Is there a difference between constants defined inside a Go function vs ones defined at the top of a package?

Is there a difference, mainly in performance, between constants defined inside vs outside a function scope?

func (this *Person) SetDefaults() *Person{
    const (
        defaultFirstName = "first"
        defaultLastName  = "last"
    )

    //do stuff with constants
    return this
}

vs.

const (
    defaultFirstName = "first"
    defaultLastName  = "last"
)
func (this *Person) SetDefaults() *Person{
    //do stuff with constants
    return this
}