title: Effects of brief time delays on matching-to-sample abilities in capuchin monkeys (Sapajus spp.).
abstract: Traditionally, studies of delayed matching-to-sample (DMTS) tasks in nonhuman species have focused on the assessment of the limits of the retrieval of information stored in short- and long-term memory systems. However, it is still unclear if visual recognition in these tasks is affected by very brief delay intervals, which are typically used to study rapidly decaying types of visual memory. This study aimed at evaluating if tufted capuchin monkeys' ability to recognise visual stimuli in a DMTS task is affected by (i) the disappearance of the sample stimulus and (ii) the introduction of delay intervals (0.5, 1.0, 2.0 and 3.0s) between the disappearance of the sample and the presentation of the comparison stimuli. The results demonstrated that the simple disappearance of the sample and the introduction of a delay of 0.5s did not affect capuchins' performance either in terms of accuracy or response time. A delay interval of 1.0s produced a significant increase in response time but still did not affect recognition accuracy. By contrast, delays of 2.0 and 3.0s determined a significant increase in response time and a reduction in recognition accuracy. These findings indicate the existence in capuchin monkeys of processes enabling a very accurate retention of stimulus features within time frames comparable to those reported for humans' sensory memory (0.5-1.0s). The extent to which such processes can be considered analogous to the sensory memory processes observed in human visual cognition is discussed.
authors.affiliation: Institute of Cognitive Sciences and Technologies, National Research Council (CNR), Via Ulisse Aldrovandi 16/B, 00197 Rome, Italy. Electronic address: valentina.truppa@istc.cnr.it.
authors.forename: Valentina
authors.initials: V
authors.lastname: Truppa
authors.affiliation: Institute of Cognitive Sciences and Technologies, National Research Council (CNR), Via Ulisse Aldrovandi 16/B, 00197 Rome, Italy; Department of Philosophy, Sapienza University of Rome, Via Carlo Fea 2, 00161 Rome, Italy. Electronic address: diegoantonio.desimone@gmail.com.
authors.forename: Diego Antonio
authors.initials: DA
authors.lastname: De Simone
authors.affiliation: Institute of Cognitive Sciences and Technologies, National Research Council (CNR), Via Ulisse Aldrovandi 16/B, 00197 Rome, Italy; Department of Neurobiology, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy. Electronic address: eva.pianomortari@gmail.com.
authors.forename: Eva
authors.initials: E
authors.lastname: Piano Mortari
authors.affiliation: School of Psychology, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK. Electronic address: cdl2@leicester.ac.uk.
authors.forename: Carlo
authors.initials: C
authors.lastname: De Lillo
mesh_terms: D000818:Animals; D002428:Cebus / Q000523:psychology*; D003071:Cognition; D003210:Concept Formation; D005260:Female; D008297:Male; D008568:Memory; D010364:Pattern Recognition, Visual; D011930:Reaction Time; D021641:Recognition, Psychology
keywords: Capuchin monkey; Matching-to-sample; Sensory memory; Short-term memory; Visual perception