Long-tailed macaques avoid conflicts during short-term crowding

Crowding has been viewed as a factor eliciting increased levels of aggression and tension in gregarious animals. The present study tested predictions derived from two models, the “density/aggression” model and the “active coping” model, which have been proposed to explain the responses of primates to crowding. In particular, we investigated the responses of a well-established group of long-tailed macaques (Macaca fascicularis) to short-term crowding. The group was periodically crowded for 2-3 hr into a familiar area. Control observations were carried out when the monkeys were in a six times larger enclosure. Data from 42 individuals belonging to different age-sex classes showed that only mild forms of aggression increased under the crowded condition. Crowding also resulted in a decrease in counteraggression, allogrooming, playing, and exploring the environment, while it produced an increase in huddling with companions. The frequency of reconciliation and redirection was not affected by crowding. These findings do not support either of the models but suggest that macaques adopt a “conflict-avoidance strategy” during short-term crowding. They reduce the risk of severe aggression in an environment where interindividual distances are small by simply decreasing the level of activity. Interestingly, however, when aggression occurs during crowding, tension reduction mechanisms such as reconciliation and redirection are used as often as in control conditions. © 1995 Wiley-Liss, Inc.     

Long-tailed macaques (Macaca fascicularis) understand what conspecifics can see in a competitive situation

Visual perspective taking (VPT), an understanding of what others can see, is a prerequisite for theory of mind (ToM). While VPT in apes is proven, its presence in monkeys is much-debated. Several different paradigms have been developed to test its existence, but all face interpretational problems since results can be explained by simpler cognitive mechanisms than VPT. Therefore, we adjusted one method where two individuals compete for access to food, visible or invisible for the dominant competitor, to preclude cognitively simpler mechanisms. The subordinate long-tailed macaques tested, selected significantly more often the food item invisible than the item visible to the dominant. In most trials, subjects retrieved only one food item and preferred the invisible food item. Surprisingly, they occasionally adopted an alternative strategy to obtain both food items, by first choosing the visible, most at risk food item. Faster animals adopted this strategy proportionally more often than slower ones. Contrary to previous research, our results cannot be explained by simpler cognitive mechanisms, since behavioural reading was prevented by a one-way mirror between the competitor and the food, and accessibility was equal to both food items. This is the first unequivocal evidence of VPT in a monkey species, suggesting that this precursor to ToM is an evolutionarily conserved capacity present in monkeys, apes and humans.     

Verbal fluency and verbal comprehension abilities in synonym tasks

Generating different synonym candidates and evaluating these candidates with respect to their synonymy with the stimulus word are two components of solving an open synonym task, which requires giving synonyms for a given word (cf. Janssen, Hoskens, & De Boeck, 1993). Separate subtasks were designed to identify these components. It is shown in this study that the generation component ability is primarily related to verbal fluency abilities, whereas the evaluation component ability is primarily related to verbal comprehension abilities. Moreover, evidence is given that these two component abilities can account for the correlations of the open synonym task with other ability measures.     

Information processing abilities and performance on two perceptual-motor tasks

The purpose of this study was to investigate whether the hypothesized information-processing mechanisms, thought to be reflected by the slope and intercept of the regression of choice reaction time on stimulus information or information transmitted could account for performance on two novel laboratory tasks. In addition, analyses were performed to determine whether these theorized mechanisms represent stable within individual abilities or task specific capabilities. Analysis indicated that the slopes obtained from two different choice reaction time paradigms were unrelated while intercepts were moderately correlated. Examination of the pattern of zero-order correlations further showed that regression components were not meaningfully related to performance on either novel task, suggesting that knowledge of information-processing mechanisms, as assessed in choice RT paradigms, did not enhance the understanding of performance in more complex tasks.     

