Direct cortical stimulation of inferior frontal cortex disrupts both speech and music production in highly trained musicians.

Music and speech are human-specific behaviours that share numerous properties, including the fine motor skills required to produce them. Given these similarities, previous work has suggested that music and speech may at least partially share neural substrates. To date, much of this work has focused on perception, and has not investigated the neural basis of production, particularly in trained musicians. Here, we report two rare cases of musicians undergoing neurosurgical procedures, where it was possible to directly stimulate the left hemisphere cortex during speech and piano/guitar music production tasks. We found that stimulation to left inferior frontal cortex, including pars opercularis and ventral pre-central gyrus, caused slowing and arrest for both speech and music, and note sequence errors for music. Stimulation to posterior superior temporal cortex only caused production errors during speech. These results demonstrate partially dissociable networks underlying speech and music production, with a shared substrate in frontal regions.

Evaluating syntactic comprehension during awake intraoperative cortical stimulation mapping.

OBJECTIVE: Electrocortical stimulation mapping (ECS) is widely used to identify essential language areas, but sentence-level processing has rarely been investigated. METHODS: While undergoing awake surgery in the dominant left hemisphere, 6 subjects were asked to comprehend sentences varying in their demands on syntactic processing. RESULTS: In all 6 subjects, stimulation of the inferior frontal gyrus disrupted comprehension of passive sentences, which critically depend on syntactic processing to correctly assign grammatical roles, without disrupting comprehension of simpler tasks. In 4 of the 6 subjects, these sites were localized to the pars opercularis. Sentence comprehension was also disrupted by stimulation of other perisylvian sites, but in a more variable manner. CONCLUSIONS: These findings suggest that there may be language regions that differentially contribute to sentence processing and which therefore are best identified using sentence-level tasks. The functional consequences of resecting these sites remain to be investigated.

Designing Virtual, Moderated Studies of Early Childhood Development.

With increased public access to the Internet and digital tools, web-based research has gained prevalence over the past decades. However, digital adaptations for developmental research involving children have received relatively little attention. In 2020, as the COVID-19 pandemic led to reduced social contact, causing many developmental university research laboratories to close, the scientific community began to investigate online research methods that would allow continued work. Limited resources and documentation of factors that are essential for developmental research (e.g., caregiver involvement, informed assent, controlling environmental distractions at home for children) make the transition from in-person to online research especially difficult for developmental scientists. Recognizing this, we aim to contribute to the field by describing three separate moderated virtual behavioral assessments in children ranging from 4 to 13years of age that were highly successful. The three studies encompass speech production, speech perception, and reading fluency. However varied the domains we chose, the different age groups targeted by each study and different methodological approaches, the success of our virtual adaptations shared certain commonalities with regard to how to achieve informed consent, how to plan parental involvement, how to design studies that attract and hold children's attention and valid data collection procedures. Our combined work suggests principles for future facilitation of online developmental work. Considerations derived from these studies can serve as documented points of departure that inform and encourage additional virtual adaptations in this field.

The peri-Sylvian cortical network underlying single word repetition revealed by electrocortical stimulation and direct neural recordings.

Verbal repetition requires the coordination of auditory, memory, linguistic, and motor systems. To date, the basic dynamics of neural information processing in this deceptively simple behavior are largely unknown. Here, we examined the neural processes underlying verbal repetition using focal interruption (electrocortical stimulation) in 58 patients undergoing awake craniotomies, and neurophysiological recordings (electrocorticography) in 8 patients while they performed a single word repetition task. Electrocortical stimulation revealed that sub-components of the left peri-Sylvian network involved in single word repetition could be differentially interrupted, producing transient perceptual deficits, paraphasic errors, or speech arrest. Electrocorticography revealed the detailed spatio-temporal dynamics of cortical activation, involving a highly-ordered, but overlapping temporal progression of cortical high gamma (75-150Hz) activity throughout the peri-Sylvian cortex. We observed functionally distinct serial and parallel cortical processing corresponding to successive stages of general auditory processing (posterior superior temporal gyrus), speech-specific auditory processing (middle and posterior superior temporal gyrus), working memory (inferior frontal cortex), and motor articulation (sensorimotor cortex). Together, these methods reveal the dynamics of coordinated activity across peri-Sylvian cortex during verbal repetition.

A valid alternative for in-person language assessments in brain tumor patients: feasibility and validity measures of the new TeleLanguage test.

BACKGROUND: Although language deficits after awake brain surgery are usually milder than post-stroke, postoperative language assessments are needed to identify these. Follow-up of brain tumor patients in certain geographical regions can be difficult when most patients are not local and come from afar. We developed a short telephone-based test for pre- and postoperative language assessments. METHODS: The development of the TeleLanguage Test was based on the Dutch Linguistic Intraoperative Protocol and existing standardized English batteries. Two parallel versions were composed and tested in healthy native English speakers. Subsequently, the TeleLanguage Test was administered in a group of 14 tumor patients before surgery and at 1 week, 1 month, and 3 months after surgery. The test includes auditory comprehension, repetition, semantic selection, sentence or story completion, verbal naming, and fluency tests. It takes less than 20 minutes to administer. RESULTS: Healthy participants had no difficulty performing any of the language tests via the phone, attesting to the feasibility of a phone assessment. In the patient group, all TeleLanguage test scores significantly declined shortly after surgery with a recovery to preoperative levels at 3 months postsurgery for naming and fluency tasks and a recovery to normal levels for the other language tasks. Analysis of the in-person language assessments (until 1 month) revealed a similar profile. CONCLUSION: The use of the TeleLanguage battery to conduct language assessments from afar can provide convenience, might optimize patient care, and enables longitudinal clinical research. The TeleLanguage is a valid tool for various clinical and scientific purposes.