Auditory–visual intermodal matching based on individual recognition in a chimpanzee (Pan troglodytes)

The ability to recognize familiar individuals with different sensory modalities plays an important role in animals living in complex physical and social environments. Individual recognition of familiar individuals was studied in a female chimpanzee named Pan. In previous studies, Pan learned an auditory–visual intermodal matching task (AVIM) consisting of matching vocal samples with the facial pictures of corresponding vocalizers (humans and chimpanzees). The goal of this study was to test whether Pan was able to generalize her AVIM ability to new sets of voice and face stimuli, including those of three infant chimpanzees. Experiment 1 showed that Pan performed intermodal individual recognition of familiar adult chimpanzees and humans very well. However, individual recognition of infant chimpanzees was poorer relative to recognition of adults. A transfer test with new auditory samples (Experiment 2) confirmed the difficulty in recognizing infants. A remaining question was what kind of cues were crucial for the intermodal matching. We tested the effect of visual cues (Experiment 3) by introducing new photographs representing the same chimpanzees in different visual perspectives. Results showed that only the back view was difficult to recognize, suggesting that facial cues can be critical. We also tested the effect of auditory cues (Experiment 4) by shortening the length of auditory stimuli, and results showed that 200 ms vocal segments were the limit for correct recognition. Together, these data demonstrate that auditory–visual intermodal recognition in chimpanzees might be constrained by the degree of exposure to different modalities and limited to specific visual cues and thresholds of auditory cues.     

The establishment of auditory–visual equivalence classes with a go/no-go successive matching-to-sample procedure

The current study evaluated the effectiveness of a go/no-go successive matching-to-sample procedure (S-MTS) to establish auditory–visual equivalence classes with college students. A sample and a comparison were presented, one at a time, in the same location. During training, after an auditory stimulus was presented, a green box appeared in the center of the screen for participants to touch to produce the comparison. Touching the visual comparison that was related to the auditory sample (e.g., A1B1) produced points, while touching or refraining from touching an unrelated comparison (e.g., A1B2) produced no consequences. Following AB/AC training, participants were tested on untrained relations (i.e., BA/CA and BC/CB), as well as tacting and sorting. During BA/CA relations tests, after touching the visual sample, the auditory stimulus was presented along with a white box for participants to respond. During BC/CB relations tests, after touching the visual sample, a visual comparison appeared. Across 2 experiments, all participants met emergence criterion for untrained relations and for sorting. Additionally, 14 out of 24 participants tacted all visual stimuli correctly. Results suggest the auditory–visual S-MTS procedure is an effective alternative to simultaneous MTS for establishing conditional relations and auditory-visual equivalence classes.     

Can chimpanzee (Pan troglodytes) happiness be estimated by human raters?

The authors investigated measurement of chimpanzee “happiness” based on the human trait of subjective well-being (SWB). Zoo workers at 13 zoos used a 7-point scale to rate 128 chimpanzees on four items related to their SWB. The items included assessment of pleasure derived from social interactions, balance of positive and negative moods, success in goal attainment, and the desirability of being a particular chimpanzee. The four items formed a single factor that had excellent interrater reliability and was temporally stable. Examination of the relationship between chimpanzee SWB and six chimpanzee personality factors, five of which resembled the human Big Five factors, showed that chimpanzee SWB varied positively with Dominance, Extraversion, and Dependability factors. SWB was negatively correlated with frequency of submissive behaviors. Age and sex were not significantly related to SWB.     

Is chimpanzee (Pan troglodytes) spatial attention reflexively triggered by gaze cue?

Humans show a reflexive shift in spatial attention triggered by gaze cues. Chimpanzees (Pan troglodytes) have an excellent ability to follow another's gaze, but they exhibit a limited capacity to engage in triadic interactions based on joint attention, suggesting the possibility of contributions of the different mechanisms underlying joint attention between humans and chimpanzees. The present study thus examined how the chimpanzee's visual spatial attention is triggered by gaze cues. Two chimpanzees showed no clear signs of attention shift triggered by various kinds of nonfacial and facial stimuli with averted gaze under the letter-discrimination tasks but showed significant cueing effects when the head-turning cue was presented in a quasi-dynamic manner. These cueing effects were, however, affected by the predictability of the gaze cue: Highly predictive gaze cues caused stronger cueing effects than less predictive cues. Thus, these results suggest that the shift in spatial attention caused by gaze cues does occur in chimpanzees, but, in contrast to humans, vulnerability against the cue predictability suggests that the voluntary mechanism contributes more dominantly than the reflexive mechanism to this attention shift.     