Complex span tasks, simple span tasks, and cognitive abilities: A reanalysis of key studies

There is great interest in the relationships between memory span tasks and cognitive abilities. However, the causes underlying their correlation remain unknown. In the present article, five key data sets were reanalyzed according to two criteria: They must consider complex span tasks (so-called working memory [WM] tasks) and simple span tasks (so-called short-term memory [STM] tasks), and they must comprise cognitive ability measures. The obtained results offer several points of interest. First, memory span tasks should be conceived from a hierarchical perspective: They comprise both general and specific components. Second, the general component explains about four times the variance explained by the specific components. Third, STM and WM measures are closely related. Fourth, STM and WM measures share the same common variance with cognitive abilities. Finally, the strong relationship usually found between memory span tasks and cognitive abilities could be tentatively interpreted by the component shared by STM and WM--namely, the capacity for temporarily preserving a reliable memory representation of any given information.     

Prime display offset modulates negative priming only for easy-selection tasks

Responses to probe targets that have been distractors in a prime display are slower than responses to new targets, a finding called negative priming (NP). The selective attention model, which attributes NP to lingering inhibition of the prime distractor, predicts that NP should occur only when the prime display has disappeared before the probe display is processed. The present study tested this prediction both in easy- and in difficult selection tasks. In Experiments 1, 2, and 3A, target selection was easy, and NP was observed only after prime display offset, regardless of whether offset was manipulated between or within participants. In Experiment 3B, target selection was difficult, and NP was found with and without prime display offset. Experiment 4 replicated the finding of NP without prime display offset in a difficult-selection task. A modified version of the selective attention model can explain the results of the present study. However, we also discuss the results in light of episodic retrieval theory and temporal discrimination theory.     

Inference-driven attention in symbolic and perceptual tasks: Biases toward expected and unexpected inputs

The aims of this paper are (a) to gather support for the hypothesis that some basic mechanisms of attentional deployment (i.e., its high efficiency in dealing with expected and unexpected inputs) meet the requirements of the inferential system and have possibly evolved to support its functioning, and (b) to show that these orienting mechanisms function in very similar ways in two perceptual tasks and in a symbolic task. The general hypothesis and its predictions are sketched in the Introduction, after a discussion of current findings concerning visual attention and the generalities of the inferential system. In the empirical section, three experiments are presented where participants tracked visual trajectories (Experiments 1 and 3) or arithmetic series (Experiments 2 and 3), responding to the onset of a target event (e.g., to a specific number) and to the repetition of an event (e.g., to a number appearing twice consecutively). Target events could be anticipated when they were embedded in regular series/trajectories; they could be anticipated, with the anticipation later disconfirmed, when a regular series/trajectory was abruptly interrupted before the target event occurred; and they could not be anticipated when the series/trajectory was random. Repeated events could not be anticipated. Results show a very similar pattern of allocation in tracking visual trajectories and arithmetic series: Attention is focused on anticipated events; it is defocused and redistributed when an anticipation is not confirmed by ensuing events; however, performance decreases when dealing with random series/trajectory—that is, in the absence of anticipations. In our view, this is due to the fact that confirmed and disconfirmed anticipations are crucial events for “knowledge revision”—that is, the fine tuning of the inferential system to the environment; attentional mechanisms have developed so as to enhance detection of these events, possibly at all levels of inferential processing.     

Inference-driven attention in symbolic and perceptual tasks: biases toward expected and unexpected inputs

The aims of this paper are (a) to gather support for the hypothesis that some basic mechanisms of attentional deployment (i.e., its high efficiency in dealing with expected and unexpected inputs) meet the requirements of the inferential system and have possibly evolved to support its functioning, and (b) to show that these orienting mechanisms function in very similar ways in two perceptual tasks and in a symbolic task. The general hypothesis and its predictions are sketched in the Introduction, after a discussion of current findings concerning visual attention and the generalities of the inferential system. In the empirical section, three experiments are presented where participants tracked visual trajectories (Experiments 1 and 3) or arithmetic series (Experiments 2 and 3), responding to the onset of a target event (e.g., to a specific number) and to the repetition of an event (e.g., to a number appearing twice consecutively). Target events could be anticipated when they were embedded in regular series/trajectories; they could be anticipated, with the anticipation later disconfirmed, when a regular series/trajectory was abruptly interrupted before the target event occurred; and they could not be anticipated when the series/trajectory was random. Repeated events could not be anticipated. Results show a very similar pattern of allocation in tracking visual trajectories and arithmetic series: Attention is focused on anticipated events; it is defocused and redistributed when an anticipation is not confirmed by ensuing events; however, performance decreases when dealing with random series/trajectory—that is, in the absence of anticipations. In our view, this is due to the fact that confirmed and disconfirmed anticipations are crucial events for “knowledge revision”—that is, the fine tuning of the inferential system to the environment; attentional mechanisms have developed so as to enhance detection of these events, possibly at all levels of inferential processing.     

