Impaired processing of rapid stimulus sequences in dyslexia

“Additional inclusion criteria were checked after a first testing session: a full-scale IQ above 100, and reading and spelling standard scores below 110 on average.”

“(There is also an attentional variant of this theory [11].”

“Perceptual attentional disorders have also been reported (Buchholz & Davies, 2005; Facoetti & Molteni, 2001; Hari & Renvall, 2001, Pammer, Lavis, Hansen & Cornelissen, 2004; and Facoetti, 2004, for a review).”

“predicted by the ‘‘sluggish attentional shifting’’ hypothesis [16] and is consistent with several findings showing that dyslexic individuals present a delayed time-course in spatiotemporal orienting of multisensory attention for different tasks [15, 28, 29].”

“Since all AVGs share an extraordinary speed in terms of transient events and moving objects, a high degree of perceptual and motor load, and an emphasis on peripheral processing, AVG training might mainly improve the efficiency of the magnocellular-dorsal pathway or ‘‘action’’ stream [6, 9, 12, 17].”

“There is ample evidence that children with LLI have difficulty with temporal order judgements over many timescales, ranging from the perception of brief, successive acoustic stimul”

“…an asymmetric distribution of attentional resources across the visual field, as shown by mild left inattention in cue-target reaction time tasks and abnormally high sensitivity in the right visual field (Facoetti & Molteni, 2001; Facoetti & Turatto, 2000; Hari, Renvall, & Tanskanen, 2001).”

“In recent years, several alternative theories have been formulated to explain this complex phenotypic profile, some of which invoke deficits in basic neuronal mechanisms that have an impact on multiple brain modalitie”

“…to elucidate cognitive limitations in elderly (Lahar et al., 2001) and people suffering from visual neglect (Husain and Rorden, 2003; Husain et al., 1997), schizophrenia (Li et al., 2002), depression (Rokke et al., 2002), ADHD (Hollingsworth et al., 2001), and dyslexia (Hari and Renvall, 2001).”

“These findings are in line with recent proposals suggesting that some interventions designed to improve language skills might also target or train selective attention (Gillam, 1999; Gillam et al., 2001a,b; Hari and Renvall, 2001; Sundberg and Lacerda, 2003).”

“…(Bogliotti et al., 2008), rhythm perception (Goswami et al., 2011; Huss et al., 2011), temporal processing (Van Ingelghem et al., 2001; Cohen-Mimran and Sapir, 2007), and difficulty directing and switching auditory attention (Hari and Renvall, 2001; Facoetti et al., 2010; Lallier et al., 2010).”

“Hari and Renvall (2001) suggested that sluggish attention shifting would prolong sensory input chunks, which would lead to degraded representation of auditory objects.”

“…1995; Eden et al. 1996; Stein & Walsh 1997; Ben-Yehudah et al. 2001; Ben-Yehudah & Ahissar 2004; Sperling et al. 2006) and auditory (Tallal 1980; McAnally & Stein 1996; Ahissar et al. 2000; Hari & Renvall 2001; Amitay et al. 2002; France et al. 2002; Goswami et al. 2002; Mengler et al. 2005) tasks.”

“In particular, graphemic parsing, that is the segmentation of a letter string into its constituent graphemes (Perry et al., 2007), requires an efficient orienting of visual-spatial attention (Cestnik & Coltheart, 1999; Facoetti et al., 2006; for a review see, Hari & Renvall, 2001).”

“…point out that dyslexics’ difficulties are not restricted to phonology and reading but include auditory (Tallal 1980), visual (Lovegrove et al. 1980), tactile (Stoodley et al. 2000), motor (Fawcett et al. 1996), learning (Nicolson & Fawcett 2000), and attention deficits (Hari & Renvall 2001).”

“Visuo-spatial attention is asymmetrically distributed in dyslexic subjects (for a recent review, see Hari & Renvall, 2001).”

“Vidyasagar (2001) and Hari and Renvall (2001) suggested that dyslexics suffer from an attentional de®cit speci®c to a parietal-lobe dysfunction.”

“Several other sensorimotor deficits have been associated with the disorder resulting in the emergence of alternative theories describing phonological deficits as secondary consequences of basal auditory [7], visual [8], attentional [9] and/or motor problems [10].”

