Periodic Reporting for period 3 - PIVOTAL (Predictive Memory Systems Across the Human Lifespan)
Periodo di rendicontazione: 2021-02-01 al 2022-07-31
If the predictive brain is indeed a unifying principle, two critical issues need to be resolved. First, the predictive coding framework has not yet delineated the nature of internal models on which predictions are based (e.g. memory of prior experience) and how our actual experiences shape them in turn. Second, how does such a universal brain principle play out in diverse brains (e.g. young versus old brains)? Addressing these knowledge gaps is important in order to make a breakthrough in our understanding of the fundamental nature of the human mind and brain and to test the adaptivity of the predictive brain principle in accommodating inherent diversities of human brains.
By connecting three separate strands of research (i.e. predictive coding, memory systems, and lifespan development), the PIVOTAL research program aims to unravel the cognitive and neural mechanisms that enable the brain to (i) generate predictions based on memory of prior experience (episodic memory) and knowledge about the world (semantic memory); (ii) verify its predictions given the actual event, and (iii) engage in subsequent processes that in turn modify the memory representation. Using cognitive neuroscience methodology (functional magnetic resonance imaging) and experimental research designs, these mechanisms are being systematically examined in children, younger adults, and older adults, whose neurocognitive landscapes are highly different from each other. The gain in knowledge will characterize the cognitive architectures that allow the human brain to perform predictive processing as a fundamental operation in its interaction with the environment.
In relation to prediction verification and subsequent memory processing, the first step we took here is to develop a paradigm that allows us to reliably measure the relationship between predictive processing and memory performance. In our paradigm, we trained young adults in associations between certain objects and contexts (e.g. musical instruments are usually found on the beach). Once these associations are acquired, we ask our participants to use them to make predictions about objects in a given context and systematically match or mismatch their expectations. Later on, we use a recognition memory test to assess the quality of the memory traces generated during those events that vary in prediction error. We ran several pilot studies and the results generally support the differential impact of different degrees of PE in shaping new memories and highlight the importance of memory consolidation in the process.
In addition to more classical approaches on behavioral data analysis, we also started using computational models that allow the quantification of PE and prior expectations. The estimations of these quantities, trial-by-trial, will permit to relate PE and priors to memory formation, which in turn will stimulate the search for their neural correlates. Preliminary results from this computational work suggests that episodic remembering is indeed related to PE. Precisely, when outcomes were better than expected (positive PE) participants’ ability to remember the items in the subsequent recognition test was improved, compared to items presented in conditions where outcomes were worse than expected (negative PE).