Processing Speed Index (PSI): An Overview

Processing speed index (PSI) is a measure of cognitive functioning that assesses an individual’s ability to quickly and accurately process information. PSI is used to evaluate an individual’s speed of mental processing and is closely related to other cognitive measures, such as attention, memory, and executive functioning. It is typically used to identify areas of cognitive deficits in individuals with neurological or developmental disorders.

The origin of PSI can be traced back to the 1970s, when it was first developed by researchers to evaluate the speed of information processing in children with learning disabilities. Since then, it has been adopted by clinicians and researchers in various fields to assess a wide range of cognitive functions.

PSI is typically assessed with a set of standardized cognitive tests that measure an individual’s ability to quickly and accurately process information. These tests typically involve a series of timed tasks, such as sorting shapes, matching numbers, and responding quickly to changes in visual or auditory stimuli. Higher scores on these tests indicate greater speed of processing and better cognitive functioning.

In addition to its use for evaluating cognitive functioning, PSI is also used to evaluate the impact of interventions on cognitive functioning. For example, research has shown that cognitive training can improve processing speed in individuals with neurological disorders. By assessing an individual’s PSI before and after intervention, researchers can assess the efficacy of the intervention on cognitive functioning.

Overall, PSI is a valuable tool for assessing cognitive functioning, particularly in individuals with neurological and developmental disorders. By measuring an individual’s ability to quickly and accurately process information, PSI can provide valuable insights into an individual’s cognitive functioning.


Gouvier, W. D., & Ryan, R. D. (2011). Processing speed assessment. In M. Hersen & V. B. Van Hasselt (Eds.), Handbook of psychological assessment (5th ed., pp. 722–737). New York, NY: Taylor & Francis.

Goh, J. S., Sella, F., & Chee, M. W. (2015). Neurocognitive training in neurological disorders: A systematic review. Neuropsychology Review, 25(3), 281–294.

McGee, R., Williams, S., & Silva, P. A. (1984). Processing speed in children with learning disabilities: A factor analytic study. Journal of Abnormal Child Psychology, 12(1), 63–77.

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