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.

"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.

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.

Regular Exercise Enhances Task-Based Industriousness in Laboratory Rats.

Individuals vary greatly in their willingness to select and persist in effortful tasks, even when high-effort will knowingly result in high-reward. Individuals who select and successively complete effortful, goal-directed tasks can be described as industrious. Trying to increase one's industriousness is desirable from a productivity standpoint, yet intrinsically challenging given that effort expenditure is generally aversive. Here we show that in laboratory rats, a basic physical exercise regimen (20 min/day, five days/week) is sufficient to increase industriousness across a battery of subsequent testing tasks. Exercised rats outperformed their non-exercised counterparts in tasks designed to tax effort expenditure, strategic decision-making, problem solving and persistence. These increases in performance led to quicker reward obtainment and greater reward gain over time, and could not be accounted for simply by increased locomotor activity. Our results suggest that a basic exercise regimen can enhance effortful goal-directed behaviour in goal-directed tasks, which highlights a potential productivity benefit of staying physically active.