Investigating Subcortical Contributions to Speech Sequencing in Deep Brain Stimulator Recipients

Conditions

• Essential Tremor
• Parkinson's Disease (PD)

Eligibility Criteria

Sex

ALL

Age

18 Years - N/A

Healthy Volunteers

Not accepted

Interventions

• Phoneme sequence learning — BEHAVIORAL
  Approximately half of subjects enrolled in the study will participate in this intervention. Subjects will read aloud monosyllabic sequences that are presented orthographically on a screen. Each sequence is formed by a non-native consonant cluster followed by a vowel and final consonant (CCVC). Speech trials will be grouped into blocks. After a Familiarization block, subjects will produce a set of twelve CCVCs in a Pretest block. Subjects will then repeatedly produce two of those CCVCs in one Training block, and two other CCVCs in a subsequent Training block. Following training, subjects will produce all four trained CCVCs and four additional novel CCVCs in each of two Test blocks. Washout blocks, during which no speech task trials are completed, will follow the Pretest, Training, and first Test block to allow subjects to rest and to complete standardized testing.
• Cessation and re-enabling of stimulation of the STN — OTHER
  20 adults with Parkinson's disease (PD) who have deep brain stimulator (DBS) implants in the subthalamic nucleus (STN). Stimulation of the STN will be intermittently turned off while subjects complete speech sequence learning tasks. After no more than 35 minutes, stimulation will be re-enabled with normal clinical parameters for each participant.
• Cessation and re-enabling of stimulation of the VIM thalamic nucleus — OTHER
  20 adults with essential tremor who have deep brain stimulator (DBS) implants in the ventral intermediate nucleus (VIM) of the thalamus will participate in this intervention. Stimulation of the VIM will be intermittently turned off (DBS OFF state) while subjects complete speech sequence learning tasks. After no more than 35 minutes, stimulation will be re-enabled with normal clinical parameters for each participant.
• Multisyllabic sequence learning — BEHAVIORAL
  Approximately half of subjects enrolled in the study will participate in this intervention. Subjects will read aloud sequences that are presented orthographically on a screen. Speech trials will be grouped into blocks. After a Familiarization block, subjects will produce 2- and 7-syllable sequences in an Assessment block to determine the appropriate length sequence for the remainder of the intervention. Subjects will produce a set of eight sequences in a Pretest block. Subjects will then repeatedly produce two of those sequences in one Training block and two other sequences in a subsequent Training block. Following training, subjects will produce all four trained sequences and two additional novel sequences in each of two Test blocks. Washout blocks, during which no speech task trials are completed, will follow the Pretest, Training, and first Test Block to allow subjects to rest and to complete standardized testing.

Study Details

This study will examine how two important brain circuits - one involving the subthalamic nucleus (STN) and one involving the ventral intermediate nucleus of the thalamus (VIM) - contribute to learning and producing speech sequences. Participants will include two groups: 1. individuals with Parkinson's disease who have deep brain stimulation (DBS) devices targeting the STN and 2. individuals with essential tremor who have DBS devices targeting the VIM. Participants will complete speech tasks involving the learning and repetition of novel sound sequences. During some parts of the study, DBS stimulation will be temporarily turned on or off in a controlled research setting. This will allow researchers to examine how stimulation affects both the learning of new speech sequences and the production of previously learned sequences. All STN participants and most VIM participants will also be equipped with a cutting-edge DBS system, the Percept PC, which will enable the recording of deep brain activity during the tasks. The results of this study will improve our understanding of how different brain circuits support speech learning and production. In particular, this study will help to differentiate the roles of the STN and VIM in learning the ordering of speech sounds within a syllable from learning of speech sequences containing multiple syllables. This knowledge may help guide future approaches to optimizing DBS settings to improve both movement and speech outcomes in individuals with neurological disorders, as well as provide greater general insight into how these brain structures contribute to speech production and learning.

Key Dates

Start date

Feb 18, 2026

Status verified

Mar 2026

Primary completion

Aug 31, 2030

Completion

Aug 31, 2030

Study Design

Enrollment

80 participants (estimated)

Allocation

NON_RANDOMIZED

Intervention model

PARALLEL

Primary purpose

BASIC_SCIENCE

Arms

• Experimental: Subthalamic nucleus with subsyllabic learning arm
  Arm 1: subjects with implanted STN deep brain stimulators will undergo learning tasks involving non-English sound sequences while their stimulators are turned on and off
• Experimental: Subthalamic nucleus with multisyllabic learning arm
  Arm 2: subjects with implanted STN deep brain stimulators will undergo learning tasks involving syllable sequences while their stimulators are turned on and off
• Experimental: Ventral intermediate thalamus with subsyllabic learning arm
  Arm 3: subjects with implanted VIM deep brain stimulators will undergo learning tasks involving non-English sound sequences while their stimulators are turned on and off
• Experimental: Ventral intermediate thalamus with multisyllabic learning arm
  Arm 4: subjects with implanted VIM deep brain stimulators will undergo learning tasks involving syllable sequences while their stimulators are turned on and off

Primary Outcome Measure

Change in speech sequencing accuracy [ Time Frame: Day 1 ]

Central Contacts

• Frank H Guenther, Ph.D.
  617-353-5765
  [email protected]
• Barbara G Holland, MA
  617-353-6181
  [email protected]

Locations (2)

Find similar trials in Boston, MA

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