A spoon full of studies helps the comparison go down: a comparative analysis of Tulving's spoon test

Chimpanzees Predict the Hedonic Outcome of Novel Taste Combinations: The Evolutionary Origins of Affective Forecasting

Affective forecasting–predicting the emotional outcome of never-before experienced situations–is pervasive in our lives. When facing novel situations, we can quickly integrate bits and pieces of prior experiences to envisage possible scenarios and their outcomes, and what these might feel like. Such affective glimpses of the future often steer the decisions we make. By enabling principled decision-making in novel situations, affective forecasting confers the important adaptive advantage of eluding the potentially costly consequences of tackling such situations by trial-and-error. Affective forecasting has been hypothesized as uniquely human, yet, in a recent study we found suggestive evidence of this ability in an orangutan. To test non-verbal subjects, we capitalized on culinary examples of affective forecasting and devised a behavioral test that required the subjects to make predictions about novel juice mixes produced from familiar ingredients. In the present study, we administered the same task to two chimpanzees and found that their performance was comparable to that of the previously tested orangutan and 10 humans, who served as a comparison group. To improve the comparability of human and animal performance, in the present study we also introduced a new approach to assessing if the subjects’ performance was indicative of affective forecasting, which relies exclusively on behavioral data. The results of the study open for the possibility that affective forecasting has evolved in the common ancestor of the great apes, providing Hominids with the adaptive advantage of e.g., quickly evaluating heterogeneous food patches using hedonic prediction.

It is about time: Conceptual and experimental evaluation of the temporal cognitive mechanisms in mental time travel

Mental time travel (MTT) is the ability that allows humans to mentally project themselves backwards in time to remember past events (i.e., episodic memory) or forwards in time to imagine future events (i.e., future thinking). Despite empirical evidence showing that animals might possess MTT abilities, some still claim that this ability is uniquely human. Recent debates have suggested that it is the temporal cognitive mechanism (i.e., ability to represent the sense of past and future) that makes MTT uniquely human. Advances in the field have been constrained by a lack of comparative data, methodological shortcomings that prevent meaningful comparisons, and a lack of clear conceptualizations of the temporal cognitive mechanism. Here I will present a comprehensive review into MTT in humans and animals-with a particular focus on great apes. I will examine three of the most prominent and influential theoretical models of human MTT. Drawing on these accounts, I suggest that a basic way of understanding time might be shared across species, however culture and language will play a critical role at shaping the way we elaborate mental representations about past and future events. This article is categorized under: Cognitive Biology > Evolutionary Roots of Cognition Psychology > Comparative Psychology.

A novel test of flexible planning in relation to executive function and language in young children

In adult humans, decisions involving the choice and use of tools for future events typically require episodic foresight. Previous studies suggest some non-human species are capable of future planning; however, these experiments often cannot fully exclude alternative learning explanations. Here, we used a novel tool-use paradigm aiming to address these critiques to test flexible planning in 3- to 5-year-old children, in relation to executive function and language abilities. In the flexible planning task, children were not verbally cued during testing, single trials avoided consistent exposure to stimulus-reward relationships, and training trials provided experience of a predictable return of reward. Furthermore, unlike most standard developmental studies, we incorporated short delays before and after tool choice. The critical test choice included two tools with equal prior reward experience-each only functional in one apparatus. We tested executive function and language abilities using several standardized tasks. Our results echoed standard developmental research: 4- and 5-year-olds outperformed 3-year-olds on the flexible planning task, and 5-year-old children outperformed younger children in most executive function and language tasks. Flexible planning performance did not correlate with executive function and language performance. This paradigm could be used to investigate flexible planning in a tool-use context in non-human species.

Children's future-oriented cognition

Children's future-oriented cognition has become a well-established area of research over the last decade. Future-oriented cognition encompasses a range of processes, including those involved in conceiving the future, imagining and preparing for future events, and making decisions that will affect how the future unfolds. We consider recent empirical advances in the study of such processes by outlining key findings that have yielded a clearer picture of how future thinking emerges and changes over childhood. Our interest in future thinking stems from a broader interest in temporal cognition, and we argue that a consideration of developmental changes in how children understand and represent time itself provides a valuable framework in which to study future-oriented cognition.

Measuring mental time travel: Is the hippocampus really critical for episodic memory and episodic foresight?