Detection performance in pop-out tasks: nonmonotonic changes with display size and eccentricity

We carried out three experiments to investigate detection performance in pop-out tasks and analysed how performance varied as a function of display size (number of elements) and retinal eccentricity of the target. Results showed that when display size was increased from 2 to 81 elements performance first decreased and then increased (replicating Sagi and Julesz, 1987 Spatial Vision 2 39-49). Performance variations differed as a function of eccentricity and often were more pronounced in the periphery than in the foveal area. This retinal-eccentricity influence suggests that processes underlying detection performance in small display sizes are different from those in large display sizes. One should be careful when using the variation of display size as an instrument to analyse visual-search processes because this analysis could be based on a comparison between non-equivalent conditions.     

Self-presentation processes in job analysis: a field experiment investigating inflation in abilities, tasks, and competencies

Although job analysis is a widely used organizational data collection technique, little research has investigated the extent to which job analysis information is affected by self-presentation processes. This study represents the first direct test of the propositions offered by F. P. Morgeson and M. A. Campion (1997) concerning self-presentation in job analysis measurement. Using an experimental design, the authors examined job incumbent response differences across ability, task, and competency statements. Results indicated that ability statements were more subject to inflation than were task statements across all rating scales. Greater endorsement of nonessential ability statements was responsible for the differences. This produced higher endorsement of ability items but lower mean ratings. Finally, frequency and importance ratings of global competency statements were generally higher than decomposed ability and task scales, but required-at-entry judgments demonstrated the opposite relationship.     

Effects of secondary tasks and display position on glance behavior during partially automated driving

The driving task is becoming increasingly automated, thus changing the driver’s role. Moreover, in-vehicle information systems using different display positions and information processing channels might encourage secondary task engagement. During manual driving scenarios, varying secondary tasks and display positions could influence driver’s glance behavior. However, their impact on the driver’s capability to monitor the partially automated driving system has not yet been determined. The current study assessed both the effects of different secondary tasks (Surrogate Reference Task (SuRT) vs. text reading) and display positions (head-up display (HUD) vs. center console) on driver’s glance behavior during partially automated driving in a simulated car following task. Different automation system failures regarding the lateral and longitudinal control occurred while driving. Furthermore, participants’ reported advantages, disadvantages and preferences regarding the investigated display positions as well as regarding the secondary task engagement during partially automated driving in general. Mixed design ANOVAs revealed that the HUD yielded considerably longer eyes-on display time (total and mean glance durations) than the center console. Moreover, the text reading task resulted in longer total and mean glance durations than the SuRT. Similar to manual driving scenarios, the results showed a consistent effect of display position and secondary task on the driver’s glance behavior. Despite the longer eyes-on display time for the HUD, its proximity to the driving environment might enable a faster identification of and reaction to critical situations (e.g., due to system failures). Participants would prefer the HUD as display position compared to the center console. Regarding secondary task engagement during partially automated driving participants seemed to be aware of the benefits but also of the risks.     

Neuropsychological abilities of preschool-aged children who display hyperactivity and/or oppositional-defiant behavior problems.

