Blog Archives

Distraction task rather than focal attention modulates gamma activity associated with auditory steady-state responses (ASSRs)

The phase-locked measures of 40Hz ASSR are attenuated when attention to the stimulation is low, i.e. the subject is effortfully focused on the competitive “distraction” task performance. Lower arousal level increases the total intensity of 40Hz ASSRs.

from Clinical Neurophysiology

Distraction task rather than focal attention modulates gamma activity associated with auditory steady-state responses (ASSRs)

The phase-locked measures of 40Hz ASSR are attenuated when attention to the stimulation is low, i.e. the subject is effortfully focused on the competitive “distraction” task performance. Lower arousal level increases the total intensity of 40Hz ASSRs.

from Clinical Neurophysiology

Spoken word processing creates a lexical bottleneck

We report 3 experiments that examined whether presentation of a spoken word creates an attentional bottleneck associated with lexical processing in the absence of a response to that word. A spoken word and a visual stimulus were presented in quick succession, but only the visual stimulus demanded a response. Response times to the visual stimulus increased as the lag between it and the spoken word decreased, suggesting a bottleneck in processing. This effect was modulated by the uniqueness point of the spoken word; bottleneck effects were strongest when the spoken word had a late uniqueness point (Experiment 1). The effect was also modulated by the nature of the second task, with the effect stronger when the visual stimulus was a word rather than a shape (Experiment 2) or face (Experiment 3). Word processing appears to create a transient lexical bottleneck that is driven by the magnitude of lexical activity.

from Language and Cognitive Processes

Compromised verbal episodic memory with intact visual and procedural memory during pregnancy

This study investigated episodic and procedural memory performance in early and late pregnancy. Twenty-six women in the third trimester of pregnancy, 20 women in the first trimester of pregnancy, and 24 nonpregnant controls were administered a battery of verbal and visual episodic memory tasks and two procedural memory tasks. Results indicated that compared to controls, both pregnant groups had reduced scores on immediate and delayed verbal episodic memory tasks, but were unimpaired on visual and procedural memory tasks. Verbal memory differences could not be accounted for by mood state or attention; however, progesterone level accounted for a small amount of the variation. Although memory differences were minor, the perception of memory problems may have implications for everyday living for pregnant women.

from the Journal of Clinical and Experimental Neuropsychology

Semantic interference in immediate and delayed naming and reading: Attention and task decisions

Disagreement exists about whether lexical selection in word production is a competitive process. Competition predicts semantic interference from distractor words in immediate but not in delayed picture naming. In contrast, Janssen, Schirm, Mahon, and Caramazza (2008) obtained semantic interference in delayed picture naming when participants had to decide between picture naming and oral reading depending on the distractor word’s colour. We report three experiments that examined the role of such task decisions. In a single-task situation requiring picture naming only (Experiment 1), we obtained semantic interference in immediate but not in delayed naming. In a task-decision situation (Experiments 2 and 3), no semantic effects were obtained in immediate and delayed picture naming and word reading using either the materials of Experiment 1 or the materials of Janssen et al. (2008). We present an attentional account in which task decisions may hide or reveal semantic interference from lexical competition depending on the amount of parallelism between task-decision and picture–word processing.<p><p>from the <a href=”Journal” _mce_href=””>null”>”><em>Journal of Memory and Language</em></a></p>

Attention and the identification of parafoveal words in school-age children and adults

The goal of this study was to examine whether reading parafoveal words is more attention-demanding in 7- to 10-year-old children (2nd to 5th grade) than in adults, and whether this increase in attention interacts with visual field. In an identification task, we presented 4-letter words in the left (LVF) or right (RVF) visual fields in single unilateral (one word in one visual field), unilateral with distractor (one word + one distractor in the opposite visual field) and bilateral (two words) conditions. We also presented object drawings. The results showed that all groups of children were more sensitive to the presence of a second stimulus (distractor or word) than adults in the block of words, but not in the block of object drawings. We interpreted this result as indicating an age-related change in the attentional demands of word identification and in attentional control when reading, thus in the interaction between the attentional control system and the language network. As well, we found the same RVF superiority for words and the same attentional bias (larger distractor effect on LVF words) in children and adults, which is not in favor of the hypothesis of an age-related change in language lateralization.

