Fixed-interval performance and self-control in infants.
Twenty-six infants, 3 to 23 months old, were trained on fixed-interval schedules ranging from 10 s to 80 s. The operant response was touching an illuminated location on a touch-sensitive screen, and 20 s of cartoon presentation was the reinforcer. The subjects were also trained in a six-phase self-control procedure in which the critical phases involved choice between 20 s of cartoon available after a 0.5-s delay (impulsive choice) and 40 s of cartoon delayed for 40 s (self-controlled choice). All the youngest children (3 to 5 months) showed long postreinforcement pauses on the fixed-interval schedule, with most intervals involving the emission of a single, reinforced, response, and all made self-controlled choices. Older subjects (9 to 23 months) either produced the same pattern as the younger ones on the fixed-interval schedule (classified as pause-sensitive subjects) or produced short pauses and higher steady response rates (classified as pause-insensitive subjects). All pause-sensitive subjects made self-controlled choices in the self-control condition, and all pause-insensitive subjects made impulsive ones.
Darcheville
J C
JC
UFR de Psychologie, Université Charles de Gaulle, Lille III, Villeneuve d'Ascq, France.
Rivière
V
V
Wearden
J H
JH
D001288:Attention; D002755:Choice Behavior; D003216:Conditioning, Operant; D005260:Female; D006801:Humans; D007206:Individuality; D007223:Infant; D007389:Internal-External Control; D007804:Language Development; D008297:Male; D009042:Motivation; D002666:Psychology, Child; D012055:Reinforcement Schedule