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Blunted vocal affect and expression is not associated with schizophrenia: A computerized acoustic analysis of speech under ambiguous conditions
Accepted Manuscript Blunted vocal affect and expression is not associated with schizophrenia: A computerized acoustic analysis of speech under ambiguous conditions
Lauren T. Meaux, Kyle R. Mitchell, Alex S. Cohen PII: DOI: Reference:
S0010-440X(18)30059-2 doi:10.1016/j.comppsych.2018.03.009 YCOMP 51963
To appear in: Please cite this article as: Lauren T. Meaux, Kyle R. Mitchell, Alex S. Cohen , Blunted vocal affect and expression is not associated with schizophrenia: A computerized acoustic analysis of speech under ambiguous conditions. The address for the corresponding author was captured as affiliation for all authors. Please check if appropriate. Ycomp(2018), doi:10.1016/j.comppsych.2018.03.009
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ACCEPTED MANUSCRIPT Blunted vocal affect and expression is not associated with schizophrenia: A computerized acoustic analysis of speech under ambiguous conditions
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Lauren T Meauxa, Kyle R Mitchella, Alex S Cohena
Louisiana State University, 236 Audubon Hall, Psychology Department, Louisiana State University,
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Baton Rouge, Louisiana 70803, United States of America
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Address correspondence to:
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Submitted as a “Research Paper” to Comprehensive Psychiatry
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Lauren Meaux, [email protected], Louisiana State University, 236 Audubon Hall, Psychology
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Department, Louisiana State University, Baton Rouge, Louisiana 70803, United States of America
ACCEPTED MANUSCRIPT Abstract INTRODUCTION: Patients with schizophrenia are consistently rated by clinicians as having high levels of blunted vocal affect and alogia. However, objective technologies have often failed to substantiate these abnormalities. It could be the case that negative symptoms are context-dependent.
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OBJECTIVES: The present study examined speech elicited under conditions demonstrated to exacerbate
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thought disorder.
METHODS: The Rorschach Test was administered to 36 outpatients with schizophrenia and 25
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nonpatient controls. Replies to separate “perceptual” and “memory” phases were analyzed using validated
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acoustic analytic methods.
RESULTS: Compared to nonpatient controls, schizophrenia patients did not display abnormal speech
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expression on objective measure of blunted vocal affect or alogia. Moreover, clinical ratings of negative symptoms were not significantly correlated with objective measures.
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CONCLUSIONS: These findings suggest that in patients with schizophrenia, vocal affect/alogia is
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generally unremarkable under ambiguous conditions. Clarifying the nature of blunted vocal affect and alogia, and how objective measures correspond to what clinicians attend to when making clinical ratings
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are important directions for future research.
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KEYWORDS: negative symptoms; thought disorder, acoustic analysis, schizophrenia
ACCEPTED MANUSCRIPT 1. Introduction Schizophrenia is a psychological disorder that severely affects an individual’s cognitive, perceptual, and motor functioning and is manifested in positive, negative and disorganized symptoms. Positive symptoms include delusions (i.e. firmly held beliefs that are unchangeable in the presence of
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incongruent evidence) and hallucinations (i.e. perceptions occurring in the absence of an external
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stimulus). Negative symptoms include speech-related behaviors such as blunted vocal affect (i.e., reduced
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vocal variability), and alogia (i.e., diminished vocal production) [1]. Negative symptoms in schizophrenia are a pernicious category of symptoms due to their chronic nature, resistance to medication, and
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indication of poor prognosis [2]. Additionally, patients with schizophrenia and other psychotic disorders demonstrate difficulty in discerning emotional affect in the speech of other individuals [3] [4] [5].
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Previous research suggests these difficulties may be moderately related to cognitive deficits or impaired theory of mind abilities in individuals with schizophrenia [6].
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Patients show profound deficits in speech affect and expression on clinician-rated measures like
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the Scale for the Assessment of Negative Symptoms (SANS) [7]. A recent review found that ratings of speech variability and production from the SANS were 3-5 standard deviations abnormal compared to
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nonpsychiatric controls [8]. Importantly, these abnormalities are seen for patients as a group, and not just
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in subgroups of patients with particularly pronounced negative symptoms [2]. While clinician-rating measures demonstrate acceptable reliability and, in some studies, convergence with a range of clinical
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phenomenon [2], they are limited in many respects. Of note, they are based on relatively ambiguous operational definitions covering a wide range of behaviors that are not well operationalized or grounded in speech sciences; they lack consideration to cultural, individual difference, and environmental factors that heavily influence speech expression, and offer limited response options that are insensitive to all but major changes over time [9] [10] [11]. However, technological developments allow for more reliable and precise measures of blunted affect and alogia based on computerized/objective acoustic analysis [10]. These measures offer potentially greater reliability, validity, and sensitivity, leading to greater accuracy in assessment [12]. To date, there have been several dozen studies employing acoustic analysis of patient
ACCEPTED MANUSCRIPT speech in some capacity. While there are promising “proof of concept” studies (e.g., [13]), the larger literature provides results that are underwhelming in magnitude and consistency. For example, a large multi-site analysis of patient speech found no statistical difference between 309 schizophrenia patients and 117 nonpsychiatric controls on a range of empirically-derived objectively-based vocal measures [14].
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Moreover, a meta-analysis of 13 published studies found that, at most, certain measures related to alogia
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(e.g., pause times/numbers) are exaggerated in some studies on the order of one standard deviation above
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controls [9] [15] and are normal in other studies [8] [16]. This is far below the 3-5 standard deviations found from clinical rating scales (see Figure 1 for a summary). Importantly, clinical ratings of blunted
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vocal affect often show statistically nonsignificant correlations (-.18 [9]) to small (.26 [17]) with acoustically-derived measures of vocal affect (e.g., intonation, emphasis) obtained during laboratory
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speaking tasks. However, negative and positive symptoms have been shown to be significantly associated with vocal production (e.g., increased pause times and decreased number of utterances) and positive
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symptoms were correlated with increased inflection [12].
It could be the case that speech production (tapping alogia) and variability (tapping blunted
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affect) are “context-dependent,” that is, their emergence is contingent upon cognitive, social, or other
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factors. For example, it has been proposed that cognitive resources related to “on-line” attentional and working memory abilities are particularly important for producing speech [19] [20]. Given that these
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resources are deficient in schizophrenia [21], a cognitive resource model may explain the symptoms of blunted affect and alogia. In support of this idea, increasing experimentally-manipulated cognitive demands causes decreased speech production and variability in schizophrenia patients [19] [21]. This could be due to the fact that allocation of cognitive resources for one task limits resources for speech; and speech becomes quantitatively and qualitatively sparser/flatter. One approach to understanding cognitive and other contextual effects on speech involves the Rorschach inkblot test, a popular measure of positive thought disorder [22]. The Rorschach is thought to be a useful measure of thought disorder because it imposes a relatively heavy “processing” load, vis a vis
ACCEPTED MANUSCRIPT the “ambiguity” of the inkblot stimuli, which potentially exacerbates thought disorder and, behaviorally, speech incoherence [23]. Although this processing load is potentially imposed via multiple systems (e.g., cognitive, affective, social), analysis of speech from Rorschach tests offers an opportunity to understand whether blunted affect/alogia are exacerbated in the same manner as positive thought disorder. The Rorschach administration utilized in this study involved three distinct phases per card. The first
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“Perceptual” phase involved participants describing the stimulus in terms of identifiable objects while viewing the card. The second “Memory” phase involved participants describing the features of the
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stimulus that provoked the aforementioned object without viewing the card. The third “Identify” phase
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involved participants physically indicating (i.e., pointing to) which areas of the stimulus corresponded with the features described in the “Memory” phase. We consider the second phase to be more taxing than
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the first because it involves communicating complex semantic material (e.g., explaining and defending their response). Therefore, the “Memory” phase requires the participant to exert more cognitive resources
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than the “Perceptual” phase.
