Semantic Verbal Fluency in Children with and without Autism Spectrum Disorder: Relationship with Chronological Age and IQ

Norms, convergent validity, test-retest reliability, and practice effects for verbal fluency overall performance, clustering, and switching in Spanish-speaking children

OBJECTIVE

We conducted two empirical studies (in a cross-sectional and a longitudinal design) with the aim at establishing normative data (including norms for strategy use [i.e., clustering and switching strategies] and performance over time), and examining the convergent validity, the test-retest reliability (3-4 wks interval) and the changes in performance with practice (1 year interval) of the different verbal fluency (VF) quantitative and qualitative scores in Spanish-speaking children and adolescents.

METHOD

In S1 (n = 620 6- to 15-year-old Spanish-speaking children and adolescents), MANCOVA and Pearson's correlations were employed. In S2 (n = 148 6- to 12-year-old Spanish-speaking children), intraclass correlation coefficient (ICC), paired t-tests, and Confirmatory Factor Analysis (CFA) were used.

RESULTS

S1 results showed an age effect on all VF measures (quantitative and qualitative). The number of switches/clusters was more related to total word productivity and to executive functions (EF) than the mean cluster size. In S2, a significant increase in phonological VF performance was observed on number of switches and word productivity scores from baseline (Time 1) to repeat testing at Time 2. Practice effects were observed at Time 3 on all measures except for semantic and phonological mean cluster size. Test-retest reliability coefficients at Time 2 for number of clusters and switches, but not for mean cluster size, fell in the moderate range, ranging from ICCs .61 to ICCs .81. Test-retest reliability coefficients for total word productivity were higher (ICCs above .80) and stronger when testing as a unity with CFA methods (ϕ=.94, p < .001).

CONCLUSIONS

These data may be relevant for informing the neuropsychological assessment of spontaneous cognitive flexibility in children with typical development (TD) and those with developmental or acquired disorders.

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

The purpose of this study was to reexamine research that used verbal fluency tasks to reinforce assumed deficits in word knowledge and retrieval in the autistic population. We identified seventeen articles that compared the performance of autistic and non-autistic people on verbal fluency measures and provided an interpretation of the observed performance. In this narrative review, we summarize many components of these studies, including a comprehensive account of how authors framed their research findings. Overall, results of the studies showed variation both between and within groups in terms of total number of correct words, how many subsequent words fell into subcategories, and how frequently participants switched between subcategories. Despite wide variation in findings across studies, authors consistently interpreted results as revealing or reinforcing autistic deficits. To contrast the deficit narrative, we offer an alternative interpretation of findings by considering how they could provide support for the autistic-led theory of monotropism. This alternative interpretation accounts for the inconsistencies in findings between studies, since wide individual variation in performance is an expected feature of the monotropic theory. We use our review as an exercise in reframing a body of literature from a neurodiversity-affirming perspective. We propose this as a case example and model for how autism research and clinical practice can move away from the consistent narrative of autism deficits that has pervaded our field for decades. Accordingly, we offer suggestions for future research and clinical practice.

A Systematic Review of Normative Data for Verbal Fluency Test in Different Languages

Verbal fluency tests are easy and quick to use in neuropsychological assessments, so they have been counted among the most classical tools in this context. To date, several normative data for verbal fluency tests have been provided in different languages and countries. A systematic review was carried out with studies that provide normative data for verbal fluency tests. Studies were collected from Scopus, PubMed and Web of Science. 183 studies were retrieved from the database search, of which 73 finally met the inclusion criteria. An analysis of the risk of bias regarding samples selection/characterization and procedure/results reports is conducted for each article. Finally, a full description of the normative data characteristics, considering country and language, verbal fluency task characteristics (type of task) and sample characteristics (number of subjects, gender, age, education) is included. The current systematic review provides an overview and analysis of internationally published normative data that might help clinicians in their search for valid and useful norms on verbal fluency tasks, as well as updated information about qualitative aspects of the different options currently available.