“The view of impaired serial attention was also promoted by Hari and colleagues, who suggested that dyslexics’ attention is “sluggish”—namely, that it works somewhat more slowly and is perhaps less spatially refined (Hari & Renvall, 2001).”

“In addition, subjects with dyslexia may have subtle signs of a dysfunctional visuo-spatial attentional system (Facoetti et al., 2000) that may be more severe for the left hemispace in a sort of mini-neglect (Hari and Renvall, 2001; Liddle et al., 2009).”

“This aspect allows integration of other approaches of developmental language disorders that focus on attention, such as the sluggish attentionshifting hypothesis (Facoetti et al., 2010; Hari & Renvall, 2001).”

“…has recently been directed towards the contribution of basic mechanisms such as attention, perception, and memory to this process (e.g. Farmer and Klein, 1995; Habib, 2000; Hari & Renvall, 2001; Hoffman & Gillam, 2004; Webster & Shevell, 2004; see Fitch & Tallal, 2003; Tallal, 2004 for a review).”

“Accurate timing up to tens or hundreds of milliseconds is important for the brain functions underlying perception, movements and learning (Hari & Renvall, 2001).”

“…1970), temporal processing (Zurif & Carson 1970), selective attention (Pelham&Ross 1977), rule learning (Manis et al. 1987), attention shifting (Hari & Renvall 2001), or—in what is arguably the prevailing theory at present—phonological processing (e.g., Carroll & Snowling 2004, Wagner 1986).”

“…psychophysical and behavioral results (i.e., temporal order judgment between visual hemifields, perception of a line motion illusion and spatial cueing tasks) suggest that dyslexic adults and children suffer from a left-side ‘‘minineglect’’ (e.g., Hari et al., 2001; Facoetti et al., 2001).”

“This faulty processing may be due to poor phaselocking [10], abnormal thalamic and cortical cytoarchitectonics [38,40,42–44], and/or sluggish attentional resources [45].”

“Dyslexics showed difficulty shifting their attention between modalities; but such ‘‘sluggish attention shifting’’ (SAS) [10] appeared only when dyslexics shifted their attention from the visual to the auditory modality.”

“However, recently visual and visual-attentional deficits of dyslexic children were put forward as alternative explanation (Hari & Renvall, 2001; Stein & Walsh, 1997).”

“Similarly, Hari and Renvall (2001) proposed that dyslexic readers exhibit ‘Sluggish Attentional Shifting’ (SAS) that impairs their ability to disengage from processing one item in order to engage with another item.”

“The “sluggish attentional shifting” hypothesis is also supported (Hari & Renvall, 2001) by Facoetti and colleagues (2003), who showed that dyslexic children had auditory and visual selective-attention deficits in the automatic orienting and focusing of spatial attention (Facoetti, Paganoni,…”

“, the SAS hypothesis and the anchoring deficit theory (10, 17).”

“Altering spatial formatting can only partially alleviate factors affecting the temporal dynamics in reading, such as slowness caused by sluggish attention shifting [17], difficulties accessing phonological representations of words [37], latencies in naming [45], or difficulties with character recognition [64,65], each…”

“Based on previous studies, we expected all children in the clinical groups (ADHD, SLD, and ADHD + SLD) to show EF impairments (Hari and Renvall, 2001; Sergeant et al., 2002; Martel et al., 2007; Bull et al., 2008; Barkley, 2011) compared to TD children.”

“As described above the ‘‘temporal processing hypothesis’’, suggests that children with DD have specific deficits in processing rapidly presented or brief sensory stimuli in either the visual or auditory modalities (see Farmer & Klein, 1995; Hari & Renvall, 2001 for reviews).”

“Hari and Renvall (2001) proposed that the causal link between reading deficits and phonological problems involves the capture of auditory and visual automatic attention .”

“Hari and Renvall (2001) proposed that the visual impairment found among poor readers is explained by difficulties with attentional shifting, that is, inefficiency in disengaging attention from one stimulus, to attend to a second stimulus.”

“Altering spatial formatting can only partially alleviate factors affecting the temporal dynamics in reading such as slowness caused by sluggish attention shifting [60], difficulties accessing phonological representations of words [70], or latencies in naming [32], each of which can act, independently of the effects ad…”

“One frequently presented hypothesis is weakness of the magnocellular pathways that normally transmits impulses to the cortex about 10 ms earlier than the other fibres [21], or the sensory slowing could be secondary to sluggish attention shifting [22].”

