Osman S. Kingo

On the development of episodic memory: Two basic questions

In this focused study, we present and discuss two basic questions related to the early development of episodic memory in children: (1) “What is an episode?” and (2) “How do preverbal children recall a specific episode of a recurring event?” First, a brief introduction to episodic memory is outlined. We argue in favor of employing a definition of episodic memory allowing us to investigate the development of episodic memory by purely behavioral measures. Second, research related to each of the two questions is presented and discussed, at first separately, and subsequently together. We argue and attempt to demonstrate that pursuing answers to both questions is of crucial importance – both conceptually and methodologically – if we are ever to understand the early development of episodic memory.

“That one makes things small”: Experimentally induced spontaneous memories in 3.5-year-olds

We introduce a new method for examining spontaneous (unprompted) autobiographical memories in 3.5-year-old children, by inducing them in a laboratory setting. Thirty-eight 3.5-year-olds, who had previously participated in a study in our lab involving highly unique props, were brought back after a one-month delay to the same lab arranged as in the original study and with the same Experimenter present. While waiting for the Experimenter in front of the props, their spontaneous verbalizations about the previous unique experiment were recorded, scored, and compared to those of 29 naïve Controls of the same age. The children in the experimental group produced significantly more spontaneous verbalizations related to the to-be-remembered event measured on a variety of dimensions. The study introduces a promising new approach to investigating spontaneous memories in young children in a controlled lab setting. The findings are discussed in relation to involuntary autobiographical memories as examined in adults.

Warm-up questions on early childhood memories affect the reported age of earliest memories in late adolescence

Researchers have recently used warm-up questions concerning childhood memories at specific early ages (e.g. 3 years of age) in an attempt to facilitate the retrieval process on the subsequent question regarding the earliest memory. Although this methodology may indeed facilitate the retrieval process by conducting the test in a manner resembling ordinary dialogue, the methodology might also unintentionally put further demand characteristics on the respondents. In the present study we systematically manipulated the target age (either 3 or 6 years of age) for the warm-up question preceding the ‘earliest memory’ question in order to test this possibility. The participants were 445 Danish high school students (M age=17.94). The results revealed that systematically manipulating the target age for the warm-up question had a strong impact on the age of the earliest memory reported by the adolescents. Participants who received warm-up questions with 3 years as the target age subsequently reported earlier first memories than the participants receiving warm-up questions with 6 years as the target age. These results have important implications for the methodology involved in research on childhood amnesia.

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

ABSTRACT 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 individuals 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 (˜100 ms) 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 (˜15–25 min, as opposed to 4 min 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 childrens 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 childrens brain that operates automatically and recruits bilateral temporal cortical circuits. HIGHLIGHTSChildren acquire novel word forms in an automatic fashion after mere 4 min.To acquire new native‐language word forms, the left perisylvian neural network is used.Bilataral hemispheric structures support acquisition of non‐native language word forms.

By-passing strategic retrieval: Experimentally induced spontaneous episodic memories in 35- and 46-month-old children

Most parents have experienced their preschool child having spontaneous episodic memories, that is, verbally reported memories of past events that come to the child almost out of the blue. Until recently such memories had only been observed outside the lab. By means of a new paradigm we report experimentally induced spontaneous memories of a unique event experienced one week earlier in 35- and 46-month-old children (N=110). At the first visit, half of the children experienced a Teddy event and the other half experienced a Game event. At the second visit the childrens spontaneous utterances were recorded while waiting. The results revealed that the children talked spontaneously about the unique event experienced previously. Age showed no systematic effect on spontaneous episodic recollection, but there was a clear effect of age on subsequent control questions requiring strategic retrieval. The results support the idea of involuntary episodic remembering being a developmentally early achievement.

Bound to remember: Infants show superior memory for objects presented at event boundaries

Following Event Segmentation Theory (EST) adult memory is enhanced at event boundaries (EB). The present study set out to explore this in infancy. Sixty-eight 21-month-olds watched a cartoon with one of two objects (counterbalanced) inserted for 3s either at EB or between EB. Ten minutes later they watched both objects (familiar and novel) in a 10s Visual Paired Comparison (VPC) test while being eye-tracked. Furthermore, they were asked to point to the previous object. Based on EST, we hypothesized that objects inserted at EB would be processed more fully, resulting in improved memory compared to objects inserted between EB. Only infants with objects at EB exhibited memory evidenced by a transient familiarity preference for the first 3s of the test. Only 18 infants completed the pointing test, but all infants presented with objects at EB (10/10) pointed to the correct (familiar) object, which was not the case for the infants presented with objects between EB (5/8).

Thirty-five-month-old children have spontaneous memories despite change of context for retrieval

ABSTRACT Many parents have experienced incidents in which their preschool child spontaneously (i.e., without prompting of any kind) recall a previously experienced event. Until recently, such spontaneous memories had only been examined in non-controlled settings (e.g., diary studies). Using a novel experimental paradigm, a previous study has shown that when young children are brought back to a highly distinct setting (same room, same experimenter, same furnishing), in which they previously experienced an interesting event (a Teddy or a Game event), spontaneous memories can be triggered. However, exactly which cues (or combination of cues) are effective for the children’s memory, remains unknown. Here, we used this novel paradigm to examine the possible impact of contextual cues at the time of retrieval. We manipulated whether the 35-month-old children returned to the same room (n = 40) or to a different, but similarly furnished, room (n = 40) after one week. The results revealed that although the children returning to a new room produced fewer spontaneous memories than the children returning to the same room, the difference was not significant. Interestingly, despite changing rooms, the children still produced spontaneous memories. Taken together the results may shed new light on the mechanisms underlying childhood amnesia.

Object Individuation or Object Movement as Attractor? A Replication of the Wide-Screen/Narrow-Screen Study by Means of (a) Standard Looking Time Methodology and (b) Eye Tracking

We report a replication experiment of a mechanized version of the seminal wide-screen/narrow-screen design of Wilcox and Baillargeon (1998) with 9.5-month-old infants (). Two different methodologies were employed simultaneously: (a) the standard looking time paradigm and (b) eye tracking. Across conditions with three different screen sizes, the results from both methodologies revealed a clear and interesting pattern: the looking times increased as a significantly linear function of reduced screen sizes, that is, independently of the number of different objects involved. There was no indication in the data that the infants made use of the featural differences between the different-looking objects involved. The results suggest a simple, novel, and thought-provoking interpretation of the infants’ looking behavior in the wide-screen/narrow-screen design: moving objects are attractors, and the more space left for visible object movement in the visual field, the longer are infants’ looks. Consequently, no cognitive interpretation may be needed.

Adults’ earliest memories of songs and melodies based on a large stratified sample:

Most parents sing to their children. Yet, little is known regarding how early musical experiences are retained later in life. This study is a first attempt to fill this gap in the literature. Based on the stratified sample, we asked 973 adults about their first memories of a song or melody. The results revealed that adults’ earliest memories of a song or melody generally were predated by memories for other events; thus, the music memories were not the very earliest memories. The earliest memories for musical experiences were rated as typical, fragmented, and positive. Women reported earlier music memories than men. Current age had no impact on the age of the earliest music memories, but older respondents rated their memories as more vivid. The reported parental communication quality during childhood was reliably related to the age and characteristics of the earliest music memories.