View:

<ListBox DataContext="{Binding Persons}"
         ItemsSource="{Binding Names}"
         SelectedIndex="{Binding SelectedIndex}">
</ListBox>


ModelView:

private List<Person> _persons = new List<Person>();
private int _selectedIndex;

public List<Person> Persons
{
    get { return _persons; }
    set { _persons = value; }
}

public int SelectedIndex
{
    get { return _selectedIndex; }
    set
    {
        _selectedIndex = value;
        OnPropertyChanged("SelectedIndex");
    }
}

Model:

public class Person
{
    private List<string> _names;

    public List<string> Names
    {
        get { return _names; }
        set { _names = value; }
    }
}