Predicting explicit memory for meaningful cartoons from visual paired comparison in infants and toddlers.

We tested the memory of 18-, 33-, and 39-month-olds (N = 120) for dynamic stimulus material (simple cartoons) after 6 months in a visual paired comparison (VPC) task. We also tested the explicit recognition memory (ERM) for the same material. Only the oldest age group (39-month-olds) showed a significant visual (familiarity) preference at the test. Similarly, only the oldest group reliably chose the correct cartoon in the ERM test. Data from the VPC and ERM tasks did not correlate in any age group. However, we suggested a novel score (coined ΔVPC) measuring how much visual preference changes during the test phase in the VPC task. We found that this ΔVPC score (and vocabulary) predicted children's performance in the ERM task, whereas other potential predictors such as age and conventional novelty preference did not. We discuss the impact of these findings in relation to the development of implicit and explicit memory. Furthermore, we propose that VPC measures are associated with explicit memory only when the participants processed the stimuli conceptually. In such cases, we suggest that the ΔVPC score is an approximation of how demanding it is to construct the mental representation of the familiar stimulus during the test phase.

Data related to measures of physiological arousal during everyday life experiences and their relation to self-reports of subjective experience of both the event and its memory.

Emotionally intense experiences lead to particularly durable and detailed autobiographical memories (AM) [1,2]. However, the influence of arousal on self-reports of the phenomenological characteristics of events and AMs is not direct, but moderated at the cognitive level [3,4]. To address how individual differences in emotional awareness moderate the physiology-subjective experience link, we collected data using a questionnaire from the mindfulness literature, the Five Facet Mindfulness Questionnaire (FFMQ [5]). In addition, objective measures of physiological arousal while events naturally unfolded in everyday life contexts-outside the lab-were collected to map them onto self-reports of their phenomenological characteristics and those of their memories. In this article, we provide the full data for the FFMQ from a sample of 60 undergraduate students. We also display analyzed data of how markers of physiological arousal (i.e., electro-dermal activity, heart rate, and temperature) related to self-reports at two time-points of interest. First, we related these measures to same day self-reports of the characteristics of the experience. Then, we related these measures to self-reports and to arousal of their memories one week later, and in the lab. Detailed interpretation of this data, as well as in depth theoretical background is presented in "How is physiological arousal related to self-reported measures of emotional intensity and valence of events and their autobiographical memories?" [6].

How is physiological arousal related to self-reported measures of emotional intensity and valence of events and their autobiographical memories?

Research suggests that emotionally intense experiences that elicit higher-than-average physiological arousal responses lead to particularly durable and detailed autobiographical memories. Yet, the lack of objective measures of physiological arousal while events unfold in everyday life makes it hard to corroborate this lab finding. Also, it is uncertain how well arousal maps onto self-reports of the phenomenological characteristics of autobiographical events and memories. Here, we examined how physiological measures of arousal, taken while everyday life events develop, correlate with self-reports. Our results showed that physiological arousal during an event not only was related to self-evaluations of its assessed physical reaction -at the time of report-, but also predicted evaluations of physical reaction, positivity, and importance of their memories one week after. Further analyses revealed that, while arousal affected evaluations of emotional intensity of events and memories, this relationship was moderated by participants' level of awareness about their own emotional processes.

Flexible, rapid and automatic neocortical word form acquisition mechanism in children as revealed by neuromagnetic brain response dynamics.

Children learn new words and word forms with ease, often acquiring a new word after very few repetitions. Recent neurophysiological research on word form acquisition in adults indicates that novel words can be acquired within minutes of repetitive exposure to them, regardless of the individual's focused attention on the speech input. Although it is well-known that children surpass adults in language acquisition, the developmental aspects of such rapid and automatic neural acquisition mechanisms remain unexplored. To address this open question, we used magnetoencephalography (MEG) to scrutinise brain dynamics elicited by spoken words and word-like sounds in healthy monolingual (Danish) children throughout a 20-min repetitive passive exposure session. We found rapid neural dynamics manifested as an enhancement of early (~100ms) brain activity over the short exposure session, with distinct spatiotemporal patterns for different novel sounds. For novel Danish word forms, signs of such enhancement were seen in the left temporal regions only, suggesting reliance on pre-existing language circuits for acquisition of novel word forms with native phonology. In contrast, exposure both to novel word forms with non-native phonology and to novel non-speech sounds led to activity enhancement in both left and right hemispheres, suggesting that more wide-spread cortical networks contribute to the build-up of memory traces for non-native and non-speech sounds. Similar studies in adults have previously reported more sluggish (~15-25min, as opposed to 4min in the present study) or non-existent neural dynamics for non-native sound acquisition, which might be indicative of a higher degree of plasticity in the children's brain. Overall, the results indicate a rapid and highly plastic mechanism for a dynamic build-up of memory traces for novel acoustic information in the children's brain that operates automatically and recruits bilateral temporal cortical circuits.

Three-year-olds' memory for a person met only once at the age of 12 months: very long-term memory revealed by a late-manifesting novelty preference.

This study examined three-year-olds' verbal and non-verbal memory for a person met only once after a 28 month interval. Children in the Test group (N=50) had participated in an earlier experiment at our lab at the age of 12 months where they met one of two possible experimenters. At this past event half of the children were tested by one, the other half by the other experimenter. At the follow-up, run by a naïve experimenter, the children were shown two videos from the original experiment in a visual paired comparison task: One with the specific experimenter testing them at the original visit (the Target) and one of the other experimenter (the Foil), with whom they had no experience. When explicitly asked, the children's responses did not differ from chance. However, eye-tracking data revealed a late-manifesting novelty preference for the "Foil" person indicating memory for the "Target" person met once before.