“…The electrodes were attached to an Amphenol 223-21-05 connector (with Amphenol 220-P01 pins) which was firmly cemented to the skull. During recording, the connector was attached to a lead-in cable by an Amphenol 223-22-05 connector (with Amphenol 220-S01 pins), which led to a swivel system described in detail elsewhere (Dixon, de Toledo, & Black, 1969), and then to a Grass Model 7 polygraph.…”