Speed of Processing

Definition

This construct measures how rapidly individuals can perceptually compare and process information (Park, 2000 in D.C. Park & N. Schwartz (Eds.)). It is highly sensitive to cognitive function and is considered a basic core component of cognition. Timothy Salthouse authored a classic paper that fully describes both theoretical importance and empirical measures of speed of processing (Salthouse,1996).

References

Salthouse, T.A. (1996). The processing-speed theory of adult age differences in cognition. Psychological Review, 103, 403-428.

Park, D.C. (2000). The basic mechanisms accounting for age-related decline in cognitive function. In D.C. Park & N. Schwartz (Eds.), Cognitive Aging: A primer, pp. 3 -21.  Psychology Press.

1.1 Digit Comparison Task

Description (task duration: 2.5 minutes): Participants have to decide whether two number strings that are either 3, 6, or 9 digits in length, have identical digits or different digits. The task is divided into 3 separate sets; a set is comprised only of 3-digits, 6-digits, or 9-digits comparisons (ie., a set doesn’t contain a mix of different string lengths).  Subjects are given 45 seconds for each set to try to complete as many comparisons as they can.  The number correctly completed for 3-, 6-, and 9-item strings, as well as total correct, is available. Higher scores are better.

Primary Reference:

Salthouse T. A., Babcock R. L. (1991). Decomposing adult age differences in working memory. Developmental Psychology, 27, 763-776.

Development of Cross-culturally Appropriate Measures

Hedden, T., Park, D. C., Nisbett, R., Ji, LJ, Jing, Q., & Jiao, S. (2002). Cultural variation in verbal versus spatial neuropsychological function across the life span. Neuropsychology, 16, 65-73. 

1.2 WAIS-III Digit Symbol

Description (Task Duration: 1.5 minutes):

• Participants are shown nine geometric symbols that are each assigned to a digit from 1 to 9. They are then presented with randomized digits and asked to draw the corresponding symbol below each digit as quickly as possible for 90 seconds.

Task Example:

Primary Reference:

Wechsler, D., (1997). WAIS-III: Administration and scoring manual: Wechsler Adult Intelligence Scale. San Antonio, TX: Psychological Corporation.

1.3 NIH Toolbox Pattern Comparison Speed Test

Description (task duration: 1.5 minutes): Participants are shown two pictures side-by-side and are asked to discern whether the pictures are the same or different. If the pictures are the same, the participant presses the “Yes” button. If the pictures are not the same, the participant presses the “No” button. The participant is instructed to only use their index finger on their dominant hand to press either button. Participants’ raw score is the number of 130 items correct in an 85-second period. The items are designed to be simple to most purely measure processing speed. Higher scores reflect faster speeds of processing.

Caution: Participants in DLBS Wave 2 performed the NIH Toolbox Pattern Comparison Speed Test on a desktop computer, whereas, participants in DLBS Wave 3 performed the task on an ipad.  NIH toolbox provides a computed score to equate the different platforms (desktop and ipad) used.  For additional details, we refer you to the the NIH Toolbox website: https://www.healthmeasures.net/explore-measurement-systems/nih-toolbox/obtain-and-administer-measures.

Primary Reference:

Gershon RC, Wagster MV, Hendrie HC, Fox NA, Cook KF, Nowinsky CJ. NIH Toolbox for Assessment of Neurological and Behavioral Function. Neurology. 2013; 80: S1-S92.

Software Reference:

NIH Toolbox for the iPad test ver. 2.1

Speed of Processing Ability Construct: Key to Names and Data Structure in Data Set

Item Name	Abbreviation	Description	Measurement
Subject Number	S#	Subject identifier
Construct Name	ConstructName	Speed of Processing
Construct Number	ConstructNumber	Construct 1
Wave	Wave	Denotes the data collection wave. See individual differences data set for more detail, including testing date intervals.	1 = Wave 1 2 = Wave 2 3 = Wave 3
Has Data	HasData	1 = Yes,  returned for wave; 2 = No, did not return for wave
Number of Tasks in Construct	NumTasks	How many tasks make up the speed of processing construct	3 Tasks for Speed of Processing
Task 1—Digit Comparison	Task1	1 = Has data 2 = Task data partial 3 = No task data
Digit Comparison 3	DigComp3_1	Total correct for 3-digit strings	Score Range: 0-64
Digit Comparison 6	DigComp6_1	Dependent Variable: total correct for 6-digit strings	Score Range: 0-64
Digit Comparison 9	DigComp9_1	Dependent Variable: total correct for 9-digit strings	Score Range: 0-64
Digit Comparison Total	DigCompTotal1	Dependent Variable: Total correct summed across T3, T6, and T9 trials	Score Range: 0-192
Task 2—Digit Symbol	Task2	1 = Has data 2 = Task data partial 3 = No task data
Digit Symbol Total	DigSymTotal2	Number of items matched correctly in 90 sec	Score Range: 0-93
Task 3—NIH Toolbox Pattern Comparison Speed Test	Task3	1 = Has data 2 = Task data partial 3 = No task data
NIH Toolbox Pattern Comparison Speed Test	NIHSpeedRaw3	The participant’s raw score is the number of items answered correctly in 85 seconds of response time, with a range of 0-130. This score is then converted to the NIH Toolbox normative standard scores.	Score Range: 0-130
NIH Toolbox Pattern Comparison Speed Test	NIHSpeedComp3	The computed score is a conversion between the desktop and ipad data present in wave 3.	Score Range: 0-130
NIH Toolbox Pattern Comparison Speed Test	NIHSpeedUn3	It compares the performance of the test-taker to those in the entire NIH Toolbox nationally representative normative sample, regardless of age or any other variable.	Normative Mean = 100, SD = 15
NIH Toolbox Pattern Comparison Speed Test	NIHSpeedAge3	This score compares the score of the test-taker to those in the NIH Toolbox nationally representative normative sample at the same age, where a score of 100 indicates performance that was at the national average for the test-taking participant’s age. Age-corrected standard scores were derived for adults (ages 18-85).	Mean = 100, Standard Deviation = 15
NIH Toolbox Pattern Comparison Speed Test	NIHSpeedPercent3	A Percentile represents the percentage of people nationally above whom the participant’s score ranks (the comparison group will be based on whichever normative score is used)	Percentile rank: 0-100
NIH Toolbox Pattern Comparison Speed Test	NIHSpeedFully3	This score compares the score of the test-taker to those in the NIH Toolbox nationally representative normative sample, while adjusting for key demographic variables (education, gender, and race/ethnicity) collected during the NIH Toolbox national norming study.	Mean = 50, Standard Deviation = 10

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