Ecology dictates the value of memory for foraging bees

Summary“Ecological intelligence” hypotheses posit that the benefits of cognitive investment vary with foraging ecology, and provide a key framework for understanding the evolution of animal learning and memory1–4. However, although certain ecological selection pressures have been found to correlate with brain or neural region size5–8, empirical evidence to show that any specific cognitive trait is useful in certain environments but not others is currently lacking. Here, we assay the short-term memory of bumblebee (Bombus terrestris audax) workers from 25 identically reared colonies, before allowing each colony to forage in a landscape where forage availability varies seasonally. Through analysis of the bees’ lifetime foraging careers, comprising >1700 foraging trips over two years, we show that performance on a task designed to test short-term memory predicts individual foraging efficiency – a fitness proxy that is key to colony reproductive output – in plentiful spring foraging conditions. However, this relationship is reversed during the summer floral dearth, when the costs of cognitive investment may outweigh the benefits. Our results provide evidence that the value of a cognitive trait depends upon the prevailing ecological conditions and suggest that temporal changes in that environment could place contrasting selection pressures on memory within a single species.

Rapid serial blinks: A high time-resolved index of cognitive overload

In recent years, natural viewing settings with video presentation has been used in neurological and psychological experiments. However, the experienced cognitive load may differ among participants. In this study, we show that rapid serial blinks (RSB) can indicate cognitive overload with high temporal resolution. We proposed a method to create a personal criterion for respective participants by using empirical blink intervals. When we focused on more than four serial blinks (i.e., three inter-blink intervals), an increased number of RSB detect participants who felt hard to understanding, indicating a poor understanding of the subject matter. By contrast, a constant criterion across participants used in previous study could not detect participant’s understanding. These results suggest that individual differences in cognitive trait of each participant may skew the results of experiments. To avoid biases, we recommend researchers to perform an operational check on individually different cognitive overloads among experimental groups.

Optimizing Cognitive PerformanceGenetic and Epigenetic Techniques

Optimizing human cognitive performance by genetic and epigenetic means requires consideration of the goal and context of the desired cognitive performance. This chapter considers two examples to illustrate how optimization will depend on deciding what qualities are desired, defining such traits or phenotypes, and then considering the environment in which genes are expressed. The warrior/worrier gene provides a way to explore the alteration of a single gene with simple dominance. The most commonly desired genetic cognitive trait, intelligence, is considered as an example of a multigenic trait. The genetic techniques for optimization of human cognition are described using plasmid introduction, direct gene editing, and genetic alteration of the microbiome. The approval of three medical genetic therapies in 2017 indicates a high probability that genetic enhancement will become possible in less than 20 years.

Maternal effects impact decision-making in a viviparous lizard

Stressful conditions experienced during early development can have deleterious effects on offspring morphology, physiology and behaviour. However, few studies have examined how developmental stress influences an individual's cognitive phenotype. Using a viviparous lizard, we show that the availability of food resources to a mother during gestation influences a key component of her offspring's cognitive phenotype: their decision-making. Offspring from females who experienced low resource availability during gestation did better in an anti-predatory task that relied on spatial associations to guide their decisions, whereas offspring from females who experienced high resource availability during gestation did better in a foraging task that relied on colour associations to inform their decisions. This shows that the prenatal environment can influence decision-making in animals, a cognitive trait with functional implications later in life.

Homo Erectus

This chapter describes Homo erectus and its lifestyle. It made more sophisticated handaxes, controlled fire, and migrated halfway around the world. Cognitively, it is likely that Homo erectus had developed self-awareness, and their brains evolved in areas associated with the cognitive trait.