The cleanest answer admits a gap up front: a direct, well-controlled cognitive comparison of these two states is largely missing. Each has been studied on its own, and the two literatures rarely meet on the same set of measures, so most of what can be said is about how each tends to work rather than how they line up side by side.
Guided hypnosis runs almost entirely on language and inward attention. A practitioner uses pacing, suggestion, and imagery, and the experience is built from the inside, with the person directing focus toward internally generated images and feelings. Some EEG work links hypnotic states to shifts in slower bands such as alpha and theta and to changes in how regions coordinate, though the findings vary and depend heavily on how readily the person enters hypnosis in the first place.
Virtual reality works from the opposite direction. It floods the visual and balance systems with a constructed environment, so attention is pulled outward and captured by what the headset shows. A VR-based induction has been used to bring people into a hypnosis-like state, and at least one study reported brain-activity patterns broadly consistent with earlier hypnosis research, suggesting overlap rather than two unrelated phenomena.
Where the honest limits sit:
What the research can support:
- hypnosis leans on top-down, internally directed attention
- immersive VR leans on bottom-up, externally captured attention
- both can produce absorbed, altered states, and VR has been used to help induce one
What it cannot yet support:
- a clean ledger of cognitive differences measured head to head
- claims that one reliably outperforms the other on memory or recall
- precise figures for attention, imagery, or embodiment differences between them
There is reasonable interest in pairing the two, using a vivid environment to settle and prime a person before a verbal induction, and small studies on combined approaches for pain exist. Researchers themselves describe the comparative mechanisms as still needing investigation. The accurate stance is to describe the plausible contrast in how attention is engaged while resisting the temptation to report measured cognitive gaps that the literature has not actually pinned down.