Infant Auditory Temporal Acuity: Gap Detection

The development of auditory temporal acuity during infancy was examined in 3-, 6-, and 12-month-old infants and in adults using the gap detection paradigm. Listeners detected a series of gaps, or silent intervals, or variable duration in a broadband noise. In order to vary the acoustic frequencies available to the listener, a high-pass noise was used to mask frequencies above specified cutoffs. High-pass maskers with cutoffs of 500, 2,000, and 8,000 Hz were used. The minimum detectable gap was determined using the Observer-based Psychoacoustic Procedure. The thresholds of 3- and 6-month-olds were considerably poorer than those of the adults, although the effect of masker condition was about the same for these 3 groups. The thresholds of 12-month-olds were significantly worse than the adults when the stimulus was unmasked or when the masker cutoff frequency was 2,000 or 8,000 Hz. When the masker cutoff frequency was 500 Hz, 12-month-olds fell into 2 groups: some had gap thresholds that were about the same as 3- and 6-month-olds, while some had gap thresholds that approached those of adults. In a second experiment, a larger group of 12-month-olds were tested with a 500-Hz masker cutoff. Average performance of 12-month-olds was about the same as that of 3- and 6-month-olds in Experiment 1. Some infants attained thresholds close to those of adults. Thus, gap detection thresholds are quite poor in infants, although the similarity of the effect of frequency on performance in infants and adults suggests that the mechanisms governing temporal resolution in infants operate qualitatively like those in adults.     

Infants'' Localization of Sounds within Hemifields: Estimates of Minimum Audible Angle

Infants' acuity in localizing sounds within hemifields was examined by determining the smallest sound shift off 60 degrees and along the horizontal axis that infants could discriminate reliably, that is, minimum audible angle (MAA). Infants 6, 12, and 18 months of age were tested using a Go/No-Go conditioned head-turn procedure in which infants received an equal number of no-change (control) trials and sound-shift (experimental) trials. A correct response (i.e., a head turn toward the loud-speakers) on an experimental trial resulted in visual reinforcement. Localization acuity for sounds within hemifields was fairly poor and improved systematically with increasing age. MAA estimates at each age were significantly higher, indicating poorer localization acuity, in comparison to those obtained previously in research examining infants' resolution of auditory space near midline. These findings are consistent with adult data and demonstrate a finer partitioning of auditory space near midline than within hemifields. The implications of these findings for our understanding of the development of auditory processing mechanisms in sound localization are discussed.     

Aircraft noise exposure affects rat behavior,plasma norepinephrine levels,and cell morphology of the temporal lobe

In order to investigate the physiological effects of airport noise exposure on organisms, in this study, we exposed Sprague-Dawley rats in soundproof chambers to previously recorded aircraft-related noise for 65 d. For comparison, we also used unexposed control rats. Noise was arranged according to aircraft flight schedules and was adjusted to its weighted equivalent continuous perceived noise levels (L _wecpn ) of 75 and 80 dB for the two experimental groups. We examined rat behaviors through an open field test and measured the concentrations of plasma norepinephrine (NE) by high performance liquid chromatography-fluorimetric detection (HPLC-FLD). We also examined the morphologies of neurons and synapses in the temporal lobe by transmission electron microscopy (TEM). Our results showed that rats exposed to airport noise of 80 dB had significantly lower line crossing number (P<0.05) and significantly longer center area duration (P<0.05) than control animals. After 29 d of airport noise exposure, the concentration of plasma NE of exposed rats was significantly higher than that of the control group (P<0.05). We also determined that the neuron and synapsis of the temporal lobe of rats showed signs of damage after aircraft noise of 80 dB exposure for 65 d. In conclusion, exposing rats to long-term aircraft noise affects their behaviors, plasma NE levels, and cell morphology of the temporal lobe.     

Timing with opportunity cost: Concurrent schedules of reinforcement improve peak timing

The temporal generalization gradient produced by the peak-interval (PI) procedure reflects behavior under the control of positive reinforcement for responding after the criterial time, but shows negligible discouragement for early responses. The lack of consequences for premature responding may affect estimates of timing accuracy and precision in the PI procedure. In two experiments, we sought to encourage more accurate timing in pigeons by establishing an opportunity cost for such responding. Concurrent ratio and interval schedules of reinforcement reduced the dispersion of keypecking around the target time. A sequence of three response-rate states (low-high-low) characterized performance in individual trials. Opportunity cost substantially reduced the mean and standard deviation of the duration of the middle-high state that typically enveloped the target time, indicating improved temporal acuity. We suggest a model as a first-order approximation to timing with opportunity cost.     

