PowerPoint Presentation

Alex Cayco GajicJournal Club 10/29/13

How does motor cortex generate muscle activity?

Representational perspective:

Muscle activity or abstract trajectory parameters? (e.g. hand velocity)

Focus on code in single neurons

2An epic, twenty-year battle was fought over the cortical representation of movement. Do motor cortex neurons represent the direction of the hand during reaching, or do they represent other features of movement such as joint rotation or muscle output?

Graziano 2011Criticism of the representational approachThe role of the motor system is to produce movement, not to describe it.

Cisek 2006How does motor cortex generate muscle activity?

Representational perspective:

Muscle activity or abstract trajectory parameters? (e.g. hand velocity)

Focus on code in single neurons Dynamical systems perspective:

How can cortex flexibly generate such a large repertoire of movements?

Focus on basis sets/ mixed signals, network properties4A few equationsRepresentational view:rn(t) = fn(param1(t),param2(t),)

Dynamical systems perspective:Neural responses muscle movement:m(t) = G[r(t)]But dimensionality of m