the left ventricular aneurysm is one of the most significant complications of myocardial infarction and is defined as the expansion of the ventricular wall. the coronary artery aneurysm is characterized by an abnormal dilation of the localized portion of the coronary artery, and its main cause is atherosclerosis. we herein report an unusual case of coronary artery and left ventricular aneurysms...

Introduction: Stress is a main factor influencing brain functions as revealed by the electroencephalogram (EEG) recordings. Moreover, different stress durations seemingly cause perturbations in brain waves and lead to mental disorders. This study investigates the effects of acute, sub-chronic and chronic stress on EEG in rats.  Methods: Twenty-eight Wistar adult male rats were randomly all...

OBJECTIVE Previous studies have been inconclusive whether dominant resting state alpha rhythms are greater or lower in amplitude in subjects with Down syndrome (DS) when compared to control subjects, ample resting alpha rhythms being considered as a reflection of good mechanisms of cortical neural synchronization. Here we tested the hypothesis that when the effects of head volume conduction are...

Imperceptible transcranial alternating current stimulation (tACS) changes the endogenous cortical oscillatory activity in a frequency-specific manner. In the human motor system, tACS coincident with the idling beta rhythm of the quiescent motor cortex increased the corticospinal output. We reasoned that changing the initial state of the brain (i.e., from quiescence to a motor imagery task that ...

Our perceptions are shaped by both extrinsic stimuli and intrinsic interpretation. The perceptual experience of a simple rhythm, for example, depends upon its metrical interpretation (where one hears the beat). Such interpretation can be altered at will, providing a model to study the interaction of endogenous and exogenous influences in the cognitive organization of perception. Using magnetoen...

Hans Berger (1873 – 1941) the German psychiatrist invented electroencephalography (EEG) for the recording of "brain waves" in 1924. He did this by measuring electrical activity in the brains of hospital patients with skull damage. He documented these alpha waves along with beta activity. He found that when alpha waves decrease and beta activity becomes dominant, we are fully awake. As he was th...

There are a number of difference brainwave frequencies which relate to different states of arousal. These frequencies are presented in Table 1 below. Individuals with AD/HD tend to experience mental wandering, often drifting in their thoughts, and are unable to centralise their attention or grasp information. This occurs during attentional tasks such as reading or listening to a story. During s...