Encoding Deficits Impede Word Learning and Memory in Adults With Developmental Language Disorders

Area of Science:

• Cognitive Psychology
• Neuroscience
• Linguistics

Background:

• Developmental Language Disorder (DLD) is characterized by persistent difficulties in language acquisition.
• Individuals with DLD often face challenges in word learning, impacting academic and social functioning.
• Understanding the specific nature of these word-learning deficits is crucial for targeted interventions.

Purpose of the Study:

• To investigate whether word-learning deficits in adults with DLD are primarily due to difficulties in encoding information or retaining it.
• To differentiate between encoding and retention as the source of word-learning challenges in DLD.

Main Methods:

• Two studies were conducted with postsecondary students. Study 1 used the California Verbal Learning Test-Second Edition. Study 2 involved learning novel words under uncued test, cued test, and passive study conditions.
• Participants with DLD and normal development (ND) were assessed on word recall, recognition, and semantic clustering.
• Retention was measured at 1 day and 1 week following initial learning.

Main Results:

• Students with DLD demonstrated poorer encoding of both familiar and novel words compared to ND peers, evidenced by lower word recall and slower learning curves.
• Encoding deficits in DLD were further indicated by reduced semantic clustering and poorer recognition.
• While retention was comparable between groups under certain conditions, DLD participants recalled less information from passive study but performed similarly to ND peers when information was learned through testing (self-testing).

Conclusions:

• The primary challenge in word learning for adults with DLD lies in the encoding stage, not in the retention of information.
• Employing self-testing strategies with feedback can mitigate the word-learning deficits associated with DLD.