Relating traffic, construction, and ventilation noise to cognitive performances and subjective perceptions

The relationship between episodic and semantic memory systems has long been debated. Some authors argue that episodic memory is contingent on semantic memory (Tulving 1984), while others postulate that both systems are independent since they can be selectively damaged (Squire 1987). The interaction between these memory systems is particularly important in the elderly, since the dissociation of episodic and semantic memory defects characterize different aging-related pathologies. Here, we investigated the interaction between semantic knowledge and episodic memory processes associated with faces in elderly subjects using an experimental paradigm where the semantic encoding of famous and unknown faces was compared to their episodic recognition. Results showed that the level of semantic awareness of items affected the recognition of those items in the episodic memory task. Event-related magnetic fields confirmed this interaction between episodic and semantic memory: ERFs related to the old/new effect during the episodic task were markedly different for famous and unknown faces. The old/new effect for famous faces involved sustained activities maximal over right temporal sensors, showing a spatio-temporal pattern partly similar to that found for famous versus unknown faces during the semantic task. By contrast, an old/new effect for unknown faces was observed on left parieto-occipital sensors. These findings suggest that the episodic memory for famous faces activated the retrieval of stored semantic information, whereas it was based on items' perceptual features for unknown faces. Overall, our results show that semantic information interfered markedly with episodic memory processes and suggested that the neural substrates of these two memory systems overlap.

Background: Identifying the point of breakdown in people with aphasia with disorders of word retrieval is not straightforward. Evidence has been sought from: (i) the nature of the errors in naming; (ii) the variables affecting naming accuracy; (iii) the effects of correct and misleading cues; (iv) performance in other word comprehension and production tasks. However, previous research has demonstrated that each of these sources of evidence provides information compatible with more than level of breakdown.Aims: The study investigates whether a combination of information from these sources can provide a coherent account of how word retrieval is breaking down in people with aphasia.Methods & Procedures: Three people with aphasia (JGr, LM, and KS) took part in four experiments. The first investigated the errors made in picture naming and the factors (target word length, imageability, frequency …) affecting naming accuracy. The second experiment investigated the effects of correct phonemic cues and miscues on word retrieval. The third examined the participants' performance in tests of spoken and written word and picture comprehension. The fourth experiment investigated whether the participants had the processing abilities necessary to generate their own phonemic cues in spoken naming from orthographic information.Outcomes & Results: Evidence from these investigations showed different levels of breakdown in the three participants. JGr's naming was characterised by semantic errors, effects of target imageability and familiarity on naming accuracy, improved naming with correct phonemic cues and semantic errors with miscues, and poor performance in word comprehension tasks. This pattern is consistent with a breakdown at a semantic level underlying JGr's difficulty in word retrieval. In contrast, LM shows performance indicating a breakdown in mapping between intact semantic and phonological representations. He makes primarily no response errors in naming and his accuracy is affected only by frequency and familiarity. Correct phonemic cues can improve his naming accuracy to near normal levels, and he makes no semantic errors, although he is slowed by miscues. His word and picture comprehension is intact. KS shows a more complex pattern of impairment. Like JGr, she shows evidence of a semantic impairment: she makes semantic errors in naming, and her accuracy is affected by target imageability. She makes errors in word comprehension and her word retrieval is adversely affected by miscues. There are two unusual features to her performance: her naming accuracy is not improved by initial phoneme cues (despite effects of miscues and more extensive phonemic cues), and she is better at naming pictures with longer names (a “reverse length effect”). Investigations in experiment four show that KS is using orthographic information on the initial letter of names to generate her own phonemic cues; it is concluded that in addition to her semantic deficit she has an impairment in access to lexical phonological representations.Conclusions: We conclude that careful investigation of the performance of people with aphasia across a range of tasks can be used to identify underlying levels of breakdown in word retrieval. However, superficial resemblances between people with aphasia can be misleading.

Cortical Networks Implicated in Semantic and Episodic Memory: Common or Unique?

Remote semantic memory in patients with Korsakoff's syndrome and herpes encephalitis.

