title: Beyond Dichotomy: Exploring the Intersection of Semantic and Sensory Information in Abstract and Concrete Words Formation and Representation. Insights from Superordinate words.
Creators: name: Battaglini, Chiara
Publisher: name: IMT Alti Studi Lucca
Year: 2023

description: This thesis is focused on the description of conceptualization mechanisms that allow to create unified and shared representations of percepts. Moreover, the differences and similarities between abstract and concrete word semantic and conceptual representations are analysed. In particular, the definitions of abstraction and abstractness are evaluated in order to disentangle them. Reviewing the available literature on the topic, from the point of view of the different disciplines that have tackled the matter, from philosophy to cognitive sciences, unresolved issues are reported and put forward, advocating the need to go beyond the classical dichotomic subdivision of abstract and concrete words. The authors put forward the need to take into account the architecture of semantic representations when dealing with studies on words and concepts processing. The aim of the study is to assess the importance of sensory information and semantic architecture in conceptual representation, particularly focusing on these questions: What is the role of sensory information in concept formation and retrieval? Does knowledge depend on modality-dependent information, or is it organized in a more abstract semantic manner? Is the presence (or lack) of sensory information (abstractness) or the different semantic architecture (abstraction) that drives the different behavioral and neural responses to concrete and abstract concepts? We hypothesize that abstract and concrete concepts may differ on the level of abstraction needed to process them. Moreover, in order to disentangle the different contributions of sensory information and semantic architecture, we included in the design superordinate concepts, which are linked to sensory information but are characterized by more general and less detailed semantic representation.180 balanced stimuli (60 concrete, 60 abstracts 60 superordinate) were selected and evaluated by 46 Italian native speakers with a 5- point-Likert-scale on concreteness, abstractness, familiarity, and generalizability. The same task was administered to 327 English native speakers to assess interlinguistic agreement in the evaluation. 99 participants were asked to produce a maximum of ten features to describe each word. These features were then segmented and lemmatized and were used to evaluate the semantic richness of the stimuli words (Relevance and Pointwise Mutual Information). 51 balanced stimuli (17 concrete, 17 abstract, and 17 superordinate) were selected for the EEG study. The stimuli were balanced both for length and frequency. Six Italian native speakers from all over Italy, three males and three females recorded the stimuli. Recordings of the stimuli were balanced for RMS and length. 20 Italian native speakers took part in the EEG study. They were instructed to listen to the words and think carefully about their meanings. As attention check, they were asked for 10% of the trials, in a randomized order, to evaluate the semantic similarity of the words heard and further words which were not part of the database. The electrophysiological data from the attention checks were then discarded and not analysed. The sub-sample of 51 stimuli was evaluated on concreteness, abstractness, familiarity, and generalizability by 18 blind participants. The aim of this study was to evaluate whether lack of sensory information experience lead to differences in the evaluation of concrete, abstract and superordinate stimuli and see whether the abstraction continuum hypothesized depended on sensory information contribution and was then disrupted or significantly different in the blind population. Behavioral results showed a continuum from concrete, characterized by higher values of sensory information and semantic architecture to superordinate to abstract concepts, with the lowest values of sensory information and sematic richness. ERPs differed significantly at the latencies 250-350ms and 650-700ms, with concrete concepts eliciting greater responses than both abstract and superordinate concepts. Despite being grounded in sensory information, EEG response to superordinate categories was indistinguishable from abstract concepts, while both were significantly different from concrete concepts. These results highlight the importance of the semantic architecture, advocating a redefinition of abstract and concrete concepts that encompass the traditional dichotomy of sensory/non-sensory grounded concepts.