Blog Archives

Functional activation for imitation of seen and heard speech

This study examined fMRI activation when perceivers either passively observed or observed and imitated matched or mismatched audiovisual (“McGurk”) speech stimuli. Greater activation was observed in the inferior frontal gyrus (IFG) overall for imitation than for perception of audiovisual speech and for imitation of the McGurk-type mismatched stimuli than matched audiovisual stimuli. This unique activation in the IFG during imitation of incongruent audiovisual speech may reflect activation associated with direct matching of incongruent auditory and visual stimuli or conflict between category responses. This study provides novel data about the underlying neurobiology of imitation and integration of AV speech.

from the Journal of Neurolinguistics

Is learning by observation impaired in children with dyslexia?

Numerous studies have shown that imitating observed actions belongs to the same category of processes involved in planning and executing actions. New competencies may be acquired by actually executing a task or by executing a task after having seen how to do it. The performance of thirty dyslexic children was compared with that of an age- and gender-matched group of thirty normally reading children on tasks of learning a visuo-motor sequence by observation or by trial and error. The children observed an actor detecting a visuo-motor sequence and then performed the task reproducing either the previously observed sequence or a new one (Learning by Observation), or detected a sequence by trial and error (Learning by Doing), or first performed the task by trial and error and then performed it after an observational training (Learning by Observation after Doing). Results demonstrate that the dyslexic children were severely impaired in learning a sequence by observation, were able to detect a sequence by trial and error, and became as efficient as normal readers in reproducing an observed sequence after a task of learning by doing. Thus, the impaired ability to learn by observation could be reversed by agentive experience that supplied dyslexic children with a powerful learning mechanism, which enabled them to efficiently transfer action information across modalities. The beneficial effect of practice on the ability to learn by observation could provide dyslexic children a useful chance to acquire new cognitive abilities through more tuned teaching approach.

from Neuropsychologia

The Impact of Object and Gesture Imitation Training on Language Use in Children With Autism Spectrum Disorder

Conclusion: These findings suggest that adding gesture imitation training to object imitation training can lead to greater gains in rate of language use than object imitation alone. Implications for both language development and early intervention are discussed.

from the Journal of Speech, Language, and Hearing Research

An On-Line Imitative Test of Speech-Pattern Contrast Perception (OlimSpac): Developmental Effects in Normally Hearing Children

Conclusions: When evaluated on a pass/fail basis, normally hearing children 3 years of age or older are likely to demonstrate auditory perception of most phonemic contrasts using this imitative test. Phonological development and other task-related factors have only a modest effect on performance by normally hearing children after 3 years of age. The effects of hearing loss, hearing age, sensory assistance, and listening experience in children with hearing loss remain to be determined.

from the Journal of Speech, Language, and Hearing Research

IMITATE: An intensive computer-based treatment for aphasia based on action observation and imitation

Conclusions: IMITATE is a novel computer-assisted treatment for aphasia that is supported by theoretical rationales and previous human and primate data from neurobiology. The treatment is feasible, and preliminary behavioural data are emerging. However, the results will not be known until the clinical trial data are available to evaluate fully the efficacy of IMITATE and to inform theoretically about the mechanism of action and the role of a human mirror system in aphasia treatment.

from Aphasiology

A comparison of maternal and child intonation: Does adult input support child production?

Intonation involves the musical aspects of speech production and consists of suprasegmental aspects of phonology (i.e., pitch, length and loudness). The development of intonation involves various changes throughout the first 2 years of life as children learn how to manipulate intonation features as their linguistic system develops. Evidence from the literature provides a mixed message related to the influence of surrounding adult models on intonation production. The current study observed intonation characteristics in 23 mother-child pairs. Results indicated that, in general, children did not directly imitate maternal intonation, but that maternal support assisted the production of wider contours.

from Infant Behavior and Development

The role of demonstrator familiarity and language cues on infant imitation from television

An imitation procedure was used to investigate the impact of demonstrator familiarity and language cues on infant learning from television. Eighteen-month-old infants watched two pre-recorded videos showing an adult demonstrating a sequence of actions with two sets of stimuli. Infants’ familiarity with the demonstrator and the language used during the demonstration varied as a function of experimental condition. Immediately after watching each video, infants’ ability to reproduce the target actions was assessed. A highly familiar demonstrator did not enhance infants’ performance. However, the addition of a narrative, developed from mothers’ naturalistic description of the event, facilitated learning from an unfamiliar demonstrator. We propose that the differential effect of demonstrator familiarity and language cues may reflect the infants’ ability to distinguish between important and less important aspects in a learning situation.

from Infant Behavior and Development

Modulation of Frontal Lobe Speech Areas Associated with the Production and Perception of Speech Movements

Conclusions: These results support the emerging view that cortical areas involved in the execution of speech movements are also recruited in the perception of the same movements in other speakers.

from the Journal of Speech, Language, and Hearing Research

Mirror neurons, the representation of word meaning, and the foot of the third left frontal convolution

Previous neuroimaging research has attempted to demonstrate a preferential involvement of the human mirror neuron system (MNS) in the comprehension of effector-related action word (verb) meanings. These studies have assumed that Broca’s area (or Brodmann’s area 44) is the homologue of a monkey premotor area (F5) containing mouth and hand mirror neurons, and that action word meanings are shared with the mirror system due to a proposed link between speech and gestural communication. In an fMRI experiment, we investigated whether Broca’s area shows mirror activity solely for effectors implicated in the MNS. Next, we examined the responses of empirically determined mirror areas during a language perception task comprising effector-specific action words, unrelated words and nonwords. We found overlapping activity for observation and execution of actions with all effectors studied, i.e., including the foot, despite there being no evidence of foot mirror neurons in the monkey or human brain. These “mirror” areas showed equivalent responses for action words, unrelated words and nonwords, with all of these stimuli showing increased responses relative to visual character strings. Our results support alternative explanations attributing mirror activity in Broca’s area to covert verbalisation or hierarchical linearisation, and provide no evidence that the MNS makes a preferential contribution to comprehending action word meanings.

from Brain and Language