Final Activity Report Summary - DNE (Developmental aspects of the neural correlates of episodic encoding)
A main known contributor to adults' superior memory performance compared to children's is their differential reliance on existing knowledge-base: compared to adults, children's semantic networks are less accessible and less established. We manipulated the encoded stimuli in the present experiment such that the use of knowledge-base at encoding was more, or less, accessible, in both children and adults: encoded stimuli consisted of noun/colour combinations that were either possible or impossible in nature (e.g. possible: strawberry-red; impossible: banana-purple). Adults' fMRI studies target a priori regions of interest for a developmental comparison - the Prefrontal cortex (PFC), the lateral parietal cortex, inferotemporal cortex and the medial-temporal lobe - as they are known to undergo prolonged anatomical and/or organizational development.
While being scanned, children (ages 8-11) and young adults (current N=33) saw printed noun / colour combinations, and were asked to indicate whether each combination existed in nature. A subsequent recognition test was administered outside the scanner, and encoding trials were analysed according to their subsequent recognition status, comparing encoding activation for items that were subsequently remembered to those that were subsequently forgotten.
While both age groups exhibited subsequent memory-related activation in left prefrontal cortex (dorsal and inferior), left parietal cortex, bilateral inferotempral cortex and bilateral MTL regions, significant between group effects were found in the left PFC and left parietal cortex. These findings were not found to be modulated by item congruity (i.e. possible vs. impossible item-colour combination).
Results show a significant developmental trend in encoding-related activation in the left lateral prefrontal and parietal cortices, regions that follow a prolonged anatomical developmental trajectory. In contrast, activation in bilateral inferotemporal regions, where functional development has been previously demonstrated in the context of object recognition, showed an identical subsequent memory pattern for adults and children.
While being scanned, children (ages 8-11) and young adults (current N=33) saw printed noun / colour combinations, and were asked to indicate whether each combination existed in nature. A subsequent recognition test was administered outside the scanner, and encoding trials were analysed according to their subsequent recognition status, comparing encoding activation for items that were subsequently remembered to those that were subsequently forgotten.
While both age groups exhibited subsequent memory-related activation in left prefrontal cortex (dorsal and inferior), left parietal cortex, bilateral inferotempral cortex and bilateral MTL regions, significant between group effects were found in the left PFC and left parietal cortex. These findings were not found to be modulated by item congruity (i.e. possible vs. impossible item-colour combination).
Results show a significant developmental trend in encoding-related activation in the left lateral prefrontal and parietal cortices, regions that follow a prolonged anatomical developmental trajectory. In contrast, activation in bilateral inferotemporal regions, where functional development has been previously demonstrated in the context of object recognition, showed an identical subsequent memory pattern for adults and children.