Sentence:  According to Fraisse (I966), “biogenic motivations," which control adaptive behaviors necessary for survival (<WSD>psychotropisms</WSD>, escape phenomena, aggression, etc), are among the most archaic and involve defense mechanisms that implicate a high degree of vigilance (i.e., so-called states of overarousal). 
Meaning of the word marked with <WSD> tags:  The desire for mental stimulation and knowledge.