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The current study used computerized acoustic analysis to examine responses from a Rorschach inkblot test. Across phases of the Rorschach, we hypothesized that patients with schizophrenia would
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exhibit abnormalities in vocal production and vocal expression, as measured by a decrease in number of
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utterances and increase in pause times, and variability, as measured by flattened intonation, pitch perturbation, emphasis, and intensity perturbation, compared to nonpsychiatric controls. Additionally, we
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hypothesized that these abnormalities would be exacerbated during the “Perceptual” phase of the Rorschach, which is potentially more taxing in cognitive, motivational, and other abilities than the “Memory” phase. Finally, we examined the relationships between clinical ratings and objectively-defined acoustic variables.
2. Methods 2.1 Participants. Participants consisted of 36 outpatients with DSM-IV diagnosed schizophrenia and 25 controls. All participants were recruited as part of a larger study and went through an informed
ACCEPTED MANUSCRIPT consent process. Portions of the data have been reported elsewhere [24]. Education level and sex didn’t differ between groups, though the control group was significantly younger than the schizophrenia group (Table 1). Exclusion criteria for both the schizophrenia and control group included the following: lack of fluency in English, a history of traumatic brain injury, a history of diagnosed organic brain disease, and a
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history of substance abuse or dependence during the previous two years.
2.2 Brief Psychiatric Rating Scale. The Brief Psychiatric Rating Scale (BPRS) is an 18-item
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semi-structured interview used to assess various psychotic and affective symptoms [26]. The questions in the interview are answered on a Likert scale of 1-7 with 1 representing “not present” and 7 representing
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“extremely severe.” A score of 0 may be selected if the item was not assessed. Half of the items are based on the patient’s self-report of his or her own behavior over the past 2-3 days, while the other half assess
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the behavior of the patient as observed by the examiner. The individual ratings for each item are then
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added to form a composite score. Items on the BPRS load on to four factors which measure Anergia (i.e., negative symptoms), Thought Disorder (i.e., positive symptoms), Disorganization (i.e., animation,
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agitation), and Affect (i.e., mood disturbances, depression, anxiety) [27].
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2.3 Rorschach inkblot test. The version used in this study involved four stimulus cards selected from a standard Rorschach administration and involved three distinct phases per card [28]. The first
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“Perceptual” and second “Memory” phases were analyzed in this study. A third “Identify” phase involving only limited vocal communication was excluded from the present analyses. Responses were digitally recorded.
2.4 Acoustic analysis. Recordings were digitally spliced and were analyzed using the Computerized Analysis of Natural Speech [10]. The following variables were selected for this study, based on findings from a principal components analysis and validity study conducted on large patient samples (n = 309; [14]) and nonpsychiatric adult (N = 1,350; [10]) samples: pause mean – mean time between utterances (in milliseconds), utterance number – total number of utterances (defined as speech
ACCEPTED MANUSCRIPT bounded by pauses ≥150 ms), Intonation– standard deviation of the fundamental frequency averaged across utterances, Pitch perturbation – absolute value of change in the fundamental frequency in successive frames, Emphasis– SD of intensity averaged across utterances, and Intensity perturbation – absolute value of change in intensity in successive frames. Pause mean and utterance number tap into
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vocal production whereas intonation, pitch perturbation, emphasis, and intensity perturbation tap vocal
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variability. These measures have been used extensively in both the clinical and nonclinical acoustic
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analysis literature.
2.5 Analyses. Analyses were conducted in three steps. First, we examined whether demographic
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and clinical variables were related to any of the dependent variables, as sex differences are often observed in studies of vocal expression [12] [17]. Second, we compared patients and controls on acoustic variables
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using multi-level modeling. We conducted six separate multilevel models (MLM) with subjects as random intercepts to examine the effect of phase (“Perceptual” phase versus “Memory” phase) and group
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(schizophrenia versus controls), as well as their interaction with the acoustic variable of interest as the
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dependent variable. Demographic variables were imputed into the multilevel models as the first step. Phase, group, and interaction variables were computed in the second step. The phase effects were used as
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a “manipulation check” to evaluate whether there were contextual effects on vocal expression. The group
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effect was used to examine whether diagnosis contributed to differences in acoustic characteristics across phase. The group by phase interaction examined whether diagnostic group disproportionally varied by
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phase as compared to controls. We predicted that, during the memory phase, patients versus controls would show decreased number of utterances, increased pause times, and decreased intonation, pitch perturbation, emphasis, and intensity perturbation. Third, we examined the correlations between clinically-rated negative, blunted affect and other symptoms and acoustic variables. Pause time and intonation variables were skewed, and hence, were Winsorized such that values exceeding three SDs were replaced with their three SD equivalent, and were group centered for the MLMs. 3. Results
ACCEPTED MANUSCRIPT Women showed significantly more utterances and intonation than men in both conditions (p’s < 0.05; across groups). Education level was positively associated with more utterances (p < .001). No other
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demographic or clinical variables were significantly related to the speech variables.
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There was a phase effect for Pause Mean and Utterance Number, in that all participants,
condition as opposed to the perceptual condition (Table 2).
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regardless of diagnostic category, exhibited fewer utterances and shorter pause times in the memory
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Results of the multi-level modeling indicate that the schizophrenia group was largely similar to controls, but did differ significantly from healthy controls on a few key variables (Table 2). Generally
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speaking, there were few significant group or interaction effects as hypothesized. Interestingly, there was a group effect in Pitch Perturbation (coefficient = .49; std. error = .26), with the schizophrenia group
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exhibiting higher, not lower pitch perturbation than controls. There was also a phase by group interaction,
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where the difference between the perceptual and memory phases was significantly different between the schizophrenia and control group. The schizophrenia group exhibited higher Intensity Perturbation during
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the perceptual phase as related to their performance in the memory phase (coefficient = -.38; std. error =
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.16), whereas performance did not vary as a function of group within the memory phase. Controls’
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performance did not differ as a function of phase.