“This interpretation could be congruent with relevant hypothesis of DD such as: (i) the multisensory “sluggish attentional shifting” in DD [71]; (ii) the “perceptual noise exclusion” deficit in DD [72,73] and a general “neural noise” enhancement in DD [74].”

“In line with the fast temporal deficit hypothesis, dyslexic readers were consistently described as exhibiting a temporal processing disorder for short interstimulus intervals (for a review: Hari & Renvall, 2001).”

“Finally, some authors have suggested that this lack of automatization (fluency) can make it difficult to establish solid representations of words, on both phonological and orthographic levels ( Hari & Renvall, 2001; Howard et al., 2006; Sperling et al., 2004).”

“This prolongation might then distort proper development on cortical representations that are essential for reading acquisition (Hari and Renvall, 2001; Lallier et al., 2009).”

“…in visual attention (VA) and visual processing have been identified in dyslexic individuals as supporting different visual-attentional models of developmental dyslexia (Hari and Renvall, 2001; Facoetti et al., 2006, 2008; Boden and Giaschi, 2007; Bosse et al., 2007; Vidyasagar and Pammer, 2010).”

“…visual attention skills would be mainly necessary for pseudoword reading and the use of phonological decoding strategies (Facoetti et al., 2006; Hari & Renvall, 2001; OnochieQuintilla et al., 2017; Perry, Ziegler, and Zorzi, 2010), since they would subtend the sequential orthographic parsing…”

“A series of studies demonstrated visual spatial attention orienting disorders and sluggish attentional shifting in developmental dyslexia (Facoetti and Molteni, 2001; Hari and Renvall, 2001).”

“Attention and EF should be allocated to the process of letter selection from irrelevant letters (Bouma, 1970; Bouma and Legein, 1977) by rapid orienting of visual attention (Yeshurun and Rashal, 2010) before the correct letter-to-speech sound integration applies (Facoetti et al., 2000; Hari and Renvall, 2001; Vidyasag…”

“…towards the contribution of basic mechanisms such as attention, perception, and memory to this process (e.g. Farmer & Klein, 1995;Habib, 2003;Hari & Renvall, 2001;Hoffman & Gillam, 2004;Gillam & Hoffman, 2004;Webster & Shevell, 2004; see Fitch & Tallal, 2003, and Tallal, 2004, for a review).”

“Moreover, sluggish attentional capture and focusing could be the cause of a multi-modal temporal processing deficit in dyslexia ( Hari & Renvall, 2001 ).”

“…more in recent years, have focused on domain-general factors related to the classical taxonomy of cognitive faculties such as attention (Hari & Renvall, 2001), memory (Perez, Majerus, Mahot, & Poncelet, 2012; Smith-Spark & Fisk, 2007), and—perhaps of greatest interest for the current…”

“Research has shown that children who had difficulty directing attention did not extract meaning efficiently from a passage (e.g., Hari & Renvall, 2001; Hari, Valta, & Uutela, 1999).”

“These findings led Hari and Renvall (2001) to propose that the temporal deficit in developmental dyslexia may be held up by a more crucial dysfunction, which they assumed to be sluggish attentional shifting (SAS).”

“…with dyslexia did not have greater difficulty in playing the videogame due to attentional impairments (which have been associated with dyslexia; Facoetti et al., 2010; Franceschini, Gori, Ruffino, Pedrolli, & Facoetti, 2012; Hari & Renvall, 2001), coordination of actions, or other factors.”

“For example, Hari and Renvall (2001) suggested that dyslexics’”

“…(e.g., Eden, VanMeter, Rumsey, Maisog et al. 1996; Eden, VanMeter, Rumsey, Zeffiro 1996; Grinter et al. 2010; Lipowska et al. 2011), auditory (e.g., Hari and Renvall 2001; Gaab, Gabrieli, Deutsch et al. 2007; Hornickel et al. 2009, 2012; Wright and Conlon 2009; Goswami, Wang et al. 2011; Stefanics…”

“For example, Hari and Renvall (2001) have proposed sluggish attentional shifting as a model to explain impaired processing of rapid sequences.”