Juan Carro

Speech in Alzheimer's Disease: Can Temporal and Acoustic Parameters Discriminate Dementia?

Aims: The study explores how speech measures may be linked to language profiles in participants with Alzheimers disease (AD) and how these profiles could distinguish AD from changes associated with normal aging. Methods: We analysed simple sentences spoken by older adults with and without AD. Spectrographic analysis of temporal and acoustic characteristics was carried out using the Praat software. Results: We found that measures of speech, such as variations in the percentage of voice breaks, number of periods of voice, number of voice breaks, shimmer (amplitude perturbation quotient), and noise-to-harmonics ratio, characterise people with AD with an accuracy of 84.8%. Discussion: These measures offer a sensitive method of assessing spontaneous speech output in AD, and they discriminate well between people with AD and healthy older adults. This method of evaluation is a promising tool for AD diagnosis and prognosis, and it could be used as a dependent measure in clinical trials.

The effects of sertraline administration from adolescence to adulthood on physiological and emotional development in prenatally stressed rats of both sexes

Sertraline (SERT) is a clinically effective Selective Serotonin Reuptake Inhibitor (SSRI) known to increase and stabilize serotonin levels. This neurotransmitter plays an important role in adolescent brain development in both rodents and humans, and its dysregulation has been correlated with deficits in behavior and emotional regulation. Since prenatal stress may disturb serotoninergic homeostasis, the aim of this study was to examine the long-lasting effects of exposure to SERT throughout adolescence on behavioral and physiological developmental parameters in prenatally stressed Wistar rats. SERT was administered (5 mg/kg/day p.o.) from the age of 1–3 months to half of the progeny, of both sexes, of gestating dams stressed by use of a restraint (PS) or not stressed. Our data reveal that long-term SERT treatment slightly reduced weight gain in both sexes, but reversed the developmental disturbed “catch-up” growth found in PS females. Neither prenatal stress nor SERT treatment induced remarkable alterations in behavior and had no effects on mean startle reflex values. However, a sex-dependent effects of PS was found: in males the PS paradigm slightly increased anxiety-like behavior in the open field, while in females, it impaired startle habituation. In both cases, SERT treatment reversed the phenomena. Additionally, the PS animals exhibited a disturbed leukocyte profile in both sexes, which was reversed by SERT. The present findings are evidence that continuous SERT administration from adolescence through adulthood is safe in rodents and lessens the impact of prenatal stress in rats.

Improvement of autobiographic memory recovery by means of sad music in Alzheimer’s Disease type dementia

Background and aims: Autobiographic memory undergoes progressive deterioration during the evolution of Alzheimer’s disease (AD). The aim of this study was to analyze mechanisms which facilitate recovery of autobiographic memories. We used a repeatedly employed mechanism, music, with the addition of an emotional factor. Methods: Autobiographic memory provoked by a variety of sounds (music which was happy, sad, lacking emotion, ambient noise in a coffee bar and no sound) was analyzed in a sample of 25 patients with AD. Results: Emotional music, especially sad music for remote memories, was found to be the most effective kind for recall of autobiographic experiences. Conclusions: The factor evoking the memory is not the music itself, but rather the emotion associated with it, and is useful for semantic rather than episodic memory.

Influence of cognitive reserve on neuropsychological functioning in Parkinson's disease.

Background: In recent years, attention has been drawn to the association between a low level of education and dementia, an almost generalized finding in the majority of studies on the prevalence of dementia where the level of education of the population was highly diversified. The protective effect of education is not limited to Alzheimers disease but is also seen in other types of dementia, Parkinsons disease (PD), and even in the cognitive deterioration linked to aging Objective: To evaluate neuropsychological performance in (PD) subjects and to evaluate the influence of cognitive reserve (RC) on their neuropsychological performance. Subjects: An extensive neuropsychological battery of tests was applied to a total of 79 subjects, 33 of whom were diagnosed with PD. Measures: RC scores were based on a combination of years of education, a measure of occupational attainment, and an estimate of premorbid intelligence. Results: As regards the specific disturbances found in the clinical group subjects, a lower performance in memory, attention, visuospatial, visuoconstructive, and perceptive skills was seen. With respect to our second objective, our results showed that patients diagnosed with PD who had a high RC reached a higher neuropsychological level of performance than those subjects with a low reserve. Conclusions: Early neuropsychological impairments in PD are most evident in individuals with lower RC. As has been found in other neurological disorders, individuals with greater RC may be less sensitive to the initial clinical effects of the underlying neuropathological process.

Medición de la visualización espacial mediante tests informatizados

ResumenDesde la corriente cognitiva que impulsa la construccion de tests polifaceticos, se han disenado cuatro tests informatizados de Visualizacion Espacial empleando tareas similares a las clasicas de doblado de papel, desarrollo de superficies, recuento de bloques y rompecabezas. En una muestra de 501 alumnos universitarios se analizan los efectos de las facetas sobre los tiempos de reaccion y la precision. Como se esperaba, solo algunas condiciones de las tareas implican el uso de las transformaciones mentales definitorias del constructo de Visualizacion. Se enfatiza la importancia de estos resultados para la construccion y validacion de los tests espaciales.

