In this episode we take a neuroethological approach to sleep, and discover why songbirds are such a good model system for studying sleep's role in learning. These include advantages like songbirds' sleep-wake patterns and sleep architecture being more similar to human's than rodents', the fact that songbirds are strongly motivated to learn their songs, which can then be easily assessed for accuracy, and the observation that population-level neuronal replay in the song system is often very easy to identify, since patterns of neural firing during replay can actually sound like the songs. We're led through this fascinating topic by Professor Dan Margoliash and Dr Tim Brawn, whose work in Zebrafinches and Starlings has revealed valuable insights into perceptual, declarative and procedural learning, as well as how reconsolidation works, and into why interference learning may sometimes even be useful.
If you'd like to find out more about their work you can find links to their research pages and to some key studies referenced in the episode below:
Here are the websites for Professor Dan Margoliash and Dr. Tim Brawn
Here are links to some of the studies mentioned in the podcast:
o Reconsolidation & interference
o Perceptual & interference learning
o Tutor song selective neurons
o Sleep for perceptual learning
o Sensorimotor integration
Glossary of terms from the podcast
Finger-tapping task = explicitly learning a numeric sequence and typing it as fast and accurately as possible with your non-dominant hand. For instance, you might be asked to type the sequence 4-1-3-2-4 repeatedly while the sequence is displayed on a screen. This primarily tests procedural learning rather than working memory.
Interference = one memory hindering the retrieval of another, e.g. because both memories have overlapping retrieval cues.
Neuronal bursting = periods of multiple action potentials clustered together, which are then followed by extended silent periods.
Reconsolidation = refers to how recalling memories returns them to a labile state, meaning they then need to be re-stabilized to commit them back to long term memory. New learning that takes place before this happens can be used to update the original memory.
Song motif = the individual phrases that make up the song. They are themselves constructed from syllables.
Song stereotypy = refers to a bird's song being repeated with great consistency once learned.
Song system = the discrete set of brain areas that controls song learning and production.