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Cited by 108Hallucinations in medical conditionsSchizophrenia research and treatmentNeurobiology of Language and Bilingualism

Distinct processing of ambiguous speech in people with non-clinical auditory verbal hallucinations

Open access
Alderson-Day, Ben, Lima, César F, Evans, Samuel, Krishnan, Saloni, Shanmugalingam, Pradheep, Fernyhough, Charles, Scott, Sophie K·2017·Brain
DOI 10.1093/brain/awx206
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Abstract

Auditory verbal hallucinations (hearing voices) are typically associated with psychosis, but a minority of the general population also experience them frequently and without distress. Such 'non-clinical' experiences offer a rare and unique opportunity to study hallucinations apart from confounding clinical factors, thus allowing for the identification of symptom-specific mechanisms. Recent theories propose that hallucinations result from an imbalance of prior expectation and sensory information, but whether such an imbalance also influences auditory-perceptual processes remains unknown. We examine for the first time the cortical processing of ambiguous speech in people without psychosis who regularly hear voices. Twelve non-clinical voice-hearers and 17 matched controls completed a functional magnetic resonance imaging scan while passively listening to degraded speech ('sine-wave' speech), that was either potentially intelligible or unintelligible. Voice-hearers reported recognizing the presence of speech in the stimuli before controls, and before being explicitly informed of its intelligibility. Across both groups, intelligible sine-wave speech engaged a typical left-lateralized speech processing network. Notably, however, voice-hearers showed stronger intelligibility responses than controls in the dorsal anterior cingulate cortex and in the superior frontal gyrus. This suggests an enhanced involvement of attention and sensorimotor processes, selectively when speech was potentially intelligible. Altogether, these behavioural and neural findings indicate that people with hallucinatory experiences show distinct responses to meaningful auditory stimuli. A greater weighting towards prior knowledge and expectation might cause non-veridical auditory sensations in these individuals, but it might also spontaneously facilitate perceptual processing where such knowledge is required. This has implications for the understanding of hallucinations in clinical and non-clinical populations, and is consistent with current 'predictive processing' theories of psychosis.

AI snapshot

Written from the paper’s full text.

TL;DR

People with non-clinical voice-hearing (NCVH) spontaneously detected speech in ambiguous sine-wave speech earlier than matched controls and showed a stronger neural intelligibility response in rostral anterior cingulate/pre-SMA regions. The effect was present before any explicit “reveal” or training, suggesting a spontaneous orientation to potentially intelligible speech rather than a general response bias or basic auditory difference.

Key findings

  • NCVH participants reported first noticing words in the sine-wave speech earlier than controls: mean recognition point 3.71 vs 4.94 blocks, t(27) = −2.17, P = 0.039; 9/12 NCVH (75%) reported words versus 8/17 controls (47%).
  • For the intelligibility contrast (intelligible > unintelligible SWS), NCVH showed greater activation than controls in a cluster peaking in rostral anterior cingulate cortex, extending to pre-SMA, middle cingulate cortex, and superior frontal gyrus (peak MNI −4, 34, 26; k = 539; t = 4.81; z = 4.05; P FWE < 0.001). This was driven by greater responses to intelligible SWS in NCVH [t(27) = 2.98, P = 0.006], with no group difference for unintelligible SWS [t(27) = −1.05, P = 0.301].
  • The group difference in ACC remained significant when recognition point was included as a covariate (peak MNI −2, 32, 26; k = 467; t = 5.27; z = 4.31; P FWE < 0.001), and NCVH already showed a stronger intelligibility response in Run 1 before the reveal. There were no supra-threshold group differences for the Run × Intelligibility interaction, and Bayesian analyses of primary auditory cortex provided no evidence for group differences.
  • On the post-scan behavioural task, groups did not differ in speech discrimination (d′), keyword accuracy, or bias to classify stimuli as speech. Greater voice-hearing in the past week in NCVH correlated with noticing speech earlier in Run 1 (r = −0.582, n = 12, P = 0.047).

