Protocol - AX-Continuous Performance Test (AX-CPT)
The AX-Continuous Performance Test (AX-CPT) is a computerized test, implemented in Eprime by the Cognitive Neuroscience Test Reliability and Clinical applications for Schizophrenia (CNTRACS) consortium, which evaluates goal maintenance in working memory. During AX-CPT, the subject views a series of cues and probe sequences (one at a time) and performs a button press indicating if the stimulus is the target or non-target. The four types of cue-probe combinations offered are AX, AY, BX, and BY, with AX being the only target (correct option). A total of 144 cue-probes are presented in four blocks of 36 with limited response windows. The majority of the cue-probes presented are AX, thus creating an expectancy for the subject to prepare a target response following a cue that is an A and to make a target response when a probe is an X.
The alternate (language-independent) task that uses a non-letter stimuli is the Dot Pattern Expectancy Task (DPX), also available at Cognitive Neuroscience Test Reliability and Clinical applications for Schizophrenia (CNTRACS).
There are a total of four neurocognitive assessments: Computerized Neurocognitive Battery (CNB) measures Global Cognitive Functioning, AX-Continuous Performance Test (AX-CPT) measures Context Processing, Relational and Item-Specific Encoding task (RiSE) measures Relational Encoding and Retrieval, and Auditory Continuous Performance Test (ACPT) battery measures Auditory Vigilance.
AX-CPT & RiSE can be run together and can be downloaded together.
AX-CPT can be combined with Task functional magnetic resonance imaging (fMRI) to assist in identifying specific neural circuits.
Tasks can be downloaded for free from the Cognitive Neuroscience Test Reliability and Clinical applications for Schizophrenia (CNTRACS) website; once a Request form has been completed and submitted. Link to the Request form can be found here:
Copies of the tasks, written in Eprime, can be downloaded off of the CNTRACS website at the link below:
Protocol Name from Source:
Modified AX-Continuous Performance Test (AX-CPT)
Personnel and Training Required
The interviewer must be trained to conduct personal interviews with individuals from the general population. The interviewer must be trained and found to be competent (i.e., tested by an expert) at the completion of personal interviews. The interviewer should be trained to prompt respondents further if a "don’t know" response is provided. Training by an experienced group in administering and analyzing the results is recommended.
The PhenX Working Group acknowledges these questions are administered in a computerized format and will require a laptop computer/handheld computer to administer this protocol. Eprime computer software is necessary to conduct this protocol.
|Specialized requirements for biospecimen collection||No|
|Average time of greater than 15 minutes in an unaffected individual||No|
Mode of Administration
Adolescent, Adult, Senior
Individuals 12 and older
Cognitive Neuroscience Test Reliability and Clinical applications for Schizophrenia (CNTRACS) tasks have been used for many years. The tasks have been well studied in CNTRACS and have good test/re-test reliability. The tasks are very easy to use and have standardized instructions and a high level of subject acceptability. CNTRACS contains psychology resources that can be used by individuals who are not psychologists.
|Common Data Elements (CDE)||Cognitive Function AX-Continuous Performance Test Assessment Score||5626695||CDE Browser|
|Common Data Elements (CDE)||Cognitive Function AX-Continuous Performance Test Assessment Score||2016428||CDE Browser|
Process and Review
The Expert Review Panel has not reviewed this measure yet.
MacDonald, A. W., III, Pogue-Geile, M. F., Johnson, M. K., &Carter, C. S. (2003). A specific deficit in context processing in the unaffected siblings of patients with schizophrenia. Archives of General Psychiatry, 60(1), 57-65. http://cntracs.ucdavis.edu/
Gold, J. M., Barch, D. M., Carter, C. S., Dakin, S., Luck, S. J., MacDonald, A. W., III, Ragland, J. D., Ranganath, C., Kovacs, I., Silverstein, S. M., & Strauss, M. (2012). Clinical, functional, and intertask correlations of measures developed by the Cognitive Neuroscience Test Reliability and Clinical Applications for Schizophrenia Consortium. Schizophrenia Bulletin, 38(1), 144-152. doi:10.1093/schbul/sbr142
Henderson, D., Poppe, A. B., Barch, D. M., Carter, C. S., Gold, J. M., Ragland, J. D., Silverstein, S. M., Strauss, M. E., & MacDonald, A. W., III. (2012). Optimization of a goal maintenance task for use in clinical applications. Schizophrenia Bulletin, 38(1), 104-113. doi:10.1093/schbul/sbr172
Sheffield, J. M., Gold, J. M., Strauss, M. E., Carter, C. S., MacDonald, A. W., III, Ragland, J. D., Silverstein, S. M., & Barch, D. M. (2014). Common and specific cognitive deficits in schizophrenia: relationships to function. Cognitive, Affective & Behavioral Neuroscience, 14(1), 161-174. doi:10.3758/s13415-013-0211-5
Strauss, M. E., McLouth, C. J., Barch, D. M., Carter, C. S., Gold, J. M., Luck, S. J., MacDonald, A. W., III, Ragland, J. D., Ranganath, C., Keane, B. P., & Silverstein, S. M. (2014). Temporal stability and moderating effects of age and sex on CNTRaCS task performance. Schizophrenia Bulletin, 40(4), 835-844. doi:10.1093/schbul/sbt089
|Variable Name||Variable ID||Variable Description||Version||dbGaP Mapping|
|PX660201000000||Protocol 660201 - proprietary. Check DCW for contact.||N/A|
January 17, 2017
Computer-administered task that measures cognitive functions.
This measure assesses deficits in cognition-specifically, working memory and long-term memory.
Auditory Working Memory, AWM, Auditory Continuous Performance Test, ACPT, Continuous Performance Task, CPT, Working Memory, WM, AX-Continuous Performance Test, AX-CPT, Dot Pattern Expectancy Task, DPX, schizophrenia, interference control, Cognitive Neuroscience Test Reliability and Clinical applications for Schizophrenia, CNTRACS, goal maintenance, early psychosis, psychometrics