Intact fluency in autism? A comprehensive approach of verbal fluency task including word imageability and concreteness

Abstract

Verbal fluency is a cognitive function reflecting executive functions and the ability to retrieve the appropriate information from memory quickly. Previous studies reported conflicting results-impaired and intact verbal fluency-in autism spectrum disorder (ASD). Most studies concentrate on overall word productivity, errors, perseverations, clustering, or switching. We used a comprehensive approach to evaluate the reported discrepancy in the literature and introduced a new angle using the concept of word abstraction and imageability. Moreover, we analyzed the performance in two-time intervals (0-30 s and 31-60 s) to assess the temporal dynamics of verbal fluency and a possible activation or initiation deficit in autism. Sixteen adults with ASD and 16 neurotypical control participants, matched by gender, age, and education level, participated in our study. Contrary to our expectations, we did not find a significant difference between groups in word productivity, the number of errors, clustering, or temporal dynamics, neither in semantic nor in phonemic fluency tasks. Surprisingly, the two study groups' performance did not differ in terms of imageability or concreteness characteristics either. Our results raise the possibility that verbal fluency performance is intact in autism. We also suggest using a comprehensive approach when measuring fluency in autism. Lay summary: People with autism tend to think and communicate differently. In our study, we tested whether people with autism come up with more concrete or imageable words and whether their performance is better compared with neurotypicals in the beginning or in the later phase of a task measuring how many words they can produce in a minute. We did not detect any difference between the two groups; however, we recommend studying verbal fluency in autism from more and different angles in the future.

Verbal fluency and autism: Reframing current data through the lens of monotropism

“…Interestingly, when group differences in TNCW were predicted but not discovered, some authors seemed doubtful that their findings could be generalized. For example, Tóth et al (2022) found no significant differences in TNCW between groups, and they acknowledge that their results replicated a lack of group difference reported by several previous studies. Rather than concluding that their results, combined with previous work, suggest unimpaired autistic verbal fluency skills, they write that this “might” be a “possibility,” but emphasize that “further studies [would be] required to… support this theory (p. 683).”…”

“…Nine studies reported data specifically focused on the number of intrusions. Of these, six studies found no significant difference in the number of intrusions produced between groups (Begeer et al, 2014; Dunn et al, 1996; Foldager et al, 2022; Tóth et al, 2022; Turner, 1999; Zarokanellou et al, 2022), while two studies found the autistic group produced more intrusions than the comparison group (Dichter et al, 2009; Inokuchi & Kamio, 2013). Tang et al (2022) found only autistic individuals with a co‐occurring diagnosis of ADHD produced more intrusions than the comparison group.…”

“…Overall, ten studies reported on the number of repetitions. Nine of these studies did not report significant differences in repetition rates between groups (Begeer et al, 2014; Dichter et al, 2009; Dunn et al, 1996; Foldager et al, 2022; Inokuchi & Kamio, 2013; Spek et al, 2009; Tóth et al, 2022; Turner, 1999; Zarokanellou et al, 2022). Similar to their reported differences for intrusions, Tang et al (2022) also found participants diagnosed with both ADHD and autism produced more repetitions than comparison groups (Tang et al, 2022).…”

“…Of those 10 studies that included 27 or fewer participants in each group and could detect a difference with a large effect size, five found no significant differences in terms of TNCW (Begeer et al, 2014;Boucher, 1988;Dunn et al, 1996;Prud'hommeaux et al, 2017;T oth et al, 2022) and five found autistic participants produced fewer total words than the non-autistic population (Carmo et al, 2015(Carmo et al, , 2017Gonzalez-Barrero & Nadig, 2017;Turner, 1999;Zarokanellou et al, 2022). Four of these studies found no difference in cluster size and/or number of switches (Carmo et al, 2015;Gonzalez-Barrero & Nadig, 2017;T oth et al, 2022;Zarokanellou et al, 2022). Turner (1999) found that autistic participants produced smaller clusters, while Begeer et al (2014) found autistic participants produced larger clusters and fewer switches.…”

Tackling emotional processing in adults with attention deficit hyperactivity disorder and attention deficit hyperactivity disorder + autism spectrum disorder using emotional and action verbal fluency tasks

“…In ASD, studies have found reduced ( 74 – 76 ) or identical word count compared to control subjects in letter and semantic VFT ( 77 – 79 ). In contrast, the process-oriented measures of VFT, including clustering, switching, imaginability, and concreteness, did not differ from the NT controls ( 75 , 77 ). These discrepant findings may be due to the heterogeneity of ASD presentations ( 80 , 81 ).…”