from the Journal of Neurolinguistics

Working memory influences processing speed and reading fluency in ADHD

Processing-speed deficits affect reading efficiency, even among individuals who recognize and decode words accurately. Children with ADHD who decode words accurately can still have inefficient reading fluency, leading to a bottleneck in other cognitive processes. This “slowing” in ADHD is associated with deficits in fundamental components of executive function underlying processing speed, including response selection. The purpose of the present study was to deconstruct processing speed in order to determine which components of executive control best explain the “processing” speed deficits related to reading fluency in ADHD. Participants (41 ADHD, 21 controls), ages 9-14 years, screened for language disorders, word reading deficits, and psychiatric disorders, were administered measures of copying speed, processing speed, reading fluency, working memory, reaction time, inhibition, and auditory attention span. Compared to controls, children with ADHD showed reduced oral and silent reading fluency and reduced processing speed—driven primarily by deficits on WISC-IV Coding. In contrast, groups did not differ on copying speed. After controlling for copying speed, sex, severity of ADHD-related symptomatology, and GAI, slowed “processing” speed (i.e., Coding) was significantly associated with verbal span and measures of working memory but not with measures of response control/inhibition, lexical retrieval speed, reaction time, or intrasubject variability. Further, “processing” speed (i.e., Coding, residualized for copying speed) and working memory were significant predictors of oral reading fluency. Abnormalities in working memory and response selection (which are frontally mediated and enter into the output side of processing speed) may play an important role in deficits in reading fluency in ADHD, potentially more than posteriorally mediated problems with orienting of attention or perceiving the stimulus.

from Child Neuropsychology

Attention Deficits After Incident Stroke in the Acute Period: Frequency Across Types of Attention and Relationships to Patient Characteristics and Functional Outcomes

Conclusion: Attention deficits are common post stroke, though frequency varies widely across the forms of attention assessed, with tests of neglect and speeded attention tasks being linked to quality of life. This variability of performance and linking to wider outcomes suggests the need for comprehensive assessment of attention and that attention is a viable target for rehabilitative efforts.

from Topics in Stroke Rehabilitation

Improving digit span assessment of short-term verbal memory

We measured digit span (DS) in two experiments that used computerized presentation of randomized auditory digits with performance-adapted list length adjustment. A new mean span (MS) metric of DS was developed that showed reduced variance, improved test-retest reliability, and higher correlations with the results of other neuropsychological test results when compared to traditional DS measures. The MS metric also enhanced the sensitivity of forward versus backward span comparisons, enabled the development of normative performance criteria with subdigit precision, and elucidated changes in DS performance with age and education level. Computerized stimulus delivery and improved scoring metrics significantly enhance the precision of DS assessments of short-term verbal memory.

from the Journal of Clinical and Experimental Neuropsychology

Functional MRI evidence for the importance of visual short-term memory in logographic reading

Logographic symbols are visually complex, and thus children’s abilities for visual short-term memory (VSTM) predict their reading competence in logographic systems. In the present study, we investigated the importance of VSTM in logographic reading in adults, both behaviorally and by means of fMRI. Outside the scanner, VSTM predicted logographic Kanji reading in native Japanese adults (n = 45), a finding consistent with previous observations in Japanese children. In the scanner, participants (n = 15) were asked to perform a visual one-back task. For this fMRI experiment, we took advantage of the unique linguistic characteristic of the Japanese writing system, whereby syllabic Kana and logographic Kanji can share the same sound and meaning, but differ only in the complexity of their visual features. Kanji elicited greater activation than Kana in the cerebellum and two regions associated with VSTM, the lateral occipital complex and the superior intraparietal sulcus, bilaterally. The same regions elicited the highest activation during the control condition (an unfamiliar, unpronounceable script to the participants), presumably due to the increased VSTM demands for processing the control script. In addition, individual differences in VSTM performance (outside the scanner) significantly predicted blood oxygen level-dependent signal changes in the identified VSTM regions, during the Kanji and control conditions, but not during the Kana condition. VSTM appears to play an important role in reading logographic words, even in skilled adults, as evidenced at the behavioral and neural level, most likely due to the increased VSTM/visual attention demands necessary for processing complex visual features inherent in logographic symbols.

