PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Brain evolution”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,387 records · Page 77Linked to original sources
PubMed2001

The dream in contemporary psychiatry.

OBJECTIVE: This article offers selective reviews of cogent sectors of research regarding the dream in contemporary psychiatry. METHOD: First, the author discusses relatively recent research (1953-1999) on the neurobiology and clinical psychophysiology of dreaming sleep; second, he reviews experimental cognitive neuroscientific studies of perception, emotion, and memory and the putative interrelationships among them in generating dream imagery; and third, he interprets psychoanalytic studies (1900-1999) on related aspects of dreams and the dream process. RESULTS: Exploration for interrelationships among information from these three areas entails discussion of the mind/brain problem. These considerations illuminate some of the logical and interpretive dilemmas that enter into debates about Freud's theory of the dream. CONCLUSIONS: The author proposes a preliminary psychobiologic concept of the dream process and discusses, in light of the foregoing considerations, the importance of collaborative research for developing a realistic perspective concerning the proper place of the dream in contemporary psychiatry.

Biological Evolution↗
PubMed2001

Chimpanzee sign language and Darwinian continuity: evidence for a neurological continuity for language.

The current article addresses the empirical validity of the Cartesian view of language by first examining a sample of the results generated by over 30 years of chimpanzee sign language studies and then examining some neurological and behavioral data that accounts for the similarity between human and nonhuman communication systems. Finally an attempt will be made to propose a unified model of language that accounts for these findings and shows how the Cartesian world view has proposed a theory of language that is incomplete.

Animals↗
PubMed2002

Putting language back in the body: speech and gesture on three time frames.

This article investigates the role that nonverbal actions play in language processing over 3 different time frames. First, we speculate that nonverbal actions played a role in how formal language systems emerged from our primate ancestors over evolutionary time. Next, we hypothesize that if nonverbal behaviors played a foundational role in the emergence of language over evolution, these actions should influence how children learn language in the present. Finally, we argue that nonverbal actions continue to play a role for adults in the moment-to-moment processing of language. Throughout, we take an embodied view of language and argue that the neural, cognitive, and social components of language processing are firmly grounded in bodily action.

Animals↗
PubMed2005

Do facial movements express emotions or communicate motives?

This article addresses the debate between emotion-expression and motive-communication approaches to facial movements, focusing on Ekman's (1972) and Fridlund's (1994) contrasting models and their historical antecedents. Available evidence suggests that the presence of others either reduces or increases facial responses, depending on the quality and strength of the emotional manipulation and on the nature of the relationship between interactants. Although both display rules and social motives provide viable explanations of audience "inhibition" effects, some audience facilitation effects are less easily accommodated within an emotion-expression perspective. In particular, emotion is not a sufficient condition for a corresponding "expression," even discounting explicit regulation, and, apparently, "spontaneous" facial movements may be facilitated by the presence of others. Further, there is no direct evidence that any particular facial movement provides an unambiguous expression of a specific emotion. However, information communicated by facial movements is not necessarily extrinsic to emotion. Facial movements not only transmit emotion-relevant information but also contribute to ongoing processes of emotional action in accordance with pragmatic theories.

Adaptation, Physiological↗
PubMed1982

Structural analysis of rodent growth hormone genes: application to genetic forms of hypopituitarism.

Analysis of GH gene structure in the mouse permits evolutionary comparisons with GH gene structure in the rat and provides information about the mechanism responsible for heritable deficiencies of anterior pituitary hormones. The little mutation in mice is analogous to autosomal recessive, isolated, partial deficiency of GH in man, whereas the Snell dwarf mutation is a model for autosomal recessive deficiency of GH, TSH, and PRL. Mouse cellular DNA was digested with the restriction enzymes Eco RI, Bam HI, Bgl II, Hind III, and Kpn I, singly and in combination. Gene sequences containing coding information for GH were detected by hybridization to a radiolabeled recombinant DNA probe complementary to a rat GH mRNA. The results of genomic restriction analysis indicate that there is a single type of mouse GH gene sequence per haploid genome with a length equal to or less than 32000 base pairs. The distances separating 6-base restriction sites close to the mouse GH gene differ from those close to the rat GH gene. A Kpn I site in the codons for amino acids 103 and 104 of rat GH is absent in the mouse gene. Restriction patterns of DNA from little and Snell dwarf mice did not differ from those of normal mice, indicating that these mutations do not involve deletions of the mouse GH gene.

Animals↗
PubMed2000

Evolution of air-breathing and central CO(2)/H(+) respiratory chemosensitivity: new insights from an old fish?

While little is known of the origin of air-breathing in vertebrates, primitive air breathers can be found among extant lobe-finned (Sarcopterygii) and ray-finned (Actinopterygii) fish. The descendents of Sarcopterygii, the tetrapods, generate lung ventilation using a central pattern generator, the activity of which is modulated by central and peripheral CO(2)/H(+) chemoreception. Air-breathing in Actinopterygii, in contrast, has been considered a 'reflexive' behaviour with little evidence for central CO(2)/H(+) respiratory chemoreceptors. Here, we describe experiments using an in vitro brainstem preparation of a primitive air-breathing actinopterygian, the longnose gar Lepisosteus osseus. Our data suggest (i) that gill and air-breathing motor patterns can be produced autonomously by the isolated brainstem, and (ii) that the frequency of the air-breathing motor pattern is increased by hypercarbia. These results are the first evidence consistent with the presence of an air-breathing central pattern generator with central CO(2)/H(+) respiratory chemosensitivity in any primitive actinopterygian fish. We speculate that the origin of the central neuronal controller for air-breathing preceded the divergence of the sarcopterygian and actinopterygian lineages and dates back to a common air-breathing ancestor.

Animals↗
PubMed1998

Müller glia cells and their possible roles during retina differentiation in vivo and in vitro.

Müller cells are astrocyte-like radial glia cells which are formed exclusively in the retina. Here we present evidence that Müller cells are crucially involved in the development of the retina's architecture and circuitry. There is increasing evidence that Müller cells are present from the very early beginning of retinogenesis. We postulate the "gradual maturation hypothesis of Müller cells". According to this hypothesis, Müller cells are continuously generated by a gradual transition of neuroepithelial stem cells into mature Müller cells. This process may be partly reversible. Müller cells, or their immature precursors, are able to subserve different functions. They are primary candidates for stabilizing the complex retinal architecture and for providing an orientation scaffold. Thereby, they introduce a reference system for the migration and correct allocation of neurons. Moreover, they may provide spatial information and microenvironmental cues for differentiating neurons, and may also be important for the segregation of cell and fibre layers. Additionally, they seem to be involved in the guidance of axonal fibres both in radial and in lateral directions, as they are involved in the support and stabilization of synapses.

Animals↗