Is internal source memory recognition modulated by emotional encoding contexts?

Filling the gap: Cloze probability and sentence constraint norms for 807 European Portuguese sentences

Sentence processing is affected by the sentence context and word expectancy. To investigate sentence comprehension experimentally, it is useful to have sentence completion norms with both context constraint and word expectancy measures. In this study, two experiments were conducted to collect norms for completion of 807 European Portuguese sentences. Context constraint was measured through type-token ratio and proportion idiosyncratic responses, while word expectancy was assessed by cloze probability. Besides establishing norms for a large sample of sentences, the study investigated the impact of the production procedure and method of analysis. In Experiment 1, a single-production procedure was used, i.e., participants completed each sentence fragment with only a single response, whereas in Experiment 2, a multiple-production procedure was used, i.e., participants have to provide up to three completion words for each sentence fragment. In Experiment 2, the analyses were obtained using two distinct methods: first-response analysis and combined-response analysis. The results showed that cloze and context measures are comparable between production paradigms and that the results from both analysis methods were correlated. The advantages of each production procedure and analysis method are discussed.

Effect of the congruity of emotional contexts at encoding on source memory: Evidence from ERPs

Emotion's influence on source memory has proven more elusive and the lack of studies investigates the effect of the congruent emotional contexts on source memory. Here, we investigated these issues using event-related potentials (ERPs) to assess emotional-induced neural correlates. During encoding, congruent word-picture (a word 'shoes' - a picture described shoes) and incongruent word-picture (a word 'pepper' - a picture described shoes) with a prompt (Common? or Natural?) were presented. At retrieval, participants indicated which prompts were concomitantly presented with the word during encoding. Behavioral results revealed that source memory accuracy was enhanced in the neutral contexts compared to the negative contexts, and enhanced in the incongruent condition relative to the congruent condition, suggesting that emotional contexts impaired source memory performance, and incongruent information enhanced source memory. ERPs results showed that early P2 old/new effect (150-250 ms) and FN400 old/new effect (300-450 ms) were observed for words with correct source that had been encoded in the congruent emotional contexts, and that a larger parietal old/new effect, between 500 and 700 ms, was observed for words with correct source that had been encoded in the incongruent condition than in the congruent condition, irrespective the nature of context. The ERPs results indicate that retrieval of source details for the associated emotionally congruent information supports the idea that emotional events could attract more attentional resources, and reflects the contribution of familiarity-based process. Meanwhile, retrieval of source details for the associated incongruent information reflects a stronger contribution of recollection-based process.

Better memory for emotional sources? A systematic evaluation of source valence and arousal in source memory

Emotion-enhanced memory (EEM) describes the robust memory advantage of emotional over non-emotional stimuli. While extensively investigated with emotional items, it is unclear whether the EEM effect extends to source memory for a neutral item's emotional context. In two pre-registered studies, we systematically manipulated source valence (positive, negative) between participants and source arousal (high, low, neutral-low) within participants. In Experiment 1 (lab study, N = 80), we used emotional sound sources and presented them together with neutral pictures as items. In Experiment 2 (online study, N = 172), we used emotional background pictures with superimposed neutral item words to similarly manipulate source emotionality. Multinomial model-based analysis showed no general effects of valence or arousal on source memory across both experiments. Source memory was impaired for the negative high-arousing source in Experiment 1 but this did not replicate in Experiment 2. Altogether, we conclude that there are no memory-enhancing effects of source emotionality (valence, arousal, or any specific combination thereof) on source memory, dissociating emotionality effects between source and item memory. Additionally, we propose that material-dependent influences carry more weight if the used emotional material is limited in number, as is the case in the standard source-monitoring paradigm employing few sources only.

Interactions of Emotion and Self-reference in Source Memory: An ERP Study

The way emotional information is encoded (e.g., deciding whether it is self-related or not) has been found to affect source memory. However, few studies have addressed how the emotional quality and self-referential properties of a stimulus interactively modulate brain responses during stimulus encoding and source memory recognition. In the current study, 22 participants completed five study-test cycles with negative, neutral, and positive words encoded in self-referential versus non-self-referential conditions, while event-related potentials of the electroencephalogram were recorded. An advantage of self-referential processing in source memory performance, reflected in increased recognition accuracy, was shown for neutral and positive words. At the electrophysiological level, self-referential words elicited increased amplitudes in later processing stages during encoding (700-1,200 ms) and were associated with the emergence of old/new effects in the 300-500 ms latency window linked to familiarity effects. In the 500-800 ms latency window, old/new effects emerged for all valence conditions except for negative words studied in the non-self-referential condition. Negative self-referential words also elicited a greater mobilization of post-retrieval monitoring processes, reflected in an enhanced mean amplitude in the 800-1,200 ms latency window. Together, the current findings suggest that valence and self-reference interactively modulate source memory. Specifically, negative self-related information is more likely to interfere with the recollection of source memory features.