Word-picture verification tasks (WPVTs) have been found to be a more sensitive measure of auditory comprehension compared to multiple choice formats (Breese & Hillis, 2004) and provide further insight into lexical-semantic processing abilities (Hillis, Tuffiash, & Wityk, 2002) in individuals with aphasia. There is a need for more empirically-supported language assessments in clinical and research practices, and nonverbal WPVTs may prove to be a useful implicit linguistic task by elucidating processing strengths and weaknesses while reducing confounding metacognitive and motor speech influences. However, no standardized WPVT protocol exists to date, and previous studies have varied in administration procedures, populations, and stimuli (Breese & Hillis, 2004; Cloutman et al., 2009; Hillis & Caramazza, 1995; Hillis, Tuffiash, & Wityk, 2002; Stadthagen-Gonzalez, Damian, Perez, Bowers, & Marin, 2009). Additionally, reaction time data on the WPVT has not been collected with clinical populations, and reaction times may better explain lexical-semantic processing abilities overlooked with measures of accuracy alone (Best, Greenwood, Grassly, Herber, & Hicken, 2013).
The current study aimed to investigate performance accuracy and reaction times on a novel computerized nonverbal WPVT in healthy adults. Since lexical retrieval differences have been observed during typical aging (e.g., Feyereisen, 1997; Gordon & Kindred, 2011; Mortensen, Meyer, & Humphreys, 2006; Nicholas, Obler, Albert, & Goodglass, 1985; Schmitter-Edgecombe, Vesneski, & Jones, 2000), younger and older adults' performances were obtained, analyzed, and compared. Participants simultaneously saw a picture and read or heard a single word presented on a laptop computer. They then judged if word-picture pairs were congruent or incongruent via button press. Words in incongruent pairs were phonologically-related, semantically related, or unrelated to the presented picture. Younger adults (M age = 23.20) responded more quickly across auditory and reading WPVT formats. However, older adults (M age = 64.47) were significantly more accurate on target word-picture pairs compared to younger adults. On the auditory WPVT, younger and older adults responded more quickly and accurately to unrelated word-picture pairs compared to phonologically-related, semantically-related, and correct pairs. They also responded more quickly on semantically-related pairs compared to phonologically-related foils. On the reading WPVT, participants responded more quickly and accurately on phonologically-related and unrelated pairs. They also responded more quickly on phonologically-related pairs compared to semantically-related and target word-picture pairs.
The current study provides support that younger and older adults respond differently to auditory and reading versions of a computerized nonverbal WPVT. Reaction time data provided additional information about lexical-semantic processing that accuracy alone could not express. Future investigation is warranted to determine the effectiveness of a nonverbal WPVT as a measure of lexical-semantic processing ability, especially in clinical populations where this ability may be obscured with verbal responses due to confounding motor-speech deficits.