False memories of emotional words as a key for understanding semantic processing in bilinguals and older adults.

The aim of the present thesis is to disentangle the effect that emotionality of the words has on verbal false memories in bilinguals and in older adults, as a key to better understand their semantic processing. Verbal false memories are measured through the DRM paradigm (Deese, 1959; Roediger & McDermott, 1995). It consists in presenting participants with some lists of words all semantically related to a not present theme (called “critical lure”). It is likely that participants will also remember the critical lure as if it would have been part of the coded lists. Verbal false memories occur in light of semantic processing. This aspect has been well addressed by Fuzzy Trace Theory (FTT; Reyna et al., 2016) and by Spreading Activation Theory (SAT; Roediger et al., 2001). The former posits that when we are called to remember items like words we code them according to two different traces, a gist one, deputed to code the meaning of the items and a verbatim one, deputed to code their shallow features (i.e., their position in a list, their size, the number of letters that compose them…). According to FTT verbal false memories would be due to gist processing, while accuracy would be due to both gist and verbatim processing. The latter posits that when words are processed their correspondent nodes are activated, leading to a spread of the semantic activation to the neighboring nodes. This activation would lead to the inaccuracies that correspond to verbal false memories. Emotionality of the words proved to boost semantic processing (Zhang, 2016). More in detail emotionality can be represented by arousal (higher or lower emotional activation elicited by the words) and valence (positive or negative). It has been demonstrated that higher arousal words are able to elicit an higher number of verbal false memories than lower arousal words (e.g., Dehon, Larøi, & Van der Linden, 2010; Sharkawy, Groth, Vetter, Beraldi, & Fast, 2008). Even if there is less unanimity concerning valence (e.g., Brainerd, Stein, Silveira, Rohenkohol, and Reyna, 2008), it has been demonstrated that words with negative valence elicit an higher number of verbal false memories. This would be in light of the “priority of elaboration” that the more emotional words acquire. These results have been well assessed on younger adults monolinguals. Nevertheless, we found a gap in the literature concerning the role that emotionality plays on semantic processing responsible for verbal false memories in bilinguals and in older adults. These two populations have opposite features concerning language and memory, that are both highly involved in semantic processing. In fact, bilinguals showed a disadvantage in terms of vocabulary as measured in each of their two language in comparison with monolingual peers; they seem to be advantaged in terms of executive functioning, including working memory (e.g., Bialystok, 2009). On the contrary, during aging it has been demonstrated that executive functioning and episodic memory tend to decline, while vocabulary seems to be preserved or in some cases even enhanced (e.g., Birren, 2006). During the present thesis we will present the results concerning these two populations.