Mental time travel is an adaptive capacity that enables humans to engage in deliberate, prudent action on the basis of remembering past episodes (episodic memory) and simulating future scenarios (episodic foresight). This capacity has become a popular and rapidly growing topic of interdisciplinary research. Perhaps the most influential and frequently tested neuroscientific hypothesis in this domain is that the hippocampus is a hub in a critical neural network for mental time travel, support for which is now commonly assumed by most researchers in the area. In light of recent findings revealing limitations with existing measures of episodic foresight, we critically evaluate the available evidence for this hypothesis and find that it is inconclusive. We suggest that this is due in significant part to the exclusive and widespread reliance on noisy verbal measures and discuss this case as an example of a more general issue pertaining to the measurement of episodic foresight. Accordingly, we suggest that an essential focus of future research should concern the development of objective measures that capture capacity differences by requiring people to put foresight not just into words, but into action.

Thinking about the future: Comparing children's forced-choice versus "generative" responses in the "spoon test"

One of the most popular methods to assess children's foresight is to present children with a problem (e.g., locked box with no key) in one room and then later, in another room, give them the opportunity to select the item (e.g., key) that will solve it. Whether or not children choose the correct item to bring back to the first room is the dependent measure of interest in this "spoon test." Although children as young as 3 or 4 years typically succeed on this test, whether they would pass a more stringent version in which they must verbally generate (vs. select) the correct item in the absence of any cues is unknown. This is an important point given that humans must often make decisions about the future without being explicitly "prompted" by the future-oriented option. In Experiment 1, using an adapted version of the spoon test, we show that as the "generative" requirements of the task increase, 3-, 4-, and 5-year-olds' (N = 99) performance significantly decreases. We replicate this effect in Experiment 2 (N = 48 3-, 4-, and 5-year-olds) and also provide preliminary evidence that the capacity to verbally generate the correct item in a spoon test may draw more heavily on children's category fluency skills than does their capacity to select this item among a set of distracters. Our findings underscore the importance of examining more generative forms of future thought in young children.

Constructive anthropomorphism: a functional evolutionary approach to the study of human-like cognitive mechanisms in animals

Anthropomorphism, the attribution of human cognitive processes and emotional states to animals, is commonly viewed as non-scientific and potentially misleading. This is mainly because apparent similarity to humans can usually be explained by alternative, simpler mechanisms in animals, and because there is no explanatory power in analogies to human phenomena when these phenomena are not well understood. Yet, because it is also difficult to preclude real similarity and continuity in the evolution of humans' and animals' cognitive abilities, it may not be productive to completely ignore our understanding of human behaviour when thinking about animals. Here we propose that in applying a functional approach to the evolution of cognitive mechanisms, human cognition may be used to broaden our theoretical thinking and to generate testable hypotheses. Our goal is not to 'elevate' animals, but rather to find the minimal set of mechanistic principles that may explain 'advanced' cognitive abilities in humans, and consider under what conditions these mechanisms were likely to enhance fitness and to evolve in animals. We illustrate this approach, from relatively simple emotional states, to more advanced mechanisms, involved in planning and decision-making, episodic memory, metacognition, theory of mind, and consciousness.

Future Thinking: Children But Not Apes Consider Multiple Possibilities

When anticipating the future, we draw on our past experience but must take uncertainty into account; for example, while preparing for a trip, we might pack a raincoat and sunglasses because of unpredictable weather. New research shows that the ability to plan for multiple future possibilities may be present in human children from as early as 3-4 years of age, but appears to be lacking in non-human apes.

"What" and "where" was when? Memory for the temporal order of episodic events in children

In the past, researchers have shown that the individual components of episodic memory (i.e "what," "where," and "when") may emerge at different points in development. Specifically, while children as young as three can accurately report the "what" and "where" of an event, they struggle to accurately report when the event occurred. One explanation for children's difficulty in reporting when an event took place is a rudimentary understanding, and ability to use, temporal terms. In the current experiment, we employed a physical timeline to aid children's reporting of the order in which a series of episodic events occurred. Overall, while 4-, 5-, and 6-year olds performed above chance, 3-year olds did not. Our findings suggest that 3-year olds' limited ability to produce temporal terms may not be the rate-limiting step preventing them from identifying when events occurred in their recent past.

