Manual Responses Are Verbally Mediated in Stroop Identification Tasks

In a typical Stroop experiment, participants view a color word written in a color that is either congruent or incongruent with the word’s meaning and identify either the target’s color (Stroop condition) or meaning (reverse Stroop condition). Incongruent words generally interfere with identifying the target color more than incongruent colors interfere with identifying the target word. A common explanation for this classic asymmetry asserts that vocally identifying the target’s color or meaning relies on a verbal code, which biases attention to the target’s meaning over its color. However, the asymmetry also occurs with nonverbal keypress responses, so participants may covertly map verbal codes onto keys to remember which key represents each color. To verify this verbal mediation hypothesis, we presented Stroop color-word targets along with 4 cues to help participants remember which key represented each color. In one condition the cues were color words, and in the other the cues were color patches. We hypothesized that the word cues would elicit the classic asymmetry and color cues would abolish this asymmetry. The results supported our hypotheses; for word cues the Stroop effect was larger than the reverse Stroop effect, p < .001, ηp2 = .64, and color cues abolished this difference, p < .001, ηp2 = .31. This study is the first to provide direct confirmation of the verbal mediation hypothesis and suggests that task demands are more important than the response modality (vocal versus manual) for biasing processing toward one of the Stroop target’s features.

The Relationship Between Language and Planning in Children With Language Impairment

Purpose This study examined the relationship between language and planning, a higher order executive function skill, in children with specific language impairment (SLI) and typically developing (TD) children. We hypothesized differences between groups in planning performance and in the role of verbal mediation during planning. Method Thirty-one children with SLI and 50 TD age-matched peers (8–12 years) participated in the study. We assessed language ability via a standardized language measure and planning via a dual-task Tower of London paradigm with 3 conditions: no secondary task (baseline), articulatory suppression secondary task (disrupted verbal mediation), and motor suppression secondary task (control for secondary task demand). Results We found similar overall accuracy between children with SLI and TD peers on the Tower of London. Children with SLI executed trials more slowly at baseline than TD peers but not under articulatory suppression, and children with SLI spent less time planning than TD children at baseline and under articulatory suppression. There was a significant interaction among group, language ability, and planning time under articulatory suppression. Children with SLI who had relatively better language ability spent less time planning than children with SLI who had poorer language ability when verbal mediation was disrupted. This pattern was reversed for TD children. Conclusions This study provides evidence for a relationship between language and planning, yet this relationship differed between children with SLI compared to TD peers. Findings suggest that children with SLI use nonlinguistic perceptual strategies to a greater degree than verbal strategies on visuospatial planning tasks and that intervention might address strategy use for planning.

A-49 Visual Memory Errors and Intelligence: The Role of Verbal Mediation

Objective Examine the relationship of verbal mediation with visual memory errors and intelligence to understand the role of spoken language on other assessment measures. Method Assessment records were obtained from a Veteran Affairs clinic for veterans (n=100) with diverse neuropsychiatric conditions who completed the Wechsler Adult Intelligence Scale, third edition (WAIS-III), Multilingual Aphasia Examination (MAE), and Benton Visual Retention Test (BVRT). A Principal Component Analysis (PCA) was used to examine the interrelationship among these assessments. The components of spoken language, types of errors on the BVRT, and the four factors of the WAIS-III were factored using the PCA to identify common sources of variance. Results A principal component analysis revealed a six-factor model explaining 68.16% of the shared variance among the WAIS-III factors, MAE components, and BVRT Errors. Omission errors loaded with Processing Speed and Controlled Word Association. Distortions and size errors loaded with Perceptual Organization. Size errors also loaded with Verbal Comprehension and Visual Naming. Misplacements loaded with Working Memory and Sentence Repetition. Misplacements, perseverations, and omissions loaded with the Token Test (a measure associated with auditory comprehension). Rotation errors loaded with Perceptual Organization. Conclusions Results indicated significant shared variance between visual memory errors, spoken language, and intelligence factors. This suggests that spoken language is involved in the process of visual memory, and deficits in spoken language may result in increased errors on visual memory tasks. Therefore, treatment recommendations for visual memory difficulties should take into consideration verbal capabilities and intelligence factors to better individualize treatment.

A-52 An Exploratory Factor Analysis Investigation of the Role of Verbal Mediation in the Interaction between Intelligence and Visual Memory Tasks

Objective Examine whether verbal mediation may play a role in the interaction between visual memory tasks and the four-factor model of intelligence as operationalized by standard neuropsychological assessment instruments. Method The assessment records of 101 American Veterans with diverse neuropsychiatric conditions were examined using Exploratory Factor and Principal Component Analyses (EFA and PCA respectively). There were no exclusion criteria. All participants completed the Wechsler Adult Intelligence Scale, third edition (WAIS-III), Benton’s Visual Retention Test (BVRT), and Multilingual Aphasia Examination (MAE). Individual assessment instruments were factored using PCA. The factor solution of the BVRT was co-factored with the scales of the WAIS-III, then the resulting factor scales were again factored with the verbal components of the MAE to identify common sources of variance. Results A three-step analysis revealed a four-factor model explaining 69.44% of the shared variance: 1) Items 1-4 of the BVRT (BVRT-E) loaded with Verbal Comprehension and Visual Naming. 2) BVRT-E also loaded with Processing Speed and Controlled Word Association. 3) Items 5-10 of the BVRT (BVRT-L) loaded with Perceptual Organization and the Token Test. 4) Working Memory loaded with Sentence Repetition on a fourth factor. Conclusions The results indicate a strong relationship between assessed performance on visual memory tasks and performance on measures based on the four-factor model of intelligence. The results also appear to support the idea that verbal mediation plays a role in the interaction between visual memory and intelligence, particularly when comparing performance on simple versus more complex visual memory tasks.