Binaural Beat Effects on Attention: A Study Based on the Oddball Paradigm.

The impact of binaural beats (BBs) on human cognition and behavior remains and various methods have been used to measure their effect, including neurophysiological, psychometric, and human performance evaluations. The few approaches where the level of neural synchronicity and connectivity were measured by neuroimaging techniques have only been undertaken in spontaneous mode. The present research proposes an approach based on the oddball paradigm to study BB effect by estimating the level of attention induced by BBs. Evoked activity of 25 young adults between 19 and 24 years old with no hearing impairments nor clinical neurological history were analyzed. The experiment was conducted in two different sessions of 24.5 min. The first part consisted of 20-min BB stimulation in either theta (BBθ) or beta (BBß). After the BB stimulation, an oddball paradigm was applied in each BB condition to assess the attentional effect induced by BBs. Attention enhancement is expected for BBß with respect to BBθ. Target event related potentials (ERPs) were mainly analyzed in the time and time-frequency domains. The frequency analysis was based on continuous wavelet transform (CWT), event-related spectral perturbation (ERSP), and inter-trial phase coherence (ITPC). The study revealed that the P300 component was not significantly different between conditions (BBθ vs. BBß). However, the target grand average ERP in BBθ condition was mainly composed of 8 Hz-frequency components, appearing before 400 ms post-stimulus, and mainly on the centro-parietal regions. In contrast, the target grand average ERP in BBß condition was mainly composed of frequency components below 6 Hz, mainly appearing at 400 ms post-stimulus on the parieto-occipital regions. Furthermore, ERPs in the BBθ condition were more phase locked than the BBß condition.

Influence of Binaural Beats Stimulation of Gamma Frequency over Memory Performance and EEG Spectral Density.

Similar to short-term memory, working memory cannot hold information for a long period of time. Studies have shown that binaural beats (BB) can stimulate the brain through sound, affecting working memory function. Although the literature is not conclusive regarding the effects of BB stimulation (stim) on memory, some studies have shown that gamma-BB stim (40 Hz) can increase attentional focusing and improve visual working memory. To better understand the relationship between BB stim and memory, we collected electroencephalographic data (EEG) from 30 subjects in 3 phases-a baseline, with gamma-BB stim, and control stim-in a rest state, with eyes closed, and while performing memory tasks. Both EEG data and memory task performance were analyzed. The results showed no significant changes in the memory task performance or the EEG data when comparing experimental and control conditions. We concluded that brain entrainment was not achieved with our parameters of gamma-BB stimulation when analyzing EEG power spectral density (PSD) and memory task performance. Hence, we suggest that other aspects of EEG data, such as connectivity and correlations with task performance, should also be analyzed for future studies.

Personalized Theta and Beta Binaural Beats for Brain Entrainment: An Electroencephalographic Analysis.

Binaural beats (BB) consist of two slightly distinct auditory frequencies (one in each ear), which are differentiated with clinical electroencephalographic (EEG) bandwidths, namely, delta, theta, alpha, beta, or gamma. This auditory stimulation has been widely used to module brain rhythms and thus inducing the mental condition associated with the EEG bandwidth in use. The aim of this research was to investigate whether personalized BB (specifically those within theta and beta EEG bands) improve brain entrainment. Personalized BB consisted of pure tones with a carrier tone of 500 Hz in the left ear together with an adjustable frequency in the right ear that was defined for theta BB (since f c for theta EEG band was 4.60 Hz ± 0.70 SD) and beta BB (since f c for beta EEG band was 18.42 Hz ± 2.82 SD). The adjustable frequencies were estimated for each participant in accordance with their heart rate by applying the Brain-Body Coupling Theorem postulated by Klimesch. To achieve this aim, 20 healthy volunteers were stimulated with their personalized theta and beta BB for 20 min and their EEG signals were collected with 22 channels. EEG analysis was based on the comparison of power spectral density among three mental conditions: (1) theta BB stimulation, (2) beta BB stimulation, and (3) resting state. Results showed larger absolute power differences for both BB stimulation sessions than resting state on bilateral temporal and parietal regions. This power change seems to be related to auditory perception and sound location. However, no significant differences were found between theta and beta BB sessions when it was expected to achieve different brain entrainments, since theta and beta BB induce relaxation and readiness, respectively. In addition, relative power analysis (theta BB/resting state) revealed alpha band desynchronization in the parieto-occipital region when volunteers listened to theta BB, suggesting that participants felt uncomfortable. In conclusion, neural resynchronization was met with both personalized theta and beta BB, but no different mental conditions seemed to be achieved.

Manejo odontológico del paciente con parálisis cerebral infantil por medio de los sonidos binaurales

El objetivo más importante de la investigación fue demostrar la eficacia de los sonidos binaurales en la consulta dental como técnica actual para disminuir la ansiedad de los pacientes con parálisis cerebral infantil, así como comprobar que el entorno odontológico genera temor en los pacientes pediátricos. Por medio de un oxímetro de pulso, un aparato reproductor mp3 y auriculares, se logró cuantificar las pulsaciones cardíacas durante tres momentos a lo largo de la investigación. Se valoraron las historias médicas de cada uno de los niños del Hogar Divina Misericordia, así como los medicamentos que consumen diariamente y las enfermedades asociadas a la parálisis cerebral. Se observaron diversos tipos de reacciones al utilizar cada uno de los sonidos, desde el llanto y enojo hasta conseguir la tranquilidad y alegría en los pacientes. Finalmente los resultados revelan los beneficios y la veracidad de los sonidos binaurales mientras que, por el contrario, se expone a los sonidos del ambiente odontológico como un método distractor y desfavorable durante las visitas dentales.

The most important objective of the research was to demonstrate the efficiency of binaural beats in the dental consultant as a current technique to reduce anxiety in child patients with cerebral palsy, also prove that the dental environment generates fear in pediatric patients. To achieve quantify the heartbeats of the children during three different moments throughout the investigation, we used fingertip pulse oximeter, a mp3 player and headphones. We evaluate the medical histories of each children from Hogar Divina Misericordia, as well the medicines they consume daily and diseases related with cerebral palsy. We observed different types of reactions when using each of the sounds, some cried and got anger until they get relax and happy. Finally the results in this research show the benefits and the veracity of the binaural beats while on the contrary are expose to the sounds of the dental environment as a distracting and unfavorable method during dental visits.