Disturbances of cognitive functions, including verbal (learning) memory, in bipolar disorder have attracted interest.1, 2 The present study was conducted to determine if type of word learning tasks (i.e., whether or not evaluation is based on a word list with categorized items) affects severity of impairment of verbal memory in patients with bipolar disorder. The protocol for this study has been approved by the Ethics Committee of the National Center of Neurology and Psychiatry, Institutional Review Board of Hokkaido University Hospital, Department of Ethics Review Committee, Nagoya University Graduate School of Medicine, and Fujita Health University Ethics Research Committee. The protocol conformed to the provisions of the Declaration of Helsinki. Thirty-six patients with bipolar disorder with mild symptoms and 42 healthy volunteers participated in the study (Table S1). All subjects gave informed consent, and their anonymity was preserved. We compared effect sizes for memory deficits in patients between the California Verbal Learning Test (CVLT)-II3 Japanese version4 and the Brief Assessment of Cognition in Schizophrenia (BACS) List-Learning Japanese version.5 The CVLT-II uses word lists with categorized items while the BACS is without such system. We also evaluated the correlations between CVLT-II scores and BACS scores by Pearson's correlation coefficient. Scores on the CVLT-II 1-5 Free Recall and Long-delay Free Recall, but not the BACS List-Learning were significantly lower for patients compared to control subjects (Table S2). CVLT-II 1-5 Free Recall (R = 0.81, P < 0.0001) and Long-Delay Free Recall (R = 0.78, P < 0.0001) scores were significantly correlated with BACS List-Learning scores. These results suggest that the degree of verbal memory deficits in bipolar disorder depends on type of word learning tasks. The ability of the CVLT-II, but not of the BACS List-Learning, to discriminate between patients and control subjects may be related to the use of memory organization strategy specific to the former word list task. The authors have no potential conflicts of interest to disclose. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

In this contribution a novel method is discussed that is of practical use for analyzing the electromagnetic compatibility behavior of electronic systems. The aim is to develop an efficient technique that mimics radiated immunity and emission tests in the presence of multiple non-collocated noise sources in simulation. The proposed method is simple in that it only relies on the simulated (or measured) radiation pattern of the devices in the system while allowing arbitrary positions. Rotation of the devices is performed by a spherical harmonics decomposition of the radiation patterns together with the application ofWigner-D rotation matrices. The adopted assumption is that the devices are spaced sufficiently far from each other such that there is no coupling via the reactive near-field. The proposed procedure shows good agreement with measurements and full-wave simulations while at the same time it has a low computational cost.

Novel plenum window with sonic crystals for indoor noise control

This study examined several factors that may be involved in the writing of summaries and the impact of these factors on the use of summaries for reading comprehension assessment. Fifty-three seventh-grade subjects of average to above-average reading ability participated in the study. Data collection took place in four sessions over a one-week duration. Levels of prior knowledge and interest in a topic, as well as general writing ability, were assessed before subjects read the target passage. Subjects read a novel passage consisting of a five-page section of a chapter in their regularly-assigned American history text. After reading, subjects wrote, in counterbalanced order, both a free recall and a summary of the passage. After a second reading, subjects answered 15 passage-dependent, multiple-choice questions. In addition, recent scores on a standardized test of reading comprehension were obtained for each subject. Data from the free recalls and summaries were analyzed in three ways. First, a multivariate analysis of variance, with repeated measures on free recalls and summaries, was performed. Next, a standard regression analysis was undertaken, using scores from the prior knowledge, topic interest, and writing ability measures as predictor variables for the free recall and summary scores. Finally, Pearson product-moment correlations coefficients were calculated for both free recalls and summaries with multiple-choice questions scores and scores on the standardized reading comprehension test. MANOVA results revealed a significant main effect for Task, and follow-up univariate tests indicated significant differences between free recalls and summaries for number of idea units and proportion of important idea units included. The regression analysis revealed that prior knowledge, topic interest, and writing ability may play at least a partial role in the writing of summaries. Finally, correlation analyses indicated that summaries measure at least some of the same aspects of reading comprehension as multiple-choice questions and standardized tests. Implications for instruction and direction for further research are cited.

