From sensation to decision: Dissociating sensory and cognitive changes in temperature and pain perception across the lifespan

📄 Publisher’s version
🐙 Data and code

Authors

Camilla E. Krænge, Alexandra G. Mitchell, Jesper F. Ehmsen, Arthur S. Courtin, Francesca Fardo

Abstract

Spatial integration of sensory inputs is critical for temperature and pain perception, yet how aging alters these processes remains poorly understood. Using psychophysics combined with drift diffusion modeling, we demonstrate that spatial summation and lateral inhibition, two fundamental mechanisms of sensory integration, exhibit dissociable patterns of age-related change that depend on thermal modality and stimulation intensity. Participants (20–80 years) received cold and warm thermal stimuli of differing intensities, made binary decisions, and provided subjective ratings. Ratings and response times were modeled for stimuli delivered in spatially summating or laterally inhibiting configurations. Spatial summation declined with age for cold but not warm, particularly at low intensities, indicating modality-specific degradation of sensory integration. Drift diffusion modeling showed that this age-related reduction was expressed at the perceptual level, but not in the spatial modulation of drift rates, suggesting preserved efficiency in transforming sensory inputs into decision evidence. Lateral inhibition remained largely stable across the lifespan but displayed modality-dependent modulations. Overall, irrespective of spatial configuration, older adults exhibited lower drift rates and adopted more cautious decision policies, with stable nondecision times during evidence accumulation but slower postdecisional responses across ages. Finally, we found no reliable evidence for either positive or negative correlations between spatial summation and lateral inhibition, both behaviorally and computationally, suggesting that these processes may operate independently rather than in competition. These findings indicate that aging impairs cold spatial summation while preserving warmth-related processing and decision-level integration efficiency. This pattern is indicative of modality-specific neural mechanisms shaping thermosensory decision making across the lifespan.