This study focused on gaining a better understanding of the neuropsychological abilities of preschool-aged children who show elevated levels of hyperactivity and oppositional-defiance. It examined the performance of children aged 48 to 67 months on tests of attention/executive function, language, memory, and sensorimotor abilities, as measured by the NEPSY and Conners' K-CPT. Two hundred thirty-seven children were divided into four subgroups based on mothers' report of behavior using rating scales and a diagnostic interview: hyperactive only (HYP), oppositional-defiant only (OD), hyperactive and oppositional-defiant (HYP/OD), and nonproblem. Children in the HYP/OD group scored significantly worse than nonproblem children on four of nine subtests on the NEPSY, including one test of executive function, one test of language comprehension, and both tests of short-term verbal memory. However, only the test of executive function (Statue) showed significant predictive power, and, while specificity of this subtest was good, sensitivity was poor. On the K-CPT, a continuous performance test, children in both the HYP and HYP/OD groups performed worse than children in the OD and nonproblem groups. When the NEPSY Statue subtest and the K-CPT were used together, overall predictive power was .74. Results suggest that neuropsychological deficits can be observed among preschool children with hyperactivity, particularly when comorbid oppositional-defiance is present; however, moderate predictive power suggests that these tests should be used in conjunction with other methods of assessment.     

Cognitive abilities required in time judgment depending on the temporal tasks used: A comparison of children and adults

The aim of this study was to examine age-related differences in time judgments during childhood as a function of the temporal task used. Children aged 5 and 8 years, as well as adults, were submitted to 3 temporal tasks (bisection, generalization and reproduction) with short (0.4/0.8?s) and long durations (8/16?s). Furthermore, their cognitive capacities in terms of working memory, attentional control, and processing speed were assessed by a wide battery of neuropsychological tests. The results showed that the age-related differences in time judgment were greater in the reproduction task than in the temporal discrimination tasks. This task was indeed more demanding in terms of working memory and information processing speed. In addition, the bisection task appeared to be easier for children than the generalization task, whereas these 2 tasks were similar for the adults, although the generalization task required more attention to be paid to the processing of durations. Our study thus demonstrates that it is important to understand the different cognitive processes involved in time judgment as a function of the temporal tasks used before venturing to draw conclusions about the development of time perception capabilities.     

Inspection time and the relationship among elementary cognitive tasks, general intelligence, and specific cognitive abilities

The relationship between inspection time (IT) and paper-and-pencil tests of cognitive ability is well documented. However, the extent to which IT relates to cognitive ability through general intelligence or through group factors such as performance has not been fully addressed. Another unresolved issue is whether IT relates to psychometric intelligence independent from other elementary cognitive tasks. The current study examined these issues in a sample of 6–13-year-old twins drawn from the Western Reserve Twin Project (WRTP) (n=568 participants). Analyses suggest that IT and other elementary tasks predict general intelligence. IT also predicts Performance ability while other elementary tasks do not. Furthermore, IT contributes variance to cognitive ability independent from other elementary tasks. These suggest that multiple indices of elementary cognitive ability are necessary to fully understand their relationship with complex psychometric measures.     

Chimpanzee (Pan troglodytes) anticipation of food return: coping with waiting time in an exchange task

Despite controversial expectations that animals achieve reciprocal altruism, it is unclear if nonhuman species possess the necessary cognitive abilities. For reciprocal altruism, individuals must anticipate the loss of a commodity and accept a delay before some return. The authors investigated the abilities of 5 chimpanzees (Pan troglodytes) to cope with increasing waiting duration in exchange tasks. Subjects had to keep a small cookie before returning it to a human partner to obtain a larger piece. For a piece 2, 4, or 8 times the size of the small piece, 3 of the 5 subjects waited for up to 4 min. For a piece 40 times larger, 4 of the 5 subjects waited up to 8 min. At long time lag, renouncement to wait occurred earlier than predicted by subjects' general waiting capacity, suggesting that the decision to wait was based on a trade-off between reward quantity and expected costs of the waiting duration. Chimpanzees could anticipate a delayed reward at a time scale of several minutes. If this reflects a cognitive limit in chimpanzees' anticipation capacity, reciprocal altruism by keeping track of costs and benefits over extended periods may be unlikely in chimpanzees.     