Pearson correlations (Table 3) revealed few statistically significant correlations between clinical ratings and acoustic variables. Scores on the Thought Disorder factor of the BPRS were associated with greater Pitch Perturbation and Emphasis during the memory phase of the Rorschach. Additionally, patients with schizophrenia who scored higher on the Affect factor of the BPRS demonstrated shorter Pause Means during the memory phase of the Rorschach. However, the magnitude of these correlations was not large, and we did not employ control for multiple comparisons.
ACCEPTED MANUSCRIPT 4. Discussion The current findings indicate that individuals with schizophrenia exhibited largely normal speech, regardless of task. Congruent with prior studies that directly manipulated the speaking task, vocal variables varied in both groups as a function of processing load [19] [21]; though this was in the opposite
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direction than expected. It is unclear why the memory phase produced speech that was more prodigious
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than in the perceptual phase, but it is likely that contextual factors other than cognitive load influenced vocal expression. Perhaps the memory phase was more arousing, or elicited content that was more
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cognitively accessible or otherwise automatic. Regardless, “ambiguous” conditions elicited by the
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Rorschach Inkblot Test failed to create a context that would result in the manifestation of negative symptoms in patients with schizophrenia.
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In fact, individuals with schizophrenia exhibited increased Pitch Perturbation and in Intensity Perturbation, suggesting increased arousal during the perceptual phase [29]. The reason behind this is
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unclear. It may be the case that the relatively increased arousal is due to poor stress reactivity in patients
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with schizophrenia. Previous research indicates that patients with schizophrenia exhibit greater reactions (i.e., increased heart rate, high frequency of nonspecific skin conductance) to minor stressors than
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controls [30]. Notably, these findings indicate that computerized acoustic analysis may be used to
as well.
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measure more than just negative symptoms, but increased stress reactivity in patients with schizophrenia
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Further, affective reactivity in language can be viewed as a component of a general increase in responsivity to emotional stimuli (particularly negative valance stimuli) in patients with schizophrenia [31]. The Rorschach Test stimuli may have been perceived by schizophrenia patients as emotional or negative, thus exacerbating their stress reactivity which resulted in increased arousal, particularly in the perceptual phase. Though the Rorschach Test is considered a valid measure of positive thought disorder [23], its utility for measuring negative thought disorder has not been well established [32]. The present results suggest that the Rorschach may not be optimal for measuring blunted vocal affect and alogia. Future research may focus on examining the emotional valence of individual cards from the Rorschach
ACCEPTED MANUSCRIPT Test in order to establish those which may elicit positive versus negative emotions, particularly in patients with schizophrenia. Acoustic analyses may then be conducted on the speech elicited from schizophrenia and control groups while being administered just the positively valenced cards. This condition may be sufficient for examining negative symptoms (e.g., blunted vocal affect, alogia).
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Limitations of this study include the inability to control for medication type or dosage level and
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group differences in age. Given medications may have a sedative effect on patients, future studies may
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aim to employ an unmedicated patient sample for comparison. Additionally, executive functioning abilities, global cognitive deficits, and effort were not assessed in this study and, therefore, not
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statistically controlled for. Similar executive or other cognitive abilities across groups may have driven the findings of mostly comparable speech production and variability. Nonetheless, these null findings are
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consistent with previous studies utilizing computerized acoustic analysis software [10] [12] [19]. 5. Conclusions
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In the current study, patients with schizophrenia were not abnormal in vocal expression, even in a
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context that was putatively cognitively taxing. This study contributes to others [8] [12] [17], which collectively, present an important question for negative symptoms research in schizophrenia: “When do
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patients with schizophrenia demonstrate the dramatic vocal deficits captured in clinical ratings”. Of note, future studies might attempt to simulate conditions under which these vocal deficits have been examined
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in clinical settings. Although memory was tapped in this study during the “Memory” phase, it was clearly
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insufficient to exacerbate blunted affect and alogia to detectable levels. It may be the case that it elicited a more perceptual or visually-aided memory by the participants, which may not be analogous to experiential memory. However, it may be the case that the latter is often elicited in clinical ratings and may need to be examined through further research.
Acknowledgements: The authors wish to thank Deborah L Levy for sharing her data with us.
ACCEPTED MANUSCRIPT Funding: This research did not receive any specific grant from funding agencies in the public,
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commercial, or not-for-profit sectors.
ACCEPTED MANUSCRIPT References [1] American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 5th ed. Arlington, VA: American Psychiatric Publishing; 2013. [2] Tandon R, Nasrallah HA, Keshavan MS. Schizophrenia, “just the facts” 4. Clinical features and
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conceptualization. Schizophr Res 2009;110:1-23.
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[3] Billingberg O, Jonsson CO. The ability of schizophrenic patients to interpret intonation. Acta Psychiat
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Scand 1965;41:218-226.
[4] Murphy D, Cutting J. Prosodic comprehension and expression in schizophrenia. J Neur Neurosurg
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Psychiatry 1990;53:727-730.
[5] Colle L, Angeleri R, Vallana M, Sacco K, Bara BG, Bosco FM. Understanding the communicative
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impairments in schizophrenia: A preliminary study. Journal of Communication Disorders 2013;46:294-308.
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[6] Parola, A, Berardinelli L, Bosco FM. Cognitive abilities and theory of mind in explaining
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communicative-pragmatic disorders in patients with schizophrenia. Psychiatry Res 2018;260:14451.
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[7] Andreasen NC. The Scale for the Assessment of Negative Symptoms (SANS). Iowa City, IA:
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University of Iowa; 1984.
[8] Cohen AS, Mitchell KR, Elvegåg B. What do we really know about blunted affect and alogia? A
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meta-analysis of objective assessments. Schizophr Res 2014;159:533-8. [9] Alpert M, Shaw RJ, Pouget ER, Lim KO. A comparison of clinical ratings with vocal acoustic measures of flat affect and alogia. J Psychiatr Res 2002;36:347-53. [10] Cohen AS, Renshaw TL, Mitchell KR, Kim Y. A psychometric investigation of “macroscopic” speech measures for clinical and psychological science. Behav Res Methods 2016;48:475-86. [11] Tawari A, Trivedi MM. Speech emotion analysis: Exploring the role of context. IEEE Trans Multimedia 2010;12:502-9.
ACCEPTED MANUSCRIPT [12] Cohen AS, Najolia GM, Kim Y, Dinzeo TJ. On the boundaries of blunt affect/alogia across severe mental illness: Implications for Research Domain Criteria. Schizophr Res 2012;140:41-5. [13] Stassen HH, Albers M, Puschel M, Scharfetter CH, Tewesmeier M, Woggon B. Speaking behavior and voice sound characteristics associated with negative schizophrenia. J Psychiat Res
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1995;29:277-296.
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[14] Cohen AS, Mitchell KR, Docherty NM, Horan WP. Vocal expression in schizophrenia: Less than meets the ear. J Abnorm Psychol 2016;125:299-309.