Methods

  • 12 NCVH participants and 17 non-voice-hearing controls, matched for age, sex, handedness, education, and National Adult Reading Test scores, completed fMRI while passively listening to intelligible sine-wave speech (SWS), unintelligible SWS, and target sounds across two 20-min runs separated by a mid-scan “reveal” and training to understand SWS.
  • After scanning, participants completed a self-paced behavioural task with 50 SWS stimuli (25 intelligible, 25 unintelligible), measuring keyword accuracy, d′, and bias; 20% of stimuli were new sentences.
  • MRI data were acquired on a 1.5 T scanner with sparse sampling and analysed in SPM8 using whole-brain GLM contrasts, with cluster-level FWE correction at P < 0.05; primary auditory cortex responses were also tested with Bayesian mixed ANOVA.

Limitations

  • The authors state that the post-scan behavioural assessment occurred outside the scanner after long training and exposure, so post-scan group differences may have been masked or trained out; neither group performed at ceiling, and keyword accuracy was reasonably low in both groups.
  • The authors state reliance on participants’ self-reports to gauge when speech was noticed during Run 1, meaning it is not certain what participants were responding to when “hearing” speech; they note possible alternative that NCVH were more likely to class unusual stimuli as speech, though they argue against this based on lack of general neural differences and no post-scan speech bias.
  • The authors state the sample was small (12 NCVH, 17 controls) relative to recommendations for clinical fMRI and group comparisons, and that recruitment for NCVH neuroimaging is extremely challenging; they also note the need for future paradigms measuring prior probability, sensory signal, and response on a trial-by-trial basis.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1093/brain/awx206

Cites

95 of 95 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

0 of 38 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    Across both runs and groups, several regions were more active for intelligible compared to unintelligible SWS, including left and right STG, left middle temporal gyrus, insula, precentral gyrus and IFG, as well as medial regions pre-SMA, ACC, and superior frontal gyrus.

    “Across both runs and groups, several regions were more active for intelligible compared to unintelligible SWS, including the left and right STG, the left middle temporal gyrus, insula, precentral gyrus and IFG, as well as medial regions, namely the pre-SMA, ACC, and superior frontal gyrus (Table 2 and Fig. 2C).”
    Quote in the paperNot a substantial claim
  • Findingown data

    The reverse contrast (Controls > NCVH) yielded no significant clusters.

    “The reverse contrast (Controls 4 NCVH) yielded no significant clusters.”
    Quote in the paperNot a substantial claim
  • Findingown data

    While being scanned, the majority of non-clinical voice-hearing participants reported perceiving speech in the sine-wave speech stimuli before the mid-scan reveal.

    “However, while being scanned, the majority of NCVH participants reported perceiving speech in the SWS stimuli before the mid-scan reveal, with one participant reporting hearing speech from the first 'three or four words' of Run 1.”
    Quote in the paperSubstantial claim
  • Findingown data

    When a model containing the group effect was compared to one without it, the Bayes Factor was 0.54, or 1:1.86 in favour of the null.

    “When a model containing the group effect was compared to one without it (i.e. the null hypothesis), the Bayes Factor was 0.54, or 1:1.86 in favour of the null (in other words, the data were almost twice as likely to occur under the null hypothesis).”
    Quote in the paperSubstantial claim
  • Findingown data

    Speech areas usually associated with effects of prior knowledge and expectation-such as left inferior frontal cortex-also showed no group differences.

    “However, speech areas that are usually associated with effects of prior knowledge and expectation-such as left inferior frontal cortex (Obleser and Kotz, 2010)-also showed no group differences.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Obleser and Kotz, 2010

      Not checked in the free run.

  • May combine two claims. 26
  • Classified as probably not a substantial claim. 12
  • The quote only partly states this claim. 6

  • May combine two claims.

    Findingown data

    The change in left pSTG was specific to intelligible stimuli; no effect was evident for the change in responses to unintelligible stimuli.

    “This change was specific to intelligible stimuli, i.e. no effect was evident for the change in responses to unintelligible stimuli (Fig. 3D, right).”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    Only one non-clinical voice-hearing participant reported experiencing a hallucination during scanning (a visual hallucination, occurring midway through Run 2); they did not report this affecting their ability to complete the task.

