Development of hemispheric specialization pattern, a model of ontogenetic plasticity

• Applicant: Professorin Dr. Martina Manns
• Subject Area: Cognitive, Systems and Behavioural Neurobiology ; General, Cognitive and Mathematical Psychology ; Human Cognitive and Systems Neuroscience
• Term: from 2014 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 247871126

• Final Report Year: 2024

Final Report Abstract

In many animal species, the left and right hemispheres of the brain are specialised to perform different functions. Functional asymmetries are based on structural and physiological left-right differences in neuronal networks and result in a complex pattern of lateralisation with different hemispheric dominances for certain aspects of perception, cognition and behaviour. The widespread distribution of brain lateralisation across the animal kingdom indicates fundamental fitness advantages, but it is still unclear how the hemispheres interact to mediate and integrate hemisphere-specific processing and how these mechanisms arise ontogenetically. Functionally lateralised brain organisation requires a finely tuned orchestration of intra- and interhemispheric mechanisms to ensure that hemisphere-specific resources are used efficiently and adapted to specific situations. This becomes particularly evident in situations in which interhemispheric conflicts occur. Hemispheric specialisation means that the two hemispheres consider different aspects of the environment, pay attention to different sensory cues and differ in the way they process information and make decisions. This can lead to interhemispheric conflicts when objects of equal importance appear in the left and right hemifields and the two hemispheres process and evaluate such a situation differently, resulting in incompatible response tendencies. Since interhemispheric conflicts slow down decisionmaking and response behaviour and are therefore potentially evolutionarily disadvantageous, there should be high selection pressure for the existence of neural mechanisms solving interhemispheric conflicts, which ensure the dominance of one hemisphere for conflict decisions (so called metacontrol). To explore the underlying mechanisms and their ontogenetic foundations, we confronted pigeons with different types of interhemispheric conflict situations. Our experiments show that the dominance of one hemisphere results from an interplay of intraand interhemispheric mechanisms, which is influenced by task conditions and ontogenetic light experiences. Optogenetic manipulation studies show a differentiated role of specific forebrain areas that alter interhemispheric interactions and thus, decision-making and behavioural control. It is likely that flexibility in interhemispheric crosstalk is a crucial component of lateralised brains, which organise and integrate specialised perceptual and cognitive processing components. These mechanisms may represent a fundamental building block for the evolutionary advantages of lateralised brains. Impairments could be related to cognitive disadvantages in developmental or psychiatric disorders in humans.

Publications

• “Dogs or cats? Categorization and hemispheric dominance in pigeons” 6th North Sea Laterality International Meeting
  Manns, Martina
  
• “Intra- and interhemispheric communication in a lateralized brain – lessons from the avian brain” Brain & Evolution – German-Japanese Summer school on Comparative Neuroscience of brain Evolution
  Manns, Martina
  
• A cat or a dog? Hemispheric dominance and categorization in pigeons. FCI Brieftaubenkongress für Tierärzte
  Manns, Martina
  
• Hemispheric Specialization. Encyclopedia of Animal Cognition and Behavior, 1-10. Springer International Publishing.
  Manns, Martina
  
• Light‐dependent development of the tectorotundal projection in pigeons. European Journal of Neuroscience, 52(6), 3561-3571.
  Letzner, Sara; Manns, Martina & Güntürkün, Onur
  
• Metacontrol based on categorization in the pigeon brain (4215) 12th FENS Forum on Neuroscience
  Manns, Martina; Otto, Tobias & Salm, Laurenz
  
• It Is Not Just in the Genes. Symmetry, 13(10), 1815.
  Manns, Martina
  
• Laterality for the next decade: Costs and benefits of neuronal asymmetries – putting lateralization in an evolutionary context. Laterality, 26(3), 315-318.
  Manns, Martina
  
• Pigeons show how meta-control enables decision-making in an ambiguous world. Scientific Reports, 11(1).
  Manns, Martina; Otto, Tobias & Salm, Laurenz
  
• Pigeons show how metacontrol enables decision-making in an ambiguous world. Laterality Friday –Laterality online colloquium
  Manns, Martina
  
• The phylogeny of brain asymmetries – benefits and drawbacks of a core organization principle across the animal kingdom First Turkish-German Summerschool on comparative neuroscience
  Manns, Martina
  
• Unfolding functional brain lateralization: the asymmetrical priors model 8th North Sea Laterality International Meeting
  Manns, Martina; Berretz, Gesa; Packheiser, Julian; Güntürkün, Onur & Ocklenburg, Sebastian
  
• Unilateral Lesions. Neuromethods, 265-305. Springer US.
  Manns, Martina