Bizarreness effects in verbal tasks and subject-performed tasks

Abstract

Recognition and cued recall of ordinary action phrases (e.g. “open the book”) and bizarre ones (e.g. “plant the hammer”) were compared under two encoding conditions: in verbal tasks (VTs), subjects learned the phrases by simply listening to them; in subject-performed tasks (SPTs), subjects learned the phrases by performing the denoted actions (without real objects). Memory performance was better after SPTs than after VTs in recognition and cued recall. In addition to this already established finding, it was observed that recognition was better for bizarre phrases than for ordinary ones after VTs and that bizarreness was unrelated to recognition after SPTs. Cued recall, on the other hand, depended on bizarreness after VTs as well as after SPTs and, in contrast to the recognition findings, ordinary phrases were recalled better than bizarre phrases. This pattern of findings was explained by the assumptions that lexical and conceptual information is encoded after VTs and motor information is additionally encoded after SPTs, and that different kinds of information are used in recognition and cued recall, and after VTs and SPTs.     

Dynamics of waiting in pigeons

Two experiments used response-initiated delay schedules to test the idea that when food reinforcement is available at regular intervals, the time an animal waits before its first operant response (waiting time) is proportional to the immediately preceding interfood interval (linear waiting; Wynne & Staddon, 1988). In Experiment 1 the interfood intervals varied from cycle to cycle according to one of four sinusoidal sequences with different amounts of added noise. Waiting times tracked the input cycle in a way which showed that they were affected by interfood intervals earlier than the immediately preceding one. In Experiment 2 different patterns of long and short interfood intervals were presented, and the results implied that waiting times are disproportionately influenced by the shortest of recent interfood intervals. A model based on this idea is shown to account for a wide range of results on the dynamics of timing behavior.     

Waiting for more: the performance of domestic dogs (Canis familiaris) on exchange tasks

Five domestic dogs (Canis familiaris) were tested in a cooperative exchange task with an experimenter, as previously tested in non-human primates. In the first task, the dogs exchanged to maximise payoffs when presented with food items of differing quality. All consistently exchanged lower-value for higher-value rewards, as determined by their individual food preference, and exchanges corresponded significantly with the spontaneous preferences of three dogs. Next, all subjects demonstrated an ability to perform two and three exchanges in succession, to gain both qualitative and quantitatively increased rewards (group mean = 72 and 92% successful triple exchanges, respectively). Finally, the ability to delay gratification over increasing intervals was tested; the dogs kept one food item to exchange later for a larger item. As previously reported in non-human primates, there was considerable individual variation in the tolerance of delays, between 10 s and 10 min for the largest rewards. For those who reached longer time lags (>40 s), the dogs gave up the chance to exchange earlier than expected by each subject’s general waiting capacity; the dogs anticipated delay duration and made decisions according to the relative reward values offered. Compared to primates, dogs tolerated relatively long delays for smaller value rewards, suggesting that the socio-ecological history of domestic dogs facilitates their performance on decision-making and delay of gratification tasks.     

Positional inference in rhesus macaques

Animal Cognition - Understanding how organisms make transitive inferences is critical to understanding their general ability to learn serial relationships. In this context, transitive inference...     

The use of the bared-teeth display during play fighting in Tonkean macaques (Macaca tonkeana): sometimes it is all about oneself

Play signals are viewed as important means by which animals inform each other that bites, strikes, and throws that occur during play fighting are indeed playful rather than serious. One such signal is the open mouth play face that is common in primates and many other mammals. Unfortunately, as most play fighting involves biting, it can be ambiguous as to whether any instance of opening the mouth is performed to communicate playful intent or is simply a preparation for biting. In this study, open mouths co-occurring with the bared-teeth display (teeth-baring) in Tonkean macaques were used to assess the context in which facial gestures only relevant for signaling (i.e., teeth-baring is not necessary for biting) are used during play. Two predictions arising from the hypothesis that play signals are used to facilitate playful contact were tested: that the open mouth with teeth-baring should (1) be most frequent preceding contact, and (2) that it should be performed most often when bites are directed at orientations that is visible to the recipient. The data only partially support these predictions. The open mouth with teeth-baring is also frequently used when a monkey withdraws from playful contact. Moreover, it is associated with bites to body targets, such as the rump, that offer little prospect for detection by the recipient; this supports the possibility that play signals may sometimes be emitted not to communicate with the partner but with the performer itself. Thus, play signals serve multiple functions during play fighting.