    “Only one NCVH participant reported experiencing a hallucination during scanning (a visual hallucination, occurring midway through Run 2); however, they did not report this affecting their ability to complete the task.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    There were no group differences in total button presses, whether or not the participant who pressed a button for every trial was included.

    “There were no group differences in total button presses, whether or not the latter participant was included (all t 5 1.4, all P 4 0.19).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    We did not observe significant group differences in primary sensory regions, either in whole-brain analysis or in follow-up Bayesian analysis.

    “We did not observe significant group differences in primary sensory regions, either in whole-brain analysis or in follow-up Bayesian analysis.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    No supra-threshold group differences were evident for the combination of intelligible and unintelligible SWS versus rest, nor for intelligible-only SWS versus rest or unintelligible-only SWS versus rest.

    “No supra-threshold group differences were evident for either the combination of intelligible and unintelligible SWS versus rest (i.e. the main effect of group during listening to sounds), nor any simple effects (i.e. the main effect of group during listening to intelligible-only SWS versus rest and unintelligible-only SWS versus rest).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    In separate analyses for Runs 1 and 2, a clear intelligibility network was observed for Run 2 but not Run 1 for both groups.

    “In the separate analyses for Runs 1 and 2 [planned contrasts (iii) and (iv)] a clear intelligibility network was observed for Run 2 but not Run 1 for both groups (Table 3), consistent with the non-significant interaction observed.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    On the post-scan behavioural task, no differences were observed between the groups in speech discrimination (d'), the ability to comprehend intelligible sine-wave speech (keyword accuracy), and bias to classify stimuli as speech.

    “On the post-scan behavioural task (i.e. after all participants had been trained to understand the SWS sentences), no differences were observed between the groups, with similar performance for speech discrimination (d'), the ability to comprehend intelligible SWS (keyword accuracy), and bias to classify stimuli as speech ( ; Supplementary Table 2).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Bayes Factor values for models containing group x run, group x intelligibility, and group x run x intelligibility were 0.26, 0.26, and 0.57, respectively (i.e. 1:3.85, 1:3.85, and 1:1.75 in favour of the null).

    “Bayes Factor values of 0.26, 0.26 and 0.57 were observed for models containing group  run, group  intelligibility, and group  run  intelligibility, respectively (i.e.1:3.85, 1:3.85 and 1:1.75 in favour of the null).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    NCVH already showed a stronger intelligibility response than controls in Run 1, in the same ACC region as in the overall analysis (MNI coordinates for peak voxel: 2, 36, 28, k = 241, t = 5.14, P FWE = 0.008) and in left middle frontal gyrus (MNI coordinates for peak voxel: -36, 54, 0, k = 190, t = 4.91, P FWE = 0.024).

    “NCVH already showed a stronger intelligibility response than controls in Run 1, in the same ACC region as in the overall analysis (MNI coordinates for peak voxel: 2, 36, 28, k = 241, t = 5.14, P FWE = 0.008) and in left middle frontal gyrus (MNI coordinates for peak voxel: À36, 54, 0, k = 190, t = 4.91, P FWE = 0.024).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingcitation

    Neither group performed at ceiling on the post-scan task: keyword accuracy after scanning was reasonably low in both groups compared to prior studies using distorted speech, despite the fact that speech/non-speech discrimination was good.

    “However, neither group performed at ceiling on the post-scan task: keyword accuracy after scanning was reasonably low in both groups compared to prior studies using distorted speech (McGettigan et al., 2012), despite the fact that speech/ non-speech discrimination was good.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites McGettigan et al., 2012 source

      Not checked in the free run.

  • May combine two claims.

    Findingown data

    Of those who realized words were present, seven non-clinical voice-hearing and five control participants mentioned that they could understand the words, with five in each group being able to accurately recall some of them.

    “Of these, seven NCVH and five control participants additionally mentioned that they could understand the words, with five in each group being able to accurately recall some of them.”
    Quote in the paperNot a substantial claim

  • The quote only partly states this claim.

    Findingown data

    The group difference in ACC remained significant when the timing of participants' noticing of speech (recognition point) was included as a covariate (MNI coordinates for peak voxel: -2, 32, 26, k = 467, t = 5.27, z = 4.31, P FWE < 0.001).

