It has further been shown that: ( 1 ) an experimental neurosis in its initial stages is associated with a reversible shift in the central autonomic balance ; ( 2 ) drugs altering the hypothalamic balance alter conditioned reactions ; ( 3 ) in a state of depression , the positive conditioned stimulus may fail to elicit a conditioned reaction but cause an increased synchrony instead of the excitatory desynchronizing ( alerting ) effect on the EEG .