A connection between neurophysiological effects and the sensory system has been established [Burks et al., 1977; Strassman, 1990]. The pineal gland has been shown to respond significantly to acoustic [Burks et al., 1977] and to olfactory [Davidson, 1987, 1988] stimuli. The pineal gland is generally linked to the central homeostasis mechanism.

The pineal, melatonin, and ambient lighting
The melatonin generating system is extremely sensitive to light. Light is the predominant environmental factor regulating its production [Nowak and Zawilska, 1997; Strassman, 1990]. The melatonin production whose levels start to rise gradually at dusk and decline slowly during the second half of the night [Nowak and Zawilska, 1997] is inhibited by white light and has been shown to be also suppressed by moonlight as well [Brainard et al., 1984; Davidson, 1988; Axt, 1989, 1996]. Melatonin production has been shown to be effected differentially by various wavelengths of monochromatic light. The strongest effect has been found to result from green, blue-green light of 509 nm [Brainard et al., 1988, 1994; Strassman, 1990; Korn, 1991; Reiter, 1994; Zawilska et al., 1995, 1996; Nowak and Zawilska, 1997]

The pineal gland and electromagnetic fields
The pineal gland has been shown to be sensitive to magnetic and electromagnetic fields [Foa et al., 1935; Evans, 1986; Davidson, 1987, 1988; Cremer-Bartles et al, 1990; Lerchl et al., 1991; Mishlove, 1993; Roney-Dougal, 1993; Reiter, 1995; Pawlicki, 1996]. It has also been shown to be sensitive to geomagnetic activity [Roney-Dougal, 1993; Spottiswoode, 1990]. Extremely low frequency electromagnetic fields have been shown to reduce nocturnal melatonin production [Reiter, 1994]. The sensitivity of the pineal gland to electromagnetic fields might explain the influence of energy bodywork techniques on the pineal system [Axt, 1989, 1996]. This subject will be discussed later in this paper.

The pineal gland and trauma
Emotional or physical trauma can cause disruption of the function of the pineal gland [Grad et al., 1970; Miline et al., 1970; Shaffi et al., 1990; Upledger, 1996; Korn, 1997]. Attachment traumas and abandonment issues in early life have been shown to result in low levels of melatonin production. As has been mentioned previously, the pineal gland and melatonin control the hormonal cues for touching and cuddling [Reiter, 1995].