Playing video games most consistently speeds visual processing and improves handling of competing demands, with modest gains in holding information in mind and switching between tasks — largest in adults over sixty, smaller and contested in younger adults. Games that add movement to mental challenge help most where thinking ability is already slipping. Summaries of the same studies disagree. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Validated cognitive battery composite | No established target; track change from own baseline, ≥0.3 standard deviations meaningful | The only direct read-out of the intended benefit |
| Useful Field of View divided-attention threshold | Below 200 ms | The attention measure most responsive to action gaming, and the one validated against real-world driving outcomes |
| Sleep onset latency | 10-20 minutes | Detects the sleep-onset delay caused by arousing late play, the most common adverse effect |
| Total sleep time | 7-9 hours | Sleep loss blunts the consolidation that any training gain depends on |
| Gaming-disorder screening score | Below the instrument's clinical cut-off, with no single criterion endorsed at maximum severity | Detects loss of control before it reaches diagnostic threshold |
| Logged weekly play hours | 3-7 hours deliberate training play | The exposure variable that drives every risk item in this review |
| Moderate-to-vigorous physical activity | ≥150 minutes per week, plus 2 resistance sessions | Confirms that gaming has not displaced the habit with stronger cognitive evidence |
| 25-hydroxyvitamin D | 40-60 ng/mL | Heavy indoor screen time reduces outdoor light exposure, and low status is associated with poorer cognitive performance |
| hs-CRP | Below 1.0 mg/L | Tracks body-wide inflammation, which rises with sedentary time |
| HbA1c | 4.8-5.4% | Captures the metabolic cost of prolonged sitting and convenience eating |
| Resting heart rate | 50-65 beats per minute | Rises with chronic sympathetic load from competitive play and with lost fitness |
| Near point of convergence | 6 cm or closer | Detects the accommodative fatigue underlying digital eye strain |
| Cervical and upper-limb pain score | 0 on a 0-10 scale, no symptom days | Catches overuse injury while it is still reversible |
| Photic-stimulation EEG | No photoparoxysmal response | Identifies almost all people at risk of screen-provoked seizure |
Cadence: Baseline before starting, then re-testing at 4 weeks, at 12 weeks, and every 6 months thereafter. The compulsive-play screen and sleep record repeat at every timepoint; the cognitive battery only at 12 weeks and annually.