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RecruitingNCT05901493Time2LearnUpdated May 29, 2026

Category Learning Retention in Adults With and Without Developmental Language Disorder

An interventional study of Perceptual category training in Developmental Language Disorder and Adults Without Language Disorder, sponsored by University of Delaware. Recruiting at 2 sites in United States. Open to participants aged 18 Years to 55 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-05-29.

Sponsored by University of Delaware · Not applicable, Interventional, and Basic science

From the registry’s dates

  • Registered 6 months after the study started (first participant enrolled Oct 2022, registered May 2023).
  • Started Oct 2022; still recruiting 4 years later.
Phase
Not applicable
Study type
Interventional
Enrollment
540
Allocation
Randomized
Ages
18 Years to 55 Years
Sex
All
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Study summary

Approximately 7% of the population experiences developmental language disorder (DLD), a language disorder with unclear causes. DLD affects communication beyond adolescence and poses challenges for education and career advancement due to difficulties in learning and memory. Recent research suggests that adults with DLD struggle with overnight memory consolidation, indicating a need for effective learning and memory support. This project aims to determine the optimal training schedule for perceptual memory retention in adults with and without DLD. The study involves recruiting 240 adults (120 with DLD, 120 without) for speech-perceptual training with different training schedules. The researchers predict that the manipulation of training schedules will interact with circadian preference and overnight consolidation, leading to the discovery of the best practice schedule for speech sound retention. Additionally, 300 more adults (150 with DLD, 150 without) will be recruited to investigate how optimal training schedules interact with reflexive and reflective learning strategies. The time course of learning and retention will be tracked during reflexive and reflective categorization training in six different training schedules.

Read the detailed description

Developmental language disorder (DLD) describes the idiopathic disorder(s) of language that occurs in approximately 7% of the population. Although DLD is understudied in adulthood, it is clear that the communication challenges in DLD extend beyond adolescence. The barriers to educational and vocational achievement for adults with DLD include persistent difficulties in learning and memory. Recent work suggests that these difficulties with learning and memory include deficits in overnight memory consolidation. Thus, an effective support for learning and memory function in adults with DLD must include strategies for both overcoming initial challenges in learning, as well as in mitigating a deficit in consolidation of learned information. In this project, the investigators combine insights from the neurobiology of learning and memory, chronobiology, and speech perception, to determine the optimal training schedule for perceptual memory retention in adults with and without DLD. The investigators have two Aims in this project: First, the investigators will recruit 240 adults (120 with/120 without DLD) to participate in a speech-perceptual training to take place in one of six different training schedules over 24 hours. The investigators predict that our manipulation of training schedules will interact with circadian preference and timing relative to overnight consolidation, to allow the discovery of the optimal practice schedule for speech sound retention for adult learners with \& without DLD. Under our second aim, the investigators will recruit an additional 300 adults (150 with/150 without DLD) in order to determine how optimal training schedules interact with reflexive and reflective learning strategies in adults with and without DLD. The investigators will achieve this aim by tracking the time course of learning and retention in adults participating in reflexive and reflective categorization training in one of six training schedules.

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Conditions studied

  • Developmental Language Disorder
  • Adults Without Language Disorder
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In context

Language Development Disorders

121 studies on the registry are indexed under Language Development Disorders; 49 are open to participants now.

This study's planned enrollment of 540 is above the median of 74 across 106 interventional studies indexed under Language Development Disorders.

Browse Language Development Disorders studies →

Lead sponsor

University of Delaware is the lead sponsor of 128 studies on the registry; 22 are open to participants now.

Counted across the registry records on this site, refreshed daily.

