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Dana F Boatman

Publications and source records attributed to Dana F Boatman.

3 recordsLinked to original sources

Cortical auditory systems: speech and other complex sounds.

The neural systems that mediate human perception of speech and other complex sounds are currently the focus of considerable research. Brain mapping studies have provided new insights into the cortical processing of complex sounds. Findings from three lines of brain mapping research--stroke-lesion, neuroimaging, and electrocortical mapping studies--are reviewed. Unresolved questions regarding the relative contributions of cortical and subcortical auditory processing and the existence of separate, functionally specialized, cortical auditory systems for processing speech and nonspeech sounds are discussed. An integrated approach is proposed for future research on the neural bases of complex sound processing.

Acoustics↗

Speech recognition impairments in patients with intractable right temporal lobe epilepsy.

PURPOSE: To evaluate speech recognition in patients with focal intractable epilepsy and surgical resections in the nondominant (right) hemisphere. METHODS: Speech recognition was tested prospectively, under different listening conditions, in 22 patients with right temporal lobe (11 patients) or extra-temporal lobe epilepsy. All were left-hemisphere dominant for language on preoperative intracarotid sodium amobarbital testing. RESULTS: All patients demonstrated normal auditory recognition of words and environmental sounds before and after surgery. However, when real-world listening conditions were simulated by using acoustically degraded (filtered) words, patients with temporal lobe epilepsy performed significantly worse than patients with frontal or parietooccipital lobe epilepsy before and after surgery (p<0.0001). CONCLUSIONS: Patients with intractable right temporal lobe epilepsy are at risk for speech recognition impairments in real-world listening environments, independent of surgery. The impact of speech recognition difficulties on verbal communication, coupled with the prevalence of adverse listening environments, underscores the importance of testing speech recognition under different listening conditions in patients with intractable right temporal lobe epilepsy.

Adolescent↗

Cortical sites critical for speech discrimination in normal and impaired listeners.

We used statistical modeling to investigate variability in the cortical auditory representations of 24 normal-hearing epilepsy patients undergoing electrocortical stimulation mapping (ESM). Patients were identified as normal or impaired listeners based on recognition accuracy for acoustically filtered words used to simulate everyday listening conditions. The experimental ESM task was a binary (same-different) auditory syllable discrimination paradigm that both listener groups performed accurately at baseline. Template mixture modeling of speech discrimination deficits during ESM showed larger and more variable cortical distributions for impaired listeners than normal listeners, despite comparable behavioral performances. These results demonstrate that individual differences in speech recognition abilities are reflected in the underlying cortical representations.

Adolescent↗