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[15] Rapcan V, D’Arcy S, Yeap S, Afzal N, Thakore J, Reilly R. Acoustic and temporal analysis of
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speech: A potential biomarker for schizophrenia. Med Eng Phys 2010;1074-1079. [16] Cohen AS, Dinzeo TJ, Donovan NJ, Brown CE, Morrison SC. Vocal acoustic analysis as a biometric
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indicator of information processing: Implications for neurological and psychiatric disorders. Psychiatr Res 2015;226:235-41.
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[17] Cohen AS, Alpert M, Nienow T, Dinzeo T, Docherty N. Computerized measurement of negative
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symptoms in schizophrenia. J Psychiatr Res 2008;42:827-36. [18] Emmerson LC et al. Prevalence and longitudinal stability of negative symptoms in healthy
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participants. Int J Geriatr Psychiatry 2009;24:1438-44.
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[19] Cohen AS, McGovern JE, Dinzeo TJ, Covington MA. Speech deficits in serious mental illness: A cognitive resource issue? Schizophr Res 2014;160:173-9.
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[20] Plass J, Brunken R, Moreno R. Cognitive Load Theory. Cambridge, UK: Cambridge University Press; 2010.
[21] Barch DM, Berenbaum H. The effect of language production manipulations on negative thought disorder and discourse coherence disturbances in schizophrenia. Psychiatry Res 1997;71:115-27. [22] Wood JM, Nezworski MT, Garb HN. Focus on empirically supported methods: What’s right with the Rorschach? The Scientific Review of Mental Health Practice 2003;2.
ACCEPTED MANUSCRIPT [23] Holzman PS, Levy DL, Johnston MH. The use of the Rorschach technique for assessing formal thought disorder. In: Bornstein RF, Masling JM, editors. Scoring the Rorschach: Seven Validated Systems, Mahwah, NJ: Lawrence Erlbaum Associates; 2005, p. 55-95. [24] Morgan CJ et al. Thought disorder in schizophrenia and bipolar disorder probands, their relatives,
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and nonpsychiatric controls. Schizophr Bull, 2017;43:523-35.
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[25] Endicott J, Spitzer RL, Fleiss JL, Cohen J. The global assessment scale. A procedure for measuring
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overall severity of psychiatric disturbance. Arch Gen Psychiatry 1976;33:766-71. [26] Garcia-Portilla M et al. Psychometric evaluation of the negative syndrome of schizophrenia. Eur
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Arch Psychiatry Clin Neurosci 2015;265:559-66.
[27] Overall JE, Gorham DR. The Brief Psychiatric Rating Scale, ECDEU Assessment Manual
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Psychopharmacology, Guy W, ed. Rockville, MD: US Department of Health Education and Welfare; 1976.
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[28] Carpenter JT et al. The Thought Disorder Index: Short-form assessments. Psychol Assessment
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1993;5:75-80.
[29] Cohen AS, Lee Hong S, Guevara A. Understanding emotional expression using prosodic analysis of
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natural speech: Refining the methodology. J Behav Ther Exp Psychiatry 2010;41:150-7.
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[30] Burbridge J, Larsen R, Barch D. Affective reactivity in language: The role of psychophysiological arousal. Emotion 2005;5:145-53.
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[31] Docherty N, Rhinewine J, Nienow T, Cohen AS. Affective reactivity of language symptoms, startle responding, and inhibition n schizophrenia. J Abnorm Psychol 2001; 110:194-9. [32] Mario B et al. Relationship between the Rorschach Perceptual Thinking Index (PTI) and the Positive and Negative Syndrome Scale (PANSS) in psychotic patients: A validity study. Psychiatry Res 2015;225:315-21.
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Table 1. Demographic and clinical information for schizophrenia (SZ) and nonpsychiatric control (CON) groups. Variable SZ CON t-value (p-value) N 36 25 Education Level 15 (2.19) 14.36 (2.14) -1.13 (.26) Sex (.97) Male 64% 60% Female 36% 40% Age 39.75 (9.99) 31.29 (12.42) -2.94 (.00) Duration of Illness 14.06 (10.37) Age of Onset 25.78 (8.15) Global Assessment 34.58 (6.69) Scale* BPRS Anergia 3.64 (0.93) Blunted Affect 5.44 (1.27) Disorganization 2.11 (0.86) Thought Disorder 3.87 (1.08) Affect 2.51 (0.95) *[25]
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Table 2. Multi-Level Modeling Results of the Effect of Group (Schizophrenia vs. Control), Rorschach Phase (Perceptual vs. Memory), and the Interaction on Speech Variables. LL-Ratio Ratio L-Ratio Step 2: Step Step 4: Effect Phase Schizophrenia Control Phase 3: Phase x Effect Group Group Effect Pause Mean Perceptual 25233.75 (17953.6) 26343.25 (15094.77) 49.81*** 0.11 0.66 Memory 11922.7 (9968.49) 11305.09 (8013.82) Utterance N Perceptual 25.89 (21.23) 53.01*** 0.25 2.04 21.11 (17.42) Memory 45.9 (24.78) 48.31 (29.16) Intonation Perceptual 1.67 (.87) 0.00 1.31 0.01 1.51 (.69) Memory 1.68 (.94) 1.5 (.57) Pitch Perceptual 0.15 (.04) 2.56 4.83* 0.6 0.14 (.02) Perturbation Memory 0.15 (.04) 0.13 (.03) Emphasis Perceptual 1.01 (.32) 0.29 0.00 0.03 0.99 (.40) Memory 1 (.23) 0.98 (.35) Intensity Perceptual 0.57 (.11) 0.20 0.44 5.88** 0.51 (.12) Perturbation Memory 0.56 (.10) 0.55 (.15) Demographic variables (sex and education) entered in Step 1. * = .02 ** = .01 *** < .001
ACCEPTED MANUSCRIPT Table 3. Correlations of Speech Variables by Rorschach Task and BPRS Factors
-0.05 0.02 0.02
0.22 0.12 0.24
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0.06 -0.01 0.26
0.35* 0.32* 0.31
Blunted Affect
0.00 0.17 0.22 0.10 0.18 0.07
0.06 -0.26 -0.13 -0.18 -0.06 -0.12
-0.37* 0.30 0.15
0.18 -0.20 -0.05
0.16 0.26 0.05
0.00 0.04 -0.01
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0.09 -0.19 0.08
Affect
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0.11 -0.05 -0.08
0.14 0.07 0.13 0.30 0.22 0.24
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-0.03 0.07 0.03 0.15 0.16 0.10
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Memory Phase Pause Mean Utterance N Intonation Pitch Perturbation Emphasis Intensity Perturbation *p <. 05
0.04 -0.08 -0.13 -0.23 -0.02 -0.15
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Perceptual Phase Pause Mean Utterance N Intonation Pitch Perturbation Emphasis Intensity Perturbation
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Anergia
BPRS Factors Disorganization Thought Disorder
ACCEPTED MANUSCRIPT Highlights
Both controls and schizophrenia patients exhibited longer pause means and decreased utterances with increased cognitive load.
