Better together: novel methods for measuring and modeling development of executive function diversity while accounting for unity

IntroductionExecutive functions (EFs) are linked to positive outcomes across the lifespan. Yet, methodological challenges have prevented precise understanding of the developmental trajectory of their organization.MethodsWe introduce novel methods to address challenges for both measuring and modeling EFs using an accelerated longitudinal design with a large, diverse sample of students in middle childhood (N = 1,286; ages 8 to 14). We used eight adaptive assessments hypothesized to measure three EFs, working memory, context monitoring, and interference resolution. We deployed adaptive assessments to equate EF challenge across ages and a data-driven, network analytic approach to reveal the evolving diversity of EFs while simultaneously accounting for their unity.Results and discussionUsing this methodological paradigm shift brought new precision and clarity to the development of these EFs, showing these eight tasks are organized into three stable components by age 10, but refinement of composition of these components continues through at least age 14

The Adolescent Brain : A second window to opportunity

Scientific advances over the past decade have contributed to a much greater understanding of the growth of the human brain from birth to adulthood. Latest evidence illuminates the adolescent brain as a ‘work in progress’, and adolescence as a critical period to build on early investments, offering a second chance for those who have not fared well in early childhood. Neuroscientific research in particular is integral to improving our understanding of the cerebral transformations that take place during this time and how they are influenced by interactions between the evolving adolescent brain and the environment in which it develops. In the field of early childhood development (ECD), neuroscientific evidence featured prominently in galvanizing positive change for children through changes in policy and programming and more of this type of evidence is needed to also provide answers regarding critical intervention junctures and approaches during adolescence. In this compendium, eight experts in adolescent neuroscience and development summarize scientific and programmatic evidence from their work, offering an insight into how to maximize the potential of adolescents during this period of opportunity, but also vulnerability. It builds on the discussions initiated at a one-day symposium entitled The Adolescent Brain: A second window of opportunity, held on 4 May 2016 at UNICEF headquarters in New York. The event brought together specialists to review the state of science related to the adolescent brain, specifically focusing on how to guide future responses to programming and policy and providing directions for research to further advance these aims. The advances and investments made in ECD must be continued for children in their second decade of life. Adolescence is a time of both opportunity and vulnerability. Many problematic and risky behaviours are activated in adolescence, including substance abuse, and behaviours that can lead to sexually transmitted diseases HIV/AIDS, road injuries, drowning and other negative outcomes (Mokdad, 2016). It is a time when mental illness and the incidence of suicide sharply increases (Petroni, Patel and Patton, 2016) and when experiences of bullying, inter-personal violence and exclusion often leave a long-term mark on the individual (Lupien, 2012). The commentaries in this compendium together summarize the state of adolescent neuroscience, reflecting on what is known about positive and negative impacts on brain development, including the effects of poverty, violence, stress, technology, but also socio-emotional learning, meditation, nutrition, counselling and positive relationships. They go beyond the science to discuss its application for maximizing the potential of adolescents. This compendium is designed to encourage further dialogue stimulated by new thinking grounded in adolescent neuroscience research and its application. It aims to challenge readers to bring science to bear on programme interventions and public policies for adolescents. An improved understanding from neuroscience is well-placed to strengthen behavioural evidence and provide a more complete picture of adolescent behaviour and development, while also stimulating fresh thinking and approaches that can be tested

Effects of study task on the neural correlates of source encoding

The present study investigated whether the neural correlates of source memory vary according to study task. Subjects studied visually presented words in one of two background contexts. In each test, subjects made old/new recognition and source memory judgments. In one study test cycle, study words were subjected to animacy judgments, whereas in another cycle the study task required syllable judgments. Functional magnetic resonance imaging (fMRI) was employed to contrast the neural activity elicited by study words that attracted accurate source judgments on the later memory test, as opposed to words for which source judgments were incorrect or for which source information was unavailable. In both tasks, relative to words for which source memory failed, study words that were later assigned to the correct source elicited enhanced activity in ventral extrastriate cortex. In addition to these common effects of subsequent source memory, additional effects were observed that were selective for each study task. The present findings add weight to the proposal that neural activity supporting successful episodic memory encoding is a reflection of both the online processing engaged by an episode as it is experienced, and the demands imposed by the later retrieval task

