Tefillin shel rosh are placed on the head, above the brain, to signify that all your decisions are made under divine influence.
The Mystery of tefillin
Tefillin - Wikipedia
Probing the Earliest Origins of Tefillin (phylacteries) Part I
The Symbolism of Tefillin Shel Rosh - Meaning of Tefillin
Tefillin - Wikipedia
The Spiritual Power Of The Tefilin: A Symbol Of Devotion And Faith
Synagogue to host program on tefillin
Touring Tefillin - Divrei Derech
Tefillin - Australia
Probing the Earliest Origins of Tefillin (phylacteries) Part I
halacha - Cylindrical Tefillin - Mi Yodeya
YK's Sofer Blog - Jewish Scribe - לבלר סופר: The Tefillin's Four