**4.3 Evaluating the brain networks involved in facilitating complex learning**

The advent of qEEG and fMRI technologies have led to the discovery of important correlations in the electrical and metabolic profiles between areas of the cerebral cortex considered to be the main nodes and hubs for learning and memory. The key networks are the cingulate, arcuate and uncinate. In this study, the qEEG data were interpreted by measuring, within each of the EEG brain wave bandwidths (beta, alpha, theta, delta), magnitude (electrical power), dominant frequency and coherence between recording sites. We have successfully used alpha and beta coherences to demonstrate correlations between the amount of communication between the cortical tissue in the vicinity of each interhemispheric recording site, a measure of network development, integrity, and function in this same cohort of medical students with apparent attentional dysregulation and academic underachievement [9]. Our study is corroborated by research demonstrating correlations between the brain's executive functions and the frontal theta, alpha and beta interhemispheric coherences of 168 Iranian university students in their twenties [31], as well as by a metanalysis suggesting that the brain's executive function is a positive predictor of academic performance in primary school children [32].

#### **4.4 The cingulate network in complex learning**

The cingulate network is also known as the dorsal pathway for cognition, and activity in this network represents the cerebral cortex's neutral or idling gear. The cingulate network may be the equivalent of a computer's default mode network, involving areas that are operating when a person's eyes are closed and in a state of "day-dreaming" or not involved in deep thought and problem-solving [33]. Linkage of electrical magnitude (voltage), dominant frequency, and coherence in the prefrontal (Fp1, Fp2), frontal (F3, F4, F7, F8), central (C3, Cz, C4), parietal (P3, Pz, P4) and occipital (O1, O2) electrodes is thought to reflect activity of the cingulate default mode network. The cingulate network is named for the anterior and posterior cingulate cortical areas, the anterior involved in high-level information processing of socialization, empathy, outcome/error monitoring and action planning. Error-related negative emotional responses are found to be diminished in individuals with anterior cingulate lesions [34]. The posterior cingulate is linked to interpreting emotional

salience and both the anterior and posterior cingulate have strong connectivity to the insular cortex, the main area for integrating and interpreting interoceptive responses [35]. The cingulate network appears to contain critical nodes and hubs for motivating emotional aspects of learning and memory [36]. Mastery of a lengthy, rigorous medical curriculum may require normal range of electrical activity in the cingulate network to support empathy-motivated and self-corrective learning paradigms. qEEG deviation from the norm in the cingulate network could, therefore, provide a key signature for academic underachievement in a medical curriculum. We have previously reported that right-sided fAA, a measurement of negatively valenced emotions, is positively correlated with negative self-perceptions of the psychosocial interactions among medical students [10]. In this chapter, we show and interpret the qEEG brain maps demonstrating a spectrum of fAA correlating with negative self-perceptions. We also provide the first depiction in the scientific literature of qEEG brain maps from subjects at both ends of an emotional scale from high to low "depressed" ISI score and from high to low nondominant hemispheric, right-sided fAA. These findings should be interpreted cautiously because of a report that there was no correlation between these variables in a robust multiverse analysis of five "clinically depressed" populations [37].

#### **4.5 The hippocampus in complex learning**

The hippocampus is a gray structure in the center of the brain and is necessary for normal learning, memory, mood, and emotion [38]. Learning and memory are also highly dependent on neurogenesis. The adult brain generates new brain cells at the rate of 700 neurons per day in the hippocampus and by the age of 50, humans are thought to exchange the entire population of neurons with which they were born [39]. In adult laboratory animals, blocking brain neurogenesis limits the animal's ability to navigate the environment, a function highly dependent on working memory [40] and blocking neurogenesis also results in depression and the inability of antidepressant medications to work [41]. Brain-derived neurotrophic factor (BDNF) is thought to be the main stimulator of neurogenesis in the human brain [42]. Aerobic exercise, learning and sexual activities, 20%–30% calorie restriction, diets high in flavonoids (e.g., curcumin), resveratrol (e.g., blueberries, grapes, dark chocolate, and red wine), omega-3 fatty acids (e.g., walnuts, fatty fish such as salmon), folic acid and zinc are known to increase BDNF and neurogenesis, whereas diets high in saturated fats, sugars and ethanol, vitamins A, B and E deficiencies, sleep deprivation, stress, aging, inflammation, as well as exposure to high plasma levels of cortisol decrease BDNF and neurogenesis [43]. We have previously shown robust correlations between hippocampal neurogenesis and physical activity, maze learning and environmental enrichment in normal healthy rats, as well as in rats recovering from kainite-induced epileptic seizures [44–46]. The results of these studies support the notion that interventions which increase hippocampal neurogenesis are also likely to increase the cognitive learning and memory functions of the human brain [47]. Studying the effects of hippocampal neurogenesis was beyond the scope of the qEEG studies reviewed herein. However, modafinil, a drug known to stimulate neurogenesis, is reported to decrease qEEG voltage, across all the standard EEG frequencies [48]. This finding of a limitation on qEEG voltage suggests that in the presence of active neurogenesis, we may not be able to observe the large global changes in theta and beta power indicative of the putative improvement in neural plasticity depicted in the (**Figure 1**) brain map from the subject with the highest exam score.

*Quantitative Electroencephalography for Probing Cognitive and Behavioral Functions… DOI: http://dx.doi.org/10.5772/intechopen.107483*