Atypical Semantic Fluency and Recall in Children and Adolescents with Autism Spectrum Disorders Associated with Autism Symptoms and Adaptive Functioning

It is unclear whether children with autism spectrum disorders have atypical semantic fluency and lower memory for the semantics of words. Therefore, we examined semantic typicality, fluency and recall for the categories of fruits and animals in 60 children with autism aged 7-15 years (boys: 48/girls: 12) compared to 60 typically developing controls. Relative to controls, the autism group had reduced animal fluency, fruit typicality and recall for fruits. Notably, these measures were associated with more autistic-like symptoms and/or lower adaptive functioning across the autism and control groups. In conclusion, atypical semantics of fruits in the autism group may reflect development of idiosyncratic semantic networks while their lower semantic fluency and recall suggest impaired executive language functions.

Phonological and semantic verbal fluency test: Scoring criteria and normative data for clustering and switching strategies for Colombian children and adolescents

BACKGROUND

Verbal fluency tests (VFT) are highly sensitive to cognitive deficits. Usually, the score on VFT is based on the number of correct words produced, yet it alone gives little information regarding underlying test performance. The implementation of different strategies (cluster and switching) to perform efficiently during the tasks provide more valuable information. However, normative data for clustering and switching strategies are scarce. Moreover, scoring criteria adapted to Colombian Spanish are missing.

AIMS

(1) To describe the Colombian adaptation of the scoring system guidelines for clustering and switching strategies in VFT; (2) to determine its reliability; and (3) to provide normative data for Colombian children and adolescents aged 6-17 years.

METHODS & PROCEDURES

A total of 691 children and adolescents from Colombia completed phonological (/f/, /a/, /s/, /m/, /r/ and /p/) and semantic (animals and fruits) VFT, and five scores were calculated: total score (TS), number of clusters (NC), cluster size (CS), mean cluster size (MCS) and number of switches (NS). The intraclass correlation coefficient was used for interrater reliability. Hierarchical multiple regressions were conducted to investigate which strategies were associated with VFT TS. Multiple regressions were conducted for each strategy, including as predictors age, age2 , sex, mean parents' education (MPE), MPE2 and type of school, to generate normative data.

OUTCOMES & RESULTS

Reliability indexes were excellent. Age was associated with VFT TS, but weakly compared with strategies. For both VFT TS, NS was the strongest variable, followed by CS and NC. Regarding norms, age was the strongest predictor for all measures, while age2 was relevant for NC (/f/ phoneme) and NS (/m/ phoneme). Participants with higher MPE obtained more NC, and NS, and larger CS in several phonemes and categories. Children and adolescents from private school generated more NC, NS and larger CS in /s/ phoneme.

CONCLUSIONS & IMPLICATIONS

This study provides new scoring guidelines and normative data for clustering and switching strategies for Colombian children and adolescents between 6 and 17 years old. Clinical neuropsychologists should include these measures as part of their everyday practice.

WHAT THIS PAPER ADDS

What is already known on the subject VFT are widely used within the paediatric population due to its sensitivity to brain injury. Its score is based on the number of correct words produced; however, TS alone gives little information regarding underlying test performance. Several normative data for VFT TS in the paediatric population exist, but normative data for clustering and switching strategies are scarce. What this paper adds to existing knowledge The present study is the first to describe the Colombian adaptation of the scoring guidelines for clustering and switching strategies, and provided normative data for these strategies for children and adolescents between 6 and 17 years old. What are the potential or actual clinical implications of this work? Knowing VFT's performance, including strategy development and use in healthy children and adolescents, may be useful for clinical settings. We encourage clinicians to include not only TS, but also a careful analysis of strategies that may be more informative of the underlying cognitive processes failure than TS.

Qualitative analysis of verbal fluency in school-age children with high-functioning autism spectrum disorders. Associations with age and IQ

This study analyzes performance on both a Semantic and a Letter verbal fluency (VF) task in school-age children with high-functioning autism spectrum disorder (HF-ASD) (n = 20) and without ASD (n = 20) and investigates the relationship between VF indicators and age, verbal and non-verbal IQ, ASD severity, and attention deficit hyperactivity disorder (ADHD) symptomatology. Furthermore, the Poor Lexical-Semantic Structure Model and the Slow-Retrieval Model are tested if they could account for semantic retrieval difficulties in children with HF-ASD. The HF-ASD group generated significantly fewer correct responses in both VF tasks in comparison to the control group. The type of task significantly affected performance and both groups showed higher word generativity on the Semantic task. The groups did not differ in clustering, switching, and errors. Age significantly correlated with the VF indicators in the ASD group, but in the control group, there was a significant negative correlation with the number of errors. Non-verbal and verbal IQ did not correlate with any VF indicators in both groups, while ASD severity and ADHD symptomatology correlated positively and significantly with error responses in the ASD group. The Slow-Retrieval Model explains VF difficulties in the HF-ASD group indicating that poorer word generativity can be attributed to slower retrieval of words from the semantic network.

