Time and lots and lots of human reaction will over come this. Obviously they were left on their own too much while growing up, so they have excluded the rest of the world from their "world". To change that will require human interaction a lot more in future. Our dogs were/are always indoor dogs. Though large mix breeds (black lab usually mixed with other stuff) they grew up around and with humans. Sirius, our nine year old Black Lab/Rott Mix has spent her whole life with us and nearly every evening the Spousal Unit "plays" with her - a little rough housing, a little get down on the floor and roll the dog - kind of stuff that I am physically unable to do. Ebony, my black lab, Rhodesian Ridgeback Mix spent her puppy years locked up in a concrete back yard, by herself, was kicked and neglected and abused. By the time she came to me she was cowed and a "loner". When she first arrived she was terrified too come indoors, she fought tooth and nail and literally had to be dragged inside. It took years to get her acclimated too human contact, she was still cowed and feared strangers. It took a lot of love and patience to undo some (not all) of the abuse and neglect she experienced. A lot of social behaviors that dogs have are learned behaviors. If they do not grow up around people or other dogs they become socially crippled. Reprogramming them to be social takes a lot of time and energy and patience. It requires taking little baby steps, spending a little time with them every day and gradually increasing the amount of time they spend with other dogs or with people. Dogs do not like to be "forced" too do anything, and each dog will have their limits as to how much they will accept graciously. Two dogs raised with only themselves as company also need to be gradually weened off of each other by having time apart. One must go someplace away, while the other spends time with a human being or another dog. There are certain body signs and behaviors that should be watched for which signal when the dog has had enough for that session. An experienced trainer will have the understanding and could teach you as well as the dogs in at home sessions. Too many people send their dogs to "dog school" not fully understanding that real dog training is a partnership between humans and dog. the human needs as much (if not more) training as the dog. Thus many times dog school is called a failure when it is the human side of the equation that lacks the training, not the dog. In all honestly without seeing your dogs and without watching them I can not even begin to tell you where to start or where they are at socially. This will require a bit of professional trainer work. Start off with your Vet, as him or her for names and numbers of dog trainers who come to homes. Yes it is expensive. But the long term investment will pay off. Besides there is no such thing as a "free dog"...

Bribe them with food or play. Most dogs that are uninterested in humans have become that way because they don't have any positive associations with them. If your interactions with the dogs mostly involve you watching them carefully and trying to hold/restrain them, you are actually sending very negative messages in doggie language. Dogs that want to invite each other to play will bring each other food or toys, stretch into a "play bow" position, and sometimes yawn. I would avoid direct eye contact, avoid any physical contact other than a nice chin-scratch. Walk by them without looking at them and throw them each a treat, if you see them start to follow you then repeat until they are following you a lot. Then try the same with a toy. Then try getting them to tug the toy with you. (Despite what is said about tug-of-war, games that you initiate with dogs are great forms of bonding and play. It does not cause aggression in dogs.)