Monthly Archives: February 2010
The inferior; anterior temporal lobes and semantic memory clarified: Novel evidence from distortion-corrected fMRI
The neural basis of semantic memory generates considerable debate. Semantic dementia results from bilateral anterior temporal lobe (ATL) atrophy and gives rise to a highly-specific impairment of semantic memory, suggesting that this region is a critical neural substrate for semantic processing. Recent rTMS experiments with neurologically-intact participants also indicate that the ATL are a necessary substrate for semantic memory. Exactly which regions within the ATL are important for semantic memory are difficult to detect from these methods (because the damage in SD covers a large part of the ATL). Functional neuroimaging might provide important clues about which specific areas exhibit activation that correlates with normal semantic performance. Neuroimaging studies, however, have not consistently found anterior temporal lobe activation in semantic tasks. A recent meta-analysis indicates that this inconsistency may be due to a collection of technical limitations associated with previous studies, including a reduced field-of-view and magnetic susceptibility artefacts associated with standard gradient echo fMRI. We conducted an fMRI study of semantic memory using a combination of techniques which improve sensitivity to ATL activations whilst preserving whole-brain coverage. As expected from SD patients and ATL rTMS experiments, this method revealed bilateral temporal activation extending from the inferior temporal lobe along the fusiform gyrus to the anterior temporal regions, bilaterally. We suggest that the inferior, anterior temporal lobe region makes a crucial contribution to semantic cognition and utilising this version of fMRI will enable further research on the semantic role of the ATL.
from Neuropsychologia
Evaluation of swallowing pressure in a patient with amyotrophic lateral sclerosis before and after cricopharyngeal myotomy using high-resolution manometry system
This is the first report showing the effect of cricopharyngeal myotomy by demonstrating, the difference in the swallowing pressure along the velopharynx and upper esophagus before and after, the surgery in an ALS patient using this HRM system.
from Auris Nasus Larynx
Discourse coherence and cognition after stroke: A dual task study
Several researchers have suggested that the maintenance of global coherence (topic maintenance) and local coherence (maintenance between utterances) in discourse requires cognitive resources. This study directly tests this hypothesis by examining the relationship between cognitive variables and coherence in narrative discourse produced by mobility-impaired stroke survivors under single (talking) and dual (talking and walking) task conditions. Although there were no effects of the dual task on coherence, global coherence was significantly disrupted regardless of the single or dual task condition. Moreover, global coherence strongly correlated with cognitive function measures, whereas local coherence did not. Findings are consistent with two interpretations: 1) that global and local coherence may be subserved by different cognitive processes or 2) that maintaining global coherence is a more difficult task and thus will show effects of cognitive impairment before local coherence is impaired. These are both testable hypotheses for future research.
from the Journal of Communication Disorders
Distinguishing between attributional and mnemonic sources of familiarity: The case of positive emotion bias
Does familiarity arise from direct access to memory representations (a mnemonic account) or from inferences and diagnostic cues (an attributional account)? These theoretically distinct explanations can be difficult to distinguish in practice, as is shown by the positivity effect, the increase in feelings of familiarity that accompanies positive emotion. Experiment 1 manipulated mnemonic and attributional sources of positivity via word valence and physical expressions of emotion, respectively. Both sources influenced the tendency to call items old, but receiver-operating characteristic analysis revealed a change in accuracy only with the mnemonic source. To further contrast the mnemonic and attributional accounts, Experiment 2 varied the ratio of positive to neutral words. A higher proportion of positive words exaggerated the pattern of increased old judgments and decreased accuracy for positive words, relative to neutral ones, consistent with the mnemonic account but inconsistent with the attributional account.
from Memory and Cognition
Musicians’ and nonmusicians’ short-term memory for verbal and musical sequences: Comparing phonological similarity and pitch proximity
Language—music comparative studies have highlighted the potential for shared resources or neural overlap in auditory short-term memory. However, there is a lack of behavioral methodologies for comparing verbal and musical serial recall. We developed a visual grid response that allowed both musicians and nonmusicians to perform serial recall of letter and tone sequences. The new method was used to compare the phonological similarity effect with the impact of an operationalized musical equivalent—pitch proximity. Over the course of three experiments, we found that short-term memory for tones had several similarities to verbal memory, including limited capacity and a significant effect of pitch proximity in nonmusicians. Despite being vulnerable to phonological similarity when recalling letters, however, musicians showed no effect of pitch proximity, a result that we suggest might reflect strategy differences. Overall, the findings support a limited degree of correspondence in the way that verbal and musical sounds are processed in auditory short-term memory.
from Memory and Cognition
The role of phonological and visual working memory in complex arithmetic for Chinese- and Canadian-educated adults
Two experiments were conducted to test cultural differences in the role of phonological and visual working memory in complex arithmetic. Canadian- and Chinese-educated students solved complex subtraction problems (e.g., 85 − 27; Experiment 1) and complex multiplication problems (e.g., 6 × 13; Experiment 2) under phonological and visual working memory loads. Problem complexity (i.e., borrow or carry operations) and presentation format (i.e., horizontal vs. vertical) were also manipulated. The results showed that both Chinese- and Canadian-educated participants relied on both phonological and visual working memory resources when solving complex subtraction and multiplication problems. Selective involvement of phonological and visual working memory as a function of operation (Lee & Kang, 2002) or presentation format (Trbovich & LeFevre, 2003) was found only for Chinese-educated participants and not for Canadian-educated participants, calling into question the generalizability of these findings across arithmetic operations and cultural groups.
