Analysis of narrative discourse structure as an ecologically relevant measure of executive function in adults.

This study examined the narrative discourse production and executive function (EF) abilities of 46 neuro-typical adults (18-98 years old). Two questions were addressed: Is the analysis of narrative structure sensitive to changes associated with aging? & What is the relationship between measures of narrative structure and EF? Narratives were elicited under two conditions and narrative structure was analyzed for the presence of organizing story grammar elements. Narrative structure was significantly correlated with age as well as linguistic and non-linguistic measures of EF. Factor analysis of story structure and EF variables yielded two factors reflecting constructs of output-fluidity and organizational-efficiency. These data suggest that narrative structure and EF represent aspects of goal-directed knowledge that are not bound by a traditional linguistic and non-linguistic division. Thus, narrative structure may represent a global and ecologically valid measure of goal-directed executive function knowledge that is also sensitive to changes associated with typical aging.

Organizational Structure Reduces Processing Load in the Prefrontal Cortex During Discourse Processing of Written Text: Implications for High-Level Reading Issues After TBI.

Adults with traumatic brain injury (TBI) can demonstrate marked difficulty producing discourse during story retell and story generation tasks. Changes in discourse production have been detailed in terms of fewer content units and infrequent use of story grammar elements essential for organization. One implication is that poor use of story grammar elements during discourse production may signal reduced ability to utilize these elements in other communication realms (e.g., reading comprehension). The neural architecture that supports discourse organization, primarily the medial prefrontal cortex, is particularly susceptible to damage secondary to acquired brain injury. In this event related functional magnetic resonance imaging (fMRI) study, we describe cortical activation patterns of unimpaired readers as they are presented with discourse that is varied in terms of structural organization. The results suggest reading discourse with less structure is associated with increased cortical activity (e.g., higher processing demands) as compared to reading discourse with more traditional structural cues (e.g., story grammar). We discuss cortical areas implicated and potential implications for supporting discourse communication in persons following TBI.

Sentence comprehension in agrammatic aphasia: history and variability to clinical implications.

Individuals with Broca's aphasia often present with deficits in their ability to comprehend non-canonical sentences. This has been contrastingly characterized as a systematic loss of specific grammatical abilities or as individual variability in the dynamics between processing load and resource availability. The present study investigated sentence level comprehension in participants with Broca's aphasia in an attempt to integrate these contrasting views into a clinically useful process. Two participants diagnosed with Broca's aphasia were assessed using a sentence-to-picture matching paradigm and a truth-value judgement task, across sentence constructions thought to be problematic for this population. The data demonstrate markedly different patterns of performance between participants, as well as variability within participants (e.g. by sentence type). These findings support the notion of individual performance variability in persons with aphasia. Syntactic theory was instructive for assessing sentence level comprehension, leading to a clinically relevant process of identifying treatment targets considering both performance variability and syntactic complexity for this population.

The effect of positioning on infant cries: implications for sudden infant death syndrome.

OBJECTIVE: A definitive cause for sudden infant death syndrome (SIDS) has not yet been identified, but some theories point to laryngeal or respiratory causes, in addition to theories of reduced arousal or reduced autonomic response. The occurrence of SIDS has dropped since the movement to place newborns to sleep in the supine position; however, some research has found a respiratory disadvantage for infants in this position. The current paper studied acoustic characteristics of infant pain cries to determine the potential differences related to prone versus supine positioning. METHODS: Fifty-one newborn infant cries were recorded during and following a blood draw screening procedure, with infants placed either in the supine or prone position. All infants were healthy, full-term infants. Complete crying episodes were audio-recorded, and results were based on compositional analysis and long-time average spectrum analysis across each crying episode. RESULTS: Spectral analysis revealed acoustic differences related to infant positioning, and acoustic analysis also revealed that there were no respiratory differences between supine-positioned and prone-positioned infants. Overall, the acoustic differences suggest decreased arousal and/or a decreased response to pain for healthy infants recorded in the prone position. CONCLUSIONS: As decreased arousal and prone positioning have been seen as possible causative factors for SIDS, the current results are seen as a successful step in evaluating the possibility of using acoustic analysis of infant cries as a means of evaluating SIDS risk for healthy infants.

Voice acoustic measures of depression severity and treatment response collected via interactive voice response (IVR) technology.