Schizophrenia patients alone did not display abnormal speech expression on any metric
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These findings suggest that in patients with schizophrenia, vocal affect/alogia is generally
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unremarkable under ambiguous conditions.
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used.
Figure 1
Lauren T. Meaux, Kyle R. Mitchell, Alex S. Cohen PII: DOI: Reference:
S0010-440X(18)30059-2 doi:10.1016/j.comppsych.2018.03.009 YCOMP 51963
To appear in: Please cite this article as: Lauren T. Meaux, Kyle R. Mitchell, Alex S. Cohen , Blunted vocal affect and expression is not associated with schizophrenia: A computerized acoustic analysis of speech under ambiguous conditions. The address for the corresponding author was captured as affiliation for all authors. Please check if appropriate. Ycomp(2018), doi:10.1016/j.comppsych.2018.03.009
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Blunted vocal affect and expression is not associated with schizophrenia: A computerized acoustic analysis of speech under ambiguous conditions
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a
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Lauren T Meauxa, Kyle R Mitchella, Alex S Cohena
Louisiana State University, 236 Audubon Hall, Psychology Department, Louisiana State University,
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Baton Rouge, Louisiana 70803, United States of America
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Address correspondence to:
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Submitted as a “Research Paper” to Comprehensive Psychiatry
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Lauren Meaux, [email protected], Louisiana State University, 236 Audubon Hall, Psychology
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Department, Louisiana State University, Baton Rouge, Louisiana 70803, United States of America
ACCEPTED MANUSCRIPT Abstract INTRODUCTION: Patients with schizophrenia are consistently rated by clinicians as having high levels of blunted vocal affect and alogia. However, objective technologies have often failed to substantiate these abnormalities. It could be the case that negative symptoms are context-dependent.
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OBJECTIVES: The present study examined speech elicited under conditions demonstrated to exacerbate
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thought disorder.
METHODS: The Rorschach Test was administered to 36 outpatients with schizophrenia and 25
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nonpatient controls. Replies to separate “perceptual” and “memory” phases were analyzed using validated
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acoustic analytic methods.
RESULTS: Compared to nonpatient controls, schizophrenia patients did not display abnormal speech
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expression on objective measure of blunted vocal affect or alogia. Moreover, clinical ratings of negative symptoms were not significantly correlated with objective measures.
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CONCLUSIONS: These findings suggest that in patients with schizophrenia, vocal affect/alogia is
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generally unremarkable under ambiguous conditions. Clarifying the nature of blunted vocal affect and alogia, and how objective measures correspond to what clinicians attend to when making clinical ratings
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are important directions for future research.
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KEYWORDS: negative symptoms; thought disorder, acoustic analysis, schizophrenia
ACCEPTED MANUSCRIPT 1. Introduction Schizophrenia is a psychological disorder that severely affects an individual’s cognitive, perceptual, and motor functioning and is manifested in positive, negative and disorganized symptoms. Positive symptoms include delusions (i.e. firmly held beliefs that are unchangeable in the presence of
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incongruent evidence) and hallucinations (i.e. perceptions occurring in the absence of an external
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stimulus). Negative symptoms include speech-related behaviors such as blunted vocal affect (i.e., reduced
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vocal variability), and alogia (i.e., diminished vocal production) [1]. Negative symptoms in schizophrenia are a pernicious category of symptoms due to their chronic nature, resistance to medication, and
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indication of poor prognosis [2]. Additionally, patients with schizophrenia and other psychotic disorders demonstrate difficulty in discerning emotional affect in the speech of other individuals [3] [4] [5].
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Previous research suggests these difficulties may be moderately related to cognitive deficits or impaired theory of mind abilities in individuals with schizophrenia [6].
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Patients show profound deficits in speech affect and expression on clinician-rated measures like
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the Scale for the Assessment of Negative Symptoms (SANS) [7]. A recent review found that ratings of speech variability and production from the SANS were 3-5 standard deviations abnormal compared to
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nonpsychiatric controls [8]. Importantly, these abnormalities are seen for patients as a group, and not just
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in subgroups of patients with particularly pronounced negative symptoms [2]. While clinician-rating measures demonstrate acceptable reliability and, in some studies, convergence with a range of clinical
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phenomenon [2], they are limited in many respects. Of note, they are based on relatively ambiguous operational definitions covering a wide range of behaviors that are not well operationalized or grounded in speech sciences; they lack consideration to cultural, individual difference, and environmental factors that heavily influence speech expression, and offer limited response options that are insensitive to all but major changes over time [9] [10] [11]. However, technological developments allow for more reliable and precise measures of blunted affect and alogia based on computerized/objective acoustic analysis [10]. These measures offer potentially greater reliability, validity, and sensitivity, leading to greater accuracy in assessment [12]. To date, there have been several dozen studies employing acoustic analysis of patient
ACCEPTED MANUSCRIPT speech in some capacity. While there are promising “proof of concept” studies (e.g., [13]), the larger literature provides results that are underwhelming in magnitude and consistency. For example, a large multi-site analysis of patient speech found no statistical difference between 309 schizophrenia patients and 117 nonpsychiatric controls on a range of empirically-derived objectively-based vocal measures [14].
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Moreover, a meta-analysis of 13 published studies found that, at most, certain measures related to alogia
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(e.g., pause times/numbers) are exaggerated in some studies on the order of one standard deviation above
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controls [9] [15] and are normal in other studies [8] [16]. This is far below the 3-5 standard deviations found from clinical rating scales (see Figure 1 for a summary). Importantly, clinical ratings of blunted
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vocal affect often show statistically nonsignificant correlations (-.18 [9]) to small (.26 [17]) with acoustically-derived measures of vocal affect (e.g., intonation, emphasis) obtained during laboratory
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speaking tasks. However, negative and positive symptoms have been shown to be significantly associated with vocal production (e.g., increased pause times and decreased number of utterances) and positive
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symptoms were correlated with increased inflection [12].
It could be the case that speech production (tapping alogia) and variability (tapping blunted
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affect) are “context-dependent,” that is, their emergence is contingent upon cognitive, social, or other
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factors. For example, it has been proposed that cognitive resources related to “on-line” attentional and working memory abilities are particularly important for producing speech [19] [20]. Given that these
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resources are deficient in schizophrenia [21], a cognitive resource model may explain the symptoms of blunted affect and alogia. In support of this idea, increasing experimentally-manipulated cognitive demands causes decreased speech production and variability in schizophrenia patients [19] [21]. This could be due to the fact that allocation of cognitive resources for one task limits resources for speech; and speech becomes quantitatively and qualitatively sparser/flatter. One approach to understanding cognitive and other contextual effects on speech involves the Rorschach inkblot test, a popular measure of positive thought disorder [22]. The Rorschach is thought to be a useful measure of thought disorder because it imposes a relatively heavy “processing” load, vis a vis
ACCEPTED MANUSCRIPT the “ambiguity” of the inkblot stimuli, which potentially exacerbates thought disorder and, behaviorally, speech incoherence [23]. Although this processing load is potentially imposed via multiple systems (e.g., cognitive, affective, social), analysis of speech from Rorschach tests offers an opportunity to understand whether blunted affect/alogia are exacerbated in the same manner as positive thought disorder. The Rorschach administration utilized in this study involved three distinct phases per card. The first
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“Perceptual” phase involved participants describing the stimulus in terms of identifiable objects while viewing the card. The second “Memory” phase involved participants describing the features of the
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stimulus that provoked the aforementioned object without viewing the card. The third “Identify” phase
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involved participants physically indicating (i.e., pointing to) which areas of the stimulus corresponded with the features described in the “Memory” phase. We consider the second phase to be more taxing than
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the first because it involves communicating complex semantic material (e.g., explaining and defending their response). Therefore, the “Memory” phase requires the participant to exert more cognitive resources
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than the “Perceptual” phase.
