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Biomedical subjects

Athena Vouloumanos

Publications and source records attributed to Athena Vouloumanos.

5 recordsLinked to original sources
PubMed2006

Do you hear what I hear? Neural correlates of thought disorder during listening to speech in schizophrenia.

Thought disorder is a fundamental symptom of schizophrenia, observable as irregularities in speech. It has been associated with functional and structural abnormalities in brain regions involved in language processing, including left temporal regions, during language production tasks. We were interested in the neural correlates of thought disorder during receptive language processing, as this function is relatively preserved despite relying on the same brain regions as expressive language. Twelve patients with schizophrenia and 11 controls listened to 30-s speech samples while undergoing fMRI scanning. Thought disorder and global symptom ratings were obtained for each patient. Thought disorder but not global symptomatology correlated positively with the BOLD response in the left posterior superior temporal lobe while listening to comprehensible speech (cluster-level corrected p=.023). The pattern of brain activity associated with thought disorder during listening to comprehensible speech differs from that seen during language generation tasks, where a reduction of the leftward laterality of language has often been observed. As receptive language is spared in thought disorder, we propose that the increase in activation reflects compensatory processing allowing for normal performance.

Acoustic Stimulation↗
PubMed2005

From semantics to syntax and back again: argument structure in the third year of life.

An essential part of the human capacity for language is the ability to link conceptual or semantic representations with syntactic representations. On the basis of data from spontaneous production, suggested that young children acquire such links on a verb-by-verb basis, with little in the way of a general understanding of linguistic argument structure. Here, we suggest that a receptive understanding of argument structure--including principles linking syntax and conceptual/semantic structure--appears earlier. In a forced-choice pointing task we have shown that toddlers in the third year of life can map a single scene (involving a novel causative action paired with a novel verb) onto two distinct syntactic frames (transitive and intransitive). This suggests that even before toddlers begin generalizing argument structure in their own speech, they have some representation of conceptual/semantic categories, syntactic categories, and a system that links the two.

Child Language↗
PubMed2004

Tuned to the signal: the privileged status of speech for young infants.

Do young infants treat speech as a special signal, compared with structurally similar non-speech sounds? We presented 2- to 7-month-old infants with nonsense speech sounds and complex non-speech analogues. The non-speech analogues retain many of the spectral and temporal properties of the speech signal, including the pitch contour information which is known to be salient to young listeners, and thus provide a stringent test for a potential listening bias for speech. Our results show that infants as young as 2 months of age listened longer to speech sounds. This listening selectivity indicates that early-functioning biases direct infants' attention to speech, granting speech a special status in relation to other sounds.

Attention↗
PubMed2003

Abnormal processing of speech during oddball target detection in schizophrenia.

Healthy subjects show increased activation in left temporal lobe regions in response to speech sounds compared to complex nonspeech sounds. Abnormal lateralization of speech-processing regions in the temporal lobes has been posited to be a cardinal feature of schizophrenia. Event-related fMRI was used to test the hypothesis that schizophrenic patients would show an abnormal pattern of hemispheric lateralization when detecting speech compared with complex nonspeech sounds in an auditory oddball target-detection task. We predicted that differential activation for speech in the vicinity of the superior temporal sulcus would be greater in schizophrenic patients than in healthy subjects in the right hemisphere, but less in patients than in healthy subjects in the left hemisphere. Fourteen patients with schizophrenia (selected from an outpatient population, 2 females, 12 males, mean age 35.1 years) and 29 healthy subjects (8 females, 21 males, mean age 29.3 years) were scanned while they performed an auditory oddball task in which the oddball stimuli were either speech sounds or complex nonspeech sounds. Compared to controls, individuals with schizophrenia showed greater differential activation between speech and nonspeech in right temporal cortex, left superior frontal cortex, and the left temporal-parietal junction. The magnitude of the difference in the left temporal parietal junction was significantly correlated with severity of disorganized thinking. This study supports the hypothesis that aberrant functional lateralization of speech processing is an underlying feature of schizophrenia and suggests the magnitude of the disturbance in speech-processing circuits may be associated with severity of disorganized thinking.

Adult↗