Efforts to develop more effective depression treatments are limited by assessment methods that rely on patient-reported or clinician judgments of symptom severity. Depression also affects speech. Research suggests several objective voice acoustic measures affected by depression can be obtained reliably over the telephone. Thirty-five physician-referred patients beginning treatment for depression were assessed weekly, using standard depression severity measures, during a six-week observational study. Speech samples were also obtained over the telephone each week using an IVR system to automate data collection. Several voice acoustic measures correlated significantly with depression severity. Patients responding to treatment had significantly greater pitch variability, paused less while speaking, and spoke faster than at baseline. Patients not responding to treatment did not show similar changes. Telephone standardization for obtaining voice data was identified as a critical factor influencing the reliability and quality of speech data. This study replicates and extends previous research with a larger sample of patients assessing clinical change associated with treatment. The feasibility of obtaining voice acoustic measures reflecting depression severity and response to treatment using computer-automated telephone data collection techniques is also established. Insight and guidance for future research needs are also identified.

Bradyphrenia and bradykinesia both contribute to altered speech in schizophrenia: a quantitative acoustic study.

OBJECTIVE: To evaluate the relative contributions of motor and cognitive symptoms on speech output in persons with schizophrenia (SZ). BACKGROUND: Studies of speech production in SZ suggest that atypical prosody (eg, pause) is related to clinical symptoms manifest in flat affect and alogia. Others have suggested that a more general motor slowing, bradykinesia, leads to measurable speech changes. METHOD: Thirteen participants with SZ and age-matched control subjects were included for between-group and by-task comparisons. Two levels of task complexity were analyzed acoustically to determine distinct and overlapping features of speech pause. RESULTS: For the free-speech task, group differences were found on measures of average pause duration, pause variability, percent pause, and cumulative pause time. Conversely, for the rote-speech task, group differences were found only on measures of average pause duration and pause variability. CONCLUSIONS: In persons with SZ, differences in the average and variability of pause duration may be reflected in speech motor slowing, whereas more global measures (eg, percentage pause) may better reflect a paucity of thought and idea generation related to the cognitive-linguistic aspects of free speech. These findings corroborate and extend the paucity of thought hypothesis in SZ to include an influence of motor slowing on speech production.

Remote capture of human voice acoustical data by telephone: a methods study.

In this pilot study we sought to determine the reliability and validity of collecting speech and voice acoustical data via telephone transmission for possible future use in large clinical trials. Simultaneous recordings of each participant's speech and voice were made at the point of participation, the local recording (LR), and over a telephone line using a dedicated in-line computerized interactive voice recording system, the remote recording (RR). All voice recordings were made from our laboratory telephone located in Groton, Connecticut to the RR system located in Madison, Wisconsin. All data points were compared on a measure-by-measure basis between the LR and RR recordings. The results suggest that both measures of frequency excursion and of speech motor timing are reliably captured over the telephone. Results are discussed in terms of specific acoustic measures that may be useful and accurately measured via telephone transmission, for examining disease severity and pharmacological intervention for use in a large-scale clinical trial.

Feigned depression and feigned sleepiness: a voice acoustical analysis.

We sought to profile the voice acoustical correlates of simulated, or feigned depression by neurologically and psychiatrically healthy control subjects. We also sought to identify the voice acoustical correlates of feigned sleepiness for these same subjects. Twenty-two participants were asked to speak freely about a cartoon, to count from 1 to 10, and to sustain an "a" sound for approximately 5s. These exercises were completed three times (within the same testing session) with three differing sets of instructions to the participants. These three conditions were presented in pseudo-random order to control for any order effects, and all subjects were naïve to the intended purpose of this study. For all three conditions, mean speaking rates and pitch ranges were calculated. A series of paired t tests showed significant differences in the speaking rates (counting numbers and free-speech exercises) between the 'normal' and feigned sleepy conditions, and between the normal and feigned depression conditions, but not between the 'sleepy' and 'depressed' conditions. The results for pitch range, for all speech exercises, were not different between the normal and either the feigned depression or feigned sleepiness conditions. These results indicate that persons feigning depression and sleepiness demonstrate some level of conscious control of their speech rate, but they did not convincingly alter their pitch ranges while feigning depression or sleepiness.

Treatment of story grammar following traumatic brain injury: a pilot study.

Recent investigations have documented a variety of discourse deficits following traumatic brain injuries (TBI). However, there is a paucity of information relating to the treatment of such deficits. The present study investigated the treatment of discourse production deficits, specifically story grammar ability, in an individual with TBI. Treatment emphasized meta-linguistic comprehension of story grammar structure and the identification and generation of episode components within stories. Over the course of treatment, a marked increase in the number of complete episodes generated by the individual with TBI was noted in story grammar probes. Follow-up probes at 1 and 3 months post-treatment, however, indicated limited carryover and poor generalization of the treatment effects. Findings are interpreted in terms of the individual's chronic cognitive deficits, disruptions in managerial knowledge, and the limitations of treating discourse acontextually.