensory signals using Bayesian inference to form a best guess about what's happening in the world. Our perceptual content is the brain's top-down predictions interacting with bottom-up sensory signals.
Sensory Expectations in Perception
The brain's predictions about the world are based on sensory expectations combined with incoming sensory signals. Through active inference, the brain continuously updates its predictions and minimizes prediction errors to ensure that the perceived content aligns with the sensory input. This process of perception involves a dynamic interplay between internal predictions and external sensory information.
Perception and Attention in Ambiguous Situations
In ambiguous perceptual situations, such as mistaken identities in hunting scenarios, paying attention involves increasing the expected precision of sensory signals to resolve uncertainties. Amplifying the signal-to-noise ratio on the senses enhances the brain's ability to adjust its previous expectations rapidly, leading to sudden perceptual flips when new sensory information challenges existing predictions.
Perception and Context in Color Perception
Our brain's ability to perceive color is influenced by contextual factors, such as lighting and background information. The perception of a checkerboard pattern or the consistent color of an object can be altered by context, leading to misinterpretations that challenge our understanding of color perception.
Hidden Diversity in Individual Perception
Individual differences in how sensory data is processed reveal the diverse ways our brains apply prior expectations. The example of the white and gold/blue and black dress phenomenon highlights how people's perceptions can vary based on internal biases. The Perception Census study aims to measure hidden diversity in perception across various dimensions, emphasizing the importance of understanding inner diversity alongside external differences.
Prediction Error Minimization and the Bayesian Brain
The brain's core function is to minimize prediction errors by continuously updating its predictions based on sensory signals. The Bayesian Brain theory suggests that the brain acts as a prediction machine, making optimal guesses about sensory causes. Active inference extends this concept by incorporating actions that align with predictive models, demonstrating how perception and action are intertwined in optimizing control and understanding of the world.