**4. Discussion**

#### **4.1 Neurophysiological markers for academic underachievement**

Most people believe that academic underachievement is caused by low intelligence, motivation, or social background [22–24]. This view fails to explain the substantial proportion of extremely bright, driven, and affluent individuals who display academic underachievement. Academic underachievement has long been hypothesized to be caused by inter-individual variations in preferred learning styles (such as auditory vs. visual learning). For instance, it has been demonstrated that in a first-year chemistry course at an Australian institution, introverted Myers-Briggs Personality Type students outperform extroverted students [25]. Students with reflective personalities and visual learning style are reported to have the best academic performance in an ophthalmology course for fifth-year students in a Chilean medical school [26]. Although learning style preferences are hard to measure, most curricula demand that students successfully use a variety of learning methods [25].

To date, research on optimizing academic performance has encountered an inability to translate what is known about learning style preferences to how effectively students use the critical nodes and hubs in their cerebral cortex for learning. This

barrier to learning outcomes research has been effectively overcome by the advent of computer-based technologies for measuring electrical and metabolic functions of the cerebral cortex such as qEEG, functional MRI (fMRI), and psychometric testing. While fMRI provides information about metabolic activity in the brain, quantitative qEEG is primarily a measure of electrical activity. Due to the tight coupling between metabolic and electrical signals in the brain [27], each can be thought of as a surrogate for the other. In that context, an inexpensive qEEG record can be useful as a surrogate for a very expensive fMRI recording [28]. qEEG has been validated by the US Food & Drug Administration as a medical device and diagnostic method for identifying children diagnosed with attention deficit disorder (ADD) and attention deficit hyperactivity disorder (ADHD) syndromes (FDA News Release July 15, 2013). qEEG has also been shown to be useful in selecting children and adults who are likely to respond to psychostimulant treatment [11–13]. qEEG is also increasingly used for neurofeedback training in sports and academia. qEEG profiles indicative of improved athletic performance in major league baseball players [29], and Olympic athletes with performance decline following injury have been reported [14]. qEEG-based neurofeedback training has also been shown to be effective in improving the neurosurgery skills of ophthalmic microsurgeons [15]. A relatively specific qEEG signature indicates working memory deficits in low-achieving high school students, compared with high-achieving students [16]. Specific changes in qEEG, indicating increased brain performance, also as a result of certain yoga practices [17, 18] suggest the ability of yoga training to produce improvements in academic performance.
