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Biomedical subjects

M Tervaniemi

Publications and source records attributed to M Tervaniemi.

44 records · Page 3Linked to original sources
PubMed1994

Neural representations of abstract stimulus features in the human brain as reflected by the mismatch negativity.

Neural sensory-memory representations that encode physical properties of incoming stimuli can be probed by recording the change-specific mismatch negativity of the event-related potential (ERP). The present study was aimed at determining whether invariant stimulus features, abstracted from the continuously changing acoustic environment, are encoded in these sensory-memory representations. Regularly descending tone sequences with an occasional ascending tone or tone repetition were presented to reading subjects. A significant MMN was elicited by the ascending tones. When instead of simple tones, Shepard tones creating an illusion of a continuous pitch decrement were used in the same paradigm, the MMN was elicited by both ascending and repeating tones. It was concluded that besides physical stimulus properties, abstract stimulus features are also encoded in the neural representations of sensory memory.

Acoustic Stimulation↗
PubMed1994

Temporal integration of auditory information in sensory memory as reflected by the mismatch negativity.

Event-related potentials (ERPs) to different types of infrequent change in a tone pair composed of two closely spaced tones of different frequencies were recorded. The mismatch negativity (MMN), a change-specific component of the ERP, was elicited by reversing the order of the two tones, by repeating the first tone, by replacing the first tone with the second tone, or by omitting the second tone. The omission of the second tone, however, elicited the MMN only when the interval between the two tones was very short (offset to onset 40 or 140 ms) but did not when this interval was somewhat longer (240 or 340 ms). The pattern of the present results suggests that sensory-memory traces, as reflected by the MMN, integrate information about two closely spaced stimuli into a unitary sensory event.

Adult↗
PubMed1993

Development of a memory trace for a complex sound in the human brain.

The development of a memory trace for a complex, unfamiliar sound in the human brain was studied by repeatedly presenting reading subjects with this sound ('standard') which was occasionally replaced by a slightly different sound ('deviant'). Deviants did not elicit the mismatch negativity, an index of automatic change detection in auditory cortex, in the beginning but did later during the session. This result reflects a gradual 'sharpening' of sensory information encoded in the memory trace: the representation of the standard stimulus eventually became precise enough to enable the cortical change-detector mechanism to detect a slight different stimulus.

Acoustic Stimulation↗
PubMed1992

Representation of abstract attributes of auditory stimuli in the human brain.

Representations of abstract attributes of auditory stimuli in the human brain were demonstrated using the mismatch negativity (MMN), an event-related potential component elicited by a change in a repetitive sound. Stimuli were pairs of sinusoidal tones. There were two types of tone pairs in each block, standard (p = 85%) and deviant pairs (p = 15%), delivered in a random order. Standard and deviant tone pairs differed only in the direction of within-pair frequency change. In addition, the frequency levels of both the standard and deviant pairs varied randomly within a wide range in a block; thus the standard pairs shared the direction of the within-pair frequency change but not the absolute frequency level. Correspondingly, the deviant pairs only shared the opposite direction of the within-pair change. Nevertheless, the deviant tone pairs elicited MMN, implying that even the direction of the within-pair frequency change of the standard stimuli, and not just their absolute frequencies, developed a neural representation.

Acoustic Stimulation↗
PubMedDate not supplied

Superior formation of cortical memory traces for melodic patterns in musicians.

The human central auditory system has a remarkable ability to establish memory traces for invariant features in the acoustic environment despite continual acoustic variations in the sounds heard. By recording the memory-related mismatch negativity (MMN) component of the auditory electric and magnetic brain responses as well as behavioral performance, we investigated how subjects learn to discriminate changes in a melodic pattern presented at several frequency levels. In addition, we explored whether musical expertise facilitates this learning. Our data show that especially musicians who perform music primarily without a score learn easily to detect contour changes in a melodic pattern presented at variable frequency levels. After learning, their auditory cortex detects these changes even when their attention is directed away from the sounds. The present results thus show that, after perceptual learning during attentive listening has taken place, changes in a highly complex auditory pattern can be detected automatically by the human auditory cortex and, further, that this process is facilitated by musical expertise.

Acoustic Stimulation↗
PubMedDate not supplied

Pre-attentive discriminability of sound order as a function of tone duration and interstimulus interval: a mismatch negativity study.

The present study addressed the pre-attentive processing of sound order. Event-related potentials were recorded from reading subjects while they were presented with pairs of two tones differing from each other in frequency (1000 vs. 1500 Hz). The within-pair (silent) interstimulus interval (ISI) was, in separate blocks, varied between 0 and 245 ms to determine the minimum separation in time needed for detecting the reversed order of the two frequencies. In standard tone pairs (p = 0.9), the frequencies were in an ascending order, whereas in the deviant pairs (p = 0.1), their order was reversed. Tone durations of 5 and 20 ms were employed in separate experiments. With the 20-ms stimulus duration, the change-specific mismatch negativity (MMN) component was elicited with all within-pair ISIs employed (0, 10, 30, 90 ms). With the 5-ms stimulus duration, however, MMN was elicited only with the 245-ms ISI but not with 95-ms or shorter ISIs. These results show that increased stimulus duration considerably improves perceiving the order of two tones at the pre-attentive level. They also indicate that the accuracy of the processing of temporal information can be probed with MMN. This finding, together with the fact that MMN elicitation does not require the subject's voluntary attention, suggests that MMN might be used in the assessment of temporal processing deficits in clinical disorders in which patients are not motivated or able to give their verbal or motor response.

Acoustic Stimulation↗
PubMedDate not supplied

Towards optimal recording and analysis of the mismatch negativity.

In this paper, the conceptual and practical issues related to the measurement of mismatch negativity (MMN) are discussed from the viewpoint of cost-efficiency. First, various criteria for efficiency or optimality of measurements are described, including reliability and signal-to-noise ratio. Then a critical look is taken at some currently used concepts and data analysis methods. Practical guidelines for the measurement and analysis of MMN are given, complementing the earlier reviews on the subject. Finally, reliability studies on MMN are critically reviewed.

Auditory Pathways↗