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Who can participate

Ages eligible
18 Years to 55 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • native speakers of American English
  • Grew up in a household in which only American English was spoken
  • 18-55 years of age
  • Typical vision \& hearing
  • (Aim 2) access to headphones/devices capable of accessing experiment script via internet
  • Must meet criteria for Group membership as either TD or DLD

Exclusion criteria

Exclusion Criteria:

  • History of neurological disorders
  • History of psychiatric disorders
  • History of socio-emotional disorders
  • On prescription medication(s) that alter sleep
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Study design

Phase
Not applicable
Primary purpose
Basic science
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
540 participants (estimated)

Study arms

  • Experimental
    Blocked Evening Only Training

    One hour training in the evening, followed by a one hour training 24 hours later

    Behavioral: Perceptual category training

  • Experimental
    Distributed Evening Training

    One hour training in the evening, followed by a two 30 min trainings 12 and 24 hours later

    Behavioral: Perceptual category training

  • Experimental
    Blocked Evening-Morning Training

    One hour training in the evening, followed by a one hour training 12 hours later

    Behavioral: Perceptual category training

  • Experimental
    Blocked Morning Only Training

    One hour training in the morning, followed by a one hour training 24 hours later

    Behavioral: Perceptual category training

  • Experimental
    Distributed Morning Training

    One hour training in the morning, followed by a two 30 min trainings 12 and 24 hours later

    Behavioral: Perceptual category training

  • Experimental
    Blocked Morning-Evening Training

    One hour training in the morning, followed by a one hour training 12 hours later

    Behavioral: Perceptual category training

Interventions

  • BehavioralPerceptual category training

    Participants complete a forced-choice categorization task with feedback, in order to learn difficult auditory and visual categories

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What researchers measure

Primary outcomes

  1. Speech discrimination - behavior

    Participants will be administered a short (approximately 4-minute) behavioral task. They will be exposed to two speech sounds, separated by a 1-second interval. Some sounds will begin with the dental stop consonant, and other sounds will begin with the retroflex stop consonant. Participants will be asked to decide if the two sounds they hear are the same or different. Accuracy will be converted to d-prime (a measure of signal detection). This d-prime score will be the primary behavioral outcome for speech discrimination.

    Time frame: 1 week

  2. category identification - behavior

    Participants will be administered a short (approximately 2 minutes) for each modality (auditory and visual). Participants will either hear (auditory - pure tone) or see (visual - gabor patch) a stimulus, and will need to choose which category the stimulus belongs to out of a choice of two. The percentage of trials that are answered correctly will be the primary behavioral outcome for auditory and visual category identification.

    Time frame: 48 hours

Secondary outcomes

  1. Speech discrimination - Event-related potential of the electroencephalogram (ERP/EEG)

    The investigators will fit the participant's head with a pre-positioned electrode cap, with electrolytic gel applied between the electrodes and the scalp. The participants will watch a silent movie while dental and retroflex speech tokens are presented in an oddball paradigm. The investigators will record the participants' electroencephalogram (EEG) while the auditory stimuli are presented. The EEG data will be segmented to examine the fluctuations in voltage recorded at the scalp (in milivolts) for a duration of one second after the onset of each stimulus. The segmented data will be averaged across dental trials, and across the retroflex trials. The resultant waveforms will be subtracted from one another. The peak of the deflection in the difference waveform found approximately 250miliseconds following stimulus onset is the mismatch negativity (MMN) component. The magnitude of the MMN component will be our primary outcome measure.

    Time frame: 1 event-related potential (ERP) session 1 week following training

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Study locations

2 of 2 sites recruiting
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References and documents

Individual participant data

Plan to share: Yes — de-identified data will be uploaded to the Open Science Framework alongside publications to stem from data from this project

Supporting information: Analytic code

Time frame: This data will be made available upon publication of the data, indefinitely

No publications or documents are linked to this record.

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Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on May 29, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT05901493
Collaborators
Northeastern University
Responsible party
Sponsor
First posted
Jun 13, 2023
Start date
Oct 23, 2022
Primary completion
Dec 31, 2026 (estimated)
Completion
Jul 31, 2027 (estimated)
Last update
May 29, 2026

Study contacts

Frances Earle, PhD
Contact
fsearle@udel.edu
6468128376

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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