To introduce and determine baseline values for a novel rapid automatized naming (RAN) test called the Staggered Uneven Number (SUN) test and to compare the SUN to the MULES (Mobile Universal Lexicon Evaluation System), an established picture naming RAN test.

RAN tests have been widely used in evaluating patients with various neurological conditions. These tests require quick and accurate identification of numbers and pictures, thus evaluating a wide network of brain pathways for vision, memory, language, and attention. The MULES has been effective in identifying concussion, multiple sclerosis, and Parkinson’s disease. We have developed a number-based RAN test called the SUN to complement the MULES.

We performed a cross-sectional observational study where we administered the SUN and MULES to 54 volunteers recruited from clinical and research offices. Participants were asked to perform two trials of each test and total time in seconds and number of errors for each trial were recorded.

Among 54 participants, aged 20-66 years old, the SUN took a greater time (45.2±8.3 s) compared to the MULES (37.4±9.9 s), although on average it took a shorter time to identify a number (0.31 s) compared to a picture (0.69 s). SUN and MULES times did not differ by gender. However, older age was associated with greater (worse) MULES, but not SUN times (r=0.43, p=0.001).  Primary language also affected MULES times (44 s for non-primary English speakers vs. 36 s for primary English speakers, p=0.03), but not SUN times. Further, MULES had a greater learning effect between trials, with a 16% improvement compared to 5% for the SUN (p=0.0001).

The SUN is a new vision-based test that complements RAN tests involving picture naming. These test types likely involve different pathways for visual processing/memory, language, attention, and eye movements and use of both may better capture changes in neurological function.