Cognitive reserve refers to the brain's ability to maintain cognitive performance despite age-related changes or neuropathology. Enhancing cognitive reserve is thought to delay cognitive decline and improve functional outcomes in aging and neurodegenerative conditions. Attention and memory-related neural processes are considered key contributors to cognitive reserve, yet it remains unclear whether these neural markers can be deliberately strengthened through targeted training and non-invasive interventions.

The goal of this clinical study is to investigate whether mindfulness-based meditation and non-invasive brain stimulation can enhance neural markers of attention and memory that serve as proxies for cognitive reserve in cognitively healthy adults and older adults diagnosed with mild cognitive impairment (MCI). Investigators hypothesize that strengthening these neural markers will lead to measurable improvements in cognitive reserve-related functions in both healthy aging and MCI populations.

This study further hypothesizes that neural markers of attention can be selectively enhanced using an electroencephalography (EEG)-based brain-computer interface (BCI) combined with non-invasive interventions such as mindfulness-based relaxation or neuromodulation. During the study, participants will perform a computerized memory task while their EEG signals are recorded in real time. A BCI will analyze these signals to decode the presence or absence of the P300 event-related potential, a well-established neural marker of attentional control and cognitive resource allocation. Real-time feedback and intervention will be used to modulate these neural processes with the goal of promoting adaptive changes in attention-related brain activity.

By integrating EEG-based decoding, behavioral training, and non-invasive interventions, this study aims to determine whether targeted modulation of attention-related neural activity can support cognitive reserve in aging and mild cognitive impairment.

Inclusion Criteria:

Younger adults:

• Good general health.
• Normal or corrected vision.
• no history of neurological/psychiatric disease
• ability to read and understand English
• ability to understand information and ability to give a free and informed consent

Older adults:

• Normal or corrected vision.
• Self-reports no current diagnosis of dementia.
• Ability to provide written/electronic, informed consent.

Exclusion Criteria:

Younger Adults:

• Neurological or psychiatric diseases that could be contraindicated for tACS (e.g., personal history of epilepsy/seizure brain damage, history of fainting, bipolar disorder, schizophrenia, current substance use disorder, etc.).
• Medications that elevate seizure threshold (e.g., stimulant medication, high dose bupropion).
• Factors hindering EEG acquisition and tACS delivery (e.g., skin infection, wounds, dermatitis, inability to access the scalp of the participant).

Older Adults:

• Neurological or psychiatric diseases that could be contraindicated for tACS (e.g., personal history of epilepsy/seizure brain damage, pacemakers, history of fainting, bipolar disorder, schizophrenia, current substance use disorder, etc.).
• Medications that elevate seizure threshold (e.g., stimulant medication, high dose bupropion).
• Factors hindering EEG acquisition and tACS delivery (e.g., skin infection, wounds, dermatitis, inability to access the scalp of the participant).
• Diagnosis of dementia.
• Do not have the capacity to provide informed consent.

All data will be made available by the online publication date. These data will be placed in public servers for any interested researcher to access it