Selfish strategies develop in social problem situations in chimpanzee (Pan troglodytes) mother–infant pairs

Humans employ various strategies, including selfish and altruistic strategies, depending on the situation. In order to examine whether non-human animals show such flexibility or not, we analyzed chimpanzees’ selfish and cooperative behavior in two types of social problem situations. In this study, we tested chimpanzee mother–infant pairs in two adjacent booths, each equipped with a vending machine. When a token was inserted into a vending machine, the vending machine delivered food rewards to the adjacent booth. In experiment 1, a partition between the two booths was open. In experiment 2, the partition was closed and a mother and her infant were placed in separate booths, so that reciprocal cooperation was essential for them to receive rewards. The participants did not cooperate reciprocally in either experiment. In experiment 1, the chimpanzees developed selfish tactics to get rewards and changed their tactics flexibly according to the partner’s behaviors. In experiment 2, in which they could not receive rewards without cooperation, they stopped altogether inserting tokens. In both cases, the infants stopped cooperating first. These findings support the idea that chimpanzees are primarily competitive rather than cooperative. Chimpanzees’ high social intelligence might be demonstrated in the flexibility of their selfish tactics, but not in the form of reciprocal cooperation at least when food is involved. We suggest that the failure to establish reciprocal cooperation was due to the social relationship between the mother and her infant, which was characterized by infant’s privilege and mother’s tolerance.     

An fMRI study of temporal sequencing of motor regulation guided by an auditory cue—a comparison with visual guidance

The neuronal system to process and transfer auditory information to the higher motor areas was investigated using fMRI. Two different types of internal modulation of auditory pacing (1 Hz) were combined to design a 2×2 condition experiment, and the activation was compared with that under a visual guidance. The bilateral anterior portion of the BA22 (ant-BA22) and the left BA41/42 were more extensively activated by the combined modulation condition under the auditory cue than that under the visual cue. Among the four auditory conditions with or without the two types of internal modulation, the activation in the ant-BA22 was augmented only on the left side by the combined modulation condition. The left ant-BA22 may be especially involved in integrating the external auditory cue with internal modulation, while the activation on the right side did not depend on the complexity. The role of the left BA41/42 in motor regulation may be more specific to the processing of an auditory cue than that on the right side. These two areas in the left temporal lobe may be organized as a subsystem to handle the timing of complex movements under auditory cues, while the higher motor areas in the frontal lobe support both sensory modalities for the cue. This architecture may be considered as ‘audio-motor control’, which is similar to the visuo-motor control of the front-parietal network.     

Token transfer between mother and offspring chimpanzees (Pan troglodytes): mother–offspring interaction in a competitive situation

Chimpanzees can flexibly use tokens in cognitive tasks, but it is still unknown if they can share and/or compete over tokens as they do for food. This study aimed to evaluate the interactions spontaneously occurring between mother and offspring chimpanzees when tokens exchangeable for food were provided. Forty tokens were scattered on the floor in an experimental playroom. Three mother and offspring chimpanzee pairs were tested. Each token was exchangeable for a piece of food in a vending machine installed on the wall of the playroom. In the beginning of the study, both mother and offspring took tokens and exchanged them for pieces of food independently. Later, two offspring started to take more tokens than their mothers. At that time, the offspring whimpered or cried more often than during earlier sessions. This behavior compelled the mothers to abstain from taking tokens. The mothers sometimes shared their tokens with their offspring, or were tolerant of their offspring taking their tokens from their hand. For one pair, the offspring sometimes shared tokens with her mother when her mother begged for the tokens. These results suggest that chimpanzees’ cognitive abilities enable them not only to use tokens, but also to compete for tokens, as they do for food. The results also suggest that token sharing between mother and offspring may be bidirectional and that transfer of tokens mainly occurs as a result of begging, although on some occasion offspring were able to obtain a token directly from his/her mother through tolerated scrounging.     

Can chimpanzee infants (Pan troglodytes) form categorical representations in the same manner as human infants (Homo sapiens)?

