Posts Tagged 'hemispheric asymmetries'

More asymmetries

Gomez-Robles et al 2013Cerebral asymmetries are a thorny issue in both paleoneurology and human neuroanatomy: despite their relevance, their origin and actual variations are elusive. Conceptual and technical problems tend to hamper conclusive statements, as evidenced by the many disagreements and uncertainties in the field. A recent paper on asymmetries in human and chimpanzee brains has added a geometric perspective to the topic. This shape analysis suggests that humans and chimpanzees have the same kind of asymmetries, with humans showing a larger degree of variation and expression of those patterns. Hence, again it seems it is more a matter of grade than of novel characters, at least in terms of geometry. Interestingly, allometry has a very minor role (if any) in intraspecific differences. In both species, shape variation and asymmetries are especially marked in the parietal areas.

Advertisements

Deep asymmetries

Stephanie Bogart and colleagues have published an interesting study on sulci asymmetries in chimps and macaques, on NeuroImage. Quantifying cortical depth and surface area, they found consistent  population-level brain asymmetries in chimpanzees but not in macaques. The paper is a good review on many issues related to brain asymmetries and evolution in primates. Asymmetries that, however, are the results of mechanisms and processes which are still poorly known.

Asymmetries

Brain asymmetries have always been a hot topic in neurosciences. Differences are often so subtle, and there are still many disagreements on this issue. If this topic is difficult to investigate in living species, when analyzing fossil taxa doubts are much more than certainties. In a recent paper Balzeau and colleagues quantify the hemispheric fronto-occipital projection in modern humans, African apes, and fossil hominids, analyzing fluctuating asymmetry, directional asymmetry, and antisymmetry. Differences between groups in distribution and variation are small, and generally related to the degree of asymmetry, not to the presence or combination of characters. It seems that differences between modern humans and apes (and fossil hominids) are a question of grade. Once more, it seems that on this issue the information available from the general endocranial morphology is necessary, but very limited.


Enter your email address to follow this blog and receive notifications of new posts by email.

RSS Cognitive archaeology

  • NEANDERTAL COGNITION OFFERED ONLINE NOW AT THE CENTER FOR COGNITIVE ARCHAEOLOGY @ UCCS
    How did Neandertals experience their world? How did their cognition and culture differ from ours? Were they pragmatic? Callous or cold-hearted? Did they love, were they charitable? Were they tough? Dogmatic? Xenophobic? Join Professors Thomas Wynn and James Hicks for our online course in the Neandertal Cognition. Together, we will explore the mind of some … […]

RSS The Skull Box

  • Anatomical Network Analysis
    Today we launch a new research line in our lab: Anatomical Network Analysis. Networks are employed in almost any field, to investigate patterns and levels of organization within different kinds of systems. In neuroanatomy, networks are frequently used to analyze connections. Anatomical Network Analysis, instead, applies network thinking and methods to macros […]

RSS Anthropology

  • Seven Million Years of Human Evolution
    This fascinating visual presentation from the American Museum of Natural History outlines what we know about human evolution by combining …Continue reading →

RSS Human Evolution

  • An error has occurred; the feed is probably down. Try again later.

RSS Neurophilosophy

  • Researchers develop non-invasive deep brain stimulation method
    Researchers at MIT have developed a new method of electrically stimulating deep brain tissues without opening the skullSince 1997, more than 100,000 Parkinson’s Disease patients have been treated with deep brain stimulation (DBS), a surgical technique that involves the implantation of ultra-thin wire electrodes. The implanted device, sometimes referred to as […]

Disclaimer

This blog publishes texts and comments of the author, which can not be referred to institutions or contexts outside of the blog itself. The published material may be partly derived or reported from the Web, and therefore evaluated in the public domain. If some content violates copyright or if it is considered inappropriate, please contact me, to promptly remove it. On the other hand, please cite this source whenever using images or texts from this website.
Advertisements