Silent Reading as Determined by Age and Visual Acuity

In this study silent reading by adults ranging in age from 35 to 90 years was investigated. The texts to be read were printed in black on white paper with character sizes varying from 1–9 mm x-height (visual angle 0.19° to 1.67°). In order to separate age effects from visual-acuity effects, subjects with different levels of visual acuity (0.1–2.5 decimal acuity) participated in the experiment. Silent reading rate was employed as the dependent variable. Visual acuity affected reading rate most, followed by letter size. In normal-acuity subjects the variance in reading rates decreased as a function of age. Reading rates initially increased rapidly with increasing letter size, but after reaching an optimum gradually declined again as letters became larger. For the different acuity classes there appeared to be clearly optimal letter sizes, varying from 1.9 for the highest acuity group to 6 mm for the lowest acuity group at the 33 cm reading distance employed. However, the optimal reading rates of visually impaired subjects found in this study remained below those of individuals with normal acuity. This suggests that visual impairment is a more general neural phenomenon rather than merely a deficient optical image. The obtained reading-rate data could be accurately described by a theoretical model encompassing a decoding process and an integration process. It appeared that the model predictions were entirely determined by the smallest letter size at which reading is just possible with a specified visual acuity. It is concluded that both decoding and integration are dependent on visual acuity and that, in the absence of specific visual defects, ageing effects in reading can be completely explained by gradual lowering of visual acuity having its origin in central mechanisms.     

The development of recollection and familiarity in childhood and adolescence: evidence from the dual-process signal detection model

Two experiments examined the development of recollection (recalling qualitative details about an event) and familiarity (recognizing the event) using the dual-process signal detection model. In Experiment 1 (n = 117; ages 6, 8, 10, 14, and 18 years), recollection improved from childhood to adolescence after semantic encoding but not after perceptual encoding and familiarity improved from ages 6 to 8 regardless of encoding condition. In Experiment 2 (n = 56; ages 6, 8, and 10 years), long duration compared to short duration of semantic encoding increased familiarity but not recollection. Age-related differences replicated those of Experiment 1, except no age difference in familiarity was found with long study duration. Overall, recollection and familiarity showed distinct developmental and functional characteristics. The dual-process signal detection model proved promising for developmental investigations.     

Pigeons’ short-term memory for temporal and visual stimuli in delayed matching-to-sample

In the present experiment, we compared directly pigeons’ short-term memory of temporal and visual stimuli in a delayed matching-to-sample task. The sample stimuli consisted of red and green lights presented for 5 and 30 sec, followed by a retention interval and blue and yellow comparisons. For subjects in the visual group, duration was irrelevant and the color of the sample was the conditional cue. For animals in the temporal group, color was irrelevant and duration of the sample was the conditional stimulus. The results showed that acquisition of the matching task was faster and accuracy was higher in the visual than in the temporal group. More importantly, memory of either sample generally declined at a similar rate when the duration of the retention interval was increased and when the intertrial interval was reduced. Taken together, the results indicate that with 1–8-sec retention intervals, short-term memory for temporal stimuli is similar to that found with color-visual samples. The findings are discussed in terms of retrospective and prospective processing.     

An improved technique for global daily sunshine duration estimation using satellite imagery

This paper presents an improved model for global sunshine duration estimation. The methodology incorporates geostationary satellite images by including snow cover information, sun and satellite angles and a trend correction factor for seasons, for the determination of cloud cover index. The effectiveness of the proposed methodology has been tested using Meteosat geostationary satellite images in the visible band with a temporal resolution of 1 h and spatial resolution of 2.5 km×2.5 km, for the Brue Catchment in the southwest of England. Validation results show a significant improvement in the estimation of global sunshine duration by the proposed method as compared to its predecessor (R ² is improved from 0.68 to 0.83, root mean squared error (RMSE) from 2.37 h/d to 1.19 h/d and the mean biased error (MBE) from 0.21 h/d to 0.08 h/d). Further studies are needed to test this method in other parts of the world with different climate and geographical conditions.     

基于形态学重建的分水岭图像分割实验教学研究

现有分水岭算法对噪声敏感,易出现过度分割现象,导致图像分割边缘不明显.在传统分水岭算法基础上,通过形态学开闭重建来清除图像中的噪声点,并采用最小覆盖运算修改梯度图像,使得局部最小区域仅出现在标记位置,从而消除过分割现象.实验结果表明,与传统标记分水岭算法相比,用改进的算法对硬币图像和火焰图像进行处理,硬币轮廓识别率提高...     

Accelerating the development of formal thinking in middle and high school students III: Testing the permanency of effects

Two years after the end of a two-year intervention program intended to promote formal operational thinking, the achievement of students initially 12 years of age was tested by their results in British National examinations, taken at age 16. The intervention methodology was set within the context of science learning, so the difference between experimental and control classes was examined first in terms of their science results. The boys achieved an average of 40% more grades of C or above than the controls. This grade is the minimum criterion for higher education in Britain. The achievement was not found equally in all students: About 40% of the boys and 25% of the girls showed effect sizes of two standard deviations in relation to comparable controls, whereas the others did not differ from the controls. Both boys and girls showed significantly higher achievement in English than comparable controls, with an effect size about half that for science. The boys—but not the girls—also showed higher achievement in mathematics. It is argued that this evidence supports the interpretation that the students' increased science achievement was caused by increased general intellectual capacity, and not just by improved domain-specific skills.     