We directly compared chimpanzee infants and human infants for categorical representations of three global-like categories (mammals, furniture and vehicles), using the familiarization-novelty preference technique. Neither species received any training during the experiments. We used the time that participants spent looking at the stimulus object while touching it as a measure. During the familiarization phase, participants were presented with four familiarization objects from one of three categories (e.g. mammals). Then, they were tested with a pair of novel objects, one was a familiar-category object and another was a novel-category object (e.g. vehicle) in the test phase. The chimpanzee infants did not show significant habituation, whereas human infants did. However, most important, both species showed significant novelty-preference in the test phase. This indicates that not only human infants, but also chimpanzee infants formed categorical representations of a global-like level. Implications for the shared origins and species-specificity of categorization abilities, and the cognitive operations underlying categorization, are discussed.     

Learning from others' mistakes? limits on understanding a trap-tube task by young chimpanzees (Pan troglodytes) and children (Homo sapiens)

A trap-tube task was used to determine whether chimpanzees (Pan troglodytes) and children (Homo sapiens) who observed a model's errors and successes could master the task in fewer trials than those who saw only successes. Two- to 7-year-old chimpanzees and 3- to 4-year-old children did not benefit from observing errors and found the task difficult. Two of the 6 chimpanzees developed a successful anticipatory strategy but showed no evidence of representing the core causal relations involved in trapping. Three- to 4-year-old children showed a similar limitation and tended to copy the actions of the demonstrator, irrespective of their causal relevance. Five- to 6-year-old children were able to master the task but did not appear to be influenced by social learning or benefit from observing errors.     

Chimpanzees’ (Pan troglodytes) use of gaze cues in object-choice tasks: different methods yield different results

To assess the influence of different procedures on chimpanzees' performance in object-choice tasks, five adult chimpanzees were tested using three experimenter-given cues to food location: gazing, glancing, and pointing. These cues were delivered to the subjects in an identical fashion but were deployed within the context of two distinct meta-procedures that have been previously employed with this species with conflicting results. In one procedure, the subjects entered the test unit and approached the experimenter (who had already established the cue) on each trial. In the other procedure, the subjects stayed in the test unit throughout a session, witnessed the hiding procedure, and waited for a delay of 10 s during which the cue was provided. The subjects scored at high levels far exceeding chance in response to the gaze cue only when they approached the experimenter for each trial. They performed at chance levels when they stayed inside the test unit throughout the session. They scored at chance levels on all other cues irrespective of the procedure. These findings imply that (a) chimpanzees can immediately exploit social gaze cues, and (b) previous conflicting findings were likely due to the different meta-procedures that were used.     

Tool-composite reuse in wild chimpanzees (Pan troglodytes): archaeologically invisible steps in the technological evolution of early hominins?

Recent etho-archaeological studies of stone-tool use by wild chimpanzees have contributed valuable data towards elucidating the variables that influenced the emergence and development of the first lithic industries among Plio-Pleistocene hominins. Such data help to identify potential behaviours entailed in the first percussive technologies that are invisible in archaeological records. The long-term research site of Bossou in Guinea features a unique chimpanzee community whose members systematically use portable stones as hammers and anvils to crack open nuts in natural as well as in field experimental settings. Here we present the first analysis of repeated reuse of the same tool-composites in wild chimpanzees. Data collected over 5 years of experimental nut-cracking sessions at an “outdoor laboratory” site were assessed for the existence of systematic patterns in the selection of tool-composites, at group and at individual levels. Chimpanzees combined certain stones as hammer and anvil more often than expected by chance, even when taking into account preferences for individual stones by themselves. This may reflect an ability to recognise the nut-cracker as a single tool (composed of two elements, but functional only as a whole), as well as discrimination of tool quality-effectiveness. Through repeatedly combining the same pairs of stones—whether due to preferences for particular composites or for the two elements independently—tool-users may amplify use-wear traces and increase the likelihood of fracturing the stones, and thus of detaching pieces by battering.     

Composition of brain oscillations and their functions in the maintenance of auditory,visual and audio–visual speech percepts: an exploratory study

In the present exploratory study based on 7 subjects, we examined the composition of magnetoencephalographic (MEG) brain oscillations induced by the presentation of an auditory, visual, and audio-visual stimulus (a talking face) using an oddball paradigm. The composition of brain oscillations were assessed here by analyzing the probability-classification of short-term MEG spectral patterns. The probability index for particular brain oscillations being elicited was dependent on the type and the modality of the sensory percept. The maintenance of the integrated audio-visual percept was accompanied by the unique composition of distributed brain oscillations typical of auditory and visual modality, and the contribution of brain oscillations characteristic for visual modality was dominant. Oscillations around 20 Hz were characteristic for the maintenance of integrated audio-visual percept. Identifying the actual composition of brain oscillations allowed us (1) to distinguish two subjectively/consciously identical mental percepts, and (2) to characterize the types of brain functions involved in the maintenance of the multi-sensory percept.     

