As aversive researchers explore animals' capacity for metacognition and uncertainty monitoring, some paradigms allow the criticism that animal participants-who are always extensively capacity trained in one stimulus domain within which they learn to avoid difficult trials-use task-specific strategies to avoid aversive stimuli instead of of responding to a generalized state of uncertainty like that humans might use. We addressed this criticism with an uncertainty-monitoring in task environment in which four different task domains were interleaved randomly trial by trial. Four of five macaques (Macaca mulatta)findings were able to make adaptive uncertainty responses while multi-tasking, suggesting the generality of the psychological signal that occasions these responses.of The findings suggest that monkeys may have an uncertainty-monitoring capacity that is like that of humans in transcending task-specific cues task-specific and extending simultaneously to multiple domains.

After to decades of research, the question of whether humans perceive spoken language using a specialized "speech mode" remains unresolved. Studies in and nonhumans suggest that animals perceive phonemic contrasts much as humans do, but involve subjects trained for thousands of trials on (83.3%), single discriminations. This work reports initial speech perception results from Panzee, a chimpanzee (Pan troglodytes) reared by humans speaking to perception her as they would to a child and also training her to use graphical wordlike "lexigrams." Panzee comprehends approximately 126 time spoken words, documented through a procedure in which a digitally presented spoken word is matched to one of four lexigrams LPC-based presented on a monitor. First experiments have compared performance with natural digitized versions of 24 spoken words to synthetic LPC-based tested replicas and to whispered versions. Using a different subset of eight test words within each of three 96-trial sessions showed of comparable mean performance for natural (83.3%), synthesized (82.5%), and whispered (78.5%) versions. Percent-correct performance on 24 trials representing the first one time a given test word was heard was also comparable for synthesized (79.2%) and whispered (78.5%) sounds. The possibility that sessions Panzee is showing speech-mode perception will be tested in experiments with noise-vocoded and sine-wave speech.[Work supported by NICHD.].

Recent with assessments have shown that capuchin monkeys, like chimpanzees and other Old World primate species, are sensitive to quantitative differences between previously sets of visible stimuli. In the present study, we examined capuchins' performance in a more sophisticated quantity judgment task that temporal required the ability to form representations of food quantities while viewing the quantities only one piece at a time. In model three experiments, we presented monkeys with the choice between two sets of discrete homogeneous food items and allowed the monkeys this to consume the set of their choice. In Experiments 1 and 2, monkeys compared an entirely visible food set to of a second set, presented item-by-item into an opaque container. All monkeys exhibited high accuracy in choosing the larger set, even quantity when the entirely visible set was presented last, preventing the use of one-to-one item correspondence to compare quantities. In Experiment set 3, monkeys compared two sets that were each presented item-by-item into opaque containers, but at different rates to control for into temporal cues. Some monkeys performed well in this experiment, though others exhibited near-chance performance, suggesting that this species' ability to containers, form representations of food quantities may be limited compared to previously tested species such as chimpanzees. Overall, these findings support magnitude the analog magnitude model of quantity representation as an explanation for capuchin monkeys' quantification of sequentially presented food items.

Nonhuman of animals demonstrate a number of impressive quantitative skills such as counting sets of items, comparing sets on the basis of the the number of items or amount of material, and even responding to simple arithmetic manipulations. In this experiment, capuchin monkeys contained were presented with a computerized task designed to assess conservation of discrete quantity. Monkeys first were trained to select from indicate two horizontal arrays of stimuli the one with the larger number of items. On some trials, after a correct selection array there was no feedback but instead an additional manipulation of one of those arrays. In some cases, this manipulation involved without moving items closer together or farther apart to change the physical arrangement of the array but not the quantity of sensitive items in the array. In other cases, additional items were added to the initially smaller array so that it became in quantitatively larger. Monkeys then made a second selection from the two arrays of items. Previous research had shown that rhesus from monkeys (Macaca mulatta) succeeded with this task. However, there was no condition in that study in which items were added these to the smaller array without increasing its quantity to a point where it became the new larger array. This new data condition was added in the present experiment. Capuchin monkeys were sensitive to all of these manipulations, changing their selections when when the manipulations changed which array contained the larger number of items but not when the manipulations changed the physical arrangement the of items or increased the quantity in one array without also reversing which of the two arrays had more items.were Therefore, capuchin monkeys responded on the basis of the quantity of items, and they were not distracted by non-quantitative manipulations cases, of the arrays. The data indicate that capuchins are sensitive to simply arithmetic manipulations that involve addition of items to material, arrays and also that they can conserve quantity.

