Table 1

Categorisation of functional magnetic resonance imaging (fMRI) responses to auditory stimuli8 9

LevelDescriptionfMRI responses
Level 0No cortical fMRI responses to any auditory stimuliNone
Level 1Cortical responses characteristic of sound perception onlyActivation of primary auditory cortex with all auditory stimuli; no significant differences in fMRI activation patterns between signal correlated noise, words and ambiguous versus non-ambiguous words
Level 2Distinction of words versus signal correlated noiseActivation of primary auditory cortex with all auditory stimuli; significant differences in fMRI activation patterns between signal correlated noise and words (bilateral activation centred on the superior temporal sulcus8 as well as a left-lateralized response in the left inferior frontal gyrus; no significant differences in fMRI activation patterns between sentences containing ambiguous and non-ambiguous words
Level 3
  • Distinction of words versus signal correlated noise

  • Distinction of ambiguous from unambiguous words

Activation of primary auditory cortex with all auditory stimuli; significant differences in fMRI activation patterns between signal correlated noise and words (bilateral activation centred on the superior temporal sulcus8 as well as a left-lateralised response in the left inferior frontal gyrus; additional significant differences in fMRI activation patterns between sentences containing ambiguous and non-ambiguous words (left and right inferior frontal gyrus (pars triangularis), and a region of the left posterior inferior temporal cortex)