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Scientific Understanding of Consciousness |
Intelligence — Recent Research
Science 8 September 2006: Vol. 313. no. 5792, pp. 1431 - 1435 Andreas Nieder, Ilka Diester, Oana Tudusciuc Primate NeuroCognition Laboratory, Hertie-Institute for Clinical Brain Research, Department of Cognitive Neurology, University of Tübingen, Otfried-Müller-Strasse 27, 72076 Tübingen, Germany. Humans and animals can nonverbally enumerate visual items across time in a sequence or rapidly estimate the set size of spatial dot patterns at a single glance. We found that temporal and spatial enumeration processes engaged different populations of neurons in the intraparietal sulcus of behaving monkeys. Once the enumeration process was completed, however, another neuronal population represented the cardinality of a set irrespective of whether it had been cued in a spatial layout or across time. These data suggest distinct neural processing stages for different numerical formats, but also a final convergence of the segregated information to form most abstract quantity representations.
Science 7 September 2007: Vol. 317. no. 5843, pp. 1360 - 1366 Esther Herrmann, Josep Call, María Victoria Hernàndez-Lloreda, Brian Hare, Michael Tomasello 1 Max Planck Institute for Evolutionary Anthropology, Leipzig, D-04103, Germany. Humans have many cognitive skills not possessed by their nearest primate relatives. The cultural intelligence hypothesis argues that this is mainly due to a species-specific set of social-cognitive skills, emerging early in ontogeny, for participating and exchanging knowledge in cultural groups. We tested this hypothesis by giving a comprehensive battery of cognitive tests to large numbers of two of humans' closest primate relatives, chimpanzees and orangutans, as well as to 2.5-year-old human children before literacy and schooling. Supporting the cultural intelligence hypothesis and contradicting the hypothesis that humans simply have more "general intelligence," we found that the children and chimpanzees had very similar cognitive skills for dealing with the physical world but that the children had more sophisticated cognitive skills than either of the ape species for dealing with the social world. Humans have brains roughly three times larger than those of their nearest primate relatives, the great apes, and of course have many cognitive skills not possessed by other primates, from language to symbolic mathematics to scientific reasoning. The questions from an evolutionary point of view—especially given the enormous energetic expense of a large brain—are how and why humans have evolved such powerful and distinctive cognitive abilities requiring so much neural tissue. One hypothesis is the general intelligence hypothesis. Larger brains enable humans to perform all kinds of cognitive operations more efficiently than other species: greater memory, faster learning, faster perceptual processing, more robust inferences, longer-range planning, and so on. The alternative is the adapted intelligence hypothesis. Cognitive abilities evolve in response to relatively specific environmental challenges, and so we may see caching birds with exceptional memory skills, homing pigeons with marked skills of spatial navigation, bees with complex systems of communication, and so forth. In the case of primates, some theorists have proposed that the distinctive aspects of primate cognition evolved mainly in response to the especially challenging demands of foraging for seasonal fruits and resources embedded in substrates [the ecological intelligence hypothesis], whereas others have proposed that the distinctive aspects of primate cognition evolved mainly in response to the especially challenging demands of a complex social life of constant competition and cooperation with others in the social group [the social intelligence hypothesis]. In the case of humans, one reasonable hypothesis involves extending the primate social intelligence hypothesis to reflect the fact that humans are not just social but "ultra-social".
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