Transfer of Metacognitive Skills and Hint Seeking in Monkeys

Metacognition is knowledge that can be expressed as confidence judgments about what we know (monitoring) and by strategies for learning what we don’t know (control). Although a substantial literature exists on cognitive processes in animals, little is known about their metacognitive abilities. Here we show that rhesus macaques, trained previously to make retrospective confidence judgments about their performance on perceptual tasks, transferred that ability immediately to a new perceptual task and to a working memory task. In a second experiment we show that monkeys can also learn to request “hints” when they are given problems that they would otherwise have to solve by trial and error. This shows, for the first time, that non-human primates share with humans the ability to monitor and transfer their metacognitive ability both within and between different cognitive tasks, and to seek new knowledge on a need to know basis.

Perceptual category learning of photographic and painterly stimuli in rhesus macaques (Macaca mulatta) and humans

Humans are highly adept at categorizing visual stimuli, but studies of human categorization are typically validated by verbal reports. This makes it difficult to perform comparative studies of categorization using non-human animals. Interpretation of comparative studies is further complicated by the possibility that animal performance may merely reflect reinforcement learning, whereby discrete features act as discriminative cues for categorization. To assess and compare how humans and monkeys classified visual stimuli, we trained 7 rhesus macaques and 41 human volunteers to respond, in a specific order, to four simultaneously presented stimuli at a time, each belonging to a different perceptual category. These exemplars were drawn at random from large banks of images, such that the stimuli presented changed on every trial. Subjects nevertheless identified and ordered these changing stimuli correctly. Three monkeys learned to order naturalistic photographs; four others, close-up sections of paintings with distinctive styles. Humans learned to order both types of stimuli. All subjects classified stimuli at levels substantially greater than that predicted by chance or by feature-driven learning alone, even when stimuli changed on every trial. However, humans more closely resembled monkeys when classifying the more abstract painting stimuli than the photographic stimuli. This points to a common classification strategy in both species, one that humans can rely on in the absence of linguistic labels for categories

Transfer of a Serial Representation between Two Distinct Tasks by Rhesus Macaques

Do animals form task-specific representations, or do those representations take a general form that can be applied to qualitatively different tasks? Rhesus monkeys (Macaca mulatta) learned the ordering of stimulus lists using two different serial tasks, in order to test whether prior experience in each task could be transfered to the other, enhancing performance. The simultaneous chaining paradigm delivered rewards only after subjects responded in the correct order to all stimuli displayed on a touch sensitive video monitor. The transitive inference paradigm presented pairs of items and delivered rewards when subjects selected the item with the lower ordinal rank. After learning a list in one paradigm, subjects’ knowledge of that list was tested using the other paradigm. Performance was enhanced from the very start of transfer training. Transitive inference performance was characterized by ‘symbolic distance effects,’ whereby the ordinal distance between stimuli in the implied list ordering was strongly predictive of the probability of a correct response. The patterns of error displayed by subjects in both tasks were best explained by a spatially coded representation of list items, regardless of which task was used to learn the list. Our analysis permits properties of this representation to be investigated without the confound of verbal reasoning

Serial cognition and personality in macaques

We examined the associations between serial cognition and personality in rhesus macaques (Macaca mulatta). Nine macaques were tested on a simultaneous chaining task to assess their cognitive abilities. They were also rated for personality traits and scored according to a previously extracted six component structure derived from free-ranging rhesus macaques. Friendliness and Openness were positively associated with good performance on three measures of accuracy on the serial learning task: Progress, Error, and Rewarded (i.e., correctly completed) Trials. Faster Reaction Times were associated with lower Friendliness and higher Confidence, as well as higher Openness when only correct responses were analyzed. We also used regularized exploratory factor analysis to extract two, three, four, five, and six factor structures, and found consistent associations between accuracy and single factors within each of these structures. Prior results on intelligence in other nonhuman primate species have focused on basic intelligence tests; this study demonstrates that more complex, abstract cognitive tasks can be used to assess intelligence and personality in nonhuman primates

The Comparative Psychology of Serially Organized Behavior

The study of serially organized behavior has benefited from a new paradigm for training sequences, from new technology for presenting multiple images in varied spatial positions and from new concepts for describing serially organized behavior. The new paradigm is the simultaneous chaining paradigm, one that presents all list items simultaneously, in a new configuration on each trial. Because there are no external cues to guide the execution of the required sequence, subjects must form a representation of the sequence and update it while moving from item to item. Experiments in which humans and monkeys were trained to learn sequences composed of arbitrary items showed that subjects acquired knowledge of the ordinal position of each item, and its relationship with other items from a list, without any requirement to do so. Symbolic distance and magnitude functions, that were obtained from both monkeys and humans, who were trained to execute arbitrary and numerical lists, provide strong evidence of an underlying ordinal knowledge, at both the behavioral and the neural level. Serial learning is one of the oldest and most widely studied phenomena of experimental psychology; as well it deserves to be. As compared to individual responses, serially organized action is the norm in everyday behavior and it is also fundamental for the mastery of skills at all levels of complexity; skills as simple as knowing how to get fro

Psychological statistics : unit four probability, unit five the binomial distribution

6aJilid IIiii, 88 p.; 24 cm

Learning ecological and artificial visual categories: rhesus macaques, humans, and machines

Comparative studies of categorization using non-human animals are difficult to conduct because studies of human categorization typically rely on verbal reports. Moreover, animal performance may reflect reinforcement learning, whereby discrete features act as discriminative cues for categorization. We trained humans, monkeys, and computer algorithms – an associative, feature-driven algorithm and a neural network – to classify four simultaneously presented visual stimuli, each belonging to a different perceptual category, in a specific order. There were two sets of categories: naturalistic photographs and close-up sections of paintings with distinctive styles. All living subjects classified stimuli better than predicted by chance or by feature-driven learning alone, even when stimuli changed on every trial. However, humans more closely resembled monkeys when classifying the more abstract painting stimuli than photographic stimuli. This points to a common, non-associative, non-linguistic classification strategy in both species, one that humans can rely on in the absence of linguistic labels for categories