The development of children's understanding of cyclic aspects of time

Developmental psychological approaches to the study of time have fallen into 3 categories: studies of time perception; studies of logical, reconstructive abilities; and studies of the understanding of conventional time systems. The present work examines problems spanning the latter 2 categories--the development of children's understanding of temporal cycles and the relationship between cyclic concepts and cognitive development. 62 children, ranging in age from 4 to 10 years, were administered Piagetian tests of classification and seriation and a variety of specially designed cyclic tasks. Results show major progress in the representation of cyclic order and recurrence during the age period examined. For a variety of particular cycles, order responses were shown before continuity responses. The ability to produce a correct order is related to seriation performance but not classification performance when the variance attributable to age is partialed out. Continuity responses appear to be unrelated to performance on either of the Piagetian tasks tested when age is controlled.     

Components of attention during infants' manipulative exploration

The purpose of the project was to investigate attention in infants as they manipulate objects. It was hypothesized that examining, in contrast to other activity, reflects focused attention and active intake of information. The first study with 7- and 12-month-olds supported the hypothesis; examining declined with increasing familiarity, while other behaviors, such as mouthing and banging, did not, and examining occurred before other behaviors temporally. The latency to examine declined significantly with age. The second and third studies investigated the effects of age and familiarity on both latency to and duration of examining. Latency again decreased with age but did not change with increasing familiarity. In contrast, duration of examining did not vary systematically with age but declined sharply with familiarity. In a fourth study, latency to examine and duration of examining were related to different measures of attention at 3 1/2 years. The combination of results suggests that the latency and duration measures reflect different aspects of attention--a short-term reaction to object novelty and a more sustained response to the object and its characteristics.     

放射状视神经切开术治疗视网膜中央静脉阻塞

[目的]探讨放射状视神经切开术(RON)治疗视网膜中央静脉阻塞(CRVO)的手术效果及其并发症.[方法]选择7例视力0.1或以下的CRVO患者,病程1～6个月,手术常规做睫状体平坦部巩膜三切口玻璃体切除术,应用显微玻璃体视网膜(MVR)切开刀,做一个RON,切口在视盘鼻侧边缘,避开损伤鼻侧视网膜血管,刺入深度约为2.2mm.[结果]7例RON手术都很成功,无有任何并发症发生.术后随访6～12个月,患者眼底表现均有好转,术后视力也都有增进.[结论]RON有助于缺血性CRVO患者视网膜内出血、渗出和黄斑水肿的消退,以及视力的改善,似可适当用于选择性治疗此种难治的眼病.     

A brief screening battery for predicting school achievement at ages seven and nine years

This article describes the development, utilization, and evaluation of an early screening battery for predicting school success or failure. The battery was administered to the pediatric population of the Southern California Permanente Medical Group, Panorama City Medical Center, at the time of the routine five-year health examination. For 411 children whose school performance was assessed by the teacher at age seven years, the Caldwell Test was the best predictor, but it had significant value for girls only (p<0.0001). In 1,251 children evaluated at age nine years, the Beery-Butkenica Developmental Test of Visual-Motor Integration (VMI) and the Caldwell Test were the best predictors (p⩽0.003). In 600 children for whom we had teacher ratings at ages seven and nine years, the VMI repeated at age seven years significantly predicted academic achievement and reading at age nine years for girls and boys (p = 0.007). Although combining the academic performance with VMI results at age seven years yielded 89% accuracy of prediction at age nine years, the false-positive rate represents a serious practical problem of mislabeling children as school failures.     

基于自适应参数的多窗谱谱减法算法改进

当今人工智能发展迅速,语音识别成为人机交互的重要方式。为提高语音识别准确度,在分析语音信号前去除语音信号噪声干扰并提高语音信号能量尤为重要。在实际应用中,不同语音信号包含不同的噪声。针对不同的语音噪声,在传统谱减法基础上,通过判断算法窗函数,根据不同的噪声能量改变多窗谱减法的过减因子参数,以增强算法自适应能力。仿真结果表明,在低信噪比情况下,通过改变过减因子值,可取得一个最优过减因子值以改进谱减法下的音乐噪声和失真度。自适应多窗谱减法改进后与基本谱减法相比,信噪比提高了 29%;与多窗谱减法相比,信噪比提高了 16%。该自适应多窗谱减法可适应不同噪声环境下的语音信号,增强语音信号中的关键信息并减少噪声干扰。     

