Rhesus macaques (Macaca mulatta) monitor uncertainty during numerosity judgments.
Two rhesus macaques (Macaca mulatta) judged arrays of dots on a computer screen as having more or fewer dots than a center value that was never presented in trials. After learning a center value, monkeys were given an uncertainty response that let them decline to make the numerosity judgment on that trial. Across center values (3-7), errors occurred most often for sets adjacent in numerosity to the center value. The monkeys also used the uncertainty response most frequently on these difficult trials. A 2nd experiment showed that monkeys' responses reflected numerical magnitude and not the surface-area illumination of the displays. This research shows that monkeys' uncertainty-monitoring capacity extends to the domain of numerical cognition. It also shows monkeys' use of the purest uncertainty response possible, uncontaminated by any secondary motivator.
Beran
Michael J
MJ
Language Research Center, Georgia State University, Atlanta, 30302, USA. mjberan@yahoo.com
Smith
J David
JD
Redford
Joshua S
JS
Washburn
David A
DA
D000818:Animals; D003071:Cognition; D007600:Judgment; D008253:Macaca mulatta / Q000523:psychology*; D008297:Male; D008433:Mathematics; D010364:Pattern Recognition, Visual; D035501:Uncertainty