There is substantial interest in identifying the behavioral means by which to improve cognitive performance. Recent research and commercial ventures have focused on cognitive training interventions, but evidence suggests that the effects of these programs are small and task-specific. Researchers have also shown interest in exploring the potential benefits of physical activity for cognitive performance. Because the effects of physical activity have been found to be small to moderate and to be more global in nature, interest in physical activity has been growing over the past several decades. Evidence regarding the efficacy of physical activity is provided through cross-sectional studies, longitudinal prospective studies, and randomized controlled trials. When reviewed meta-analytically, small-to-moderate beneficial effects are reported for children, adults, older adults, and cognitively impaired older adults, and these effects are evident for a wide range of cognitive domains, including executive function, memory, and information processing. Researchers are currently focused on identifying the mechanisms of these effects. Most of this research has been conducted using animal models, but there is a growing body of literature with humans. From this evidence, there is support for the role of changes in cerebral structure, hippocampal perfusion, and growth factors in explaining the observed benefits. Thus far, however, the literature is quite sparse, and future research is needed to clarify our understanding of the mechanisms that provide the causal link between physical activity and cognitive performance. Research is also focused on understanding how to increase the benefits by potentially combining cognitive training with physical activity and by identifying the genetic moderators of the effects. These lines of work are designed to elucidate ways of increasing the magnitude of the benefits that can be obtained. At this point in time, the evidence with respect to the potential of physical activity for benefiting cognitive performance is quite promising, but it is critical that funding agencies commit their support to the continued exploration necessary to allow us to ultimately be able to prescribe physical activity to specific individuals with the express purpose of improving cognition.
Jennifer L. Etnier
Laurence B. Leonard
Children with specific language impairment (SLI) have a significant deficit in their ability to acquire language that cannot be attributed to intellectual disability, neurological damage, hearing loss, or a diagnosis of autism. These deficits can be long-standing, and adversely affect other aspects of the affected individual’s life. There seems to be a genetic component to SLI, but the disorder is not likely to be traced to a single gene. The problem appears to be universal, but symptoms vary depending on the language being learned. Current attempts to account for SLI have increased our understanding of the most salient symptoms of the disorder, but a full understanding of SLI is not yet within reach.
DeMond M. Grant and Evan J. White
Cognitive control is the ability to direct attention and cognitive resources toward achieving one’s goals. However, research indicates that anxiety biases multiple cognitive processes, including cognitive control. This occurs in part because anxiety leads to excessive processing of threatening stimuli at the expense of ongoing activities. This enhanced processing of threat interferes with several cognitive processes, which includes how individuals view and respond to their environment. Specifically, research indicates that anxious individuals devote their attention toward threat when considering both early, automatic processes and later, sustained attention. In addition, anxiety has negative effects on working memory, which involves the ability to hold and manipulate information in one’s consciousness. Anxiety has been found to decrease the resources necessary for effective working memory performance, as well as increase the likelihood of negative information entering working memory. Finally, anxiety is characterized by focusing excessive attention on mistakes, and there is also a reduction in the cognitive control resources necessary to correct behavior. Enhancing our knowledge of how anxiety affects cognitive control has broad implications for understanding the development of anxiety disorders, as well as emerging treatments for these conditions.
Robin I. M. Dunbar
Primate societies are unusually complex compared to those of other animals, and the need to manage such complexity is the main explanation for the fact that primates have unusually large brains. Primate sociality is based on bonded relationships that underpin coalitions, which in turn are designed to buffer individuals against the social stresses of living in large, stable groups. This is reflected in a correlation between social group size and neocortex size in primates (but not other species of animals), commonly known as the social brain hypothesis, although this relationship itself is the outcome of an underlying relationship between brain size and behavioral complexity. The relationship between brain size and group size is mediated, in humans at least, by mentalizing skills. Neuropsychologically, these are all associated with the size of units within the theory of mind network (linking prefrontal cortex and temporal lobe units). In addition, primate sociality involves a dual-process mechanism whereby the endorphin system provides a psychopharmacological platform off which the cognitive component is then built. This article considers the implications of these findings for the evolution of human cognition over the course of hominin evolution.