phenomenon · claim-type · cross-domain-transfer · mechanism · claim-relation · replication-status · limitation — grounded in the full text| phenomenon | spatial cognition in birds— “Spatial cognition in birds is an exciting, forming research field which will continue to provide important insights on the evolution and mechanisms of spatial cognition.” | |
| claim-type | existence— “Taken together, these and other results are compelling evidence that the hippocampus serves as a center for spatially related behaviors in birds, as in mammals.” | |
| method — evidence | — “The aim of this primer is to highlight the insights and questions in the field of spatial cognition in birds, with an emphasis on recent research attempting to close the knowledge gap between birds and mammals by shedding light on the neural mechanisms of spatial cognition in birds.” | |
| mechanism | Species differ in place-cell abundance because the ecological demand for spatial memory differs: caching and homing species that must remember many locations develop robust place coding, species that do not need it show little— “A hypothesis explaining this diversity is that the occurrence of place cells across species is correlated with strong reliance on spatial memory capacities.” | mechanisms[0] |
| mechanism | Because caching birds must retrieve many hidden items, selection for that behaviour is what produces the enlarged hippocampus and abundant place cells, so place cells are proposed to serve spatial memory rather than merely accompany it— “finding robust place cells in a bird that specializes in its food-caching behaviors, and not in a species that does not exhibit such behavior, provides strong support for the hypothesis that place cells contribute to spatial memory.” | mechanisms[1] |
| mechanism | Head direction tuning in a migratory seabird is anchored by the earth's magnetic field, the cells encoding head angle relative to magnetic north— “The plausible explanation is that the cells are sensitive to the angle of the head relative to the magnetic north.” | mechanisms[2] |
| mechanism | Knowing one's own place and heading requires converting head- and body-centred sensory input into an environment-fixed frame, a transformation performed in and upstream of the hippocampus— “To know one’s own position and direction requires a transformation from egocentric sensory inputs that move with the animal’s head and body to allocentric representations that are fixed in the environment.” | mechanisms[3] |
| builds-on | Edward Tolman, 'Cognitive maps in rats and men'— “This metaphor, dated to the early days of spatial cognition research, stresses the importance of studying cognitive maps in birds.” | claim_relations[0] |
| sense | a place cell - A RODENT-DERIVED CRITERION APPLIED ACROSS A PHYLUM: about 2% of more than 2,000 quail hippocampal units passed the criterion, and most of those lacked the clear single field of activity the classical rodent place cells show, so the category is being tested in birds by a standard defined on the animal it was discovered in— “Extensive analysis of more than 2,000 single units in the hippocampus of quails found little evidence of place cells in quails: only ~2% of the recorded units passed the criterion for place cells, and even in this small population of cells, most units did not show a clear single field of activity as expected from the classical place cells… | senses[0] |
| sense | the avian hippocampus - A HOMOLOGUE THAT DIFFERS FUNDAMENTALLY: identified as the avian homologue of the mammalian hippocampus by development, connectivity and cellular markers, and stated in the next sentence to have an architecture fundamentally different after three hundred million years of independent evolution - the correspondence and the difference are asserted together— “Research on the development, connectivity and cellular markers of avian brains has identified the avian homologue of the mammalian hippocampus. Three hundred million years of independent evolution have given rise to an hippocampal architecture in birds which differs fundamentally from that of the mammalian hippocampus” | senses[1] |
| sense | a cognitive map - A DIFFERENT ORDER OF MAGNITUDE IN BIRDS: the well-studied rodent maps cover small areas while avian maps must represent ranges of hundreds and thousands of kilometres, so the same term names representations whose spatial scale differs by several orders— “Unlike the wellstudied cognitive maps in rodents traversing small areas, however, these cognitive maps need to represent, in some species of birds, ranges of hundreds and thousands of kilometers” | senses[2] |
| for which use | limitation — any mechanistic claim in the review: OUR UNDERSTANDING OF THE NEURAL MECHANISMS OF SPATIAL COGNITION IN BIRDS IS STILL POOR | limitations[0] |
| for which use | limitation — every avian hippocampal recording in the literature: TO DATE, ALL THE EXPERIMENTS IN WHICH BRAIN ACTIVITY WAS RECORDED IN THE HIPPOCAMPUS OF BIRDS HAVE BEEN CONDUCTED IN RELATIVELY SMALL ENVIRONMENTS - unlike the scales at which birds navigate | limitations[1] |
| for which use | limitation — the magnetic-field question specifically: FURTHER EXAMINATION OF HEAD DIRECTION CELLS IN STREAKED SHEARWATER AND OTHER BIRDS IS NECESSARY TO RESOLVE HOW THE HEAD DIRECTION SYSTEM IN THE AVIAN HIPPOCAMPUS IS INFLUENCED BY THE EARTH'S MAGNETIC FIELD Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | limitations[2] |
| for which use | limitation — any claim about place cells in birds: of more than 2,000 single units recorded in quail hippocampus, only about 2% passed the criterion for place cells, and most of those did not show the clear single field expected from the classical place cells found in rodents Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | limitations[3] |
