“ Accordingly, we held that protection of the privilege against self-incrimination during pretrial questioning requires application of special "procedural safeguards." Id., at 444, 86 S.Ct., at 1612. "Prior to any questioning, the person must be warned that he has a right to remain silent, that any statement he does make may be used as evidence against him, and that he has a right to the presence of an attorney, either retained or appointed." ”

“ The appellate court agreed that when Muniz was asked "to submit to a field sobriety test, and later perform these tests before the videotape camera, no Miranda warnings were required" because such sobriety tests elicit physical, rather than testimonial, evidence within the meaning of the Fifth Amendment. 377 Pa.Super., at 387, 547 A.2d, at 422. The court concluded, however, that "when the physical nature of the tests begins to yield testimonial and communicative statements . . . the protections afforded by Miranda are invoked." ”

“ Rather, the privilege "protects an accused only from being compelled to testify against himself, or otherwise provide the State with evidence of a testimonial or communicative nature." Id., at 761, 86 S.Ct., at 1830. " [I] n order to be testimonial, an accused's communication must itself, explicitly or implicitly, relate a factual assertion or disclose information. Only then is a person compelled to be a 'witness' against himself." ”

“ The Commonwealth and the United States as amicus curiae argue that this incriminating inference does not trigger the protections of the Fifth Amendment privilege because the inference concerns "the physiological functioning of [Muniz's] brain," Brief for Petitioner 21, which is asserted to be every bit as "real or physical" as the physiological makeup of his blood and the timbre of his voice. ”

“ The content of his truthful answer supported an inference that his mental faculties were impaired, because his assertion (he did not know the date of his sixth birthday) was different from the assertion (he knew the date was (correct date) ) that the trier of fact might reasonably have expected a lucid person to provide. Hence, the incriminating inference of impaired mental faculties stemmed, not just from the fact that Muniz slurred his response, but also from a testimonial aspect of that response. ”

“ We disagree. Officer Hosterman's dialogue with Muniz concerning the physical sobriety tests consisted primarily of carefully scripted instructions as to how the tests were to be performed. These instructions were not likely to be perceived as calling for any verbal response and therefore were not "words or actions" constituting custodial interrogation, with two narrow exceptions not relevant here. ”

“ This conclusion is consistent with our recognition in Doe that " [t] he vast majority of verbal statements thus will be testimonial" because " [t] here are very few instances in which a verbal statement, either oral or written, will not convey information or assert facts." 487 U.S., at 213, 108 S.Ct., at 2349. Whenever a suspect is asked for a response requiring him to communicate an express or implied assertion of fact or belief, [11] the suspect confronts the "trilemma" of truth, falsity, or silence, and hence the response (whether based on truth or falsity) contains a testimonial component. ”

“ But "without proper safeguards the process of in-custody interrogation of persons suspected or accused of crime contains inherently compelling pressures which work to undermine the individual's will to resist and to compel him to speak where he would not otherwise do so freely." ”

“ Miranda v. Arizona, 384 U.S. 436, 467, 86 S.Ct. 1602, 1624, 16 L.Ed.2d 694 (1966) . Moreover, false testimony does not give rise directly to sanctions (either religious sanctions for lying under oath or prosecutions for perjury) , but only indirectly (false testimony might itself prove incriminating, either because it links (albeit falsely) the suspect to the crime or because the prosecution might later prove at trial that the suspect lied to the police, giving rise to an inference of guilty conscience) . ”

“ Muniz does not challenge the state court's conclusion on this point, and therefore we have no occasion to review it.↑ The two exceptions consist of Officer Hosterman's requests that Muniz count aloud from 1 to 9 while performing the "walk and turn" test and that he count aloud from 1 to 30 while balancing during the "one leg stand" test. Muniz's counting at the officer's request qualifies as a response to custodial interrogation. ”

“ Finally, Officer Deyo asked Muniz to submit to a breathalyzer test designed to measure the alcohol content of his expelled breath. Officer Deyo read to Muniz the Commonwealth's Implied Consent Law, 75 Pa. Cons. Stat. § 1547 (1987) , and explained that under the law his refusal to take the test would result in automatic suspension of his driver's license for one year. Muniz asked a number of questions about the law, commenting in the process about his state of inebriation. ”

“ The test is premised on the understanding that, whereas everyone's eyes exhibit some jerking while turning to the side, when the subject is intoxicated "the onset of the jerking occurs after fewer degrees of turning, and the jerking at more extreme angles becomes more distinct." ”

“ The patrol officer arrested Muniz and transported him to the West Shore facility of the Cumberland County Central Booking Center. Following its routine practice for receiving persons suspected of driving while intoxicated, the booking center videotaped the ensuing proceedings. ”