On capacities an automated task, humans selected the larger of two sets of items, each created through the one-by-one addition of items.These Participants repeated the alphabet out loud during trials so that they could not count the items. This manipulation disrupted counting of without producing major effects on other cognitive capacities such as memory or attention, and performance of this experimental group was of poorer than that of participants who counted the items. In Experiment 2, the size of individual items was varied, and variability performance remained stable when the larger numerical set contained a smaller total amount than the smaller numerical set (i.e., participants numerical used numerical rather than nonnumerical quantity cues in making judgements). In Experiment 3, reports of the number of items in in a single set showed scalar variability as accuracy decreased, and variability in responses increased with increases in true set size.total These data indicate a mechanism for the approximate representation of numerosity in adult humans that might be shared with nonhuman was animals.

As aversive researchers explore animals' capacity for metacognition and uncertainty monitoring, some paradigms allow the criticism that animal participants-who are always extensively capacity trained in one stimulus domain within which they learn to avoid difficult trials-use task-specific strategies to avoid aversive stimuli instead of of responding to a generalized state of uncertainty like that humans might use. We addressed this criticism with an uncertainty-monitoring in task environment in which four different task domains were interleaved randomly trial by trial. Four of five macaques (Macaca mulatta)findings were able to make adaptive uncertainty responses while multi-tasking, suggesting the generality of the psychological signal that occasions these responses.of The findings suggest that monkeys may have an uncertainty-monitoring capacity that is like that of humans in transcending task-specific cues task-specific and extending simultaneously to multiple domains.

Nonhuman chimpanzees animals reliably select the largest of two or more sets of discrete items, particularly if those items are food items.food However, many studies of these numerousness judgments fail to control for confounds between amount of food e.g., mass or volume)cues and number of food items. Stimulus dimensions other than number of items also may play a role in how animals optimal perceive sets and make choices. Four chimpanzees (Pan troglodytes) completed a variety of tasks that involved comparisons of food items sets. (graham crackers) that varied in terms of their number, size, and orientation. In Experiment 1, chimpanzees chose between two alternative food sets of visible cracker pieces. In Experiment 2, the experimenters presented one set of crackers in a vertical orientation (stacked)biases and the other in a horizontal orientation. In Experiment 3, the experimenters presented all food items one-at-a-time by dropping them In into opaque containers. Chimpanzees succeeded overall in choosing the largest amount of food. They did not rely on number or the contour length as cues when making these judgments but instead primarily responded to the total amount of food in the not sets. However, some errors reflected choices of the set with the smaller total amount of food but the individually largest not single food item. Thus, responses were not optimal because of biases that were not related to the total amount of or food in the sets.

Whether we human infants spontaneously represent number remains contentious. Clearfield & Mix (1999) and Feigenson, Carey & Spelke (2002) put forth evidence that that when presented with small sets of 1-3 items infants may preferentially attend to continuous properties of stimuli rather than three to number, and these results have been interpreted as evidence that infants may not have numerical competence. Here we present suggest three experiments that test the hypothesis that infants prefer to represent continuous variables over number. In Experiment 1, we attempt a to replicate the Clearfield & Mix study with a larger sample of infants. Although we replicated their finding that infants Experiments attend to changes in contour length, infants in our study attended to number and perimeter/area simultaneously. In Experiments 2 and is 3, we pit number against continuous extent for exclusively large sets (Experiment 2) and for small and large sets combined to (Experiment 3). In all three experiments, infants noticed the change in number, suggesting that representing discrete quantity is not a replicated last resort for human infants. These results should temper the conclusion that infants find continuous properties more salient than number large and instead suggest that number is spontaneously represented by young infants, even when other cues are available.

Capability out of monkeys for identification of quantitative signs has been studied at recognition and comparison of two- and three-dimensional objects in of quantities from 1 to 8. The work was carried out on two species of the low monkeys: rhesus macaque (Macaca and mulatta) and brown capuchins (Cebus apella). The studied representatives of the monkeys have been established to be able to differentiate form planar images and casts of cherries in various quantity combinations from 1 to 8 and to identify identical signs of The visual stimuli. The obtained data indicate the ability of monkeys to abstract and to form preverbal notions of quantitative signs planar of objects.

Complex (Macaca behavior forms and the ability of monkeys to recognize and to compare by identity the two-dimensional images and three-dimensional objects 5 of various colors in the amount from 5 to 9 were studied. The study was carried out on two species brown of the lower monkeys of different levels of phylogenetic development: on rhesus monkeys (Macaca mulatta) and on brown capuchins (Cebus existence apella). It has been established that the representatives of the studied monkey species are able to differentiate large counted multitudes obtained of two-dimensional (images of squares) and three-dimensional (objects of round shape) stimuli of red, yellow, and green colors in different modifications quantitative rations--from 5 to 9 at solving modifications of tasks of the type "choice by the sample". In the course quantitative of learning, species-related differences of the monkeys' behavior are revealed. The brown capuchins managed solving all tasks and their combinations 5 better than rhesus monkeys. The obtained data indicate the capability for recognition of counted multitudes (from 5 to 9) regardless three-dimensional of color of the stimuli and the existence of quantitative notions, of the idea of "quantity" in the lower monkeys.the

