I know nothing about cockroaches. In fact, wouldn't know one end from the other, which could be a distinct disadvantage in this case. However...some snippets from
http://discovermagazine.com/2007/jan/cockroach-consciousness-neuron-similarity :
'From this tedious analysis Strausfeld concludes that insects possess "the most sophisticated brains on this planet."'
'Neurosciences Institute (NSI) in San Diego, finds hints of higher cognitive functions in insects—clues to what one scientific journal called "the remote roots of consciousness."'
'"We have literally no idea at what level of brain complexity consciousness stops," says Christof Koch, another Caltech neuroscientist. "Most people say, 'For heaven's sake, a bug isn't conscious.' But how do we know?'
"Reichert's own studies of the brain's origin lead to a little-known ancestor, a humble creature called Urbilateria, which wriggled and swam nearly a billion years ago. The granddaddy of all bilaterally symmetrical animals, Urbilateria is the forebear of spiders, snails, insects, amphibians, fish, worms, birds, reptiles, mammals, crabs, clams—and yes, humans."