Nir Shalev
@haifa.ac.il
Department of Gerontology, Faculty of Social Welfare and Health Sciences
University of Haifa
RESEARCH, TEACHING, or OTHER INTERESTS
Experimental and Cognitive Psychology, Aging, Neuropsychology and Physiological Psychology, Cognitive Neuroscience
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Leah Snapiri, Yael Kaplan, Nir Shalev, and Ayelet N. Landau
Wiley
AbstractThe impact of external rhythmic structure on perception has been demonstrated across different modalities and experimental paradigms. However, recent findings emphasize substantial individual differences in rhythm‐based perceptual modulation. Here, we examine the link between spontaneous rhythmic preferences, as measured through the motor system, and individual differences in rhythmic modulation of visual discrimination. As a first step, we measure individual rhythmic preferences using the spontaneous tapping task. Then we assess perceptual rhythmic modulation using a visual discrimination task in which targets can appear either in‐phase or out‐of‐phase with a preceding rhythmic stream of visual stimuli. The tempo of the preceding stream was manipulated over different experimental blocks (0.77 Hz, 1.4 Hz, 2 Hz). We find that visual rhythmic stimulation modulates discrimination performance. The modulation is dependent on the tempo of stimulation, with maximal perceptual benefits for the slowest tempo of stimulation (0.77 Hz). Most importantly, the strength of modulation is also linked to individuals' spontaneous motor tempo. Individuals with slower spontaneous tempi show greater rhythmic modulation compared to individuals with faster spontaneous tempi. This finding suggests that different tempi affect the cognitive system with varying levels of efficiency and that self‐generated rhythms impact our ability to utilize rhythmic structure in the environment for guiding perception and performance.
Nir Shalev, Sage Boettcher, Hannah Wilkinson, Gaia Scerif, and Anna C. Nobre
Wiley
AbstractChildren's ability to benefit from spatiotemporal regularities to detect goal‐relevant targets was tested in a dynamic, extended context. Young adults and children (from a low‐deprivation area school in the United Kingdom; N = 80; 5–6 years; 39 female; ethics approval did not permit individual‐level race/ethnicity surveying) completed a dynamic visual‐search task. Targets and distractors faded in and out of a display over seconds. Half of the targets appeared at predictable times and locations. Search performance in children was poorer overall. Nevertheless, they benefitted equivalently from spatiotemporal regularities, detecting more predictable than unpredictable targets. Children's benefits from predictions correlated positively with their attention. The study brings ecological validity to the study of attentional guidance in children, revealing striking behavioral benefits of dynamic experience‐based predictions.
Nir Shalev and Anna C. Nobre
Elsevier BV
Nir Shalev
Springer Science and Business Media LLC
Méadhbh B. Brosnan, Nir Shalev, Jivesh Ramduny, Stamatios N. Sotiropoulos, and Magdalena Chechlacz
Oxford University Press (OUP)
AbstractExposure to enriched environments throughout a lifetime, providing so-called reserve, protects against cognitive decline in later years. It has been hypothesized that high levels of alertness necessitated by enriched environments might strengthen the right fronto-parietal networks to facilitate this neurocognitive resilience. We have previously shown that enriched environments offset age-related deficits in selective attention by preserving grey matter within right fronto-parietal regions. Here, using neurite orientation dispersion and density imaging, we examined the relationship between enriched environments, microstructural properties of fronto-parietal white matter association pathways (three branches of the superior longitudinal fasciculus), structural brain health (atrophy), and attention (alertness, orienting and executive control) in a group of older adults. We show that exposure to enriched environments is associated with a lower orientation dispersion index within the right superior longitudinal fasciculus 1 which in turn mediates the relationship between enriched environments and alertness, as well as grey and white matter atrophy. This suggests that enriched environments may induce white matter plasticity (and prevent age-related dispersion of axons) within the right fronto-parietal networks to facilitate the preservation of neurocognitive health in later years.
