An investigation of young infants' perceptual representations of speech sounds.

The present study examined the ability of newborns and 2-month-olds to detect phonetic differences between syllables. By relying on the modified high-amplitude sucking procedure, which did not permit the infants to use a simple same–different response, the present experiments tapped the perceptual representations of the speech sounds. Infants as young as a few days old displayed some capacity to represent differences in a set of syllables varying in their phonetic composition, although there was no convincing evidence that their representations were structured in terms of phonetic segments. Finally, evidence of developmental changes in speech processing were noted for the first time with infants in this age range. The change noted was a tendency from global toward more specific representations on the part of the older infants. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Representation of speech sounds by young infants.

The perceptual representation of speech by young infants was investigated using a modification of the high-amplitude sucking (HAS) procedure. Two-month-old infants were presented with a series of consonant-vowel syllables differing in their phonetic structure. After familiarization with a set of syllables that shared the same initial consonant, the infants' responses to an additional syllable with either the familiar or a novel consonant were examined. The results demonstrated that the infants' representations preserved rather detailed information about both the consonantal and vocalic portions of the syllables. However, there was no indication that the representations were structured as a consonant-vowel sequence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Valsartan, a new angiotensin II antagonist: antihypertensive effects over 24 hours

This study was done to assess the antihypertensive efficacy of once-daily valsartan 20 mg, 80 mg, 160 mg, and 320 mg over 24 hours using ambulatory blood pressure monitoring (ABPM). A total of 217 adult outpatients with uncomplicated essential hypertension (office mean sitting diastolic blood pressure [DBP] of > or = 95 to < or = 115 mm Hg) participated in this multicenter, double-masked, placebo-controlled study. Patients were randomized to receive valsartan 20 mg, 80 mg, 160 mg, 320 mg, or placebo for 8 weeks. Twenty-four-hour ABPM was done at baseline and after 8 weeks of treatment. All valsartan doses produced significant decreases in average ambulatory systolic blood pressure (SBP) and DBP over 24 hours compared with placebo. A trend to greater reductions compared with placebo was observed for doses of valsartan 80 mg and greater (80 mg, -6.61 mm Hg DBP, -11.04 mm Hg SBP; 160 mg, -5.51 mm Hg DBP, -10.61 mm Hg SBP; 320 mg, -8.44 mm Hg DBP, -14.34 mm Hg SBP) compared with valsartan 20 mg (-3.52 mm Hg DBP, -5.92 mm Hg SBP). Valsartan produced consistent reductions compared with placebo during both day (> 6 AM to < or = 10 PM) and night (> 10 PM to < or = 6 AM). However, in all groups, the circadian pattern of blood pressure over 24 hours was preserved and was similar to that observed at baseline (but shifted into the normotensive range in a parallel fashion). The data show that single daily doses of valsartan 80 mg and greater provide effective control of both DBP and SBP over a 24-hour period without loss of diurnal variation.     

Variations in prothrombin time and international normalized ratio over 24 hours in warfarin-treated patients

STUDY OBJECTIVE: To determine the variation of prothrombin times and international normalized ratio (INR) over 24 hours in humans. DESIGN: Prospective, parallel study. SETTING: University-affiliated general clinical research center. PATIENTS: Six patients receiving long-term warfarin therapy and six sex-matched controls. INTERVENTIONS: Warfarin was administered to the patients at 6:00 P.M. MEASUREMENTS AND MAIN RESULTS: Prothrombin times and INR were determined every 2 hours over 24 hours. Time of study entry, meals, and sleep cycles were controlled. A significant cosinor rhythm for prothrombin times and INR (p < or = 0.03) occurred in warfarin-treated patients, suggesting that diurnal variation occurs. The mean difference between the peak and trough prothrombin times was 1.8 +/- 0.9 seconds (range 0.8-3 sec) with a mean change of 9.3% +/- 3.7%. The peak prothrombin time and INR values occurred between 4:00 A.M. and 8:00 A.M. in five patients, and trough values between 6:00 P.M. and midnight in five. No significant cosinor rhythm was noted for controls (p > 0.5). CONCLUSION: Significant variations in prothrombin time and INR occurred in patients receiving warfarin therapy, with the highest values occurring in the morning and the lowest in the evening. These results may have clinical implications for patients receiving either high- or low-intensity warfarin therapy.     