    “The group difference in ACC remained significant (MNI coordinates for peak voxel: À2, 32, 26, k = 467, t = 5.27, z = 4.31, P FWE 5 0.001)”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Findingown data

    In Run 2, intelligible versus unintelligible SWS elicited activation in a right superior temporal gyrus cluster (peak MNI: 64, -2, -6; 868 voxels; t=6.18; z=4.84; P FWE <0.001).

    “R superior temporal gyrus | 64 | À2 | À6 | 868 | 6.18 | 4.84 | 50.001”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Findingown data

    In Run 2, intelligible versus unintelligible SWS elicited activation in a right inferior frontal gyrus cluster (peak MNI: 32, 20, -2; 216 voxels; t=5.52; z=4.48; P FWE=0.019).

    “R inferior frontal gyrus | 32 | 20 | À2 | 216 | 5.52 | 4.48 | 0.019”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Findingown data

    Across both runs and groups combined, intelligible versus unintelligible SWS elicited activation in a right superior temporal gyrus cluster (peak MNI: 62, -6, -4; 468 voxels; t=5.71; z=4.58; P FWE <0.001).

    “R superior temporal gyrus | 62 | À6 | À4 | 468 | 5.71 | 4.58 | 50.001”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Findingown data

    Across both runs and groups combined, intelligible versus unintelligible SWS elicited activation in a right superior temporal gyrus cluster (peak MNI: 48, -36, 6; 238 voxels; t=5.49; z=4.46; P FWE=0.001).

    “R superior temporal gyrus | 48 | À36 | 6 | 238 | 5.49 | 4.46 | 0.001”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Findingown data

    In Run 2, intelligible versus unintelligible SWS elicited activation in a left inferior parietal cortex cluster (peak MNI: -68, -42, 20; 2125 voxels; t=8.96; z=6.05; P FWE <0.001).

    “Run 2 | L inferior parietal cortex | À68 | À42 | 20 | 2125 | 8.96 | 6.05 | 50.001”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    There are correlations between the recognition point when participants noticed words and intelligibility response across both runs and in Run 1 only.

    “Correlations between the recognition point when participants noticed words and intelligibility response across both runs (A), and in Run 1 only (B and C).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    People with an 'at risk' mental state outperformed controls in their ability to identify objects in ambiguous, Mooney-style visual stimuli, but only once they were given priming information about the objects.

    “People with an 'at risk' mental state (i.e. in early stages of psychosis) outperformed controls in their ability to identify objects in ambiguous, Mooney-style visual stimuli (Mooney, 1957), but only once they were given priming information about the objects.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Teufel et al., 2015 source

      Not checked in the free run.

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    Sine-wave speech is typically unintelligible on first exposure and may not be noticed as being speech-like; once the listener knows that it is potentially intelligible, relatively high levels of comprehension can be achieved.

    “SWS is typically unintelligible on first exposure and may not be noticed as being speech-like (often sounding like 'aliens' or birdsong).Once the listener knows that it is potentially intelligible, though, relatively high levels of comprehension can be achieved (Remez et al., 2011;Rosen et al., 2011).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites Remez et al., 2011 source

      Not checked in the free run.

    • cites Rosen et al., 2011 source

      Not checked in the free run.

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    Non-clinical voice-hearing is featurally similar to auditory verbal hallucinations described in psychosis, but usually more controllable and positive in content.

    “Such non-clinical voice-hearing (NCVH) is featurally similar to auditory verbal hallucinations described in psychosis, but usually more controllable and positive in content (Daalman et al., 2011).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Daalman et al., 2011 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Posterior temporal cortex appears to track changes in sensory detail and predictability.

    “while posterior temporal cortex appears to track changes in sensory detail (Sohoglu et al., 2012) and predictability (Gagnepain et al., 2012).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Sohoglu et al., 2012 source

      Not checked in the free run.

    • cites Gagnepain et al., 2012 source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    The general response to intelligibility-and general effects of training with SWS-involved regions consistent with previous research on distorted speech.

