Neuropsychological test validation of speech markers of cognitive impairment in the Framingham Cognitive Aging Cohort.

AIM: Although clinicians primarily diagnose dementia based on a combination of metrics such as medical history and formal neuropsychological tests, recent work using linguistic analysis of narrative speech to identify dementia has shown promising results. We aim to build upon research by Thomas JA & Burkardt HA et al. (J Alzheimers Dis. 2020;76:905-22) and Alhanai et al. (arXiv:1710.07551v1. 2020) on the Framingham Heart Study (FHS) Cognitive Aging Cohort by 1) demonstrating the predictive capability of linguistic analysis in differentiating cognitively normal from cognitively impaired participants and 2) comparing the performance of the original linguistic features with the performance of expanded features. METHODS: Data were derived from a subset of the FHS Cognitive Aging Cohort. We analyzed a sub-selection of 98 participants, which provided 127 unique audio files and clinical observations (n = 127, female = 47%, cognitively impaired = 43%). We built on previous work which extracted original linguistic features from transcribed audio files by extracting expanded features. We used both feature sets to train logistic regression classifiers to distinguish cognitively normal from cognitively impaired participants and compared the predictive power of the original and expanded linguistic feature sets, and participants' Mini-Mental State Examination (MMSE) scores. RESULTS: Based on the area under the receiver-operator characteristic curve (AUC) of the models, both the original (AUC = 0.882) and expanded (AUC = 0.883) feature sets outperformed MMSE (AUC = 0.870) in classifying cognitively impaired and cognitively normal participants. Although the original and expanded feature sets had similar AUC, the expanded feature set showed better positive and negative predictive value [expanded: positive predictive value (PPV) = 0.738, negative predictive value (NPV) = 0.889; original: PPV = 0.701, NPV = 0.869]. CONCLUSIONS: Linguistic analysis has been shown to be a potentially powerful tool for clinical use in classifying cognitive impairment. This study expands the work of several others, but further studies into the plausibility of speech analysis in clinical use are vital to ensure the validity of speech analysis for clinical classification of cognitive impairment.

Social media use while listening to new material negatively affects short-term memory in college students.

Increased access to electronic devices and the ubiquity of social media has resulted in a rapid rise in the prevalence of students "multitasking" while in a classroom setting. While some data indicate the use of electronic devices in class can improve the classroom environment, other studies demonstrate the opposite finding. Moreover, it remains unclear if using social networking sites such as Instagram impacts performance on cognitive tasks when students are presented new material and, if so, what features of Instagram modulate this response. Therefore, in the current study we examined if social media use during or after being presented new information affected short-term memory in college students. Additionally, we assessed if the type or quantity of topics displayed had a modulatory impact on memory. Forty-five college-aged (18-24 years of age) students completed the Logical Memory Immediate Recall (LM I) component of the Wechsler Memory Scale IV, a measure of auditory recognition memory. Subjects were randomly divided into a group that completed the LM I without distraction (controls), a group that completed the LM I while scrolling through their Instagram feed, or a group that completed the LM I after scrolling through their Instagram feed. Subjects that used Instagram while being presented new information demonstrated worse short-term memory recall ability compared to subjects that did not use Instagram during the presentation (71.56% correct answers vs. 80.89%; p = 0.01). Recall ability in the group that used Instagram after hearing the story was not statistically different from the controls. Differences were not observed in the number of topics appearing in subjects' Instagram feeds and no correlation was found between the number of topics on a subject's Instagram feed and memory recall ability. Collectively, these results suggest that individuals who use their phones to browse Instagram during class or in social settings might have a reduced ability to retain the information given to them when compared to those that are not using their phones scrolling on social media.

Assessing the Utility of Language and Voice Biomarkers to Predict Cognitive Impairment in the Framingham Heart Study Cognitive Aging Cohort Data.

BACKGROUND: There is a need for fast, accessible, low-cost, and accurate diagnostic methods for early detection of cognitive decline. Dementia diagnoses are usually made years after symptom onset, missing a window of opportunity for early intervention. OBJECTIVE: To evaluate the use of recorded voice features as proxies for cognitive function by using neuropsychological test measures and existing dementia diagnoses. METHODS: This study analyzed 170 audio recordings, transcripts, and paired neuropsychological test results from 135 participants selected from the Framingham Heart Study (FHS), which includes 97 recordings of cognitively normal participants and 73 recordings of cognitively impaired participants. Acoustic and linguistic features of the voice samples were correlated with cognitive performance measures to verify their association. RESULTS: Language and voice features, when combined with demographic variables, performed with an AUC of 0.942 (95% CI 0.929-0.983) in predicting cognitive status. Features with good predictive power included the acoustic features mean spectral slope in the 500-1500 Hz band, variation in the F2 bandwidth, and variation in the Mel-Frequency Cepstral Coefficient (MFCC) 1; the demographic features employment, education, and age; and the text features of number of words, number of compound words, number of unique nouns, and number of proper names. CONCLUSION: Several linguistic and acoustic biomarkers show correlations and predictive power with regard to neuropsychological testing results and cognitive impairment diagnoses, including dementia. This initial study paves the way for a follow-up comprehensive study incorporating the entire FHS cohort.