Episodic foresight beyond the very next event in 3- and 4-year-old children

Testing episodic foresight in children generally involves presenting them with a problem in one location (e.g., Room A) and, after a spending a delay in a different location, telling them they will be returning to Room A. Before they go, children are presented with a number of items, one of which will allow them to solve the problem in Room A. At around 3 to 4 years of age children display episodic foresight, selecting the item that will allow them to solve the problem. To date, however, no study has assessed whether 3- and 4-year-old children can plan beyond the very next event, selecting the correct item when there is a delay before returning to Room A. Here, we show that 3- and 4-year-old children can pass when a delay is imposed but that their performance is significantly worse than when they are planning for an immediate event.

Zebrafish and relational memory: Could a simple fish be useful for the analysis of biological mechanisms of complex vertebrate learning?

Analysis of the zebrafish allows one to combine two distinct scientific approaches, comparative ethology and neurobehavioral genetics. Furthermore, this species arguably represents an optimal compromise between system complexity and practical simplicity. This mini-review focuses on a complex form of learning, relational learning and memory, in zebrafish. It argues that zebrafish are capable of this type of learning, and it attempts to show how this species may be useful in the analysis of the mechanisms and the evolution of this complex brain function. The review is not intended to be comprehensive. It is a short opinion piece that reflects the author's own biases, and it draws some of its examples from the work coming from his own laboratory. Nevertheless, it is written in the hope that it will persuade those who have not utilized zebrafish and who may be interested in opening their research horizon to this relatively novel but powerful vertebrate research tool.

Too cool? Symbolic but not iconic stimuli impair 4-year-old children's performance on the delay-of-gratification choice paradigm

A common method of improving the performance of children and non-human primates on the delay-of-gratification maintenance paradigm and measures of executive function (e.g., the Less is More task) is to represent the rewards subjects can acquire symbolically. This method, known as symbolic distancing, is thought to lower activation of the "hot" impulsive system and allow the "cool" rational system to dominate processing. Surprisingly, in contrast to its impact on the measures noted above, recent developmental and comparative studies have reported that symbolic distancing has a null or negative impact on performance on the delay-of-gratification choice paradigm. Here, we add to this literature by demonstrating that 4-year-old children's performance on the choice paradigm is impaired when symbolic stimuli, but not iconic stimuli (i.e., pictures of the rewards), are used to represent rewards. These data add to a growing body of comparative work demonstrating task manipulations have a similar impact on children and non-human primates and also support other research suggesting different decision making processes may underlie performance on the delay-of-gratification choice and maintenance paradigms.

Affective forecasting in an orangutan: predicting the hedonic outcome of novel juice mixes

Affective forecasting is an ability that allows the prediction of the hedonic outcome of never-before experienced situations, by mentally recombining elements of prior experiences into possible scenarios, and pre-experiencing what these might feel like. It has been hypothesised that this ability is uniquely human. For example, given prior experience with the ingredients, but in the absence of direct experience with the mixture, only humans are said to be able to predict that lemonade tastes better with sugar than without it. Non-human animals, on the other hand, are claimed to be confined to predicting-exclusively and inflexibly-the outcome of previously experienced situations. Relying on gustatory stimuli, we devised a non-verbal method for assessing affective forecasting and tested comparatively one Sumatran orangutan and ten human participants. Administered as binary choices, the test required the participants to mentally construct novel juice blends from familiar ingredients and to make hedonic predictions concerning the ensuing mixes. The orangutan's performance was within the range of that shown by the humans. Both species made consistent choices that reflected independently measured taste preferences for the stimuli. Statistical models fitted to the data confirmed the predictive accuracy of such a relationship. The orangutan, just like humans, thus seems to have been able to make hedonic predictions concerning never-before experienced events.

Possible evolutionary and developmental mechanisms of mental time travel (and implications for autism)

Through an interdisciplinary perspective integrating behavior, neurobiology and evolution, we present a cognitive framework underpinning the development of 'time in mind' in animals (phylogeny) and humans (ontogeny). We distinguish between conscious processing of events immediately available (in the present) to those that are hypothetical (in the past or future). The former is present in animals and neonates, whereas the latter emerges later in phylogeny and ontogeny (around 4 years of age in humans) and is related to the development of episodic memory (expanded working memory, complex actions, social-cognitive abilities). We suggest that forms of temporal representation that rely upon current bodily sensation across time, space, and action (through embodied interoceptive and motor systems) may be critical causal factors for the evolution of mental time travel.