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Richard W Byrne

Publications and source records attributed to Richard W Byrne.

13 recordsLinked to original sources
PubMed2006

Reproducing human actions and action sequences: "Do as I Do!" in a dog.

We present evidence that a dog (Philip, a 4-year-old tervueren) was able to use different human actions as samples against which to match his own behaviour. First, Philip was trained to repeat nine human-demonstrated actions on command ('Do it!'). When his performance was markedly over chance in response to demonstration by one person, testing with untrained action sequences and other demonstrators showed some ability to generalise his understanding of copying. In a second study, we presented Philip with a sequence of human actions, again using the 'Do as I do' paradigm. All demonstrated actions had basically the same structure: the owner picked up a bottle from one of six places; transferred it to one of the five other places and then commanded the dog ('Do it!'). We found that Philip duplicated the entire sequence of moving a specific object from one particular place to another more often than expected by chance. Although results point to significant limitations in his imitative abilities, it seems that the dog could have recognized the action sequence, on the basis of observation alone, in terms of the initial state, the means, and the goal. This suggests that dogs might acquire abilities by observation that enhance their success in complex socio-behavioural situations.

Animals↗
PubMed2006

Animal cognition: know your enemy.

Food-storing corvids are able to remember which individual saw them store food, and take preventive action that is tailored to that particular competitor's knowledge. This raises the question of whether abilities like 'theory of mind' have arisen independently more than once in evolution.

Animals↗
PubMed2006

Primates take weather into account when searching for fruits.

Temperature and solar radiation are known to influence maturation of fruits and insect larvae inside them . We investigated whether gray-cheeked mangabeys (Lophocebus albigena johnstonii) of Kibale Forest, Uganda, take these weather variables into account when searching for ripe figs or unripe figs containing insect larvae. We predicted that monkeys would be more likely to revisit a tree with fruit after several days of warm and sunny weather compared to a cooler and more cloudy period. We preselected 80 target fig trees and monitored whether they contained ripe, unripe, or no fruit. We followed one habituated monkey group from dawn to dusk for three continuous observation periods totalling 210 days. Whenever the group came within a 100 m circle of a previously visited target tree for a second time, we noted whether or not individuals proceeded to the trunk, i.e., whether they "revisited" or simply "bypassed" the tree. We found that average daily maximum temperature was significantly higher for days preceding revisits than bypasses. The probability of a revisit was additionally influenced by solar radiation experienced on the day of reapproach. These effects were found only for trees that carried fruit at the previous visit but not for trees that had carried none. We concluded that these nonhuman primates were capable of taking into account past weather conditions when searching for food. We discuss the implication of these findings for theories of primate cognitive evolution.

Animals↗
PubMed2005

Social cognition: imitation, imitation, imitation.

Monkeys recognize when they are being imitated, but they seem unable to learn by imitation. These facts make sense if imitation is seen as two different capacities: social mirroring, when actions are matched and have social benefits; and learning by copying, when new behavioural routines are acquired by observation.

Animals↗
PubMed2005

Animal evolution: foxy friends.

Red foxes that have been selected since 1959 for tameness to humans show some of the sociocognitive abilities of domestic dogs, raising questions for theories of the evolution of cognition.

Animals↗
PubMed2005

Successful repair of an intracranial nail-gun injury involving the parietal region and the superior sagittal sinus. Case report.

Intracranial nail injuries to the brain are rare. Various techniques for the removal of penetrating nails have been reported, but to date successful nail extraction following an injury involving the superior sagittal sinus (SSS) has not been reported. The authors report the case of a nail-gun injury to the midline parietal region with penetration of the SSS. They describe an original surgical technique involving the use of a graft patch of temporal fascia and muscle to repair the SSS following extraction of the nail. The procedure resulted in preservation of distal flow across the sinus and a good neurological outcome. Technical considerations in the repair of penetrating posterior SSS injuries are discussed. Penetrating nail injuries to the brain involving the SSS can be successfully repaired with maintenance of sinus patency.

