Short-term crossmodal plasticity of the auditory steady-state response in blindfolded sighted individuals.
Level 3 - non-randomized controlled study
Prospective repeated-measures experimental study in humans without an independent control group
PubMed 22509989 · doi:10.1111/j.1460-9568.2012.08088.x
What was done
Researchers measured the effect of short-term visual deprivation (blindfolding) on the auditory steady-state response (ASSR) to amplitude-modulated tones in sighted individuals. Magnetoencephalography (MEG) was recorded while subjects performed an auditory detection task under monaural and dichotic presentation conditions. Spectral power, mean amplitudes, and dipole positions of the ASSR were assessed at baseline (onset of blindfolding) and after 2, 4, and 6 hours of continuous visual deprivation.
What was found
After 6 hours of visual deprivation, ASSR spectral power at stimulus-specific frequencies was modulated, primarily in the dichotic condition. Participants developed two spectral peaks within the occipital cortex at the 6-hour mark, mirroring activity typically seen in the auditory cortex. The abstract reports no exact numerical values, confidence intervals, or sample sizes, but notes that the occipital spectral response occurred in only 50% of participants.
Why it matters
This demonstrates that crossmodal cortical reorganization can occur rapidly in sighted adults, with input-deprived visual cortex adopting auditory-like processing characteristics within hours of deprivation.
Limits
The abstract omits the total sample size, participant demographics, and statistical values. There was no non-blindfolded control group to account for time-of-day or practice effects, and substantial individual variability was present, with half the cohort failing to show occipital crossmodal recruitment.
Cited by
- supports In a 2013 Harvard study, blindfolded sighted participants showed neural activity in the visual cortex in response to touch or sound after 60 to 90 minutes of blindfolding.