Cognitive flexibility in autism: Evidence from young autistic children

We examined the cognitive flexibility performance of young autistic children and a group of neurotypical peers. Thirty-six autistic children (72-83 months) and 200 age-matched typically-developing children were assessed on the Children's Color Trails Test (CCTT), a semantic and a phonemic verbal fluency task. The results showed that the autistic children performed worse than their neurotypical peers in the switching component of the CCTT. In the fluency tests, the autistic group generated overall fewer word items than their neurotypical peers, however, their poorer performance was driven by specific linguistic stimuli in the fluency tasks. The findings suggest that cognitive flexibility for the autistic children was affected in the nonverbal CCTT only, while poor performance in semantic and phonemic fluency seemed to be inherent to the language properties of the verbal fluency tasks.

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

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.

Lexical Semantic Knowledge of Children with ASD—a Review Study

Studies on the lexical semantic abilities of children with autism have yielded contradicting results. The aim of the current review was to explore studies that have specifically focused on the lexical semantic abilities of children with ASD and try to find an explanation for these contradictions. In the 32 studies reviewed, no single factor was found to affect lexical semantic skills, although children with broader linguistic impairment generally, but not universally, also showed impaired lexical semantic skills. The need for future studies with young ASD participants, with differing intellectual functioning, longitudinal studies, and studies assessing a wide range of language domains are discussed.

The impact of sensory processing on executive and cognitive functions in children with autism spectrum disorder in the school context

BACKGROUND

Theoretical approaches propose a hierarchical organization of sensory and higher-order cognitive processes, in which sensory processing influence some cognitive and executive functions.

AIMS

The main objective of this study was to analyze whether sensory processing dysfunctions can predict the cognitive and executive dysfunctions evaluated in a group of children with level 2 autism spectrum disorder (ASD) in the school context.

METHODS AND PROCEDURES

Two groups of children participated: an ASD group (n = 40) and a group of children with typical development (the comparison group, n = 40). The children's sensory processing was evaluated based on their teachers' perceptions, and the children's executive and cognitive functions were evaluated using direct performance measures.

RESULTS

In the ASD group, the sensory processing difficulties predicted executive and cognitive dysfunctions in the specific domains of inhibitory control, auditory sustained attention, and short-term verbal memory, after controlling the possible effect of ASD severity. Moreover, the ASD group showed higher levels of sensory, executive, and cognitive dysfunction than the comparison group.

CONCLUSIONS AND IMPLICATIONS

Future research should investigate whether adequate sensory interventions in children with ASD in the school context can improve these specific executive and cognitive functions.

Children's development of semantic verbal fluency during summer vacation versus during formal schooling

Purpose: Children's results on school-related achievements tests, such as aspects of math, reading and writing, have been shown to decline following a lengthy summer vacation. Few studies have investigated whether this also applies to vocabulary skills. The purpose of this study is to investigate how lexical organization and retrieval, assessed by a semantic verbal fluency (SVF) task, develops during a lengthy summer vacation versus formal schooling.Method: Sixty-eight children with mean age of 7.9 (ranging from 6.5 to 9.1), were assessed pre- and post-summer vacation and post-fall semester using two SVF categories (Animals and Clothes). The number of words produced in both categories gave the total score.Results: The result of the SVF tests decreased following summer vacation. The loss was recouped at the post-fall semester assessment, but no gains compared to initial testing were shown. Neither level of parental education, general language ability, non-verbal IQ, nor bilingualism explained the variance in development during the summer vacation or the fall semester.Conclusions: Our findings indicate that a lengthy summer vacation causes a recess in the expected development of SVF ability and that this recess is recouped after a semester of formal schooling. The findings are in line with previous research indicating that summer vacation may have negative impact on the development of important scholastic abilities in children.