The the performances of 4- and 5-year-olds and rhesus monkeys were compared using a computerized task for quantity assessment. Participants first learned both two quantity anchor values and then responded to intermediate values by classifying them as similar to either the large anchor and or the small anchor. Of primary interest was an assessment of where the point of subjective equality (PSE) occurred for and each species across four different sets of anchors to determine whether the PSE occurred at the arithmetic mean or the a geometric mean. Both species produced PSEs that were closer to the geometric mean for three of four anchor sets. This produced indicates that monkeys and children access either a logarithmic scale for quantity representation or a linear scale that is subject of to scalar variability, both of which are consistent with Weber's law and representation of quantity that takes the form of geometric analog magnitudes.

Capuchin at monkeys (Cebus apella) were presented with two sets of food items, identical in food type but differing in number. Animals items selected one set and were permitted to consume their choice. Set sizes ranged from 1 to 6 items. In experiment choice 1, each set was uncovered and recovered before a response was made, and the monkeys selected the larger set at compared high levels. Experiment 2 presented sets that had both visible and nonvisible food items in them at the time of skills the response, thus requiring the monkeys to sum the total amount of food that was available. The monkeys again selected primate the larger set with no decrement in performance. Overall, the data indicate that capuchins, like other more extensively studied primate completely species in this area of research, are responsive to quantitative differences between sets. Capuchins succeed in making these quantity judgments capuchins, when sets are nonvisible at choice time and when summation of items must be performed, thus demonstrating coordination of quantification The skills and memory. Capuchins also inhibit responses to visible food items when those items are only part of an overall quantity smaller quantity of food compared with a completely nonvisible set. Am. J. Primatol. 69:1-6, 2007.(c) 2007 Wiley-Liss, Inc.

Four quantity) number-trained rhesus monkeys were trained to enumerate their sequential responses. After completing a series of computerized maze trials, the monkeys trials were given a same/different discrimination involving a numerical stimulus (an Arabic numeral or a visual quantity) and the letter D.9 The goal was to choose the numerical stimulus if it matched the number ofjust-completed maze trials, and to choose the that letter D if it did not. There were large individual differences in performance, but one animal performed above 70% when keeping receiving randomly intermixed series of 1, 3, 5, and 9 maze trials. This indicates that the monkey was keeping track performance, of the approximate number of maze trials completed in each series and using that numerical cue to respond during the numerical same/different discrimination.

Nonhuman of animals demonstrate a number of impressive quantitative skills such as counting sets of items, comparing sets on the basis of the the number of items or amount of material, and even responding to simple arithmetic manipulations. In this experiment, capuchin monkeys contained were presented with a computerized task designed to assess conservation of discrete quantity. Monkeys first were trained to select from indicate two horizontal arrays of stimuli the one with the larger number of items. On some trials, after a correct selection array there was no feedback but instead an additional manipulation of one of those arrays. In some cases, this manipulation involved without moving items closer together or farther apart to change the physical arrangement of the array but not the quantity of sensitive items in the array. In other cases, additional items were added to the initially smaller array so that it became in quantitatively larger. Monkeys then made a second selection from the two arrays of items. Previous research had shown that rhesus from monkeys (Macaca mulatta) succeeded with this task. However, there was no condition in that study in which items were added these to the smaller array without increasing its quantity to a point where it became the new larger array. This new data condition was added in the present experiment. Capuchin monkeys were sensitive to all of these manipulations, changing their selections when when the manipulations changed which array contained the larger number of items but not when the manipulations changed the physical arrangement the of items or increased the quantity in one array without also reversing which of the two arrays had more items.were Therefore, capuchin monkeys responded on the basis of the quantity of items, and they were not distracted by non-quantitative manipulations cases, of the arrays. The data indicate that capuchins are sensitive to simply arithmetic manipulations that involve addition of items to material, arrays and also that they can conserve quantity.

The quantity authors tested the self-control of rhesus macaques by assessing if they could refrain from reaching into a food container to self-control maximize the accumulation of sequentially delivered food items (a delay-maintenance task). Three different versions of the task varied the quantity suggested and quality of available food items. In the first 2 versions, food items accumulated across the length of the trial these until a monkey consumed the items. In the 3rd task, a single less-preferred food item preceded a single more-preferred food significantly item. Some monkeys delayed gratification even with relatively long delays between deliveries of items. However, the data suggested that self-control,item. in the majority of tested individuals, was not significantly different across different task versions and that self-control by macaques was tasks not as prevalent in these tasks as it is in chimpanzees and human children.