BS-3016_2024-25_Matheson_Lecture_01

Birdsong and Language

Course Information

• BS3016 Neuroscience Futures

• Instructor: Tom Matheson

• Affiliation: School of Biological Sciences

• Contact: tm75@le.ac.uk

Outline of Presentation

Part I: Song Learning

• Who sings, and what comprises a song?

• What is it good for, and when is it produced?

• The development of song.

Part II: Neuronal Basis for Song Learning

• Parts of the brain associated with song learning and production.

• Roles of individual neurons.

• Additional comments are included in the notes field of the slideshow.

Who Sings and Why?

• Focus on Passerine (perching) songbirds.

• Communicative purposes of songs:

  • Territoriality: Establishing individual identity.

  • Courtship: Attracting mates.

• Primarily sung by male birds.

• Varying levels of song complexity and repertoires can range from 1 to several thousand songs, with around 100 being typical.

• Songs must be learned and remembered for extended periods, under hormonal control.

  • Notable Species: Canary, White-crowned sparrow, Zebra finch.

Song Learning in Passerines

• Provides a model to analyze behavioral, neuroanatomical, and cellular mechanisms behind learned behaviors in vertebrates.

• May offer insights into human language acquisition.

  • Reference: Williams, H. (1997) - Zebra Finch Song Archive.

Song Structure and Terminology

Examples:

• White-crowned sparrow:

  • Phrase A: Whistle

  • Phrase B: Trill

• Canary:

  • Variety of song elements.

  • Key characteristics illustrated through sonograms and spectrograms showing time-frequency sound analysis.

Genetic Specification vs. Learning

• Songs can be a combination of learned and genetically specified traits.

• Comparison Models:

  • Model 1: Composite copy of elements from tutors.

  • Model 2: Representation in swamp sparrows.

Song Training Methods

• Categories:

  • Isolation and training

  • Normal vs. Untrained conditions.

• Implications for understanding song learning in young birds through exposure during development.

Overview of Learning Process

• Adult songs are largely learned, emphasizing the need for understanding the learning process during development.

Development of Song

Development Stages:

1. Subsong:

   • Early phase, similar to babbling in human infants.

2. Plastic Song:

   • Refinement of sounds, imitating adult songs.

3. Crystallized Song:

   • Stabilized version of adult song retained over time.

• Open-ended learners like canaries revisit this process each year.

Critical Periods in Learning

• Important for song development, requiring exposure to adult songs during sensitive phases.

• Species-specific differences in when singing begins.

Variability in Learned Songs

• Songs are unique, incorporating three elements:

  • Imitation: Direct copies of tutor songs.

  • Improvisation: Variations on the tutor song.

  • Invention: New elements not present in tutor songs.

• Birds reduce their syllable repertoire for social integration as they mature.

Genetic Encoding and Tutor Songs

• White-crowned sparrows can learn songs from both their species and different species but ultimately crystallize their species-specific song.

• Suggests existence of a genetically encoded template for song learning.

Transition to Neuronal Basis of Song Learning

• Presentation will continue with insights into the neuronal framework supporting song acquisition and production.

Neuronal Basis of Song Learning

Pathways Involved:

1. Anterior Forebrain Pathway:

   • Includes LMAN, Area X, DLM.

2. Song Production Pathway:

   • Involves HVc, RA, nXIIts.

Neuronal Plasticity

Observations:

• Volume of HVc and RA increases in spring, correlating with song refinement.

• Neuronal growth and new synapses contribute to learning processes.

Role of Neurogenesis in Learning

• Neurogenesis happens in HVc during the learning phase before actual song output begins, suggesting a critical link to memory formation.

Auditory Feedback During Learning

• LMAN's role: critical in juvenile phase for song learning but not in adult song maintenance or production.

• Effects of disruption indicate its importance in auditory feedback provision.

Production Pathway Dynamics

• Stimulation of HVc and RA impacts song patterns, highlighting the functional dynamics in the song production pathways.

Characteristics of Neurons in HVc

• Neurons fire in specific patterns in response to the bird's own song and that of conspecifics, demonstrating a mechanism for vocal learning.

• Functions akin to 'mirror neurons' observed in primates, suggesting a sensory-motor integration role.

Conclusion

• Insights from scientific study of songbirds contribute to broader understanding of communication, behavior, and neuronal function analogous to human language learning.