from Memory and Cognition
Verbal memory impairment in severe closed head injury: The role of encoding and consolidation
We applied the item-specific deficit approach (ISDA) to California Verbal Learning Test data obtained from 56 severe, acceleration-deceleration closed head injury (CHI) participants and 62 controls. The CHI group demonstrated deficits on all ISDA indices in comparison to controls. Regression analyses indicated that encoding deficits, followed by consolidation deficits, accounted for most of the variance in delayed recall. Additionally, level of acquisition played a partial role in CHI-associated consolidation difficulties. Finally, CHI encoding deficits were largely driven by low semantic clustering during list learning. These results suggest that encoding (primary) and consolidation (secondary) deficits account for CHI-associated verbal memory impairment.
from the Journal of Clinical and Experimental Neurophysiology
Motivational priming and processing interrupt: Startle reflex modulation during shallow and deep processing of emotional words
Valence-driven modulation of the startle reflex, that is larger eyeblinks during viewing of unpleasant pictures and inhibited blinks while viewing pleasant pictures, is well documented. The current study investigated, whether this motivational priming pattern also occurs during processing of unpleasant and pleasant words, and to what extent it is influenced by shallow versus deep encoding of verbal stimuli. Emotional and neutral adjectives were presented for 5 seconds, and the acoustically elicited startle eyeblink response was measured while subjects memorized the words by means of shallow or deep processing strategies. Results showed blink potentiation to unpleasant and blink inhibition to pleasant adjectives in subjects using shallow encoding strategies. In subjects using deep encoding strategies, blinks were larger for pleasant than unpleasant or neutral adjectives. In line with this, free recall of pleasant words was also better in subjects who engaged in deep processing. The results suggest that motivational priming holds as long as processing is perceptual. However, during deep processing the startle reflex appears to represent a measure of “processing interrupt”, facilitating blinks to those stimuli that are more deeply encoded.
Cough and Swallowing Dysfunction
The symptom of cough may result from a multitude of etiologies involving different parts of the aerodigestive tract. This article focuses on the association of cough and swallowing dysfunction in the sense that cough may be an indicator of swallow dysfunction and in the importance of cough in preventing aspiration and aspiration-related disorders. Whereas these associations have been known for a long time, research is starting to connect the dots, allowing targeting of strategies aimed at diagnosing and preventing illness in certain dysphagic patients.
The Role of Voice Therapy in the Management of Paradoxical Vocal Fold Motion, Chronic Cough, and Laryngospasm
This article describes the assessment and behavioral treatment for paradoxical vocal fold motion disorder (PVFM), chronic cough, and laryngospasm. Behavioral treatment for these disorders is coordinated by the speech–language pathologist. Assessment of PVFM involves a detailed behavioral analysis of the triggers for the conditions and incorporation of the medical findings as they relate to the symptoms. Treatments developed originally by the group at the National Jewish Hospital in Denver, Colorado, and then expanded by others have been shown to reduce or eliminate the symptoms and improve overall quality of life in patients who have these diagnoses.
Vocal Cord Dysfunction, Paradoxic Vocal Fold Motion, or Laryngomalacia? Our Understanding Requires an Interdisciplinary Approach
This article presents disorders of periodic occurrence of laryngeal obstruction (POLO) resulting in noisy breathing and dyspnea and a variety of secondary symptoms. Included in this classification are glottic disorders, such as paradoxic vocal fold movement and vocal cord dysfunction. The supraglottic disorder, termed, intermittent arytenoid region prolapse or laryngomalacia, is also reviewed. Three categories of POLO are defined as irritant, exertional, and psychological.
Cepstral Analysis of Voice in Persons With Vocal Nodules
The present study investigated the CPP in subjects with vocal nodules. Cepstral deviations in the clinical group are explained due to the presence of laryngeal pathology leading to the lower values of CPP.
from the Journal of Voice
Clinical Outcome of Window Partial Laryngectomy for Stage T2-3 Glottic Laryngeal Carcinoma
This study showed that window partial laryngectomy was successful for treating properly selected stage T2-3 glottic laryngeal carcinoma. This operation was effective for reducing surgical invasion and facilitated the resumption of respiratory and vocal function.
from the Journal of Voice
Glottoplasty for Male-to-Female Transsexualism: Voice Results
Wendler’s glottoplasty can contribute to feminize the voice.
from the Journal of Voice
Prolonged Ulcerative Laryngitis: A New Disease Entity
Over the last decade, a new disease entity, prolonged ulcerative laryngitis (PUL), with unique clinical presentation and prolonged disease course, has been recognized. Until now, very few studies dealing with this disease have been reported in the literature. From 1999 to 2008, we analyzed clinical data from a series of 39 PUL patients who were treated with an observational approach without implementing specific treatments. This disease affects adults, predominantly females. The age of patients in our series ranged from 26 to 76 years with a median of 49.5 years. This disease is characterized by ulcers and signs of acute inflammation on the membranous portion of the vocal folds with a prolonged clinical course. The recovery times of patients ranged from 4 to 20 weeks with an average of 9.4 weeks. The data in this study may reflect a natural history of this disease. PUL seems to be a self-limited disease, but the etiology of this disease is unknown. Specific infections or systemic inflammatory processes involving the larynx must be ruled out before diagnosis, and conservative treatments are suggested.
from the Journal of Voice