    “Notwithstanding the small sample size of the present study, it is also important to note that the general response to intelligibility-and general effects of training with SWS-involved regions consistent with previous research on distorted speech.”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites McGettigan et al., 2012 source

      Not checked in the free run.

    • cites Rosen et al., 2011 source

      Not checked in the free run.

    • cites Möttönen et al., 2006 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductown data

    Button-press responses for four participants (one non-clinical voice-hearing, three control) did not record correctly and one non-clinical voice-hearing participant accidentally pressed a button for every trial.

    “However, button-press responses for four participants (one participant with NCVH, three control subjects) did not record correctly and one NCVH participant accidentally pressed a button for every trial.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationcitation

    The negative correlation with left IFG activation is consistent with the deployment of this region for parsing speech in adverse listening conditions, and may reflect the accessing of word meanings and segments to support perception via prior knowledge.

    “The negative correlation with left IFG activation is consistent with the deployment of this region for parsing speech in adverse listening conditions, and may reflect the accessing of word meanings and segments to support perception via prior knowledge (Davis and Johnsrude, 2003;Obleser and Kotz, 2010;Sohoglu et al., 2012;Du et al., 2014).”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites Davis and Johnsrude, 2003

      Not checked in the free run.

    • cites Obleser and Kotz, 2010

      Not checked in the free run.

    • cites Sohoglu et al., 2012 source

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    Comparable levels of discrimination and accuracy in the post-scanner task, and the absence of group differences in how the reveal and training affected brain responses, suggest that the explicit modulation of expectation does not play a major role in how NCVH process ambiguous speech.

    “Indeed, the comparable levels of discrimination and accuracy in the post-scanner task, and the absence of group differences in how the reveal and training affected brain responses, suggest that the explicit modulation of expectation does not play a major role in how NCVH process ambiguous speech.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    All participants reported being able to hear the sounds without any difficulty.

    “All participants reported being able to hear the sounds without any difficulty.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    A permutation test produced similar results for the recognition point difference (mean difference = -1.23, P = 0.041).

    “[Due to non-normal data in the control group this comparison was also run using a permutation test in the perm package for R, producing similar results (mean difference = À1.23,P = 0.041), Monte Carlo method used with 2000 replications.]”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationown data

    The stronger intelligibility response in NCVH could be seen even before the reveal and training, so was therefore not dependent on the modulation of expectation.

    “This effect could be seen even before the reveal and training, so was therefore not dependent on the modulation of expectation.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Effects of prior knowledge and training on the processing of sine-wave speech and similar stimuli are reflected in the greater involvement of inferior frontal cortex, pre-supplementary motor area, and dorsolateral prefrontal cortex.

    “Effects of prior knowledge and training on the processing of SWS and similar stimuli are reflected in the greater involvement of inferior frontal cortex (Davis and Johnsrude, 2003), pre-SMA, and dorsolateral prefrontal cortex (Eisner et al., 2010;Rosen et al., 2011), while posterior temporal cortex appears to track changes in sensory detail (Sohoglu et al., 2012) and predictability (Gagnepain et”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Davis and Johnsrude, 2003

      Not checked in the free run.

    • cites Eisner et al., 2010 source

      Not checked in the free run.

    • cites Rosen et al., 2011 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    This combination of distorted auditory presentation and clear written feedback has previously been used to demonstrate effective intelligibility training effects on similar degraded stimuli.

    “This combination of distorted auditory presentation and clear written feedback has previously been used to demonstrate effective intelligibility training effects on similar degraded stimuli (Davis et al., 2005).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Davis et al., 2005 source

      Not checked in the free run.

  • May combine two claims.

    Study design and conductown data

    The study included 12 non-clinical voice-hearing participants and 17 non-voicehearing control participants, matched for age, sex, handedness, education, and National Adult Reading Test scores.

    “The study included 12 NCVH participants and 17 non-voicehearing control participants, matched for age, sex, handedness, education, and National Adult Reading Test scores (Nelson, 1982) (Table 1).”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Following training, sine-wave speech engages a left-lateralized 'speech mode' network including anterior and posterior temporal cortex (superior temporal gyrus and middle temporal gyrus), inferior frontal gyrus and insula.