Cellular organization of normal mouse liver: a histological, quantitative immunocytochemical, and fine structural analysis.

The cellular organization of normal mouse liver was studied using light and electron microscopy and quantitative immunocytochemical techniques. The general histological organization of the mouse liver is similar to livers of other mammalian species, with a lobular organization based on the distributions of portal areas and central venules. The parenchymal hepatocytes were detected with immunocytochemical techniques to recognize albumin or biotin containing cells. The macrophage Kupffer cells were identified with F4-80 immunocytochemistry, Ito stellate cells were identified with GFAP immunocytochemistry, and endothelial cells were labeled with the CD-34 antibody. Kupffer cells were labeled with intravascularly administered fluorescently labeled latex microspheres of both large (0.5 mum) and small (0.03 mum) diameters, while endothelial cells were labeled only with small diameter microspheres. Neither hepatocytes nor Ito stellate cells were labeled by intravascularly administered latex microspheres. The principal fine structural features of hepatocytes and non-parenchymal cells of mouse liver are similar to those reported for rat. Counts of immunocytochemically labeled cells with stained nuclei indicated that hepatocytes constituted approximately 52% of all labeled cells, Kupffer cells about 18%, Ito cells about 8%, and endothelial cells about 22% of all labeled cells. Approximately, 35% of the hepatocytes contained two nuclei; none of the Kupffer or Ito cells were double nucleated. The presence of canaliculi and a bile duct system appear similar to that reported for other species. The cellular organization of the mouse liver is quite similar to that of other mammalian species, confirming that the mouse presents a useful animal model for studies of liver structure and function.

Comparison of germanium oxide fibers with silica and sapphire fiber tips for transmission of erbium: YAG laser radiation.

BACKGROUND AND OBJECTIVES: Endoscopic applications of the Erbium:YAG laser have been limited due to the lack of a suitable optical fiber delivery system. The purpose of this study was to compare the transmission of Er:YAG laser radiation through germanium oxide trunk fibers with silica and sapphire fiber tips for potential use in contact tissue ablation during endoscopy. STUDY DESIGN/MATERIALS AND METHODS: Er:YAG laser radiation with a wavelength of 2.94 microm, pulse length of 300 microseconds, pulse energies from 5 to 1,360 mJ, coupled into pulse repetition rates of 3-10 Hz, was through 1-m-long germanium oxide fibers with either 1-cm-long, 550-microm-diameter silica or sapphire tips. RESULTS: Transmission through the germanium oxide/sapphire fibers measured 65+/-5% compared with 55+/-4% for the germanium oxide/silica fibers (P<0.05). The damage threshold for the hybrid fibers averaged 309+/- 44 mJ and 126+/-43 mJ, respectively (n = 7 fibers each) (P<0.05). The highest pulse energies transmitted through the fibers were 700 mJ and 220 mJ, respectively. CONCLUSIONS: Improved index-matching of the trunk fiber and fiber tip at 2.94 microm resulted in higher transmission and damage thresholds for the germanium oxide/sapphire fibers. The germanium oxide/sapphire fiber may represent a promising mid-infrared optical fiber delivery system for use in endoscopic applications of the Er:YAG laser requiring a flexible, biocompatible, and robust fiber delivery system for contact tissue ablation.

Side-firing germanium oxide optical fibers for use with erbium:YAG laser.

BACKGROUND AND PURPOSE: During recent experimental studies, the erbium:YAG laser has been shown to be more efficient for lithotripsy and more precise for incision of soft urinary tissues than the conventional holmium:YAG laser. Mid-infrared optical fibers are being developed to allow endoscopic delivery of Er:YAG laser radiation. This paper describes the simple construction and characterization of a side-firing germanium oxide fiber for potential use with the Er:YAG laser in endourology. MATERIALS AND METHODS: The 450-microm-core side-firing fibers were constructed from germanium oxide fibers by polishing the distal tip at a 45 degrees angle and placing a protective quartz cap over the tip. The Er:YAG laser radiation, with a wavelength of 2.94 microm, was transmitted through the fibers. RESULTS AND CONCLUSION: The fiber transmission rate and damage threshold measured 48 +/- 4% and 149 +/- 37 mJ, respectively (n = 6 fibers). Sufficient pulse energies were transmitted through the side-firing fibers to produce contact tissue ablation.