Interference and auditory short-term memory in the bottlenosed dolphin

Interference in auditory short-term memory in the bottlenosed dolphin,Tursiops truncatus (Montagu), was studied using a delayed matching-to-sample task. At each trial, one of two sample sounds, chosen randomly, was projected underwater for 4 sec and then, after a variable delay interval, both sounds were presented. A response to the sound matching the initial sample was reinforced. Correct matching was significantly reduced following short intervals between trials in combination with long delays after the sample (proactive interference), or when a near continuous irrelevant sound was inserted into the delay interval (retroactive interference). There was rapid habituation to interference if the irrelevant sound was short in duration relative to the delay interval. For both proactive and retroactive interference, the errors were predominantly responses to the sample sound appropriate to the prior trial rather than to the current trial, indicating that memory for the relative recency of events (temporal memory) was degraded by interference. When interference was deleted or minimized, temporal memory remained nearly perfect over 30-sec delay intervals, the longest tested. The importance of distinguishing between temporal memory and nontemporal, or event, memory in different forms of the delayed matching task was emphasized.     

The neuropathology of developmental dysphasia: Behavioral,morphological, and physiological evidence for a pervasive temporal processing disorder

Over the past twenty years, Tallal and colleagues have directed their research toward defining the neuropathological mechanisms responsible for developmental dysphasia. We have hypothesized that higher level auditory processing dysfunction, which has previously been associated with developmental dysphasia, may result from more basic temporal processing deficits which interfere with the resolution of rapidly presented, brief duration stimuli. This temporal processing deficit interferes with adequate perception of specific verbal stimuli which require resolution of brief duration formant transitions, resulting in disordered language development. The temporal processing deficit occurs across multiple sensory modalities, and also affects rapid and sequential motor production skills. Despite relatively normal clinical neuroradiological examinations, in vivo morphological analysis, utilizing magnetic resonance imaging techniques for quantitative volumetric measurements of specific brain structures, has identified abnormalities in superior parietal, prefrontal, and temporal cortices, as well as diencephalic and caudate nuclei. Abnormalities in structures which are involved in multimodal processing and sensory motor integration is consistent with the behavioral profile of developmental dysphasia. Two alternative hypotheses regarding the neurophysiological basis of the multimodal temporal processing disorder include: dysfunction in specific cellular systems which subserve rapid, transient processing; and abnormal gating of sensory relay by intralaminar and reticular thalamic nuclei.     

How Do the Different Components of Episodic Memory Develop? Role of Executive Functions and Short‐Term Feature‐Binding Abilities

This study investigated the development of all 3 components of episodic memory (EM), as defined by Tulving, namely, core factual content, spatial context, and temporal context. To this end, a novel, ecologically valid test was administered to 109 participants aged 4-16 years. Results showed that each EM component develops at a different rate. Ability to memorize factual content emerges early, whereas context retrieval abilities continue to improve until adolescence, due to persistent encoding difficulties (isolated by comparing results on free recall and recognition tasks). Exploration of links with other cognitive functions revealed that short-term feature-binding abilities contribute to all EM components, and executive functions to temporal and spatial context, although ability to memorize temporal context is predicted mainly by age.     

Exploring the Relationship between Students' Understanding of Conventional Time and Deep (Geologic) Time

Many geologic processes occur in the context of geologic or deep time. Students of all ages demonstrate difficulty grasping this fundamental concept which impacts their ability to acquire other geoscience concepts. A concept of deep time requires the ability to sequence events on an immense temporal scale (succession) and to judge the durations of geologic processes based on the rates at which they occur. The twin concepts of succession and duration are the same ideas that underlie a concept of conventional time. If deep time is an extension of conventional time and not qualitatively different from it, students should display similar reasoning patterns when dealing with analogous tasks over disparate temporal periods. Thirty-five US students aged 13–24 years participated in individual task-based interviews to ascertain how they thought about succession and duration in conventional and deep time. This is the first attempt to explore this relationship in the same study in over 30 years. Most students successfully completed temporal succession tasks, but there was greater variability in responses on duration tasks. Conventional time concepts appear to impact how students reason about deep time. The application of spatial reasoning to temporal tasks sometimes leads to correct responses but in other instances does not. Implications for future research and teaching strategies are discussed.     

Effects of Treatment of Hearing Loss in Middle‐Aged Persons with Down Syndrome: A Pilot Study

The extent to which therapeutic intervention of hearing loss may yield better communication and social interaction was investigated in a pilot study during seven months after treatment in twelve hearing impaired subjects with Down syndrome with a mean age of 50.6 years. Although according to spontaneous observations of staff subtle positive reactions to treatment occurred in five subjects, no significant improvement could be measured by means of objective methods. The influence of personal factors like degree of retardation and language development, severity and duration of hearing impairment, age, period of habituation and training, and environmental factors, is to be studied further.