    “Following training, SWS engages a left-lateralized 'speech mode' network including anterior and posterior temporal cortex (STG and middle temporal gyrus), IFG and insula (Vouloumanos et al., 2001;Dehaene-Lambertz et al., 2005;Benson et al., 2006;Mo ¨tto ¨nen et al., 2006;McGettigan et al., 2012).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Vouloumanos et al., 2001 source

      Not checked in the free run.

    • cites Dehaene-Lambertz et al., 2005 source

      Not checked in the free run.

    • cites Benson et al., 2006 source

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    NCVH participants did not show a specific benefit in intelligibility once trained to listen for speech, indicating that the effect of the reveal and subsequent training had a broadly similar influence on intelligibility responses across groups.

    “That is, NCVH participants did not show a specific benefit in intelligibility once trained to listen for speech, indicating that the effect of the reveal and subsequent training had a broadly similar influence on intelligibility responses across groups.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    The fundamental mechanisms underlying hallucination involve-and may develop from-ordinary perceptual processes, illustrating the continuity of mundane and unusual experience.

    “This suggests that the fundamental mechanisms underlying hallucination involve-and may develop from-ordinary perceptual processes, illustrating the continuity of mundane and unusual experience.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationown data

    The functional MRI results indicate that this capacity appears to rely less on enhanced speech-specific feedback to auditory regions, and more on the engagement of sensorimotor and domain-general attentional resources, selectively for potentially intelligible speech stimuli.

    “The functional MRI results indicate that this capacity appears to rely less on enhanced speech-specific feedback to auditory regions, and more on the engagement of sensorimotor and domaingeneral attentional resources, selectively for potentially intelligible speech stimuli.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Such individuals do not appear to be differentially affected by explicit modulations of expectation-instead, people in this group report being able to spontaneously extract speech from degraded auditory signals (and report doing so earlier than matched controls).

    “Such individuals do not appear to be differentially affected by explicit modulations of expectation-instead, people in this group report being able to spontaneously extract speech from degraded auditory signals (and report doing so earlier than matched controls).”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Activation maps are presented at an uncorrected threshold of P < 0.001 peak level, FWE corrected (P < 0.05) at cluster level.

    “Activation maps are presented at an uncorrected threshold of P 5 0.001 peak level, FWE corrected (P 5 0.05) at cluster level.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationcitation

    The primarily left-lateralized network seen across both groups is consistent with intelligibility effects using very similar stimuli, as is the involvement of the SMA.

    “The primarily left-lateralized network seen across both groups is consistent with intelligibility effects using very similar stimuli (McGettigan et al., 2012), as is the involvement of the SMA (Rosen et al., 2011).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites McGettigan et al., 2012 source

      Not checked in the free run.

    • cites Rosen et al., 2011 source

      Not checked in the free run.

39 of 39

  • The paper relies on this without support.

    Additional clinical factors in schizophrenia (e.g., additional symptoms, medication use) make it challenging to investigate neurocognitive mechanisms that are hallucination-specific.

    “However, the presence of other clinical factors, such as additional symptoms or the use of medication, makes it challenging to investigate neurocognitive mechanisms that are hallucination-specific.”

  • The paper relies on this without support.

    A similar effect in voice-hearers has never been demonstrated for the auditory domain.

    “A similar effect in voice-hearers has never been demonstrated for the auditory domain, but can be tested using an ambiguous auditory stimulus: sine-wave speech (SWS).”

  • The authors state this as an assumption.

    The accuracy of participants' self-reports is sufficient to gauge when participants noticed speech during Run 1.

    “Second, we are reliant on the accuracy of participants' self-reports to gauge when participants noticed speech during Run 1, and cannot know for sure what participants were responding to when 'hearing' speech.”

  • The paper relies on this without support.

    The in-scanner recognition point measure reflects the moment participants actually noticed speech, not merely when they pressed a button.

    “Given the subjective nature of our in-scanner 'recognition point' measure, the finding that group differences in the neural responses to SWS were specific to potentially intelligible signals is key.”
4 of 4

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • The impact of priors on perception may be enhanced in those with hallucinations.

