An Exploratory Study to Evaluate Attention Biases in Adults With Multiple Sclerosis, Breast Cancer, and Lung Cancer

Inclusion Criteria: * A participant will be eligible for entry into the study if all of the following criteria are met: 1. Fluent in written and spoken English, confirmed by ability to read, understand, and sign the informed consent form 2. Lives in the United States 3. Adult between 22 and 65 years old 4. Meets indication-specific including criteria, as reported by the study participant with adequate clinical documentation (to be provided to the study team upon request) 5. Has an active email address and is willing and able to receive and respond to email messages 6. Has access to an internet connection during the study duration 7. Has an active PayPal account to receive study compensation, or is willing to create one 8. Willing and able to comply with study protocol and assessments 9. Is the sole user of an iPhone with an iPhone operating system (iOS) version 14 or later or a smartphone with an Android operating system (OS) version 10 or later for the duration of the study 10. Is willing and able to receive Short Message Service (SMS) text messages and notifications on their smartphone 11. Has access to operating headphones Exclusion Criteria: * A participant will not be eligible for study entry if any of the following criteria are met: 1. Visual, dexterity or cognitive deficit so severe that it precludes the use of an App-based reaction time-based activity per investigator judgment 2. Severe psychiatric disorder involving a history of psychosis (e.g., schizophrenia, bipolar disorder, severe personality disorders) 3. Psychiatric hospitalization in the past 6 months 4. Participation in any research study (including studies on psychotherapy, mindfulness, cognitive training or pharmacological treatment) during the past 3 months 5. Initiation or change in primary disease-specific medication within 30 days prior to entering the study 6. Planning the introduction of new therapies (including studies on psychotherapy, mindfulness, cognitive training or pharmacological treatment) during the study duration (6 weeks) 7. Anticipating a change in current pharmacological or psychotherapy treatment regimen during the study period (6 weeks) 8. Self-reported substance use disorder within the past 1 year 9. Severe neurological disorders impairing brain function (e.g., previous stroke, dementia, primary brain function, brain metastases, Alzheimer's disease, Parkinson's disease, history of significant head trauma followed by persistent neurologic deficits or known structural brain abnormalities) 10. Mild, moderate, severe or profound unilateral or bilateral hearing loss