Development and Testing of a Smartphone-Based Cognitive/Neuropsychological Evaluation System for Substance Abusers.
In methamphetamine (MA) users, drug-induced neurocognitive deficits may help to determine treatment, monitor adherence, and predict relapse. To measure these relationships, we developed an iPhone app (Neurophone) to compare lab and field performance of N-Back, Stop Signal, and Stroop tasks that are sensitive to MA-induced deficits.



Twenty healthy controls and 16 MA-dependent participants performed the tasks in-lab using a validated computerized platform and the Neurophone before taking the latter home and performing the tasks twice daily for two weeks.



N-Back task: there were no clear differences in performance between computer-based vs. phone-based in-lab tests and phone-based in-lab vs. phone-based in-field tests. Stop-Signal task: difference in parameters prevented comparison of computer-based and phone-based versions. There was significant difference in phone performance between field and lab. Stroop task: response time measured by the speech recognition engine lacked precision to yield quantifiable results. There was no learning effect over time. On an average, each participant completed 84.3% of the in-field NBack tasks and 90.4% of the in-field Stop Signal tasks (MA-dependent participants: 74.8% and 84.3%; healthy controls: 91.4% and 95.0%, respectively). Participants rated Neurophone easy to use.



Cognitive tasks performed in-field using Neurophone have the potential to yield results comparable to those obtained in a laboratory setting. Tasks need to be modified for use as the app's voice recognition system is not yet adequate for timed tests.
a Assistant Research Scientist, Friends Research Institute , Addiction & Pharmacology Research Laboratory , San Francisco , CA , USA.
Reshmi
R
Pal
b Senior Research Scientist, Friends Research Institute , Addiction & Pharmacology Research Laboratory , San Francisco , CA , USA.
John
J
Mendelson
c Engineer, Creare Inc. , Hanover , NH , USA.
Odile
O
Clavier
d Data Scientist , Genentech , South San Francisco , CA , USA.
Mathew J
MJ
Baggott
e Ph.D. Candidate, University of California-Berkeley , Biostatistics , Berkeley , CA , USA.
Jeremy
J
Coyle
f Senior Research Scientist, Friends Research Institute , Addiction & Pharmacology Research Laboratory , San Francisco , CA , USA.
Gantt P
GP
Galloway
D000328:Adult; D019969:Amphetamine-Related Disorders / Q000150:complications / Q000523:psychology*; D016022:Case-Control Studies; D003071:Cognition / Q000187:drug effects; D060825:Cognitive Dysfunction / Q000175:diagnosis* / Q000209:etiology; D055030:Drug Users; D005260:Female; D006801:Humans; D008297:Male; D008694:Methamphetamine / Q000008:administration & dosage / Q000009:adverse effects*; D008875:Middle Aged; D009483:Neuropsychological Tests; D011930:Reaction Time / Q000187:drug effects; D000068997:Smartphone; D057190:Stroop Test; D013997:Time Factors; D055815:Young Adult
D008694:Methamphetamine
Methamphetamine; N-Back task; Neurophone; Stop Signal task; Stroop task; neurocognitive