Developmental changes across childhood in the perception of non-native speech sounds.

Tested 12 English-speaking children at each of 3 ages (4, 8, and 12 yrs) on 3 speech contrasts of English and Hindi sounds. As a control procedure, 2 bilingual Hindi–English speaking children (aged 4 and 5 yrs) were also tested. Results show that the loss of ability to discriminate the nonnative (Hindi) speech contrasts was evident by 4 yrs of age, suggesting that important reorganizations in linguistic perceptual abilities occur in early childhood. Results support the notion that learning a 2nd language may not necessarily be easier in young childhood. (French abstract) (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Errors in short-term memory for speech: A developmental study.

In a previous study (R. Treiman & C. Danis, 1988), adults who were presented with lists of spoken consonant-vowel-consonant (CVC) nonsense syllables for immediate recall produced many errors that combined the initial consonant onset of one to-be-remembered syllable with the vowel-consonant rime of another to-be-remembered syllable. These onset-rime recombination errors were more common than other types of recombination errors and also more common than serial position errors. These findings suggest that nonwords are remembered in terms of smaller phonological units. To replicate the previous results and to determine whether they generalize to children, the author tested kindergartners, 3rd graders, 6th graders, and adults on lists of nonsense CVCs. Onset-rime conjunction errors were the most frequent type of recombination error, even among kindergartners, suggesting that children code spoken syllables in terms of onset and rime units from a young age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of perceived discrimination on ambulatory blood pressure and affective responses to interpersonal stress modeled over 24 hours.

Objective: This research examined the impact of perceived discrimination on ambulatory blood pressure (ABP) and daily level affect during social interaction. Design: For 24 hrs, adult Black and White participants wore an ABP monitor and completed palm pilot diary entries about their social interactions. Main Outcome Measures: Mean level and time-trend trajectories of blood pressure and heart rate were examined as well as mean level measures of positive and negative affect after stressful and nonstressful social interactions. Results: Analyses showed that, after controlling for important covariates, perceived discrimination predicted the slopes of both wake and nocturnal ABP responses, with those who reported more discrimination having steeper daytime trajectories for systolic and diastolic blood pressure and less nighttime dipping in heart rate over time as compared to those who had reported relatively infrequent discrimination. High levels of perceived discrimination were also related to positive and negative affective responses after stressful encounters. Conclusions: These results suggest that, regardless of race, perceived discrimination is related to cardiovascular and affective responses that may increase vulnerability to pathogenic processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Processing speed, speech rate, and memory.

In each of 2 studies, 24 9-yr-olds and 24 adults were administered measures of memory and measures of processing speed. In addition, in Study 2, articulation rate was measured. Age was correlated positively with memory but was correlated negatively with processing speed and articulation rate. The results of path analyses were consistent with the hypothesis that age and processing speed independently contribute to articulation rate, which determines memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nipple attachment in rats during the first 24 hours of life.

Investigated nipple attachment in 49 Purdue-Wistar laboratory rat pups during the 1st 24 hrs of life and identified determinants that influenced its expression. In Exp I, nipple attachment was shown to be age dependent: 1-hr-old pups exhibited a low percentage of attachment, and 12- and 24-hr-old pups exhibited high percentages when tested against an anesthetized lactator. Exps II–VI established the time course of nipple attachment as age related. Exps VII–X explored the behavioral mechanism responsible for the increase in attachment from Hr 1 to Hr 12. They showed that nipple experience, independent of milk acquisition, was the responsible factor for the increase. The findings suggest that learning is employed as a behavioral strategy by the newborn, and they reemphasize the value of using species-relevant measures in the assessment of behavioral development. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Process and strategy in memory for speech among younger and older adults.

Younger and older adults listened to and immediately recalled short passages of speech that varied in the rate of presentation and in the degree of linguistic and prosodic cuing. Although older adults showed a differential decrease in recall performance as a function of increasing speech rate, age differences in recall were reduced by the presence of linguistic and prosodic cues. Under conditions of optimum linguistic redundancy, older adults were also found to add more words and to make more meaning-producing reconstructions in recall. Differences in overall performance are accounted for in terms of age-related changes in working memory processing and strategy utilization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual flexibility: Maintenance or recovery of the ability to discriminate non-native speech sounds.

