Obesity and insulin resistance are associated with reduced activity in core memory regions of the brain

Increasing research in animals and humans suggests that obesity may be associated with learning and memory deficits, and in particular with reductions in episodic memory. Rodent models have implicated the hippocampus in obesity-related memory impairments, but the neural mechanisms underlying episodic memory deficits in obese humans remain undetermined. In the present study, lean and obese human participants were scanned using fMRI while completing a What-Where-When episodic memory test (the “Treasure-Hunt Task”) that assessed the ability to remember integrated item, spatial, and temporal details of previously encoded complex events. In lean participants, the Treasure-Hunt task elicited significant activity in regions of the brain known to be important for recollecting episodic memories, such as the hippocampus, angular gyrus, and dorsolateral prefrontal cortex. Both obesity and insulin resistance were associated with significantly reduced functional activity throughout the core recollection network. These findings indicate that obesity is associated with reduced functional activity in core brain areas supporting episodic memory and that insulin resistance may be a key player in this association.This study was funded by an MRC Centenary Early Career Award to LGC and a James S. McDonnell Foundation Scholar Award to JSS. LGC was funded by the Sarah Woodhead Research Fellowship at Girton College Cambridge. NSC was funded by an Experimental Psychology Society Mid-Career Award and the ERC

Evaluating object permanence in embodied agents using the animal-AI environment

This is the final version. Available from CEUR Workshop Proceedings via the URL in this record. Object permanence, the understanding and belief that objects continue to exist even when they are not directly observable, is important for any agent interacting with the world. Psychologists have been studying object permanence in animals for at least 50 years, and in humans for almost 50 more. In this paper, we apply the methodologies from psychology and cognitive science to present a novel testbed for evaluating whether artificial agents have object permanence. Built in the Animal-AI environment, Object-Permanence In Animal-Ai: GEneralisable Test Suites (O-PIAAGETS) improves on other benchmarks for assessing object permanence in terms of both size and validity. We discuss the layout of O-PIAAGETS and how it can be used to robustly evaluate OP in embodied agents.Future of Life Institute (FLI)European Union’s Horizon 2020DARPAEconomic and Social Research Counci

Corvid Re-Caching without ‘Theory of Mind’: A Model

Scrub jays are thought to use many tactics to protect their caches. For instance, they predominantly bury food far away from conspecifics, and if they must cache while being watched, they often re-cache their worms later, once they are in private. Two explanations have been offered for such observations, and they are intensely debated. First, the birds may reason about their competitors' mental states, with a ‘theory of mind’; alternatively, they may apply behavioral rules learned in daily life. Although this second hypothesis is cognitively simpler, it does seem to require a different, ad-hoc behavioral rule for every caching and re-caching pattern exhibited by the birds. Our new theory avoids this drawback by explaining a large variety of patterns as side-effects of stress and the resulting memory errors. Inspired by experimental data, we assume that re-caching is not motivated by a deliberate effort to safeguard specific caches from theft, but by a general desire to cache more. This desire is brought on by stress, which is determined by the presence and dominance of onlookers, and by unsuccessful recovery attempts. We study this theory in two experiments similar to those done with real birds with a kind of ‘virtual bird’, whose behavior depends on a set of basic assumptions about corvid cognition, and a well-established model of human memory. Our results show that the ‘virtual bird’ acts as the real birds did; its re-caching reflects whether it has been watched, how dominant its onlooker was, and how close to that onlooker it has cached. This happens even though it cannot attribute mental states, and it has only a single behavioral rule assumed to be previously learned. Thus, our simulations indicate that corvid re-caching can be explained without sophisticated social cognition. Given our specific predictions, our theory can easily be tested empirically

What is the Role of Episodic Foresight in Planning for Future needs? Theory and two experiments.

Considerable evidence suggests that episodic memory and foresight rely on the same underlying cognitive processes. Some theorists have suggested that the key role of episodic foresight is to allow an individual to disengage from current states to plan for future needs. However, the contribution of episodic cognition to this type of planning has not been investigated. We present two experiments exploring future-state planning in 3-6 year old children and healthy young adults, finding that both groups were consistently biased towards current states. We further found that there were few relationships between episodic memory ability and future-state planning. Where there was a relationship, the degree of bias was positively related to episodic memory ability, such that those with better episodic were more biased by their current motivational state. These findings are consistent with previous research suggesting that episodic cognition is particularly vulnerable to bias from current feelings. We propose an account in which episodic cognition allows for cross-talk between current and future motivational states, and that while this can aid prospective decision making in some scenarios, it may hinder it in others.MRC doctoral training grant, Girton college Sarah Woodhead Junior Research Fellowship, ERC Advanced Investigator Gran

Western scrub-jays (Aphelocoma californica) solve multiple-string problems by the spatial relation of string and reward.

String-pulling is a widely used paradigm in animal cognition research to assess what animals understand about the functionality of strings as a means to obtain an out-of-reach reward. This study aimed to systematically investigate what rules Western scrub-jays (Aphelocoma californica) use to solve different patterned string tasks, i.e. tasks in which subjects have to choose between two or more strings of which only one is connected to the reward, or where one is more efficient. Arranging strings in a parallel configuration showed that the jays were generally capable of solving multiple-string tasks and acted in a goal-directed manner. The slanted and crossed configurations revealed a reliance on a "proximity rule", that is, a tendency to choose the string-end closest to the reward. When confronted with strings of different lengths attached to rewards at different distances the birds chose according to the reward distance, preferring the reward closest to them, and were sensitive to the movement of the reward, but did not consistently prefer the shorter and therefore more efficient string. Generally, the scrub-jays were successful in tasks where the reward was closest to the string-ends they needed to pull or when string length and reward distance correlated, but the birds had problems when the wrong string-end was closest to the reward or when the food items were in close proximity to each other. These results show that scrub-jays had a partial understanding of the physical principles underlying string-pulling but relied on simpler strategies such as the proximity rule to solve the tasks.University of Cambridge, Biotechnology and Biological Sciences Research Council, Cambridge Home, European Union Scholarship Scheme (CHESS), German National Academic FoundationThis is the final version of the article. It first appeared from Springer via http://dx.doi.org/10.1007/s10071-016-1018-

Research data supporting "Obesity and Insulin Resistance are Associated with Reduced Activity in Core Memory Regions of the Brain"

These are the behavioural results, bloods and betas from peak voxels during different tasks

The development of support intuitions and object causality in juvenile Eurasian jays (Garrulus glandarius\textit{Garrulus glandarius})

Knowledge about the causal relationship between objects has been studied extensively in human infants, and more recently in adult animals using differential looking time experiments. How knowledge about object support develops in non-human animals has yet to be explored. Here, we studied the ontogeny of support relations in Eurasian jays ($\textit{Garrulus glandarius}$), a bird species known for its sophisticated cognitive abilities. Using an expectancy violation paradigm, we measured looking time responses to possible and impossible video and image stimuli. We also controlled for experience with different support types to determine whether the emergence of support intuitions is dependent upon specific interactions with objects, or if reasoning develops independently. At age 9 months, birds looked more at a tool moving a piece of cheese that was not in contact than one that was in direct contact. By the age of 6 months, birds that had not experienced string as a support to hold up objects looked more at impossible images with string hanging from below (unsupported), rather than above (supported). The development of support intuitions may be independent of direct experience with specific support, or knowledge gained from interactions with other objects may be generalised across contexts.European Research Council under the European Union’s Seventh Framework Programme (FP7/2007–2013)/ERC Grant Agreement No. 339993