Sage E. P. Boettcher, Nir Shalev, Jeremy M. Wolfe, and Anna C. Nobre
American Psychological Association (APA)
Visual search is a fundamental element of human behavior and is predominantly studied in a laboratory setting using static displays. However, real-life search is often an extended process taking place in dynamic environments. We have designed a dynamic-search task in order to incorporate the temporal dimension into visual search. Using this task, we tested how participants learn and utilize spatiotemporal regularities embedded within the environment to guide performance. Participants searched for eight instances of a target that faded in and out of a display containing similarly transient distractors. In each trial, four of the eight targets appeared in a temporally predictable fashion with one target appearing in each of four spatially separated quadrants. The other four targets were spatially and temporally unpredictable. Participants’ performance was significantly better for spatiotemporally predictable compared to unpredictable targets (Experiments 1–4). The effects were reliable over different patterns of spatiotemporal predictability (Experiment 2) and primarily reflected long-term learning over trials (Experiments 3, 4), although single-trial priming effects also contributed (Experiment 4). Eye-movement recordings (Experiment 1) revealed that spatiotemporal regularities guide attention proactively and dynamically. Taken together, our results show that regularities across both space and time can guide visual search and this guidance can primarily be attributed to robust long-term representations of these regularities.
Nir Shalev and Freek van Ede
Elsevier BV
Margaret Jane Moore, Nir Shalev, Celine R. Gillebert, and Nele Demeyere
Informa UK Limited
ABSTRACT Consistently lateralized reading errors are commonly understood as side-effects of visuospatial neglect impairment. There is however a qualitative difference between systematically omitting full words presented on one side of passages (egocentric neglect dyslexia) and lateralized errors when reading single words (allocentric neglect dyslexia). This study aims to investigate the relationship between egocentric and allocentric neglect dyslexia and visuospatial neglect. 1209 stroke survivors completed standardized reading and cancellation tests. Stringent criteria identified unambiguous cases of allocentric neglect dyslexia (N = 17) and egocentric neglect dyslexia (N = 35). These conditions were found to be doubly dissociated with all cases of egocentric and allocentric neglect dyslexia occurring independently. Allocentric neglect dyslexia was dissociated from both egocentric and allocentric visuospatial neglect. Additionally, two cases of allocentric neglect dyslexia which co-occurred with oppositely lateralized domain-general visuospatial neglect were identified. Conversely, all cases of egocentric neglect dyslexia were found in the presence of domain-general visuospatial neglect. These findings suggest that allocentric neglect dyslexia cannot be fully understood as a consequence of visuospatial neglect. In contrast, we found no evidence for a dissociation between egocentric neglect dyslexia and visuospatial neglect. These findings highlight the need for new, neglect dyslexia specific rehabilitation strategies to be designed and tested.
Nir Shalev, Anna-Katharina R Bauer, and Anna C Nobre
Elsevier BV
Nir Shalev, Ann Steele, Anna C. Nobre, Annette Karmiloff-Smith, Kim Cornish, and Gaia Scerif
Elsevier BV
Margaret Jane Moore, Kathleen Vancleef, Nir Shalev, Masud Husain, and Nele Demeyere
BMJ
Unilateral visual neglect is characterised by lateralised spatial–attentional deficits, resulting in dramatic behavioural impairments.1 Neglect negatively impacts functional outcome and needs to be successfully detected in order to inform neglect-specific as well as general post-stroke rehabilitation goals and strategies. It is therefore critically important to evaluate current clinical methods for detecting and measuring the extent of this syndrome.
Observational neurological assessments, such as the National Institutes of Health Stroke Scale (NIHSS), rely predominantly on subjective impression of impairment levels rather than objective measurements.2 Although the NIHSS was not designed as an individual diagnostic tool, it is frequently employed as one. However, previous research has suggested that observational assessments may not be sufficiently sensitive to visual neglect.2–4 The purpose of this study was to evaluate the diagnostic sensitivity of the NIHSS’ visual neglect item compared with a brief neuropsychological cancellation test and to identify factors which modulate this sensitivity.
428 patients who had an acute stroke (mean age, 71 (SD 12.8); mean time post-stroke, 7.3 days (SD 7.4)) completed the NIHSS and Oxford Cognitive Screen (OCS) Cancellation Task (mean interval, 1.2 days). 63.1% of patients completed both tests on the same day and the NIHSS was administered first in 33.9% of cases. The NIHSS Extinction/Inattention and Visual Field items were considered in this investigation, with Extinction/Inattention scores of 0 (none), 1 (mild) or 2 (profound) and Visual Field scores of 0 (normal), 1 (partial) or 2 (complete).
The OCS is a brief stroke-specific cognitive screen which includes a highly sensitive Cancellation Task.5 This test was therefore used as the comparison standard for NIHSS …
Nir Shalev, Signe Vangkilde, Matt J. Neville, Elizabeth M. Tunbridge, Anna C. Nobre, and Magdalena Chechlacz
Elsevier BV
Nir Shalev, Anna C. Nobre, and Freek van Ede
Elsevier BV
Peter Brown, Aik-Choon Tan, Mohamed A El-Esawi, Thomas Liehr, Oliver Blanck, Douglas P Gladue, Gabriel M F Almeida, Tomislav Cernava, Carlos O Sorzano, Andy W K Yeung,et al.