Voice Markers of Lexical Access in Mild Cognitive Impairment and Alzheimer's Disease

BACKGROUND Recent studies have identified the correlation between dementia and certain vocal features, such as voice and speech changes. Vocal features may act as early markers of Alzheimers disease (AD). Despite being present in non-pathological senescence and Mild Cognitive Impairment, especially in its amnesic subtype (aMCI), these voice- and speech-related symptoms are the first signs of AD. The purpose of this study is to verify whether these signs are related to deficits in lexical access, which appear early in AD. METHOD Anomic deficits in persons with MCI and AD are assessed through tests on verbal memory, denomination by confrontation, and verbal fluency. In addition, an acoustic analysis of speech is conducted in a reading task to identify the acoustic parameters associated with the groups analyzed, and their relation to the degree of anomic impairment observed in each one of them. RESULTS AND CONCLUSIONS The results show a direct relationship between the different acoustic parameters present in AD and the verbal fluency tests results.

Improvement of encoding and retrieval in normal and pathological aging with word-picture paradigm.

Objectives: During the aging process, there is a progressive deficit in the encoding of new information and its retrieval. Different strategies are used in order to maintain, optimize or diminish these deficits in people with and without dementia. One of the classic techniques is paired-associate learning (PAL), which is based on improving the encoding of memories, but it has yet to be used to its full potential in people with dementia. In this study, our aim is to corroborate the importance of PAL tasks as instrumental tools for creating contextual cues, during both the encoding and retrieval phases of memory. Additionally, we aim to identify the most effective form of presenting the related items. Method: Pairs of stimuli were shown to healthy elderly people and to patients with moderate and mild Alzheimers disease. The encoding conditions were as follows: word/word, picture/picture, picture/word, and word/picture. Results: Associative cued recall of the second item in the pair shows that retrieval is higher for the word/picture condition in the two groups of patients with dementia when compared to the other conditions, while word/word is the least effective in all cases. Conclusion: These results confirm that PAL is an effective tool for creating contextual cues during both the encoding and retrieval phases in people with dementia when the items are presented using the word/picture condition. In this way, the encoding and retrieval deficit can be reduced in these people.

Relations between Sensorimotor Integration and Speech Disorders in Parkinson's Disease

BACKGROUND Sensorimotor integration mechanisms can be affected by many factors, among which are those involving neuromuscular disorders. Parkinsons disease (PD) is characterized by well-known motor symptoms, among which lately have been included motor speech deficits. Measurement of the acoustic startle reflex (ASR) and its modulations (prepulse inhibition and prepulse facilitation, PPI and PPF respectively) represent a simple and quantifiable tool to assess sensorimotor function. However, it remains unknown whether measures of the PPI and PPF are associated with motor speech deficits in PD. METHODS A total of 88 subjects participated in this study, 52 diagnosed with PD and 36 control subjects. After obtaining written informed consent, participants were assessed with PPI at several interstimulus intervals, and PPF at 1000 ms using the SRH-Lab system (San Diego, CA). Percentage of change in the amplitude and latency of the ASR was analyzed between groups. Voice recordings were register of a specific text given to the subjects with a professional recorder and temporal patterns of speech were analyzed. RESULTS Statistical analysis conducted in this study showed differences in PPI and PPF in subjects with PD compared to controls. In addition, discriminative parameters of voice abnormalities were observed in PD subjects related to control subjects showing a reduction in phonation time, vowel pulses, breaks, breakage and voice speech periods. CONCLUSIONS PD presents a disruption in sensorimotor filter mechanisms and speech disorders, and there is a relationship between these alterations. The correlation between the PPI and PPF with an alteration of the voice in PD subjects contributes toward understanding mechanism underlying the neurophysiological alterations in both processes. Overall, easy and non-invasive tests such as PPI, PPF together with voice analysis may be useful to identify early stages of PD.

Speech rhythm alterations in Spanish-speaking individuals with Alzheimer’s disease

ABSTRACT Rhythm is the speech property related to the temporal organization of sounds. Considerable evidence is now available for suggesting that dementia of Alzheimer’s type is associated with impairments in speech rhythm. The aim of this study is to assess the use of an automatic computerized system for measuring speech rhythm characteristics in an oral reading task performed by 45 patients with Alzheimer’s disease (AD) compared with those same characteristics among 82 healthy older adults without a diagnosis of dementia, and matched by age, sex and cultural background. Ranges of rhythmic-metric and clinical measurements were applied. The results show rhythmic differences between the groups, with higher variability of syllabic intervals in AD patients. Signal processing algorithms applied to oral reading recordings prove to be capable of differentiating between AD patients and older adults without dementia with an accuracy of 87% (specificity 81.7%, sensitivity 82.2%), based on the standard deviation of the duration of syllabic intervals. Experimental results show that the syllabic variability measurements extracted from the speech signal can be used to distinguish between older adults without a diagnosis of dementia and those with AD, and may be useful as a tool for the objective study and quantification of speech deficits in AD.