▁but ▁Hof ▁and ▁Van ▁Der ▁G ucht ▁believe ▁that ▁they ▁act ▁as ▁some ▁sort ▁of ▁" high - speed ▁connections ▁that ▁fast - track ▁information ▁to ▁and ▁from ▁other ▁parts ▁of ▁the ▁cor tex ". ▁They ▁compared ▁them ▁to ▁express ▁trains ▁that ▁by pass ▁unnecessary ▁connections , ▁en abling ▁organ isms ▁to ▁instantly ▁process ▁and ▁act ▁on ▁emot ional ▁c ues ▁during ▁complex ▁social ▁interactions . ▁ ▁However , ▁Hof ▁and ▁Van ▁Der ▁G ucht ▁clarify ▁that ▁they ▁do ▁not ▁know ▁the ▁nature ▁of ▁such ▁feelings ▁in ▁these ▁animals ▁and ▁that ▁we ▁cannot ▁just ▁apply ▁what ▁we ▁see ▁in ▁great ▁ap es ▁or ▁ourselves ▁to ▁wh ales . ▁ ▁They ▁believe ▁that ▁more ▁work ▁is ▁needed ▁to ▁know ▁whether ▁emot ions ▁are ▁the ▁same ▁for ▁humans ▁and ▁wh ales . ▁ ▁V ocal izations ▁Though ▁non - human ▁animals ▁cannot ▁provide ▁useful ▁ver bal ▁feedback ▁about ▁the ▁exper ient ial ▁and ▁cogn itive ▁details ▁of ▁their ▁feelings , ▁various ▁emot ional ▁vocal izations ▁of ▁other ▁animals ▁may ▁be ▁indic ators ▁of ▁potential ▁affect ive ▁states . ▁Begin ning ▁with ▁Dar win ▁and ▁his ▁research , ▁it ▁has ▁been ▁known ▁that ▁ch imp anze es ▁and ▁other ▁great ▁ap es ▁perform ▁laugh - like ▁vocal izations , ▁providing ▁scient ists ▁with ▁more ▁symbol ic ▁self - re ports ▁of ▁their ▁emot ional ▁experiences . ▁ ▁Research ▁with ▁r ats ▁has ▁revealed ▁that ▁under ▁particular ▁conditions , ▁they ▁emit ▁ 5 0 - k Hz ▁ul tr ason ic ▁voc alis ations ▁( US V