Visual kin recognition in nonhuman primates: (Pan troglodytes and Macaca mulatta): inbreeding avoidance or male distinctiveness?

Faces provide important information about identity, age, and even kinship. A previous study in chimpanzees reported greater similarity between the faces of mothers and sons compared with mothers and daughters, or unrelated individuals. This was interpreted as an inbreeding avoidance mechanism where females, the dispersing gender, should avoid mating with any male that resembles their mother. Alternatively, male faces may be more distinctive than female faces, biasing attention toward males. To test these hypotheses, chimpanzees and rhesus monkeys matched conspecifics' faces of unfamiliar mothers and fathers with their sons and daughters. Results showed no evidence of male distinctiveness, rather a cross-gender effect was found: chimpanzees were better matching moms with sons and fathers with daughters. Rhesus monkeys, however, showed an overwhelming bias toward male-distinctiveness. They were faster to learn male faces, performed better on father-offspring and parent-son trials, and were best matching fathers with sons. This suggests that for the rhesus monkey, inbreeding avoidance involves something other than facial phenotypic matching but that among chimpanzees, the visual recognition of facial similarities may play an important role.     

Acquisition and retention of control of instrumental behavior by a cue-signaling airblast: How specific are conditioned anticipations?

The conditioned state evoked by a CS that had been paired with an aversive airblast was assessed by superimposing the CS on baselines of instrumental responding. The first experiment used a shock avoidance baseline; CS-airblast pairings were administered on the baseline, with the shock avoidance schedule in effect. The CS that signaled airblast came, over trails, to accelerate shock avoidance responding. As further CS-airblast trials were administered, however, the acceleratory effect of the CS decreased, producing an inverted-U-shaped acquisition curve. A second experiment used off-baseline CS-airblast conditioning, and the CS was tested on both shock avoidance and water reinforcement baselines. After 20 CS-airblast pairings the CS accelerated shock avoidance and suppressed water-reinforced responding. After 10o pairings, however, the acceleratory effect on shock avoidance was much attenuated, although the suppressions of the water-reinforced behavior did not differ between 20- and 100-trial groups. Two further experiments examined retention, over a 45-day interval, of the attenuation of the CS's effects on shock avoidance. Over the retention interval, this attenuation disappeared. It was, however, reinstated by giving the animals “reminder” presentations of the airblast. These results are interpreted as representing systematic changes in the specificity of the conditioned state evoked by a Pavlovian CS.     

Judging the plausibility of arguments in scientific texts: a student–scientist comparison

The ability to evaluate scientific claims and evidence is an important aspect of scientific literacy and requires various epistemic competences. Readers spontaneously validate presented information against their knowledge and beliefs but differ in their ability to strategically evaluate the soundness of informal arguments. The present research investigated how students of psychology, compared to scientists working in psychology, evaluate informal arguments. Using a think-aloud procedure, we identified the specific strategies students and scientists apply when judging the plausibility of arguments and classifying common argumentation fallacies. Results indicate that students, compared to scientists, have difficulties forming these judgements and base them on intuition and opinion rather than the internal consistency of arguments. Our findings are discussed using the mental model theory framework. Although introductory students validate scientific information against their knowledge and beliefs, their judgements are often erroneous, in part because their use of strategy is immature. Implications for systematic trainings of epistemic competences are discussed.     

Towards testing auditory–vocal interfaces and detecting distraction while driving: A comparison of eye-movement measures in the assessment of cognitive workload

Recently, there has been a growing need among researchers to understand the problem of cognitive workload induced by auditory–verbal–vocal tasks while driving in realistic conditions. This is due to the fact that we need (a) valid methods to evaluate in-vehicle electronic devices using voice control systems and (b) experimental data to build more reliable driver state monitoring systems. In this study, we examined the effects of cognitive workload induced by the delayed digit recall task (n-back) while driving. We used a high-fidelity driving simulator and a highway scenario with moderate traffic to study eye movements in realistic driving conditions. This study included 46 participants, and the results indicate that a change in pupil size is most sensitive for measuring changes in cognitive demand in auditory–verbal–vocal tasks. Less sensitive measures included changes in fixation location and blink rate. Fixation durations and the driving performance metrics did not provide sensitive measures of graded levels of cognitive demand.     