Posterior parietal cortex and episodic retrieval: Convergent and divergent effects of attention and memory

Functional neuroimaging studies of humans engaged in retrieval from episodic memory have revealed a surprisingly consistent pattern of retrieval-related activity in lateral posterior parietal cortex (PPC). Given the well-established role of lateral PPC in subserving goal-directed and reflexive attention, it has been hypothesized that PPC activation during retrieval reflects the recruitment of parietal attention mechanisms during remembering. Here, we evaluate this hypothesis by considering the anatomical overlap of retrieval and attention effects in lateral PPC. We begin by briefly reviewing the literature implicating dorsal PPC in goal-directed attention and ventral PPC in reflexive attention. We then discuss the pattern of dorsal and ventral PPC activation during episodic retrieval, and conclude with consideration of the degree of anatomical convergence across the two domains. This assessment revealed that predominantly divergent subregions of lateral PPC are engaged during acts of episodic retrieval and during goal-directed and reflexive attention, suggesting that PPC retrieval effects reflect functionally distinct mechanisms from these forms of attention. Although attention must play a role in aspects of retrieval, the data reviewed here suggest that further investigation into the relationship between processes of attention and memory, as well as alternative accounts of PPC contributions to retrieval, is warranted

Differential Medial Temporal Lobe and Parietal Cortical Contributions to Real-world Autobiographical Episodic and Autobiographical Semantic Memory.

Autobiographical remembering can depend on two forms of memory: episodic (event) memory and autobiographical semantic memory (remembering personally relevant semantic knowledge, independent of recalling a specific experience). There is debate about the degree to which the neural signals that support episodic recollection relate to or build upon autobiographical semantic remembering. Pooling data from two fMRI studies of memory for real-world personal events, we investigated whether medial temporal lobe (MTL) and parietal subregions contribute to autobiographical episodic and semantic remembering. During scanning, participants made memory judgments about photograph sequences depicting past events from their life or from others' lives, and indicated whether memory was based on episodic or semantic knowledge. Results revealed several distinct functional patterns: activity in most MTL subregions was selectively associated with autobiographical episodic memory; the hippocampal tail, superior parietal lobule, and intraparietal sulcus were similarly engaged when memory was based on retrieval of an autobiographical episode or autobiographical semantic knowledge; and angular gyrus demonstrated a graded pattern, with activity declining from autobiographical recollection to autobiographical semantic remembering to correct rejections of novel events. Collectively, our data offer insights into MTL and parietal cortex functional organization, and elucidate circuitry that supports different forms of real-world autobiographical memory

Differential Medial Temporal Lobe and Parietal Cortical Contributions to Real-world Autobiographical Episodic and Autobiographical Semantic Memory.

Autobiographical remembering can depend on two forms of memory: episodic (event) memory and autobiographical semantic memory (remembering personally relevant semantic knowledge, independent of recalling a specific experience). There is debate about the degree to which the neural signals that support episodic recollection relate to or build upon autobiographical semantic remembering. Pooling data from two fMRI studies of memory for real-world personal events, we investigated whether medial temporal lobe (MTL) and parietal subregions contribute to autobiographical episodic and semantic remembering. During scanning, participants made memory judgments about photograph sequences depicting past events from their life or from others' lives, and indicated whether memory was based on episodic or semantic knowledge. Results revealed several distinct functional patterns: activity in most MTL subregions was selectively associated with autobiographical episodic memory; the hippocampal tail, superior parietal lobule, and intraparietal sulcus were similarly engaged when memory was based on retrieval of an autobiographical episode or autobiographical semantic knowledge; and angular gyrus demonstrated a graded pattern, with activity declining from autobiographical recollection to autobiographical semantic remembering to correct rejections of novel events. Collectively, our data offer insights into MTL and parietal cortex functional organization, and elucidate circuitry that supports different forms of real-world autobiographical memory