Table 1.
Tests of the NIH Toolbox Cognition Battery (NIHTB-CB) Adult Version (Age ≥ 18)
| Test | Abbreviation | Cognition domain | Score type | Possible score range |
|---|---|---|---|---|
| Flanker Inhibitory Control and Attention | Flanker | Attention, executive function | Computed | 0 – 10 |
| Dimensional Change Card Sort | DCCS | Executive function | Computed | 0 – 10 |
| Pattern Comparison Processing Speed | Processing Speed | Processing speed | Raw | 0 – 130 |
| List Sorting Working Memory | Working Memory | Working memory | Raw | 0 – 26 |
| Picture Sequence Memory | Episodic Memory | Episodic memory | IRT theta | Unlimited |
| Picture Vocabulary | Vocabulary | Language (vocabulary) | IRT theta | Unlimited |
| Oral Reading Recognition | Reading | Language (reading) | IRT theta | Unlimited |
Note. Score type = the name of score type exported from the iPad; IRT = Item Response Theory. For Flanker and DCCS, an accuracy score and a reaction time score are first calculated. The accuracy score is calculated as 0.125 * the number of correctly answered trials. The reaction time score is calculated as a function of the log (base 10) of the median reaction time using only correct trials with time length between 100ms and 3SD away from the participant’s mean time. The computed score is equal to the accuracy score if the participant has an accuracy rate ≤ 80%, and is the sum of the accuracy score and the reaction time score otherwise. For Processing Speed and Working Memory, the raw score is the number of items correctly answered. For Episodic Memory, Vocabulary, and Reading, scoring is based on the Item Response Theory (IRT). IRT models the probability of a correct response to an item given the underlying latent cognitive ability. The theta score represents the latent cognitive ability level (NIH & Northwestern University, 2006–2016). Higher score indicates better performance for each test. Two supplemental tests were also provided for the NIHTB-CB, including Auditory Verbal Learning Test (AVLT; Rey) Immediate Recall (trials 1, 2, 3) measuring learning, and Oral Symbol Digit Test measuring processing speed. However, these two tests were not included in this study.