Frontal lobe dysfunction underlies the differential word retrieval impairment in adolescents with high-functioning autism

There is substantial evidence of word retrieval impairment as indicated by poor performance on the category fluency test in autism spectrum disorder (ASD). However, little is known about the neural mechanisms underlying this impairment. Functional neuroimaging studies have shown that the lateral frontal cortex plays a key role in flexible word retrieval. Thus, we examined whether individuals with ASD exhibited altered frontal processing during the category fluency test using functional near-infrared spectroscopy (fNIRS). Twenty-two adolescents with high-functioning ASD (20 males) and 22 typically developing (TD) adolescents (16 males) aged 11-18 years were recruited. All underwent a category fluency paradigm, which required production of animal or means of transportation words for 1 min each although their frontal hemodynamic changes were recorded with fNIRS. We found that adolescents with ASD produced fewer animal but not transportation words (group-by-category interaction: P = 0.003), suggesting differential word retrieval impairment. In addition, unlike TD adolescents who exhibited activation primarily in lateral frontal regions during word production, adolescents with ASD had comparable activation across lateral and medial frontal regions. More importantly, this lack of lateral-medial distinction of activation, which was associated with poor word retrieval, differed significantly between groups only in the animal category (group-by-category interaction: P = 0.018). Thus, our findings implicate frontal lobe dysfunction in the impairment of differential word retrieval in adolescents with ASD. The relatively greater involvement of the medial frontopolar cortex might reflect the use of nonspecialized brain regions to compensate for the category-dependent difficulties with word retrieval in ASD. Autism Res 2019, 12: 600-613. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Using an optical imaging tool, we found that adolescents with autism had difficulties with producing semantically related words and exhibited frontal lobe dysfunction. Nonetheless, poor word production and altered brain processing was only seen when these adolescents were asked to produce words from a category of living things but not nonliving things (i.e., animals but not means of transportation). Category-dependent word retrieval problems and frontal lobe dysfunction might be two features of this disorder.

Thinking about the future: Comparing children's forced-choice versus "generative" responses in the "spoon test"

One of the most popular methods to assess children's foresight is to present children with a problem (e.g., locked box with no key) in one room and then later, in another room, give them the opportunity to select the item (e.g., key) that will solve it. Whether or not children choose the correct item to bring back to the first room is the dependent measure of interest in this "spoon test." Although children as young as 3 or 4 years typically succeed on this test, whether they would pass a more stringent version in which they must verbally generate (vs. select) the correct item in the absence of any cues is unknown. This is an important point given that humans must often make decisions about the future without being explicitly "prompted" by the future-oriented option. In Experiment 1, using an adapted version of the spoon test, we show that as the "generative" requirements of the task increase, 3-, 4-, and 5-year-olds' (N = 99) performance significantly decreases. We replicate this effect in Experiment 2 (N = 48 3-, 4-, and 5-year-olds) and also provide preliminary evidence that the capacity to verbally generate the correct item in a spoon test may draw more heavily on children's category fluency skills than does their capacity to select this item among a set of distracters. Our findings underscore the importance of examining more generative forms of future thought in young children.

Intact verbal fluency abilities in the Broad Autism Phenotype

This study attempted to replicate the findings of Camodeca and Voelker (2016), who demonstrated that controlled processing weaknesses were evident in the Broad Autism Phenotype (BAP), and that these weaknesses were predictive of real-world pragmatic language problems. One hundred eighty-two undergraduates completed the Delis-Kaplan Executive Function System Verbal Fluency (D-KEFS-VF) test and the Broad Autism Phenotype Questionnaire (BAPQ). Results were partially replicated. Contrary to the previous study, the BAP group (n = 31) did not demonstrate comparative weaknesses in controlled processing, nor were controlled processing abilities predictive of BAPQ Pragmatic Language score. Similar to the previous study, controlled processing did not predict pragmatic language abilities for Non-BAP (n = 151) subjects. For each group, letter fluency score predicted 2nd 15″ interval score (controlled processing abilities); automatic processing (1st 15″ interval) did not. Results suggest that verbal fluency skills in the BAP are similar to controls, and that controlled processing does not account for significant variance in real-world social language in the BAP.