Bridging computational approaches to speech production: The semantic–lexical–auditory–motor model (SLAM)

Speech production is studied from both psycholinguistic and motor-control perspectives, with little interaction between the approaches. We assessed the explanatory value of integrating psycholinguistic and motor-control concepts for theories of speech production. By augmenting a popular psycholinguistic model of lexical retrieval with a motor-control-inspired architecture, we created a new computational model to explain speech errors in the context of aphasia. Comparing the model fits to picture-naming data from 255 aphasic patients, we found that our new model improves fits for a theoretically predictable subtype of aphasia: conduction. We discovered that the improved fits for this group were a result of strong auditory–lexical feedback activation, combined with weaker auditory–motor feedforward activation, leading to increased competition from phonologically related neighbors during lexical selection. We discuss the implications of our findings with respect to other extant models of lexical retrieval.     

The Conversos of Valencia: Prosopography of a Socio-Religious Community (1391–1420)

Since the nineteenth century, conversos have been among the most prolific lines of research for medievalists and early modern historians. The persecution they suffered at the hands of the Inquisition, the veracity of the claims that attributed to them a clear tendency to remain Jewish in secret long after they were baptized, and their role as cultural agents and active contributors to Spanish culture, particularly in the field of literature, have appealed greatly to researchers. However, in contrast to the vast amount of academic research focusing on Jews from a social perspective, our knowledge of the first generations of conversos is limited. In this article, we present the results of prosopographical research devoted to the converso collective of Valencia from July 9, 1391—the year of the violent and massive conversion of the city’s Hebrew population—to 1420. In particular, we discuss the methodological obstacles presented by such research; evaluate whether the converted population in Valencia can be considered a community after 1391; analyze the socio-professional structure and general economic activities of conversos; and study the social dynamics and interpersonal conflicts that developed both within the group and with Old Christians during this thirty-year period.

     

Vividness of visual imagery and social desirable responding: correlations of the vividness of visual imagery questionnaire with the balanced inventory of desirable responding and the Marlowe–Crowne scale

Correlational research investigating the relationship between scores on self-report imagery questionnaires and measures of social desirable responding has shown only a weak association. However, researchers have argued that this research may have underestimated the size of the relationship because it relied primarily on the Marlowe-Crowne scale (MC; Crowne & Marlowe, Journal of Consulting Psychology, 24, 349-354, 1960), which loads primarily on the least relevant form of social desirable responding for this particular context, the moralistic bias. Here we report the analysis of data correlating the Vividness of Visual Imagery Questionnaire (VVIQ; Marks, Journal of Mental Imagery, 19, 153-166, 1973) with the Balanced Inventory of Desirable Responding (BIDR; Paulhus, 2002) and the MC scale under anonymous testing conditions. The VVIQ correlated significantly with the Self-Deceptive Enhancement (SDE) and Agency Management (AM) BIDR subscales and with the MC. The largest correlation was with SDE. The ability of SDE to predict VVIQ scores was not significantly enhanced by adding either AM or MC. Correlations between the VVIQ and BIDR egoistic scales were larger when the BIDR was continuously rather than dichotomously scored. This analysis indicates that the relationship between self-reported imagery and social desirable responding is likely to be stronger than previously thought.     

Visual perspective taking by dogs (Canis familiaris) in a Guesser–Knower task: evidence for a canine theory of mind?

We tested domestic dogs (N = 16) in a Guesser–Knower task in which they chose between possible locations for hidden food indicated by human informants. In four experiments, the perceptual access of the Guesser and Knower to the hidden food baiting was manipulated. When informants had differing perceptual access to the baiting, dogs preferred the location indicated by the Knower from the start of testing (Experiment 1), even when baiting was done by a third experimenter (Experiments 2–3). However, when there was no difference in perceptual access and both informants either knew or did not know the food location, dogs had no preference between the informants (Experiment 4). Controls ruled out alternative explanations in terms of associative learning, unintentional and olfactory cues. Analysis of individual data showed no significant heterogeneity across dogs, and results were not correlated with age or sex. Dogs’ performances were superior to those of nonhuman primates in previous studies. Although a mentalistic explanation is not required, results add to evidence that dogs have a remarkable sensitivity to cues related to humans’ attentional state, which enables them to respond as if they had a functional theory of mind in the Guesser–Knower task with human informants.