Double invisible displacement understanding in orangutans: testing in non-locomotor and locomotor space

Abstract

The nonadjacent double invisible displacement task has been used to test for the ability of different species to mentally represent the unperceived trajectory of an object. The task typically requires three occluders/boxes in a linear array and involves hiding an object in one of two nonadjacent boxes visited in succession. Previous research indicates that 19-, 26-, and 30-month-old children and various nonhuman species cannot solve these displacements. It has been hypothesized that this is because individuals are unable to inhibit searching in the unbaited center box that was never visited by the experimenter. It has been suggested that presenting the task in a large-scale locomotor space might allow individuals to overcome this inhibition problem. In the present study, we tested orangutans on adjacent and nonadjacent double invisible displacements with the traditional setup (experiment 1) and in locomotor space with boxes placed 1.22 m apart (experiment 2). In both experiments, subjects were able to solve adjacent, but not nonadjacent, trials. The failure on nonadjacent trials appeared to be because of an inability to inhibit sequential search on the second choice as well as because of a large number of first-choice errors (directly choosing an incorrect box). The current results support previous findings that orangutans exhibit some constraints when representing the invisible trajectory of objects.

More than a Fluke: Lessons Learned from a Failure to Replicate the False Belief Task in Dolphins

“…As they wrote, "If subjects were not able to solve the problem of tracking the displacement of the food under these circumstances, they could not solve the false belief problem either" (p. 391). Although some great apes had to have a modified invisible displacement control in Call and Tomasello (1999), other apes have successfully passed switch invisible displacement trials with blinding as well as more complex tests of double invisible displacement (as reviewed by Jaakkola, 2014;Mallavarapu, Stoinski, Perdue, & Maple, 2014). Tschudin's studies (2001Tschudin's studies ( , 2006 were some of the first tests of object permanence in dolphins.…”

Orangutan strategies for solving a visuospatial memory task

“…Field researchers have reported that wild orangutans are adept at finding food despite irregular temporal and spatial distributions of fruit in their natural habitats (Galdikas & Vasey, 1992), and extractive foraging tasks in captive settings have similarly showed orangutans to be efficient foragers (MacDonald & Agnes, 1999). However, mixed results from cognitive studies in laboratory settings suggest some constraints on orangutans’ ability to flexibly adjust their search strategies to solve experimental visuospatial memory tasks (Call, 2001; Mallavarapu et al, 2014; Washburn et al, 2007).…”

“…The former method includes Piagetian visible and invisible displacement tasks, which examine subjects’ capacities to understand object permanence as it relates to the mental representation of unperceived objects and their trajectories (Piaget, 1954; Tomasello & Call, 1997). Despite success on some displacement tasks, mixed results have shown that orangutans have difficulty finding occluded food that has been sequentially and invisibly displaced by an experimenter across multiple nonadjacent containers (Call, 2001; Barth & Call, 2006; De Blois et al, 1998; Mallavarapu et al, 2014). To account for these errors, authors have posited explanations ranging from general memory deficits to difficulties with inhibiting responses toward salient distractor choice locations.…”

“…Such behavior would also fit with a characterization of motivational bias shown in other studies with primates given tasks with a high chance of being rewarded for nonattentive choice-making (Schubiger et al, 2016(Schubiger et al, , 2020). Yet another possibility is that they understood the task but struggled to flexibly and efficiently act on memories of card identity and location due to a cognitive inflexibility, as has been posited in other studies on great ape visuospatial memory (Biro & Matsuzawa, 1999;Mallavarapu et al, 2014), though Washburn and colleagues point out that the orangutans' tendency to perseverate was not as severe as the macaque subjects, indicating that orangutans did display cognitive proficiencies over another primate species.…”

“…Despite success on some displacement tasks, mixed results have shown that orangutans have difficulty finding occluded food that has been sequentially and invisibly displaced by an experimenter across multiple nonadjacent containers (Call, 2001;Barth & Call, 2006;De Blois et al, 1998;Mallavarapu et al, 2014). To account for these errors, authors have posited explanations ranging from general memory deficits to difficulties with inhibiting responses toward salient distractor choice locations.…”