Oxford University Press (OUP)
Abstract Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency–Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.
Nir Shalev, Linde De Wandel, Paul Dockree, Nele Demeyere, and Magdalena Chechlacz
Elsevier BV
Nir Shalev, Glyn Humphreys, and Nele Demeyere
Springer Science and Business Media LLC
Nir Shalev, Glyn Humphreys, and Nele Demeyere
Elsevier BV
Lilach Shalev, Tamar Kolodny, Nir Shalev, and Carmel Mevorach
SAGE Publications
Attention-deficit/hyperactivity disorder (ADHD) is characterized by high levels of inattention, hyperactivity, and impulsivity; however, these symptoms can result from a variety of reasons. To obtain a comprehensive understanding of the various difficulties of individuals with ADHD, especially when co-occurrence difficulties are present, it is essential to combine neuropsychological and subjective assessment tools. In the present field study the authors investigated a group of adolescents with multiple deficits (MD) using neuropsychological and subjective measures. Teachers’ ratings verified extremely high levels of symptoms of oppositional behavior, inattention, hyperactivity-impulsivity, social problems, and emotional problems in this group. As expected, MD group participants showed decreased abilities to maintain attention on task for a long period of time, focus attention and effectively inhibit adjacent distractors, and resist conflicting irrelevant information. Importantly, although significant differences in the attention measures were observed at the group level, not all MD participants displayed deviant performance. Thus, we conclude that the heterogeneous group of adolescents with MD comprises individuals with primary attention deficits as well as those with other nonattentional deficits that show equivalent behavioral symptoms. Using neuropsychological tools can be useful in differentiating between different core deficits and in guiding appropriate interventions.
Limor Lukov, Naama Friedmann, Lilach Shalev, Lilach Khentov-Kraus, Nir Shalev, Rakefet Lorber, and Revital Guggenheim
Frontiers Media SA
We examine whether attention deficits underlie developmental dyslexia, or certain types of dyslexia, by presenting double dissociations between the two. We took into account the existence of distinct types of dyslexia and of attention deficits, and focused on dyslexias that may be thought to have an attentional basis: letter position dyslexia (LPD), in which letters migrate within words, attentional dyslexia (AD), in which letters migrate between words, neglect dyslexia, in which letters on one side of the word are omitted or substituted, and surface dyslexia, in which words are read via the sublexical route. We tested 110 children and adults with developmental dyslexia and/or attention deficits, using extensive batteries of reading and attention. For each participant, the existence of dyslexia and the dyslexia type were tested using reading tests that included stimuli sensitive to the various dyslexia types. Attention deficit and its type was established through attention tasks assessing sustained, selective, orienting, and executive attention functioning. Using this procedure, we identified 55 participants who showed a double dissociation between reading and attention: 28 had dyslexia with normal attention and 27 had attention deficits with normal reading. Importantly, each dyslexia with suspected attentional basis dissociated from attention: we found 21 individuals with LPD, 13 AD, 2 neglect dyslexia, and 12 surface dyslexia without attention deficits. Other dyslexia types (vowel dyslexia, phonological dyslexia, visual dyslexia) also dissociated from attention deficits. Examination of 55 additional individuals with both a specific dyslexia and a certain attention deficit found no attention function that was consistently linked with any dyslexia type. Specifically, LPD and AD dissociated from selective attention, neglect dyslexia dissociated from orienting, and surface dyslexia dissociated from sustained and executive attention. These results indicate that visuospatial attention deficits do not underlie these dyslexias.
Dominique Lamy, Limor Alon, Tomer Carmel, and Nir Shalev
SAGE Publications
A mental process that is independent of conscious perception should run equally well with or without it. Previous investigations of unconscious processing have seldom included this comparison: They typically demonstrated only processing without conscious perception. In the research reported here, we showed that attentional capture is largely independent of conscious perception and that updating the episodic information stored about an object is entirely contingent on conscious perception. We used a spatial-cuing paradigm, in which the cue was a color-singleton distractor rendered liminal by continuous flash suppression or brief exposure. When the cue matched the participant’s attentional set, it strongly captured attention whether it was subliminal or consciously perceived. In contrast, a nonmatching cue did not capture attention but instead produced a same-location cost, which was contingent on consciously perceiving the cue. Our findings demonstrate a dissociation between attention and conscious perception and unveil an important boundary condition of object-file updating.