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As we navigate in the environment, our brain receives only a restricted amount of information from a complex yet structured external world. The intrinsic ambiguity of such sensory input calls for “prior experience” to help perception, and to parse stimuli into predefined categories. In this talk, I present two sets of studies, one based on a rodent auditory Parametric Working Memory (PWM) task that involves the sequential comparison of two graded stimuli separated by a few seconds’ delay. This allows us to study “prior experience” via “contraction bias”, the progressive shift of the first stimulus representation towards the center of a prior distribution built from the past sensory experience.  Using data from high-throughput semi-automated training protocols, we developed statistical models to quantify behaviour and characterise how and on what timescales priors are distributed, and how they interact with other factors to form the final decision. Combining quantitative behavioural analyses with recordings and perturbations in Posterior Parietal Cortex (PPC), we discovered PPC’s crucial history-dependent contribution to working memory behaviours; specifically, its impact on “contraction bias”, via the memory of previous sensory events. The other study is based on psychophysical paradigms of priming vs. adaptation aftereffect in humans, where the perception of an ambiguous target stimulus is affected by an immediately preceding stimulus, the ‘adapter’.I explore the hypothesis that these perceptual phenomena may arise from universal computational mechanisms of local cortical networks.