WASHINGTON — The House committee investigating the Jan. 6 assault at the U.S. Capitol is weighing whether to hire staff members who can analyze social media posts and examining the role foreign adversaries played in sowing divisions among Americans over the outcome of the presidential election, according to two people briefed on the committee’s decision making.

The new avenues of inquiry come as the committee, which currently has about 40 staff members, continues to subpoena testimony and documents.

Witnesses this week included William J. Walker, the former commander of the D.C. National Guard, who has said military leaders delayed the guard response on Jan. 6, and the conservative activist Dustin Stockton, whose lawyer said he is turning over a “treasure trove” of documents that would have senior Trump allies and lawmakers “quivering in their boots.”

Mr. Stockton and his fiancée, Jennifer L. Lawrence, assisted in organizing rallies after the election advancing false claims about its outcome. But Mr. Stockton has said he was concerned that a march to the Capitol on Jan. 6 while Congress was certifying the election would mean “possible danger,” and that his urgent concerns were escalated to Mark Meadows, the White House chief of staff at the time, according to the committee.

The political operative Roger J. Stone Jr., a close ally of former President Donald J. Trump, appeared before the committee for a deposition on Friday. But he invoked his Fifth Amendment right against self-incrimination to each of the panel’s questions because, he said, he feared that Democrats would fabricate perjury charges.

“I did my civic duty and I responded as required by law,” Mr. Stone said after the deposition. He then criticized the investigation as “Witch Hunt 3.0,” and accused the government of hiding potentially exculpatory video evidence about the attack on the Capitol.

Mr. Stone has claimed that he was leaving town as rioters stormed the Capitol. “I did not march to the Capitol. I was not at the Capitol,” he said, adding that he believed the violence was “illegal and politically counterproductive.”

But Mr. Stone promoted his attendance at the rallies on Jan. 5 and 6, solicited support to pay for security through the website stopthesteal.org and used members of the Oath Keepers militia group as personal security guards while he was in Washington. At least two of those members have been indicted on charges that they were involved in the Capitol attack.

To bolster the public’s understanding of the attack, the committee is considering hiring several new staff members to analyze the vast amount of information that Mr. Trump’s supporters posted on sites like Twitter, Facebook, Parler and YouTube in the weeks before and after the attack. These digital footprints could help congressional investigators connect players and events, or bring to light details that witnesses might not know or remember.

Federal prosecutors have relied on hundreds of thousands of pieces of digital evidence to identify and support charges against more than 700 defendants who have been arrested in nearly every state for their part in the attack.

The committee’s investigators are also seeking to understand whether foreign governments were able to exploit and deepen social divisions created by Mr. Trump’s refusal to concede his election loss. Foreign adversaries have long tried to damage America’s national security interests by exacerbating social unrest and polarization.

The committee has also discussed examining whether foreign adversaries had any other connections to the assault on Congress, according to a person briefed on that part of the inquiry.

In mid-December, an “enemies list” of prominent people who did not support Mr. Trump’s lies about the election circulated online, including on a website called Enemies of the People. The F.B.I. investigated and attributed the list to an Iranian disinformation campaign that sought to capitalize on the “Stop the Steal” movement to sow divisions.

In November, the Justice Department indicted two Iranian hackers for seeking to influence the 2020 election by sending threatening messages to several thousand voters. Many of the messages were designed to look like they were from the Proud Boys, the right-wing extremist group.

Even as House Republicans have condemned the investigation as a political witch hunt, the committee found support this week from Senator Mitch McConnell of Kentucky, the top Republican in the chamber. Mr. McConnell, who in May led a filibuster that blocked the creation of an independent commission to investigate the attack, said this week that he believed the House committee was uncovering valuable information.

“It was a horrendous event,” Mr. McConnell said of the Capitol siege in a TV interview. “I think what they are seeking to find out is something the public needs to know.”