INSIGHT, A Comprehensive, Multidisciplinary Brain Training System — INSIGHT  

Cognitive Ability, General Clinical Trial

Official title: An Integrative System for Enhancing Fluid Intelligence (Gf) Through Human Cognitive Activity, Fitness, High-definition Transcranial Direct-current Brain Stimulation (HD-tDCS), and Nutritional Intervention

Status Completed

Clinical Trial Summary

Adaptive reasoning and problem-solving are critical skills that allow for accurate decisions to be made based on varying levels of information. In many situations these decisions must be made and communicated under stressful, time-sensitive conditions. In such contexts, an ability to apply inductive and deductive reasoning to complex, ambiguous, and/or novel problems is critical. The objective of the INSIGHT project is to establish a comprehensive and rigorous brain training protocol to significantly improve adaptive reasoning and problem solving. We will examine a variety of interventions (cognitive training, physical fitness training, physiological stimulation, , and combinations thereof) to assess their ability to improve adaptive reasoning and problem solving abilities. Multimodal interventions are hypothesized to act synergistically to significantly enhance fluid intelligence (Gf) and underlying brain structure and function.

Clinical Trial Description

Recent innovations in cognitive neuroscience have advanced understanding of the neurobiological foundations of fluid intelligence (Gf) and adaptive reasoning and problem solving (ARP). Rather than engaging a single brain structure (e.g., prefrontal cortex) or operating at a fixed level of performance throughout adulthood, emerging neuroscience evidence indicates that Gf and ARP are mediated by a distributed neural system whose functions can be significantly enhanced by specific types of interventions, including cognitive training, high-definition transcranial direct-current brain stimulation (HD-tDCS), and physical fitness training. The main objective of the INSIGHT project is to establish and validate a comprehensive and rigorous brain training protocol that incorporates the best available interventions for the enhancement of Gf and ARP.

The project was divided into two phases, with the first occurring in February -November 2014 and the second occurring February - December 2015. The two phases were similar in structure and goals/hypotheses, but had several methodological differences in terms of interventions, arms, and outcome measures. This document contains information pertinent to only the 2014 phase, which examined the relative contributions of physical fitness intervention, video-game based training, and high-definition transcranial direct-current brain stimulation (HD-tDCS) to the improvement of Gf/ARP, executive function, working memory, relational memory, physical fitness level, and brain structure/function.

Arms/groups completed 1 week of testing to establish baseline measurements of cognitive abilities, physical fitness, and brain structure/function. 16 weeks of various intervention protocols. These protocols could include single or multiple intervention type(s) with varying schedules. Three 70-min training sessions were completed per week, so all arms completed 56 hours of training, total. Following completion of the intervention period was 1 week of post-assessment to measure changes in cognitive abilities, physical fitness, and brain structure/function.

Technical Justification for Physical Fitness Intervention: The beneficial effects of physical fitness on cognitive performance and brain health have been documented in many studies. For example, this literature suggests that increased exercise leads to the birth of new neurons in the hippocampus (a key brain region underlying Gf), increased connections among neurons throughout the brain, the development of new vasculature structure, increased production of neurotrophic proteins, enhanced learning and memory, and enhanced executive control including attention and inhibition, working memory, mental flexibility, and action monitoring. In particular, (1) exercise effects are largest for tasks that involve executive control functions for working memory, planning, and problem solving - abilities that are essential for Gf and ARP; and (2) aerobic exercise training, when combined with strength and flexibility training, had a greater positive effect on cognition compared to exercise training programs that included only aerobic components. Such findings provide important justification for the physical activity intervention proposed here. Hence, the proposed fitness intervention employs a combined aerobic/resistance training program to further enhance the benefits of cognitive training on Gf and ARP.

Technical Justification for Video Game-Based Training: Training on five cognitive skills - (1) processing speed, (2) attention, (3) working memory, (4) relational memory, and (5) cognitive flexibility - has been shown to provide promising transfer results to Gf and other relevant constructs. This training regime is the basis for the design of the Mind Frontiers software platform. Mind Frontiers includes an integrated suite of mini-games that are designed to train these five core cognitive skills. The mechanics, as abstractions of the cognitive exercises, ensure that the scientific integrity and the training effect of the exercises are preserved, but the exercises are implemented as games with motivational features and adaptive difficulty.

Technical justification for HD-tDCS: It has been hypothesized that Gf and ARP are critically dependent on a fronto-parietal brain network, and thus that bilateral, specific stimulation of the frontal cortex with high definition transcranial direct current stimulation (HD-tDCS) would have an excitatory effect on neurons within that network, making them more likely to fire, and thereby enabling faster learning and facilitating transfer to Gf.

Technical Justification for Active Control: Change detection and visual search tasks were selected as the active control tasks because previous work had indicated that training low-level perceptual abilities did not transfer to Gf and ARP. ;

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Investigator, Outcomes Assessor)

Related Conditions & MeSH terms

• Cognitive Ability, General

• NCT number: NCT02780739
• Study type: Interventional
• Source: University of Illinois at Urbana-Champaign
• Status: Completed
• Phase: N/A
• Start date: March 2014
• Completion date: November 2014