MEXICO CITY — The leader of Mexico’s governing party has said it will stop hiring neuroscience consultants to register voters’ brain waves and read their facial expressions, responding to a political outcry over its use of the tools of neuromarketing to shape its campaign and governing messages.

Manlio Fabio Beltrones, a longtime political boss who in August became leader of the governing Institutional Revolutionary Party, said last week after The New York Times reported on the methods that the party would stick to tried and trusted campaign tools, like polls and political intuition, “the old-fashioned way,” in its future campaigns.

The Times reported last week that the party, known in Spanish as the PRI, had hired neuromarketing experts during President Enrique Peña Nieto’s 2012 campaign to measure potential voters’ brain waves, skin arousal, heart rates and facial expressions. One company, Neuropolitika, said it was asked to assess opposing candidates and the best way for Mr. Peña Nieto to connect emotionally with voters.

Dan Hill, a facial coder in the United States, was paid by a Mexican market research firm to analyze the expressions on voters’ faces during a presidential debate. He reviewed data from 100 voters and presented his findings to campaign strategists in the early morning hours after the debate, he said.