“…Shortly after Katkin and Murray (1968) concluded that these studies demonstrated" the only convincing evidence of instrumental conditioning of ANS responses independently of possible mediators" (p.65), successful results were reported for a variety of autonomic responses (for review, see Harris & Brady, 1974). The responses most extensively investigated so far have been concerned with cardiovascular functions, among which heart rate has been the most often studied (e. g. Black, 1967;Canabac & Serres, 1976;DiCara & Miller, 1968;Engel & Gottlieb, 1970;Fields, 1970;Hothersall & Brener, 1969;Miller & Di-Cara, 1967;Slaughter, Hahn, & Rinaldi, 1970;Trowill, 1967).…”