Examined the influence of prior training and linguistic experience on the perception of nonnative speech in 2 experiments. Exp I assessed the effect of laboratory training on the ability of 30 English-speaking adults (aged 18–35 yrs) to discriminate 2 speech contrasts that are used to contrast meaning in Hindi but not in English. Short-term training resulted in an amelioration of the initial poor performance of Ss in discriminating a nonnative voicing contrast, but training had no such effect in the case of a Hindi contrast involving a place of articulation distinction. In Exp II, the performance of 3 groups of English-speaking adults (aged 20–38 yrs)—Ss who had studied Hindi for 5 yrs or more, Ss who were studying Hindi as a 2nd language with early experience of Hindi, and Ss studying Hindi as a 2nd language with no early experience of Hindi—was examined to investigate the effect of studying Hindi as a 2nd language for different periods. Ss who had studied Hindi for at least 5 yrs discriminated both Hindi speech contrasts. While 1 yr of 2nd language experience also improved performance of Ss with no early Hindi experience on the voicing contrast, it had little influence on their ability to discriminate the Hindi place contrast. Ss who had early experience hearing the contrasts being used, but no further exposure, could discriminate both the voicing and place distinctions prior to language study. Findings are discussed in terms of the recovery and maintenance of linguistic perceptual ability. (French abstract) (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Young infants' sensitivity to optical information for collision.

Four experiments explored the properties of the stimulus event that will evoke blinking and backward head movements in 100 3–4 wk old infants. Measured by a sensitive pressure transducer, backward head movements did not occur when Ss viewed displays that specified an object approaching on a collision course, except when some of the object's contours rose in the S's visual field. Thus, such head movements may reflect a tendency of young infants to fixate and pursue contours that move upward. In contrast, displays specifying collision evoked more frequent blinking than displays specifying an object's withdrawal, whether or not rising contours were present. The reliability of the blink response suggests that very young infants are sensitive to some optical information for collision. (French abstract) (9 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of visual, haptic, and manipulatory experiences on infants' visual recognition memory of objects.

To determine the effects of visual, haptic, and manipulatory experiences on visual recognition of objects' shapes, 108 6-, 9-, and 12-mo-old infants were randomly assigned to 1 of 3 stimulus familiarization conditions in which they either only looked at an object (visual), looked at and manipulated an object (visual-haptic), or looked at an object encased in a transparent box that the infant manipulated (visual-manipulatory). Visual recognition memory was assessed by the paired-comparison technique in which memory is indexed by infants' differential preferences for novel and familiar stimuli. The major findings were that (a) 12-mo-olds showed evidence of memory in all conditions, (b) younger Ss showed evidence of memory only in the visual condition, and (c) at all ages Ss' preference for novel relative to familiar stimuli was significantly greater in the visual condition than in the visual-haptic and visual-manipulatory conditions, with the latter conditions not differing significantly. It is argued that the manipulatory activity per se depressed Ss' differential preferences in the visual-haptic and visual-manipulatory conditions. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Changing i.v. administration sets: is 48 versus 24 hours safe for neutropenic patients with cancer?

Epidemiological evidence suggests that heavy consumption of betel quid and tobacco with areca nuts is the cause of high incidence of oral cancer in eastern part of Indian population, which is distinctly different from the etiology of oral squamous cell carcinomas (SCCs) in western countries. Here, expression of p53 and c-myc protein was studied in oral SCCs from this etiologically distinct population by immunohistochemistry. Out of 48 specimens of oral SCCs, 22 (45.8%) exhibited p53 positivity and 27 (56.3%) showed immunoreactivity with c-myc antibody. Considering the p53/c-myc expression pattern, either alone or in combination, the population was divided into four groups, i.e., both p53 and c-myc positive; p53 positive-c-myc negative; c-myc positive - p53 negative; and both p53 and c-myc negative. Tumours with both p53 and c-myc positivity were in advanced stages of the disease (poorly differentiated, tumour stage 3, nuclear grade III), whereas earliest stage of oral SCCs was detected in tumours with neither p53 nor c-myc immunoreactivity. Tumours of remaining two groups were generally restricted to early to moderate stages. These observations suggest that rapid progression of the betel- and tobacco-related oral SCCs may be associated with a simultaneous involvement of these two oncoproteins. The study also attempted to find out the relationship of p53/c-myc expression with spontaneous apoptosis. More apoptotic cells were found in c-myc positive but p53 negative tumours. This preliminary observation requires further molecular investigation of the role of p53 and c-myc genes for the progression of this epidemiologically distinct oral carcinogenesis.     