MULTIPLE REFERENCE FEEDFORWARD ACTIVE NOISE CONTROL PART II: REFERENCE PREPROCESSING AND EXPERIMENTAL RESULTS

Background: The role of hippocampal connectivity for good memory performance is well known in persons with high educational level. However, it is understudied the role of hippocampal connectivity in illiterate populations. Objectives: To determine whether the hippocampal connectivity correlate with episodic memory in illiterate adults. Methods: Thirty-nine illiterate adults underwent resting state functional MRI and an episodic memory test (Free and Cued Selective Reminding Test). We correlated the hippocampal connectivity at rest with the free recall scores. Analyzes were corrected for head motion and physiological BOLD signal. Results: Participants were most female (66%) and black (79%) and the mean age was 49 years-old (±13.9). The mean score on free recall was 27.2 (±10.7) out of 48 points. We found a significant correlation between both hippocampi and the posterior cingulate and ventral medial prefrontal cortex. However, we did not find an association between the hippocampal connectivity and the memory scores. Conclusions: The lack of association with memory scores might be associated with low brain reserve in this group of individuals.

Memory encoding and retrieval in frontotemporal dementia and Alzheimer's disease.

Introduction: The Rey 15-item Test is a public-domain, memory-based performance validity test, frequently used in clinical settings. Various efforts have been made to modify the test to make it more sensitive and more robust to effects of lower education and intelligence. The most promising of these is the addition of a recognition trial to the existing free recall paradigm. Method: The present study explored the use of the Rey-15 + Recognition Trial in a sample of 155 younger U.S. military veterans seen for evaluation of mild traumatic brain injury or attention deficit hyperactivity disorder (50 cases classified as invalid, 105 classified as valid). Results: Optimal classification accuracy was obtained on the Combination index (cutoff ≤23, sensitivity = 50%, specificity = 95%) and the Recognition Hits score (cutoff ≤11, sensitivity = 52%, specificity = 93%). The Free Recall score had somewhat lower sensitivity when a similar 95% specificity threshold was set (cutoff ≤11, 38% sensitivity). A qualitative error score used in previous studies did not improve classification accuracy. Conclusions: The Rey-15 + Recognition Trial proved to be effective, with particular advantage bestowed by the recognition trial. Implications of these findings in the context of the study’s clinical sample of military veterans and in the broader literature are discussed.

We have previously advocated the deliberate addition of noise to cochlear implant signals to enhance the speech comprehension of cochlear implant users. The function of the additive noise is to mimic noise sources that are present in a healthy ear (originating, for example, from Brownian motion of the hair cells and the fluctuations induced by the opening and closing of ion channels) but are largely absent in a deafened ear where the hair cells have been damaged or destroyed. The normal ear, however, also contains multiplicative noise sources that result from the quantal nature of synaptic transmission between the inner hair-cells and the cochlear nerve. These noise synaptic noise sources are also largely absent in the deafened ear. Given that previous studies suggest that additive noise can enhance information coding by sensory systems, we have investigated whether multiplicative noise also enhances coding in a model of electrical stimulation of the cochlear nerve by a cochlear implant. The model was based on leaky integrate-and-fire dynamics and modelled refractory and accommodation effects by a threshold dependency derived from the sodium-inactivation dynamics of the Frankenhauser-Huxley equations for myelinated nerves. We show that multiplicative noise leads to a fundamental change in the coding mechanism and can lead to a marked increase in the transmitted information compared with additive noise or a control condition with no noise. These results suggest that multiplicative noise in the normal auditory system might have a functional role.

The role of knowledge base in the memory performance of good and poor readers

Alzheimer’s disease leads to a decline in both episodic and semantic memory. Free recall tasks are commonly used in assessments designed to diagnose and monitor cognitive impairment, but tend to focus only on episodic memory. Our goal is to understand the influence of semantic memory on the sequence of free recall in a clinical data set. We develop a cognitive process model that incorporates the influence of semantic similarity and other stimulus properties on the order of free recall. The model also incorporates a decision process based on the Luce choice rule, allowing for different levels of response determinism. We apply the model to a real-world data set including free recall data from 2392 Alzheimer’s patients and their caregivers. We find that semantic similarity between items strongly influences the order of free recall, regardless of impairment. We also observe a trend for response determinism to decrease as impairment increases.