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The current study used computerized acoustic analysis to examine responses from a Rorschach inkblot test. Across phases of the Rorschach, we hypothesized that patients with schizophrenia would
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exhibit abnormalities in vocal production and vocal expression, as measured by a decrease in number of
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utterances and increase in pause times, and variability, as measured by flattened intonation, pitch perturbation, emphasis, and intensity perturbation, compared to nonpsychiatric controls. Additionally, we
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hypothesized that these abnormalities would be exacerbated during the “Perceptual” phase of the Rorschach, which is potentially more taxing in cognitive, motivational, and other abilities than the “Memory” phase. Finally, we examined the relationships between clinical ratings and objectively-defined acoustic variables.
2. Methods 2.1 Participants. Participants consisted of 36 outpatients with DSM-IV diagnosed schizophrenia and 25 controls. All participants were recruited as part of a larger study and went through an informed
ACCEPTED MANUSCRIPT consent process. Portions of the data have been reported elsewhere [24]. Education level and sex didn’t differ between groups, though the control group was significantly younger than the schizophrenia group (Table 1). Exclusion criteria for both the schizophrenia and control group included the following: lack of fluency in English, a history of traumatic brain injury, a history of diagnosed organic brain disease, and a
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history of substance abuse or dependence during the previous two years.
2.2 Brief Psychiatric Rating Scale. The Brief Psychiatric Rating Scale (BPRS) is an 18-item
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semi-structured interview used to assess various psychotic and affective symptoms [26]. The questions in the interview are answered on a Likert scale of 1-7 with 1 representing “not present” and 7 representing
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“extremely severe.” A score of 0 may be selected if the item was not assessed. Half of the items are based on the patient’s self-report of his or her own behavior over the past 2-3 days, while the other half assess
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the behavior of the patient as observed by the examiner. The individual ratings for each item are then
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added to form a composite score. Items on the BPRS load on to four factors which measure Anergia (i.e., negative symptoms), Thought Disorder (i.e., positive symptoms), Disorganization (i.e., animation,
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agitation), and Affect (i.e., mood disturbances, depression, anxiety) [27].
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2.3 Rorschach inkblot test. The version used in this study involved four stimulus cards selected from a standard Rorschach administration and involved three distinct phases per card [28]. The first
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“Perceptual” and second “Memory” phases were analyzed in this study. A third “Identify” phase involving only limited vocal communication was excluded from the present analyses. Responses were digitally recorded.
2.4 Acoustic analysis. Recordings were digitally spliced and were analyzed using the Computerized Analysis of Natural Speech [10]. The following variables were selected for this study, based on findings from a principal components analysis and validity study conducted on large patient samples (n = 309; [14]) and nonpsychiatric adult (N = 1,350; [10]) samples: pause mean – mean time between utterances (in milliseconds), utterance number – total number of utterances (defined as speech
ACCEPTED MANUSCRIPT bounded by pauses ≥150 ms), Intonation– standard deviation of the fundamental frequency averaged across utterances, Pitch perturbation – absolute value of change in the fundamental frequency in successive frames, Emphasis– SD of intensity averaged across utterances, and Intensity perturbation – absolute value of change in intensity in successive frames. Pause mean and utterance number tap into
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vocal production whereas intonation, pitch perturbation, emphasis, and intensity perturbation tap vocal
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variability. These measures have been used extensively in both the clinical and nonclinical acoustic
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analysis literature.
2.5 Analyses. Analyses were conducted in three steps. First, we examined whether demographic
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and clinical variables were related to any of the dependent variables, as sex differences are often observed in studies of vocal expression [12] [17]. Second, we compared patients and controls on acoustic variables
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using multi-level modeling. We conducted six separate multilevel models (MLM) with subjects as random intercepts to examine the effect of phase (“Perceptual” phase versus “Memory” phase) and group
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(schizophrenia versus controls), as well as their interaction with the acoustic variable of interest as the
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dependent variable. Demographic variables were imputed into the multilevel models as the first step. Phase, group, and interaction variables were computed in the second step. The phase effects were used as
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a “manipulation check” to evaluate whether there were contextual effects on vocal expression. The group
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effect was used to examine whether diagnosis contributed to differences in acoustic characteristics across phase. The group by phase interaction examined whether diagnostic group disproportionally varied by
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phase as compared to controls. We predicted that, during the memory phase, patients versus controls would show decreased number of utterances, increased pause times, and decreased intonation, pitch perturbation, emphasis, and intensity perturbation. Third, we examined the correlations between clinically-rated negative, blunted affect and other symptoms and acoustic variables. Pause time and intonation variables were skewed, and hence, were Winsorized such that values exceeding three SDs were replaced with their three SD equivalent, and were group centered for the MLMs. 3. Results
ACCEPTED MANUSCRIPT Women showed significantly more utterances and intonation than men in both conditions (p’s < 0.05; across groups). Education level was positively associated with more utterances (p < .001). No other
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demographic or clinical variables were significantly related to the speech variables.
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There was a phase effect for Pause Mean and Utterance Number, in that all participants,
condition as opposed to the perceptual condition (Table 2).
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regardless of diagnostic category, exhibited fewer utterances and shorter pause times in the memory
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Results of the multi-level modeling indicate that the schizophrenia group was largely similar to controls, but did differ significantly from healthy controls on a few key variables (Table 2). Generally
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speaking, there were few significant group or interaction effects as hypothesized. Interestingly, there was a group effect in Pitch Perturbation (coefficient = .49; std. error = .26), with the schizophrenia group
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exhibiting higher, not lower pitch perturbation than controls. There was also a phase by group interaction,
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where the difference between the perceptual and memory phases was significantly different between the schizophrenia and control group. The schizophrenia group exhibited higher Intensity Perturbation during
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the perceptual phase as related to their performance in the memory phase (coefficient = -.38; std. error =
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.16), whereas performance did not vary as a function of group within the memory phase. Controls’
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performance did not differ as a function of phase.
