Think family-friendly viewing times mean family-friendly content?

Maybe not.

The Parents Television Council (PTC), a nonprofit organization dedicated to educating parents about television content, has released a new study looking at nudity on prime-time broadcast television which reveals a major increase over the 2011-2012 season.

The study found that there were 76 incidents of full nudity on 37 shows compared to 15 incidents in 14 shows the previous ratings season, representing a 407 percent rise in incidents. Almost 70 percent of the scenes that featured such nudity were on shows which aired prior to 9pm, compared to 50 percent of the full nudity scenes which aired before 9pm during the 2010-2011 season.

In addition, the study says only five of the 76 full-nudity depictions contained an “S” descriptor to warn parents to the explicit nature of the episode.

But perhaps the most jaw-dropping finding was in regard to full-frontal nudity. While just one incidence of this occurred during the 2010-2011 study period, 64 documented full-frontal incidences occurred this past season, a 6,300 percent increase .

Examples of the content used to illustrate this point included a scene from ABC’s “Don’t Trust the B- in Apartment 23” in which Chloe sits on the kitchen counter – her breasts, buttocks, and genitals pixilated. On “Suburgatory,” George and Noah argue in the steam room and Fred opens his towel, his genitals pixilated. NBC’s “The Office” contained a scene in which Robert jumps into the pool during a party, his genitals blurred, and on “America’s Got Talent,” Nick Cannon takes a camera behind-the-scenes and knocks on Howie’s trailer. He invites him in despite being totally naked, where his genitals are blurred out.

A full breakdown of the study can be viewed here.

Melissa Henson, director of communications for the PTC, said the findings didn't surprise her.

“For years executives at the broadcast networks have been telegraphing their intent to follow in the footsteps of premium cable networks like HBO, Cinemax, and Showtime, and as this data shows, they are doing exactly that,” she told FOX411’s Pop Tarts column. “They have been aggressively increasing the amount and explicitness of sexual content, nudity, foul language and violence in their primetime offerings, while excusing it by saying that’s what they have to do to ‘stay competitive’ with premium channels that garner only 1/10th the audience, even on their highest-rated programs. Nevertheless, it’s shocking to see a more than 400 percent increase in just two years.”

She stressed that the pixilated or blurred nudity does not give the networks a free pass.

“The impact is virtually the same as actually showing it. Just as ‘bleeping’ an ‘f-word’ or ‘s-word’ is virtually the same as airing the actual word,” Henson continued. “It just calls attention to the thing that has been edited out.”

L.A.-based therapist Dr. Nancy Irwin agrees.

"Simulated or blurred nudity can be just as titillating as real nudity in the human brain. Upon any stimulus, the brain searches for anything remotely similar or familiar, and reacts in a similar manner," she said. "If something is missing -- as in pixelization -- the brain will fill in the blanks from the existing storehouse of knowledge. Indeed, it will work harder to do so than if the real image were there. This explains why fantasy is many times better than reality. It triggers our imagination, which is endless."

The report findings prompted PTC President Tim Winter to send a letter to Congress, requesting that they urge the Federal Communications Commission to move forward in clearing the accumulation of 1.6 million unexamined indecency complaints.

“The networks have made it abundantly clear they have no intention of respecting either the broadcast licenses they’ve been granted or the public in whose interest they are licensed to serve,” he wrote. “Therefore the American people, whose values are being assaulted on a nightly basis, must insist that the Federal Communications Commission vigorously enforce broadcast decency laws, as mandated by the Congress and affirmed by the Supreme Court.”

Winter said without pressure from the public, networks will continue to push - or blur - the boundaries.

“I think we can safely assume the networks will continue on this path unless and until they start to feel push-back from viewers and sponsors,” Henson added. “As long as there are companies willing to pay for ad time on shows featuring this type of content, the networks will continue to produce it. Consumers need to communicate their concerns to the companies that sponsor content like this.”

CBS and FOX declined to comment on the study, and ABC, CW and NBC – all of which had programs mentioned in the study – did not respond to a request for comment. In addition, the FCC did not respond for comment.

Danielle Jones-Wesley contributed to this report.