Tulving's seminal work distinguishing episodic from semantic memory reminds us that “even when
we do not remember an event, we may still know something about it”1,2. By linking familiarity
with semantic processing and recollection with episodic memory, he showed us that information
retrieval can be guided by remembering or knowing, which refers to the Remember/Know
procedure. Despite not being fully embraced by subsequent research, Tulving's innovative insight
inspires us to explore the nuances of memory and cognitive processes. Indeed, we believe that the
impact of familiarity on memory is more complex than has been previously appreciated. Familiarity
may arise from weak memory due to perceptual processing, as claimed by many3–5. Still, it may
also stem from well-encoded information, leading to the fading of detailed episodic memory in
favor of semantic processing. Current research has not fully addressed this latter form of familiarity.
Temporal factors, such as the delay between encoding and testing and the complexity of materials
used, pose challenges. We expect familiarity associated with semantic processing to become more
evident over time, rather than during immediate retrieval, which is often the focus of testing. In
addition, previous studies of familiarity have mainly used word lists, but we believe that the
integration of information is more likely to occur in everyday events that are multimodal and
ecologically relevant, leading to the semantization of episodic information. In our most recent work
(in preparation, BIAL Foundation Grants Programme 2022/23, No. 250/2022), we have shown that
semantization is a slow process that stabilizes with time and episodic information repetition and that
it benefits from multimodal encodings, such as the presentation of audiovisual ecological material.
Neuroimaging studies support our proposal, showing that familiarity and semantic processes are
reliant on the temporopolar cortex, suggesting a common neural basis, in contrast to the literature
on episodic memory, which would mainly involve hippocampal formation6–8. Nevertheless, no
study has delved into the neural underpinnings of familiarity and semantic memory within the same
framework and experimental materials. Furthermore, it would be interesting to investigate the role
of sulcal morphology, which we have seen to be involved in cognitive processes of general
memory9, considering the specific distinction between vivid memory and a sense of familiarity, as
they may be involved in different processes. To address these gaps, we aim to investigate the
concept of familiarity, and in particular its relationship to semantic memory, from a neuro-
behavioural perspective. Specifically, we will investigate the neural basis of episodic and semantic
processes for familiar/remembered stimuli with a new experimental procedure. In addition, we will
test whether the morphological pattern of the regions involved influences episodic/semantic
performance in the context of familiar/remembered item discrimination. We will use a novel
experimental paradigm with ecological episodic and semantic tasks, already tested in our laboratory,
to maximize the process of episodic encoding and semantic transformation.
In our study, twenty-four participants will watch a movie while their attention is monitored with an
eye-tracker, which will help to control the focus of attention during the encoding of specific frames
that will be used in subsequent tasks. Immediately after, participants will perform an immediate
Remember/Known (iR/K) task on the movie’s frames. After a three-day delay, they will repeat the
same task (delayed Remember/Know task, dR/K) under fMRI scanning. Finally, participants will
complete a semantic and an episodic memory task using the same stimuli. In the semantic task,
participants will be asked to judge the characters' social relationships in each f