Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

The evolution of isocortex

J H Kaas1

  • 1Department of Psychology, Vanderbilt University, Nashville, TN 37240-0009, USA.

Brain, Behavior and Evolution
|January 1, 1995
PubMed
Summary
This summary is machine-generated.

The evolution of the mammalian isocortex is complex, with early mammals having small brains. Over time, various mammalian lines independently evolved larger brains with more isocortical areas.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

The laminar organization of cell types in macaque cortex and its relationship to neuronal oscillations.

bioRxiv : the preprint server for biology·2024
Same author

Functionally matched domains in parietal-frontal cortex of monkeys project to overlapping regions of the striatum.

Progress in neurobiology·2020
Same author

Distributions of vesicular glutamate transporters 1 and 2 in the visual system of tree shrews (Tupaia belangeri).

The Journal of comparative neurology·2014
Same author

Why does the brain have so many visual areas?

Journal of cognitive neuroscience·2013
Same author

Faster scaling of visual neurons in cortical areas relative to subcortical structures in non-human primate brains.

Brain structure & function·2012
Same author

Cortical networks subserving upper limb movements in primates.

European journal of physical and rehabilitation medicine·2012
Same journal

"Mind Over Muscle": Neural and Biomechanical Signatures of Expertise in Early Stone Tool Use.

Brain, behavior and evolution·2026
Same journal

A step forward in encephalization: the virtual endocast of the Middle Pleistocene hominin from Ceprano, Italy.

Brain, behavior and evolution·2026
Same journal

Anatomical and Volumetric Description of the Baird's Beaked Whale (Berardius bairdii) brain from Magnetic Resonance Imaging.

Brain, behavior and evolution·2026
Same journal

Immunohistochemical Staining of the Brain of the Tuatara Sphenodon punctatus.

Brain, behavior and evolution·2026
Same journal

Macroevolutionary patterns of endocast lateralization in catarrhines and fossil hominins.

Brain, behavior and evolution·2026
Same journal

Phylogenetic patterns and genomic correlates of pronounced neocortical reduction in New World monkeys.

Brain, behavior and evolution·2026
See all related articles

Area of Science:

  • Neuroscience
  • Evolutionary Biology
  • Comparative Anatomy

Background:

  • Detailed theories on isocortex evolution are lacking due to limited comprehensive studies across mammalian taxa.
  • Existing theories are sometimes confounded by outdated concepts or questionable premises from early research.
  • Current methods allow reliable definition of cortical areas, but in-depth analysis is incomplete for most species.

Purpose of the Study:

  • To review the current understanding and challenges in theorizing isocortex evolution in mammals.
  • To identify supportable conclusions regarding the evolutionary trajectory of the mammalian isocortex.
  • To explore the potential mechanisms for the emergence of new cortical areas.

Main Methods:

  • Review of existing literature on mammalian brain evolution and cortical development.

Related Experiment Videos

  • Comparative analysis of brain size and isocortex proportions across diverse mammalian lineages.
  • Examination of paleontological and anatomical evidence for cortical area conservation and divergence.

    • Main Results:

    • Early mammals possessed small brains with a limited isocortex.
    • Multiple mammalian lineages independently evolved larger brains with expanded isocortex.
    • A common set of approximately 20 cortical areas, including primary and secondary sensory fields, is conserved across mammals.
    • Some cortical areas show significant expansion and structural modification in specific taxa.
    • The number of cortical areas has increased independently in several mammalian branches.
    • New areas may arise from existing ones through modularization and fusion processes.

    Conclusions:

    • Mammalian isocortex evolution is characterized by both conserved ancestral areas and independent expansions.
    • Increased cortical complexity, indicated by more subdivisions, may enhance cognitive functions in larger brains.
    • The evolution of the isocortex is a dynamic process involving modification, expansion, and potential emergence of new areas over evolutionary time.