    “However, recent neural data suggest that they do (72, 73), and that the impact of priors on perception may be enhanced in those with hallucinations (74–76).”

    From The Predictive Coding Account of Psychosis (2018) · cites this paper as [76]

Statistics recomputed

Every reported test result, recomputed from its test statistic and degrees of freedom. A result shows as not adding up only once an independent check has confirmed it.

  • Consistentt(27) = -2.17reported p = .039 · recomputed p = .039

    “t(27) = À2.17,p = .039”

  • Consistentt(27) = 2.98reported p = .006 · recomputed p = .006

    “t(27) = 2.98, p = .006”

  • Consistentt(27) = -1.05reported p = .301 · recomputed p = .303

    “t(27) = À1.05,p = .301”

  • Consistentt(28) = 0.12reported p = .909 · recomputed p = .905

    “t(28) = 0.12, p = .909”

4 of 4

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Planned interaction contrast adds the Run 1 intelligibility effect

    Minor

    As written, the contrast subtracts (unintelligible Run 1 − intelligible Run 1), so it adds the Run 1 intelligibility effect to the Run 2 effect. It therefore does not test whether the intelligibility response is larger in Run 2 than Run 1, as claimed.

1 of 1

Cites

Flagged first, then by citations

Research works printed but not linked: 3

  1. Alderson-Day, 2014, Do you hear voices? You are not alone
  2. Brett, 2002, Region of interest analysis using the MarsBar toolbox for SPM 99, Neuroimage, 16, S497
  3. Shanmugalingam, 2012, Sinewave speech and non-speech can reveal distinct speech-mode and speech-intelligibility effects in the cortical speech perception network

Cited by

Sorted by citations

Related

Authors
Alderson-Day, B., Lima, C. F., Evans, S., Krishnan, S., Shanmugalingam, P., Fernyhough, C., & Scott, S. K.
Affiliations
  • Department of Psychology, Durham University, Science Laboratories, South Road, Durham, DH1 3LE, UK
  • Universidade do Porto (PT)
  • University College London (GB)
  • University of Oxford (GB)
  • Durham University (GB)
ORCID
Venue
Brain
Publisher
Oxford University Press (OUP)
Published
2017-08-20
Volume
140
Issue
9
Pages
2475-2489
ISSN
  • 0006-8950 (ISSN-L)
  • 1460-2156
DOI
10.1093/brain/awx206
OpenAlex
W2730439666
Semantic Scholar
1c4f186c0a63a819367d3d19537835ec63375634
Cited by
108
References
95
Citations by year
2026: 10 · 2025: 11 · 2024: 9 · 2023: 9 · 2022: 11 · 2021: 16 · 2020: 20 · 2019: 7 · 2018: 12 · 2017: 3
FWCI
6.59
Type
journal article
Language
en
Open access
Licence
cc-by
Locations
  • Brain (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • WestminsterResearch (University of Westminster) (acceptedVersion)
  • Durham Research Online (Durham University) (acceptedVersion, other-oa)
  • WestminsterResearch (University of Westminster) (acceptedVersion, cc-by)
  • Durham Research Online (Durham University) (submittedVersion, cc-by)
  • UCL Discovery (University College London) (submittedVersion)
  • Portuguese National Funding Agency for Science, Research and Technology (RCAAP Project by FCT) (submittedVersion)
Funders
Wellcome Trust (WT098455 and WT108720)
Topics
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Hallucinations in medical conditions
  • Health Sciences › Medicine › Psychiatry and Mental health › Schizophrenia research and treatment
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Neurobiology of Language and Bilingualism
Keywords
auditory verbal hallucinations, sine-wave speech, speech intelligibility, dorsal anterior cingulate cortex, superior frontal gyrus, predictive processing, prior expectations, attention, sensorimotor processing
MeSH terms
Acoustic Stimulation, Adult, Auditory Perception, Female, Gyrus Cinguli, Hallucinations, Humans, Magnetic Resonance Imaging, Male, Case-Control Studies, Prefrontal Cortex, Uncertainty, Young Adult

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-10.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-10.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

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