Pearson correlations (Table 3) revealed few statistically significant correlations between clinical ratings and acoustic variables. Scores on the Thought Disorder factor of the BPRS were associated with greater Pitch Perturbation and Emphasis during the memory phase of the Rorschach. Additionally, patients with schizophrenia who scored higher on the Affect factor of the BPRS demonstrated shorter Pause Means during the memory phase of the Rorschach. However, the magnitude of these correlations was not large, and we did not employ control for multiple comparisons.
ACCEPTED MANUSCRIPT 4. Discussion The current findings indicate that individuals with schizophrenia exhibited largely normal speech, regardless of task. Congruent with prior studies that directly manipulated the speaking task, vocal variables varied in both groups as a function of processing load [19] [21]; though this was in the opposite
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direction than expected. It is unclear why the memory phase produced speech that was more prodigious
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than in the perceptual phase, but it is likely that contextual factors other than cognitive load influenced vocal expression. Perhaps the memory phase was more arousing, or elicited content that was more
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cognitively accessible or otherwise automatic. Regardless, “ambiguous” conditions elicited by the
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Rorschach Inkblot Test failed to create a context that would result in the manifestation of negative symptoms in patients with schizophrenia.
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In fact, individuals with schizophrenia exhibited increased Pitch Perturbation and in Intensity Perturbation, suggesting increased arousal during the perceptual phase [29]. The reason behind this is
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unclear. It may be the case that the relatively increased arousal is due to poor stress reactivity in patients
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with schizophrenia. Previous research indicates that patients with schizophrenia exhibit greater reactions (i.e., increased heart rate, high frequency of nonspecific skin conductance) to minor stressors than
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controls [30]. Notably, these findings indicate that computerized acoustic analysis may be used to
as well.
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measure more than just negative symptoms, but increased stress reactivity in patients with schizophrenia
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Further, affective reactivity in language can be viewed as a component of a general increase in responsivity to emotional stimuli (particularly negative valance stimuli) in patients with schizophrenia [31]. The Rorschach Test stimuli may have been perceived by schizophrenia patients as emotional or negative, thus exacerbating their stress reactivity which resulted in increased arousal, particularly in the perceptual phase. Though the Rorschach Test is considered a valid measure of positive thought disorder [23], its utility for measuring negative thought disorder has not been well established [32]. The present results suggest that the Rorschach may not be optimal for measuring blunted vocal affect and alogia. Future research may focus on examining the emotional valence of individual cards from the Rorschach
ACCEPTED MANUSCRIPT Test in order to establish those which may elicit positive versus negative emotions, particularly in patients with schizophrenia. Acoustic analyses may then be conducted on the speech elicited from schizophrenia and control groups while being administered just the positively valenced cards. This condition may be sufficient for examining negative symptoms (e.g., blunted vocal affect, alogia).
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Limitations of this study include the inability to control for medication type or dosage level and
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group differences in age. Given medications may have a sedative effect on patients, future studies may
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aim to employ an unmedicated patient sample for comparison. Additionally, executive functioning abilities, global cognitive deficits, and effort were not assessed in this study and, therefore, not
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statistically controlled for. Similar executive or other cognitive abilities across groups may have driven the findings of mostly comparable speech production and variability. Nonetheless, these null findings are
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consistent with previous studies utilizing computerized acoustic analysis software [10] [12] [19]. 5. Conclusions
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In the current study, patients with schizophrenia were not abnormal in vocal expression, even in a
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context that was putatively cognitively taxing. This study contributes to others [8] [12] [17], which collectively, present an important question for negative symptoms research in schizophrenia: “When do
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patients with schizophrenia demonstrate the dramatic vocal deficits captured in clinical ratings”. Of note, future studies might attempt to simulate conditions under which these vocal deficits have been examined
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in clinical settings. Although memory was tapped in this study during the “Memory” phase, it was clearly
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insufficient to exacerbate blunted affect and alogia to detectable levels. It may be the case that it elicited a more perceptual or visually-aided memory by the participants, which may not be analogous to experiential memory. However, it may be the case that the latter is often elicited in clinical ratings and may need to be examined through further research.
Acknowledgements: The authors wish to thank Deborah L Levy for sharing her data with us.
ACCEPTED MANUSCRIPT Funding: This research did not receive any specific grant from funding agencies in the public,
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commercial, or not-for-profit sectors.
ACCEPTED MANUSCRIPT References [1] American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 5th ed. Arlington, VA: American Psychiatric Publishing; 2013. [2] Tandon R, Nasrallah HA, Keshavan MS. Schizophrenia, “just the facts” 4. Clinical features and
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conceptualization. Schizophr Res 2009;110:1-23.
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[3] Billingberg O, Jonsson CO. The ability of schizophrenic patients to interpret intonation. Acta Psychiat
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Scand 1965;41:218-226.
[4] Murphy D, Cutting J. Prosodic comprehension and expression in schizophrenia. J Neur Neurosurg
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Psychiatry 1990;53:727-730.
[5] Colle L, Angeleri R, Vallana M, Sacco K, Bara BG, Bosco FM. Understanding the communicative
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impairments in schizophrenia: A preliminary study. Journal of Communication Disorders 2013;46:294-308.
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[6] Parola, A, Berardinelli L, Bosco FM. Cognitive abilities and theory of mind in explaining
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communicative-pragmatic disorders in patients with schizophrenia. Psychiatry Res 2018;260:14451.
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[7] Andreasen NC. The Scale for the Assessment of Negative Symptoms (SANS). Iowa City, IA:
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University of Iowa; 1984.
[8] Cohen AS, Mitchell KR, Elvegåg B. What do we really know about blunted affect and alogia? A
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meta-analysis of objective assessments. Schizophr Res 2014;159:533-8. [9] Alpert M, Shaw RJ, Pouget ER, Lim KO. A comparison of clinical ratings with vocal acoustic measures of flat affect and alogia. J Psychiatr Res 2002;36:347-53. [10] Cohen AS, Renshaw TL, Mitchell KR, Kim Y. A psychometric investigation of “macroscopic” speech measures for clinical and psychological science. Behav Res Methods 2016;48:475-86. [11] Tawari A, Trivedi MM. Speech emotion analysis: Exploring the role of context. IEEE Trans Multimedia 2010;12:502-9.
ACCEPTED MANUSCRIPT [12] Cohen AS, Najolia GM, Kim Y, Dinzeo TJ. On the boundaries of blunt affect/alogia across severe mental illness: Implications for Research Domain Criteria. Schizophr Res 2012;140:41-5. [13] Stassen HH, Albers M, Puschel M, Scharfetter CH, Tewesmeier M, Woggon B. Speaking behavior and voice sound characteristics associated with negative schizophrenia. J Psychiat Res
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1995;29:277-296.
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[14] Cohen AS, Mitchell KR, Docherty NM, Horan WP. Vocal expression in schizophrenia: Less than meets the ear. J Abnorm Psychol 2016;125:299-309.