The influence of linguistic experience on the cognitive processing of pitch in speech and nonspeech sounds.

In the present experiment, the authors tested Mandarin and English listeners on a range of auditory tasks to investigate whether long-term linguistic experience influences the cognitive processing of nonspeech sounds. As expected, Mandarin listeners identified Mandarin tones significantly more accurately than English listeners; however, performance did not differ across the listener groups on a pitch discrimination task requiring fine-grained discrimination of simple nonspeech sounds. The crucial finding was that cross-language differences emerged on a nonspeech pitch contour identification task: The Mandarin listeners more often misidentified flat and falling pitch contours than the English listeners in a manner that could be related to specific features of the sound structure of Mandarin, which suggests that the effect of linguistic experience extends to nonspeech processing under certain stimulus and task conditions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Note on immediate memory for digits: Invariance over the years.

Reviews previous studies of immediate memory for digits in which exposure time per digit was 1 sec. .3 sec., and results could be derived as percentages correct at each numerosity level. The survey indicates that the channel capacity (>90% correct) of unpracticed adolescents and adults of average and above average intelligence is 6, 1. There is some evidence that, at exposure times of 1 sec/stimulus array, the span of apprehension falls within this same range. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Examining infants' preferences for tempo in lullabies and playsongs.

Caregivers around the world sing to their infants. Infants not only prefer to listen to infant-directed singing over adult-directed singing, but infant-directed singing also serves a function, communicating affective information to preverbal infants to aid in adjusting arousal levels. Pitch variation has previously been identified as one performance feature that may help to convey the message. Earlier research has indicated that infants' pitch preferences are context dependent, suggesting that infants are tuned in to the communicative intent of infant-directed singing. However, there are several other performance-based features present in infant-directed singing that may also contribute to the affective message. The current study examined the role of context on infants' tempo preferences in sung playsongs and lullabies. Using a head-turn preference procedure, we measured 24 preverbal infants' natural preferences for foreign language playsongs and lullabies as a function of tempo. Infants showed a preference for fast over slow tempo playsongs, but no such context dependent preference was found within lullabies. Results partially support the role of tempo as a communicative feature of infant directed singing. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Disruption of short-term memory by changing and deviant sounds: Support for a duplex-mechanism account of auditory distraction.

The disruption of short-term memory by to-be-ignored auditory sequences (the changing-state effect) has often been characterized as attentional capture by deviant events (deviation effect). However, the present study demonstrates that changing-state and deviation effects are functionally distinct forms of auditory distraction: The disruption of visual-verbal serial recall by changing-state speech was independent of the effect of a single deviant voice embedded within the speech (Experiment 1); a voice-deviation effect, but not a changing-state effect, was found on a missing-item task (Experiment 2); and a deviant voice repetition within the context of an alternating-voice irrelevant speech sequence disrupted serial recall (Experiment 3). The authors conclude that the changing-state effect is the result of a conflict between 2 seriation processes being applied concurrently to relevant and irrelevant material, whereas the deviation effect reflects a more general attention-capture process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Irrelevant tones produce an irrelevant speech effect: Implications for phonological coding in working memory.

Addresses the possibility that tones disrupt serial recall of visually presented material in the same way as speech. A stream of changing tones is as disruptive of visual serial recall as 4 syllables (Exps 1 and 2). Similar effects were also shown with a repeated syllable that changed only in pitch (Exp 3). Just as for speech, the effect of tones is not at encoding but during storage of the serial lists (Exp 4 and 5). The results suggest that speech and tones are equipotent in their capacity to disrupt short-term memory. A "blackboard" model of working memory to account for the effects is outlined. (PsycINFO Database Record (c) 2010 APA, all rights reserved)