Non-goal-directed recall of specific events in apes after long delays

Turns around periodic spatial boundaries facilitate increasing event segmentation over time

Event segmentation is a neurocognitive process bridging perception and episodic memory. To our knowledge, almost all segmentation work is framed towards humans, yet evolutionarily conserved mechanisms in event cognition exist across species. Here, we addressed segmentation in a way that is applicable to humans and non-human animals, inspired by research in rats; specifically, the fragmentation of grid-cell spatial representations following the insertion of boundaries into an environment (forming a corridor maze). Participants indicated when they felt a meaningful unit of activity ended and another began, while watching an agent traverse from a first-person perspective. A virtual corridor maze (experiment 1) and two other mazes were used (experiment 2), with participants viewing/segmenting the same stimuli twice. We found that people segmented more during turns relative to corridors, with elevated segmentation occurring in discrete moments around turns. Interestingly, we also found that boundaries of the corridor maze facilitated an increase in segmentation within and across viewings. These results suggest that segmentation can be driven by recognized repeating activity that can become more meaningful over time, highlighting an important link between event segmentation and pattern separation that is relevant to many species in their formation of episodic-(like) memory.

Direct retrieval as a theory of involuntary autobiographical memories: evaluation and future directions

I evaluate the conception of direct retrieval as originally formulated in the Self-Memory System model (Conway & Pleydell-Pearce [2000]. The construction of autobiographical memories in the self-memory system. Psychological Review, 107(2), 261-288. https://doi.org/10.1037/0033-295X.107.2.261). In the hierarchical memory organisation proposed in the Self-Memory System model, direct retrieval is described as a bottom-up associative process. While its theoretical role within this model is clear, systematic empirical examination of direct retrieval, viewed as a natural and observable phenomenon, has been hampered by inconsistent operationalisations. Here, I suggest that direct retrieval should be treated as a theoretical concept, aiming at explaining the phenomenon of involuntary (spontaneously arising) autobiographical memories. I evaluate predictions derived from the concept of direct retrieval against findings on involuntary autobiographical memories obtained over the past 25 years. Most of these predictions are consistent with the evidence, notably, the enhanced episodic specificity and constructive nature of involuntary autobiographical memories. However, the theory also has critical limitations. It did not predict the frequent occurrence of involuntary recollections in daily life, exceeding the prevalence of voluntary memories. Additionally, it overlooked the early emergence of spontaneously arising event memories in ontogenesis and their presence in other species, such as great apes. Future advancements of the Self-Memory System model should integrate evolutionary perspectives to address these limitations.

Functional fixedness in chimpanzees

Differences in the tool use of non-human primates and humans are subject of ongoing debate. In humans, representations of object functions underpin efficient tool use. Yet, representations of object functions can lead to functional fixedness, which describes the fixation on a familiar tool function leading to less efficient problem solving when the problem requires using the tool for a new function. In the current study, we examined whether chimpanzees exhibit functional fixedness. After solving a problem with a tool, chimpanzees were less efficient in solving another problem which required using the same tool with a different function compared to a control group. This fixation effect was still apparent after a period of nine months and when chimpanzees had learned about the function of a tool by observation of a conspecific. These results suggest that functional fixedness in our closest living relatives likely exists and cast doubt on the notion that stable function representations are uniquely human.

Autobiographical memory and the self on the psychosis continuum: investigating their relationship with positive- and negative-like symptoms

Autobiographical memory is severely impaired in schizophrenia, but previous work has largely treated both as unitary concepts. Here, we examined how various dimensions of autobiographical memory relate to different aspects of psychosis. Participants were recruited from the general population (Study 1, N = 264) and a university subject pool (Study 2, N = 305). We examined different measures of autobiographical memory and self (i.e., involuntary memory, autobiographical recollection, self-knowledge and self-awareness), at the trait level in Study 1 and both trait and state levels in Study 2, as a function of positive-and negative-like symptoms of psychosis. Across both studies, positive and negative dimensions of psychosis were found to be related to an increase in involuntary memories (i.e., the spontaneous recall of personal memories), and to lower self-concept clarity and insight. Positive and negative dimensions of psychosis correlated differently with autobiographical recollection characteristics, measured at both trait (Studies 1 and 2) and state levels (Study 2). Positive-like symptoms (in particular hallucination-proneness) showed a stronger and more consistent pattern of correlations than negative-like symptoms. These findings call for a dimensional approach to the relationship between autobiographical memory and psychosis symptoms in clinical and non-clinical individuals, to better understand the breakdown of autobiographical memory in the psychopathology of psychosis.

Distinct environmental cues trigger spontaneous recall of past events in 3- and 4-year-old children even after long delays

Verbally reported long-term memory for past events typically improves with age. However, such findings are based exclusively on studies, where children are directly asked to recall. The present study showed that when 3- (n = 113, 59 girls) and 4-year-olds (n = 113, 62 girls), predominantly White, were brought back to a distinct laboratory-setting after either 1-, 4.5-, or 13-weeks, children-regardless of age and delay-spontaneously recalled the distinct event experienced at their first visit (all Cohen's ds > 1.00). Meanwhile, the oldest children outperformed the youngest when being asked directly to retrieve the event ( η p 2 > . 088 ). These findings suggest that spontaneous retrieval facilitated by distinct environmental cues provides a short-cut to young children's event memories.

