Neural Design Principles for Subjective Experience: Implications for Insects

Area of Science:

• Neuroscience
• Animal Consciousness
• Sensory Processing

Background:

• Subjective experience in animals is a significant scientific challenge.
• Understanding which animals possess consciousness is debated.
• Current approaches rely on behavioral and brain homology, which have limitations.

Purpose of the Study:

• To propose a neurobiological framework for subjective experience.
• To determine if fruit flies (Drosophila) possess the neural architecture for subjective experience.
• To resolve debates on animal sentience and pain perception.

Main Methods:

• Proposed a model where subjective experience depends on awareness of internal neural processing.
• Hypothesized conscious awareness relies on hierarchical forward models for prediction.
• Analyzed Drosophila neuroanatomy for the required neural connectivity for these models.

Main Results:

• Drosophila brains lack the specific internal neural connectivity required for hierarchical forward models.
• Disruptions in neural processing or awareness states affect subjective experience.
• The proposed model offers an alternative to homology-based assessments of animal feeling.

Conclusions:

• Drosophila, and insects with similar neuroanatomy, do not subjectively experience noxious stimuli.
• These insects are therefore concluded to be incapable of feeling pain.
• The findings challenge assumptions about consciousness in invertebrates.