A disjunctive analysis of neonatal approach stimulus prepotence
A disjunctive analysis technique was developed to investigate the relative importance of auditory and visual stimuli in eliciting initial approach and following responses in domestic fowl. 72 Canadian Athens random-bred chicks were tested at 24 or 36 hours post-hatch. A repetitive, tapping tone (4 per sec., 50 msec. duration, 500 Hz) served as the auditory stimulus, and a flickering light (3.5 pps, .8 fcl. intensity) served as the visual stimulus. Results are in agreement with previous reports that chicks of the ages tested respond primarily to auditory stimuli. However, a nonsignificant trend for an age-dependent increase in attractiveness of visual stimuli, with a concomitant decrease in attractiveness of auditory stimuli, was found.