Use of Interactive Technology in Captive Great Ape Management

The conservation status of great apes (chimpanzees Pan troglodytes, gorillas Gorilla sp., orangutans Pongo sp., and bonobos Pan paniscus) is grave and zoological institutions are vital for maintaining numbers of these species and educating the public about their importance. Technology provides tools that can assist zoos in meeting these objectives. However, the extant research on technology use in zoos is potentially constrained by small sample sizes and there is no framework detailing the methodologies necessary for the successful incorporation of technology into great ape management. Therefore, this study aimed to determine current technology use in the management of captive great apes and whether technology-directed behaviour differs between ape genera. Primary carers of great apes in zoos were surveyed using a 43-question, online questionnaire. The purpose of integrating interactive technology into captive ape management was primarily for enrichment (53% of respondents), followed by research (20% of respondents). However, only 25% of respondents had apes directly engaged with technology. There were no differences in technology-directed behaviours between ape genera. By identifying differences in practice, this research marks the initial stage in developing a best practice framework for using technology.

Location and temporal memory of objects declines in aged marmosets (Callithrix jacchus)

Episodic memory decline is an early marker of cognitive aging in human. Although controversial in animals and called “episodic-like memory”, several models have been successfully developed, however they rarely focused on ageing. While marmoset is an emerging primate model in aging science, episodic-like memory has never been tested in this species and importantly in aged marmosets. Here, we examined if the recall of the what-when and what-where building blocks of episodic-like memory declines in ageing marmosets. We developed a naturalistic approach using spontaneous exploration of real objects by young and old marmosets in the home cage. We implemented a three-trial task with 1 week inter-trial interval. Two different sets of identical objects were presented in sample trials 1 and 2, respectively. For the test trial, two objects from each set were presented in a former position and two in a new one. We quantified the exploratory behaviour and calculated discrimination indices in a cohort of 20 marmosets. Young animals presented a preserved memory for combined what-where, and what-when components of the experiment, which declined with aging. These findings lead one to expect episodic-like memory deficits in aged marmosets.

Involuntary autobiographical memories and their relation to other forms of spontaneous thoughts

Involuntary autobiographical memories are memories of personal events that come to mind spontaneously-that is, with no conscious initiation of the retrieval process. Such spontaneously arising memories were long ignored in cognitive psychology, which generally has focused on controlled and strategic forms of remembering, studied in laboratory settings. Recent evidence shows that involuntary memories of past events are highly frequent in daily life, and that they represent a context-sensitive, and associative way of recollecting past events that involves little executive control. They operate by constraints that favour recent events and events with a distinct feature overlap to the current situation, which optimizes the probability of functional relevance to the ongoing situation. In addition to adults, they are documented in young children and great apes and may be an ontogenetic and evolutionary forerunner of strategic retrieval of past events. Findings suggest that intrusive involuntary memories observed clinically after traumatic events should be viewed as a dysfunctional subclass of otherwise functional involuntary autobiographical memories. Because of their highly constrained, situation-dependent and automatic nature, involuntary autobiographical memories form a distinct category of spontaneous thought that cannot be equated with mind wandering. This article is part of the theme issue 'Offline perception: voluntary and spontaneous perceptual experiences without matching external stimulation'.

Are the roots of human economic systems shared with non-human primates?

We review and analyze evidence for an evolutionary rooting of human economic behaviors and organization in non-human primates. Rather than focusing on the direct application of economic models that a priori account for animal decision behavior, we adopt an inductive definition of economic behavior in terms of the contribution of individual cognitive capacities to the provision of resources within an exchange structure. We spell out to what extent non-human primates' individual and strategic decision behaviors are shared with humans. We focus on the ability to trade, through barter or token-mediated exchanges, as a landmark of an economic system among members of the same species. It is an open question why only humans have reached a high level of economic sophistication. While primates have many of the necessary cognitive abilities (symbolic and computational) in isolation, one plausible issue we identify is the limits in exerting cognitive control to combine several sources of information. The difference between human and non-human primates' economies might well then be in degree rather than kind.

Innovative problem solving in great apes: the role of visual feedback in the floating peanut task

Nonhuman great apes show remarkable behavioural flexibility. Some individuals are even able to use water as a tool: They spit water into a vertical tube to make a peanut float upwards until it comes into reach (floating peanut task; FPT). In the current study, we used the FPT to investigate how visual feedback, an end-state demonstration and a social demonstration affect task performance in nonhuman great apes in three experiments. Our results indicate that apes who had acquired the solution with a clear tube maintained it with an opaque one. However, apes starting with an opaque tube failed to solve the task. Additionally, facing the peanut floating on a water-filled tube (i.e., an end-state demonstration) promoted success independent on the availability of visual feedback. Moreover, experiencing how water was poured into the tube either by a human demonstrator or by a water tap that had been opened either by the ape or a human did not seem to be of further assistance. First, this study suggests that great apes require visual feedback for solving the FPT, which is no longer required after the initial acquisition. Second, some subjects benefit from encountering the end-state, a finding corroborating previous studies.

Long-Term Memory of Past Events in Great Apes

It has been claimed that the ability to recall personal past events is uniquely human. We review recent evidence that great apes can remember specific events for long periods of time, spanning months and even years, and that such memories can be enhanced by distinctiveness (irrespective of reinforcement) and follow a forgetting curve similar to that in humans. Moreover, recall is enhanced when apes are presented with features that are diagnostic of the event, consistent with notions of encoding specificity and cue overload in human memory. These findings are also consistent with the involuntary retrieval of past events in humans, a mode of remembering that is thought to be less cognitively demanding than voluntary retrieval. Taken together, these findings reveal further similarities between the way humans and animals remember past events and open new avenues of research on long-term memory in nonhuman animals.

The dynamics of episodic memory functions

There is no doubt that episodic memory serves communicative functions, but Mahr & Csibra (M&C) overlook that this is not the only function served by memories of past events. Autobiographical memory research has identified several other functions, including purely directive functions. The functionality of episodic memory is not stable across situations; it varies dynamically with the demands of the retrieval context.