Adult↗
PubMed2004

Neocortex size predicts deception rate in primates.

Human brain organization is built upon a more ancient adaptation, the large brain of simian primates: on average, monkeys and apes have brains twice as large as expected for mammals of their size, principally as a result of neocortical enlargement. Testing the adaptive benefit of this evolutionary specialization depends on finding an association between brain size and function in primates. However, most cognitive capacities have been assessed in only a restricted range of species under laboratory conditions. Deception of conspecifics in social circumstances is an exception, because a corpus of field data is available that encompasses all major lines of the primate radiation. We show that the use of deception within the primates is well predicted by the neocortical volume, when observer effort is controlled for; by contrast, neither the size of the rest of the brain nor the group size exert significant effects. These findings are consistent with the hypothesis that neocortical expansion has been driven by social challenges among the primates. Complex social manipulations such as deception are thought to be based upon rapid learning and extensive social knowledge; thus, learning in social contexts may be constrained by neocortical size.

Adaptation, Physiological↗
PubMed2004

Sex difference in chimpanzee handedness.

Chimpanzees at Mahale, Tanzania, show strong individual hand preferences when they use bimanual actions in processing the fruit of Saba florida and Citrus lemon. The direction of hand preference differs between the sexes: most males are left-handed, whereas most females are right-handed. Monkeys and apes are considered to lack "handedness," in the sense of a population mode of left- or right-hand preference; they are normally ambidextrous. Indeed, strong individual preferences were previously seldom found in natural tasks. We propose that lateralization of manual actions becomes advantageous in bimanual tasks, which involve role differentiation between the hands and a need to combine power and precision. If the pattern of lateralization found here reflects the ancestral state, common to chimpanzees and humans, this may explain why, in modern humans, women tend more strongly to be right-handed than men, who include a larger minority of left-handers.

Animals↗
PubMed2004

Understanding culture across species.

Recent claims of culture in great apes have provoked fervent argument about the 'true' definition of culture, most of which has been unhelpful. Instead, a range of definitions should be used to explore different aspects of the cognitive processes that together result in human culture, many of which can be productively studied in non-humans. A richer cognitive account of the contents of culture needs to be developed and used to compare animal and human cultures, instead of sterile searching for a cognitive Rubicon between them. Exploring six views of culture, this article highlights the fundamental contrast of whether culture evolves as a by-product of cumulative change in cognitive mechanisms, or whether it is actively selected for its advantages.

Adaptation, Psychological↗
PubMed2004

Munchausen's syndrome in neurosurgery: report of two cases and review of the literature.

OBJECTIVE AND IMPORTANCE: Munchausen's syndrome is a rare psychiatric condition, in which patients seek medical treatment for factitious or self-induced medical problems. Reports in the literature of postoperative Munchausen's syndrome are extremely rare. The major obstacle to improving management of the patients with Munchausen's syndrome is increasing physicians' awareness and recognition of the disease. Although Munchausen's syndrome is rare, physicians probably will encounter at least one such patient at some point during their career and therefore should be aware of this disorder. CLINICAL PRESENTATION: We report two documented cases of postoperative Munchausen's syndrome in patients who underwent cranial neurosurgery. Both patients received complex flaps for closure of their cranial defects. Both patients later admitted to deliberately reopening their cranial wounds because of a psychological desire to continue their illness. INTERVENTION: The primary therapeutic objective is to achieve wound healing and stop the cycle of surgical procedures. Immediate confrontation with the patient often does more harm than good. Instead, psychiatric consultation, with the potential for nonsurgical management and behavior modification, should be obtained. CONCLUSION: Munchausen's syndrome is a rare psychiatric diagnosis, especially in the postoperative patient. The common clues to diagnosis are: 1) a nonhealing wound in the absence of risk factors for wound failure, 2) a history of psychiatric illness, 3) repeated bleeding from the wound site, and 4) a desire to continue the sick role. Early detection will allow proper psychiatric referral to prevent injuries to the patient, abuses to the medical system, and unnecessary operations.

Adult↗