To have and to hold: embodied ownership is established in early childhood

The ownership memory self-reference effect shifts recognition criterion but not recognition sensitivity

Information referenced to the self is retrieved more accurately than information referenced to others, known as the memory self-reference effect. It is unclear, however, whether social context (identity of the other) or task factors alter decision-making processes. In a virtual object allocation task, female participants sorted objects into their own or another's (stranger or mother) basket based on a colour cue. Subsequently, they performed a recognition memory task in which they first indicated whether each object was old or new, and then whether it had been allocated to themselves or to the other. We obtained owner-specific hit rates and false-alarm rates and applied signal detection theory to derive separate recognition sensitivity (d') and recognition criterion parameters (c) for self- and other-owned objects. While there was no clear evidence of a recognition self-reference effect, or a change in sensitivity, participants adopted a more conservative recognition criterion for self- compared with other-owned objects, and particularly when the other-referent was the participant's mother compared with the stranger. Moreover, when discriminating whether the originally presented objects were self- or other-owned, participants were biased toward ascribing ownership to the 'other'. We speculate that these findings reflect ownership-based changes in decisional processing during the recognition memory self-reference paradigm.

Mine for life: Charting ownership effects in memory from adolescence to old age

This study investigates the self-reference effect (SRE) with an ownership memory task across several age groups, providing the first age exploration of implicit ownership memory biases from adolescence to older adulthood (N = 159). Using a well-established ownership task, participants were required to sort images of grocery items as belonging to themselves or to a fictitious unnamed Other. After sorting and a brief distractor task, participants completed a surprise one-step source memory test. Overall, there was a robust SRE, with greater source memory accuracy for self-owned items. The SRE attenuated with age, such that the magnitude of difference between self and other memory diminished into older adulthood. Importantly, these findings were not due to a deterioration of memory for self-owned items, but rather an increase in memory performance for other-owned items. Linear mixed effects analyses showed self-biases in reaction times, such that self-owned items were identified more rapidly compared with other owned items. Again, age interacted with this effect showing that the responses of older adults were slowed, especially for other-owned items. Several theoretical implications were drawn from these findings, but we suggest that older adults may not experience ownership-related biases to the same degree as younger adults. Consequently, SREs through the lens of mere ownership may attenuate with age.

Object coding in peripersonal space depends on object ownership

Previous studies have shown that objects located in the peripersonal space (PPS) receive enhanced attention, as compared with extrapersonal space (EPS), However, most objects in the environment belong to someone in particular and how object ownership influences object coding in relation to PPS representation is still unclear. In the present study, after having chosen their own mug, participants performed a reachability judgement task of self-owned and other-owned mugs presented at different distances while facing a virtual character. This task was followed, on each trial, by a localisation task in which participants had to indicate where the mug, removed from view, was previously located. The two tasks were separated by a 900-ms visual mask during which the virtual character was unnoticeably shifted by 3° to evaluate the spatial frame-of-reference used. The results showed that self-owned mugs were processed faster than other-owned mugs, but only when located in the PPS. Furthermore, reachability judgements were biased for self-owned mugs, leading to an extension of the PPS representation, especially for participants with a high score on the fantasy scale of Interpersonal Reactivity Index (IRI). Finally, the virtual character shift altered the localisation performance but only for the distant mugs, suggesting a progressive shift from egocentric to allocentric frame-of-reference when moving from the PPS to EPS, irrespective of object ownership. Overall, our data reveal that the representations of ownership and PPS interact to facilitate the processing of manipulable objects, to an extent that depends on individual sensitivity to the social presence of others.

The extended development of mapping spatial demonstratives onto space

Spatial demonstratives (this and that in English) convey distance relative to speaker (within reach vs. out of reach) and object characteristics such as ownership. Previous studies indicate that object characteristics affect adult demonstrative choice, for example, greater use of this for owned objects. Here, production of spatial demonstratives was studied developmentally to identify when demonstrative production is sensitive to both distance and ownership. In two experiments, 7-year-olds, 11-year-olds, and adults completed an object location memory task, and a language task eliciting this or that to indicate an object. Results indicate that adult-like demonstrative production starts around 7 years of age and continues to develop beyond 11 years. Nonlinguistic spatial memory did not vary significantly across age groups. Spatial demonstratives encode both semantic and spatial object characteristics throughout development, revealing the fundamental importance of semantic factors for demonstrative production.