Despite a slowing economy and rising gas prices, Massachusetts residents last year spent more than $1 billion for the fifth year in a row at Connecticut and Rhode Island gambling sites, and about one-fifth of the spending went to Rhode Island’s slot parlors, according to a new study by the Center for Policy Analysis at the University of Massachusetts-Dartmouth.

The Bay State gamblers last year dropped $195 million at Twin River in Lincoln and Newport Grand in Newport. Massachusetts residents also spent $846 million at Foxwoods and the Mohegan Sun in Connecticut.

The study found that the renovated Twin River attracted $177 million from Bay State gamblers last year, up $32 million from 2006. About 42 percent of Twin River’s gambling base comes from Massachusetts, the study found.

Clyde Barrow, a professor and author of the study, said the $1 billion that Massachusetts residents gambled in Connecticut and Rhode Island last year showed that there is little sign that the soft economy is stifling gambling. That total is about the same as 2006, according to the study.

“Massachusetts’ patronage of Connecticut and Rhode Island gaming venues remains strong and resilient,” said Barrow. “It is an extraordinary indication of Massachusetts residents’ fervor for gaming-related entertainment, hospitality and tourism in a $5-billion New England gaming market that still has about $2 billion in untapped demand outstanding.”

Gambling opponents in the past have been critical of Barrow’s methodology and findings, arguing that his results tend to be pro-gambling and highlight the untapped growth of revenue and taxes for the host states.

His studies are based in part on the number of Massachusetts license plates counted at the gambling facilities during a five-day span. Based on those surveys and others, Barrow said Massachusetts residents made 8 million trips to casinos and gambling venues in Connecticut, Rhode Island and Maine.

Barrow’s study was released as New England’s gambling industry is undergoing debate and changes.

Last week, state legislators in Massachusetts defeated Governor Patrick’s proposal to license three resort casinos in different parts of the state, including one in the southeast. The vote killed the proposal for this year, but Patrick is weighing bringing his plan back next year.

Meanwhile, the federal Bureau of Indian Affairs will be in Middleboro, Mass., today to hold a public hearing on the plans of the Mashpee Wampanoag Indian tribe to build a gambling facility on 540 acres about 20 miles from Rhode Island’s border.

In Connecticut, Foxwoods is planning the opening of its $700-million MGM Grand hotel and complex in May, and Mohegan Sun is in the midst of a $750-million expansion.

At Twin River, the company that owns the slots parlor has until Friday to work out its financial problems with its lenders. UTGR Inc., which owns Twin River, missed a loan payment earlier this month, prompting negotiations with its lenders and collection efforts by contractors that worked on the building’s $225-million reconstruction.

Barrow’s report said Rhode Island residents last year spent an estimated $261 million at Foxwoods and Mohegan Sun and $271 million at Twin River and Newport Grand. For the first time, Rhode Islanders spent more patronizing Rhode Island’s slot parlors than at Connecticut’s destination resort casinos, the report said.

He added that Twin River’s recent renovation and expansion is aimed at generating a stronger penetration of the Southeastern Massachusetts and southern Worcester County regions. While that has been somewhat successful, Barrow said it appears that Twin River is still attracting convenience players and lower denomination players — 1-cent to 10-cent slot players — who diverted one or more trips from Foxwoods to Twin River. It also appears that Twin River cannibalized a portion of the revenues from Newport Grand last year.

If the trends continue, Barrow said, Twin River would increase its share of lower denomination convenience gamblers from Massachusetts and Rhode Island, but experience marginal success in luring Massachusetts and Rhode Island’s destination casino patrons.