[Purpose] This study used radiography measurements and brain wave analysis to examine the correlations between the forward head posture (FHP) of the neck, the range of motion of cervicospinal area, and neurological measures of mental rest, and concentration of college students in their 20s. [Subjects] The subjects of this study were 22 college students (10 males, 12 females) in their 20s. [Methods] The cervical lordosis angle, FHP, and the flexion and extension angles of the cervicospinal area were analyzed from lateral view radiographs, and mental rest and concentration of the brain were measured with a neuro-feedback device. [Results] A higher absolute rotation angle (ARA) was associated with lower anterior weight bearing (AWB) and greater range of flexion and extension motions (RFEM). A higher AWB was associated with a lower RFEM and mental resting state score. Positive correlations were found between increased range of motion of the cervicospinal area and the mental resting state score and between increased RFEM and mental concentration score. [Conclusion] The FHP decreases the range of motion of the cervicospinal area, and this biomechanical problem negatively influences the mental resting state and concentration.