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[15] Rapcan V, D’Arcy S, Yeap S, Afzal N, Thakore J, Reilly R. Acoustic and temporal analysis of
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speech: A potential biomarker for schizophrenia. Med Eng Phys 2010;1074-1079. [16] Cohen AS, Dinzeo TJ, Donovan NJ, Brown CE, Morrison SC. Vocal acoustic analysis as a biometric
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indicator of information processing: Implications for neurological and psychiatric disorders. Psychiatr Res 2015;226:235-41.
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[17] Cohen AS, Alpert M, Nienow T, Dinzeo T, Docherty N. Computerized measurement of negative
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symptoms in schizophrenia. J Psychiatr Res 2008;42:827-36. [18] Emmerson LC et al. Prevalence and longitudinal stability of negative symptoms in healthy
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participants. Int J Geriatr Psychiatry 2009;24:1438-44.
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[19] Cohen AS, McGovern JE, Dinzeo TJ, Covington MA. Speech deficits in serious mental illness: A cognitive resource issue? Schizophr Res 2014;160:173-9.
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[20] Plass J, Brunken R, Moreno R. Cognitive Load Theory. Cambridge, UK: Cambridge University Press; 2010.
[21] Barch DM, Berenbaum H. The effect of language production manipulations on negative thought disorder and discourse coherence disturbances in schizophrenia. Psychiatry Res 1997;71:115-27. [22] Wood JM, Nezworski MT, Garb HN. Focus on empirically supported methods: What’s right with the Rorschach? The Scientific Review of Mental Health Practice 2003;2.
ACCEPTED MANUSCRIPT [23] Holzman PS, Levy DL, Johnston MH. The use of the Rorschach technique for assessing formal thought disorder. In: Bornstein RF, Masling JM, editors. Scoring the Rorschach: Seven Validated Systems, Mahwah, NJ: Lawrence Erlbaum Associates; 2005, p. 55-95. [24] Morgan CJ et al. Thought disorder in schizophrenia and bipolar disorder probands, their relatives,
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and nonpsychiatric controls. Schizophr Bull, 2017;43:523-35.
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[25] Endicott J, Spitzer RL, Fleiss JL, Cohen J. The global assessment scale. A procedure for measuring
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overall severity of psychiatric disturbance. Arch Gen Psychiatry 1976;33:766-71. [26] Garcia-Portilla M et al. Psychometric evaluation of the negative syndrome of schizophrenia. Eur
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Arch Psychiatry Clin Neurosci 2015;265:559-66.
[27] Overall JE, Gorham DR. The Brief Psychiatric Rating Scale, ECDEU Assessment Manual
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Psychopharmacology, Guy W, ed. Rockville, MD: US Department of Health Education and Welfare; 1976.
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[28] Carpenter JT et al. The Thought Disorder Index: Short-form assessments. Psychol Assessment
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1993;5:75-80.
[29] Cohen AS, Lee Hong S, Guevara A. Understanding emotional expression using prosodic analysis of
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natural speech: Refining the methodology. J Behav Ther Exp Psychiatry 2010;41:150-7.
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[30] Burbridge J, Larsen R, Barch D. Affective reactivity in language: The role of psychophysiological arousal. Emotion 2005;5:145-53.
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[31] Docherty N, Rhinewine J, Nienow T, Cohen AS. Affective reactivity of language symptoms, startle responding, and inhibition n schizophrenia. J Abnorm Psychol 2001; 110:194-9. [32] Mario B et al. Relationship between the Rorschach Perceptual Thinking Index (PTI) and the Positive and Negative Syndrome Scale (PANSS) in psychotic patients: A validity study. Psychiatry Res 2015;225:315-21.
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Table 1. Demographic and clinical information for schizophrenia (SZ) and nonpsychiatric control (CON) groups. Variable SZ CON t-value (p-value) N 36 25 Education Level 15 (2.19) 14.36 (2.14) -1.13 (.26) Sex (.97) Male 64% 60% Female 36% 40% Age 39.75 (9.99) 31.29 (12.42) -2.94 (.00) Duration of Illness 14.06 (10.37) Age of Onset 25.78 (8.15) Global Assessment 34.58 (6.69) Scale* BPRS Anergia 3.64 (0.93) Blunted Affect 5.44 (1.27) Disorganization 2.11 (0.86) Thought Disorder 3.87 (1.08) Affect 2.51 (0.95) *[25]
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Table 2. Multi-Level Modeling Results of the Effect of Group (Schizophrenia vs. Control), Rorschach Phase (Perceptual vs. Memory), and the Interaction on Speech Variables. LL-Ratio Ratio L-Ratio Step 2: Step Step 4: Effect Phase Schizophrenia Control Phase 3: Phase x Effect Group Group Effect Pause Mean Perceptual 25233.75 (17953.6) 26343.25 (15094.77) 49.81*** 0.11 0.66 Memory 11922.7 (9968.49) 11305.09 (8013.82) Utterance N Perceptual 25.89 (21.23) 53.01*** 0.25 2.04 21.11 (17.42) Memory 45.9 (24.78) 48.31 (29.16) Intonation Perceptual 1.67 (.87) 0.00 1.31 0.01 1.51 (.69) Memory 1.68 (.94) 1.5 (.57) Pitch Perceptual 0.15 (.04) 2.56 4.83* 0.6 0.14 (.02) Perturbation Memory 0.15 (.04) 0.13 (.03) Emphasis Perceptual 1.01 (.32) 0.29 0.00 0.03 0.99 (.40) Memory 1 (.23) 0.98 (.35) Intensity Perceptual 0.57 (.11) 0.20 0.44 5.88** 0.51 (.12) Perturbation Memory 0.56 (.10) 0.55 (.15) Demographic variables (sex and education) entered in Step 1. * = .02 ** = .01 *** < .001
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-0.05 0.02 0.02
0.22 0.12 0.24
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0.06 -0.01 0.26
0.35* 0.32* 0.31
Blunted Affect
0.00 0.17 0.22 0.10 0.18 0.07
0.06 -0.26 -0.13 -0.18 -0.06 -0.12
-0.37* 0.30 0.15
0.18 -0.20 -0.05
0.16 0.26 0.05
0.00 0.04 -0.01
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0.09 -0.19 0.08
Affect
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0.11 -0.05 -0.08
0.14 0.07 0.13 0.30 0.22 0.24
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-0.03 0.07 0.03 0.15 0.16 0.10
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Memory Phase Pause Mean Utterance N Intonation Pitch Perturbation Emphasis Intensity Perturbation *p <. 05
0.04 -0.08 -0.13 -0.23 -0.02 -0.15
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Perceptual Phase Pause Mean Utterance N Intonation Pitch Perturbation Emphasis Intensity Perturbation
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Anergia
BPRS Factors Disorganization Thought Disorder
ACCEPTED MANUSCRIPT Highlights
Both controls and schizophrenia patients exhibited longer pause means and decreased utterances with increased cognitive load.
Schizophrenia patients alone did not display abnormal speech expression on any metric
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These findings suggest that in patients with schizophrenia, vocal affect/alogia is generally
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unremarkable under ambiguous conditions.
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used.
Figure 1