An examination of speech characteristics under conditions of affective reactivity and variable cognitive load as distinguishing feigned and genuine schizophrenia

Proper assessment of schizophrenia is complicated by the need for clinicians to be cognizant of the possibility of malingering, i.e., the intentional production of false or grossly exaggerated symptoms, motivated by external incentives. Current standardized schizophrenia malingering detection methods rely on endorsement of improbable or exaggerated, mainly positive, symptoms. However, these detection methods may be vulnerable to successful manipulation by sophisticated malingerers, particularly if coached regarding response style assessment strategies. This paper explored the utility of supplemental variables to examine in schizophrenia malingering detection by using a simulation study design to compare schizophrenia patients, a community participant sample instructed to feign schizophrenia symptoms, and an honest responder control group on behavioral speech characteristics indicative of thought disorganization (i.e., referential disturbances) and negative symptoms (i.e., alogia and flat affect) under experimentally-manipulated conditions of affective reactivity and cognitive load. Results indicated that the feigning group was distinguishable from the schizophrenia group based on differences in magnitude of speech disorganization during conditions of affective reactivity, due to feigners’ inability to mimic the schizophrenia group’s referential failures, and in magnitude of flat affect during conditions of affective reactivity and cognitive load, due to feigners’ excessively impaired use of formant inflection (i.e., vocal inflection related to tongue movement). Feigning and schizophrenia groups were also distinguishable due to feigners’ excessive impairment in cognitive task performance, observed both in group comparisons and differential patterns of change in cognitive task accuracy across cognitive load conditions

The effect of limited cognitive resources on communication disturbances in serious mental illness

Semantically incoherent speech is a pernicious clinical feature of serious mental illness (SMI). The precise mechanisms underlying this deficit remain unclear. Prior studies have found that arousal of negative emotion exaggerates the severity of these communication disturbances; this has been coined "affective reactivity". Recent research suggests that "cognitive reactivity" may also occur, namely reflecting reduced "on-line" cognitive resources in SMI. We tested the hypothesis that communication disturbances manifest as a function of limited cognitive resources in SMI above and beyond that associated with state affectivity. We also investigated individual differences in symptoms, cognitive ability, and trait affect that may be related to cognitive reactivity. We compared individuals with SMI (n=52) to nonpsychiatric controls (n=27) on a behavioral-based coding of communication disturbances during separate baseline and experimentally-manipulated high cognitive-load dual tasks. Controlling for state affective reactivity, a significant interaction was observed such that communication disturbances decreased in the SMI group under high cognitive-load. Furthermore, a reduction in communication disturbances was related to lower trait and state positive affectivity in the SMI group. Contrary to our expectations, limited cognitive resources temporarily relieved language dysfunction. Implications, particularly with respect to interventions, are discussed

Psychiatric symptom versus neurocognitive correlates of diminished expressivity in schizophrenia and mood disorders

Diminished expressivity is a poorly understood, but important construct for a range of mental diseases. In the present study, we employed computerized acoustic analysis of natural speech to understand diminished expressivity in patients with schizophrenia and mood disorders. We were interested in the degree to which speech characteristics tapping alogia (i.e., average pause duration) and blunted affect (i.e., prosody computed from fundamental frequency and intensity) reflected psychiatric symptoms (i.e., depression, anxiety, paranoia and bizarre behavior) versus neurocognitive deficits. Twenty-six subjects with schizophrenia and 22 subjects with mood disorders provided speech samples in response to a variety of laboratory stimuli and completed neuropsychological batteries assessing a range of abilities. For both the schizophrenia and mood disorder groups, attentional coding deficits were significantly correlated with increased pause time (at large effect size levels) and, for the schizophrenia group only, reduced prosody (also at a large effect size level). For the mood disorder but not the schizophrenia group, increased average pause time was also significantly associated with neurocognitive deficits on a range of other tests (medium to large effect size levels). Psychiatric symptoms were not significantly associated with speech characteristics for either group (generally, negligible effect sizes). These results suggest that there is a link between expressivity and neurocognitive dysfunctions for both patients with schizophrenia and mood disorders. Implications and future research directions are discussed