Emotion through cognition: the role of cognitive limitations in shaping emotional speech identification among adults with intellectual and developmental disabilities

Recognising emotions in speech is vital for social interactions. Adults with intellectual disabilities (AwID) often experience difficulties with emotion perception, affecting integration. However, less is known about spoken-emotion processing among AwID. The current research examines whether difficulties stem from a primary impairment in emotional processing associated with intellectual disability (ID) or a secondary impairment due to cognitive limitations associated with ID. Using an AwID-adapted version of the Test for Rating Emotions in Speech (T-RES), we assessed emotion identification in two studies. Study 1 examined spoken-emotion recognition across different levels of ID severity, focusing on lexical (semantic) and prosodic (tone of voice) cues separately. Results indicated that as ID severity increased, emotion recognition declined. Study 2 investigated the effects of task complexity on spoken-emotion perception among adults with mild ID. Findings revealed that while emotion identification was intact in simple (congruent, lexical and prosodic emotional cues match) conditions, performance deteriorated significantly in complex (incongruent, cues mismatch) conditions, suggesting a cognitive load effect. Additionally, unlike typically developed adults, AwID did not show prosodic bias. These findings support the secondary cognitive account, suggesting that spoken-emotion processing difficulties in AwID may stem from broader cognitive limitations, rather than specific impairments in emotional perception.