from the European Journal of Neuroscience

Right parietal hypoactivation in a cocaine-dependent group during a verbal working memory task

It has been suggested that cocaine addiction affects the engagement of the frontoparietal networks in executive functions, such as attention and working memory. Thus, our objective was to investigate brain differences between cocaine-dependent subjects and healthy controls during the performance of a verbal working memory task. Nineteen comparison men and nineteen cocaine-dependent men performed a 2-back task. Data was acquired on a 1.5 T Siemens Avanto. Image processing and statistical analyses were carried out using SPM5; Biological Parametric Mapping (BPM) was used for further morphometric and correlation analyses. No performance differences were found between groups. However, the dorsal part of the right inferior parietal cortex (BA 40) was less activated in the cocaine-dependent group. Cocaine patients did not overactive any brain area when compared with controls. Our results show reduced activation in the brain areas related to the attention system in cocaine-dependent men while performing a verbal working memory task. Chronic cocaine use may affect the attentional system in the right parietal lobe, making patients more prone to attentional deficits.

from Brain Research

Mild hearing loss: performance in the Sustained Auditory Attention Ability Test*

BACKGROUND: hearing loss during childhood is considered a risk factor for developmental delay.
AIM: to verify the performance of children diagnosed with mild hearing loss, conductive and sensorineural, in the Sustained Auditory Attention Ability Test (SAAAT). The purpose of the study was to verify if the test is influenced by the presence of hearing impairment.
METHOD: a clinical study of the SAAAT considering three groups: Group 1 (G1) control group composed by children with normal hearing, Group 2 (G2) composed by children with mild bilateral sensorineural hearing loss and Group 3 (G3), composed by children with mild bilateral conductive hearing loss. Participants were children with ages between 7 and 11 years; 30 children in each group. A prospective study. Interventions: Pure Tone Audiometry, Acoustic Imittance Measures and SAAAT. Result: children with sensorineural and conductive hearing loss presented a lower performance in all of the SAAT results when compared to the control group.
CONCLUSION: the SAAAT was influenced by the presence of mild hearing impairment, considering that the greatest influence was observed in the presence of sensorineural hearing loss.

Developmental Trajectories From Birth to School Age in Healthy Term-Born Children

In healthy children the stability of motor development from birth until school age is low. Maternal socioeconomic status and verbal intelligence rather than the infants’ scores on early motor tests signified added value for complex cognitive functions at school age

from Pediatrics

The Association Between Developmental Coordination Disorder and Other Developmental Traits

Children with probable DCD had an increased risk of difficulties in attention, social skills, reading, and spelling. These additional difficulties need to be screened for during assessment and considered when formulating interventions.

from Pediatrics

Basic processes in reading: On the relation between spatial attention and familiarity

Two experiments combined a spatial cueing manipulation (valid vs. invalid spatial cues) with a stimulus repetition manipulation (repeated vs. nonrepeated) in order to assess the hypothesis that familiar items need less spatial attention than less familiar ones. The magnitude of the effect of cueing on reading aloud time for items that were repeated throughout the experiment was smaller than the magnitude of the cueing effect for items that were not repeated within the experiment. These results are consistent with the idea that familiarity within an experiment modulates the spatial attentional demands of word processing. Implications for understanding spatial attention’s role in reading are discussed.

from Language and Cognitive Processes