| for which use | limitation — any transfer of a mammalian hippocampal result to birds: the avian homologue of the mammalian hippocampus has an architecture that, after three hundred million years of independent evolution, differs fundamentally from the mammalian one Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | limitations[4] |
| replication | untested | |
| limitation | The neural mechanisms of avian spatial cognition remain poorly understood. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | limitations[0] |
| limitation | All avian hippocampal recordings so far come from small enclosures, unlike the scales at which birds actually navigate. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | limitations[1] |
| limitation | How the earth's magnetic field shapes the avian head-direction system is not yet resolved. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | limitations[2] |
| limitation | The category's criterion comes from another species, and 2% of the units tested meet it. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | limitations[3] |
| limitation | The structure is called a homologue and stated to differ fundamentally in architecture. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | limitations[4] |
finding · quantity · variable · definition · key-term — grounded in the full text| finding | The avian hippocampus is a neuronal sheet on the dorsal surface of the caudal medial pallium, whereas the mammalian hippocampus is a folded structure below the neocortex. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[0] |
| finding | The avian hippocampus lacks the granule layer that defines the mammalian structure. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[1] |
| finding | Hippocampal-lesioned homing pigeons consistently show impaired homing. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[2] |
| finding | Immediate-early gene expression rises in hippocampal neurons of birds searching remembered food locations, a second line of evidence tying the structure to spatial memory. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[3] |
| finding | In food-caching species such as titmice, chickadees and jays, the hippocampus is larger than in most non-caching birds. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[4] |
| finding | Recordings in Japanese quail found that only about 2% of units passed the place-cell criterion, and most of these lacked a clear single field. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[5] |
| finding | The tufted titmouse recordings gave the first clear evidence of place cells in a bird species. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[6] |
| finding | In the non-caching zebra finch, place cells were significantly rarer and less robust. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[7] |
| finding | Preliminary recordings found hippocampal cells in flying barn owls that fired reliably when the owl flew through a confined region of the flight room. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[8] |
| finding | Head direction cells in these birds mostly pointed to or near north. Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.findings[9] |
| quantity | ~2% — Proportion of recorded quail hippocampal units meeting the place-cell criterion Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.quantities[0] |
| quantity | about 12% — Proportion of quail hippocampal cells classified as head direction cells Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.quantities[1] |
| quantity | More than 60% — Proportion of recorded tufted titmouse hippocampal cells classified as place cells Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.quantities[2] |
| quantity | more than 2,000 — Single units analysed in the quail hippocampus study Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.quantities[3] |
| quantity | around 300 million years — Time since the bird and mammal lineages diverged, the evolutionary distance that makes the comparison informative Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.quantities[4] |
| quantity | 200-meter-long — Length of the tunnel in which flying bats showed multifocal place fields, the cited evidence that spatial coding changes with environment scale Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.quantities[5] |
| definition | spatial cognition Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.definitions[0] |
| definition | place cell Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.definitions[1] |
| definition | cognitive map Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.definitions[2] |
| definition | border cells Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.definitions[4] |
| evidence status note | definition — THE QUOTE CONTINUES A SENTENCE THAT THIS COPY CUTS IN TWO - another paragraph, moved between the list and its tail, stands between it and the words it follows, which read 'a whole range of spatial cell types have been discovered'. | content_tags.definitions[4] |
| definition | central-place foraging Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.definitions[5] |
| definition | place cells Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.definitions[6] |
| definition | head direction cells Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.definitions[7] |
| definition | grid cells Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | content_tags.definitions[8] |
| concept | place cells Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | concepts[0] |
| concept | avian homologue Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | concepts[1] |
| concept | mammalian hippocampus Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | concepts[2] |
| concept | cognitive maps Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | concepts[3] |
| concept | criterion Quotation withheld — this paper is not ours to reproduce, and the page has already quoted as much of it as the rights layer allows. The tag, its field and its confidence stand; the sentence is at the publisher. | concepts[4] |
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