Memory Functioning in Children with Reading Disabilities and/or Attention Deficit/Hyperactivity Disorder: A Clinical Investigation of their Working Memory and Long-Term Memory Functioning

“Some prior research also has found reduced visual-spatial STM in ADHD (Martinussen et al., 2005; McInnes et al., 2003).”

“Reading disability is also linked with reduced short-term verbal memory that requires phonetic coding of material, but not necessarily with executive functions or long-term memory [67,68].”

“These complex demands could explain the deficits in tasks such as spoonerism usually found in dyslexic children (Jeffries and Everatt, 2004; Berninger et al., 2008; Kibby and Cohen, 2008; Menghini et al., 2011).”

“Links between working memory and reading are well documented (Kibby et al. 2004; Swanson & Jerman 2007; Kibby & Cohen 2008).”

“Although a first paper provided some support for the phenocopy hypothesis (Pennington et al., 1993), a number of subsequent studies based on much larger samples have yielded insufficient support for this model (Kibby & Cohen, 2008; Martinussen & Tannock, 2006; Willcutt et al., 2010).”

“For ADHD patients, no impairment of long-term memory is reported (Kaplan et al. 1998; Kibby and Cohen 2008 ).”

“Neurocognitive functioning of the comorbid group As reported by previous studies (Kibby & Cohen, 2008; Shanahan et al., 2006; Willcutt, Pennington, et al., 2005), the comorbid group exhibited significant weakness on almost all neurocognitive measures compared with TDC, but did not perform…”

“Another important contributor to reading performance beyond phonological processing is WM (Vellutino et al., 2004; Kibby and Cohen, 2008; Sesma et al., 2009; Christopher et al., 2012).”

“…been no meta-analysis, individual studies have also found episodic verbal memory deficits in children and adolescents with ADHD (Cutting, Koth, Mahone, & Denckla, 2003; Udal, Øygarden, Egeland, Malt, & Groholt, 2012)(but see Kibby & Cohen, 2008; Vakil, Blachstein, Wertman-Elad, & Greenstein, 2012).”

“…function associated with typical reading ability, we investigated oral language (Chiappe, Chiappe, & Gottardo, 2004; Lindsey, Manis, & Bailey, 2003), verbal reasoning (Berninger, Abbott, Vermeulen, & Fulton, 2006), and verbal memory skills (Kibby & Cohen, 2008; Steinbrink & Klatte, 2008).”

“…(see e.g. Gooch, Snowling, & Hulme, 2011; Helland & Asbjørnsen, 2000; Reiter, Tucha, & Lange, 2005), long term memory (LTM) (see e.g. Baddeley, 2000; Kibby & Cohen, 2008) and language comprehension (see e.g. Helland, 2007; Helland & Kaasa, 2005; Snowling, Bishop, & Stothard, 2000; Xiao & Ho,…”

“Although some studies found that children with ADHD perform poorly on delayed recall tasks (for visual material, Aloisi, McKone, Heubeck, 2004; Barnett, Maruff, & Vance, 2005), others provide evidence for intact delayed recall (Kaplan, Dewey, Crawford, & Fisher, 1998; Kibby & Cohen, 2008).”

“Between studies selected for this review, some research observed no significant differences between ADHD and TD groups (Shapiro et al., 1993; Guyer et al., 2007; Kibby and Cohen, 2008; Greenbaum et al., 2009; Ahmadi et al., 2011; Schwenck et al., 2013; Noordermeer et al., 2015; Berggren et al., 2016; Lee et al., 2016).”

“Impaired working memory is a benchmark in dyslexia, whereas there is little evidence of impaired long-term memory in dyslexia (Kibby & Cohen, 2008).”

“…storage of material that has been read is dependent on working memory, and working memory impairments have been related to specific characteristics of children with DD (Beneventi, Tønnessen, Ersland, & Hugdahl, 2010; Fiorello, Hale, & Snyder, 2006; Kibby & Cohen, 2008; Swanson, 1999, 2011).”

“…together, these findings suggest VSTM for familiar words is intact in children with RD, consistent with prior literature in this area (Kibby, 2008; Kibby & Cohen, 2008; Lee & Obrzut, 1994; McDougall & Donohoe, 2002), likely due to an adequate ability to code/ store/retrieve items by their meaning.”

“In particular the meta-analysis by Martinussen, Hayden, Hogg-Johnson, and Tannock (2005), evaluating evidence on verbal and visuospatial working memory in relation to ADHD, suggests that impairments may be stronger for visuospatial working memory (see also Kibby & Cohen, 2008).”

“This carries over to visual STM, as visual STM may be intact when spatial demands are low but impaired when spatial demands are high (McInnes et al., 2003; Karatekin, 2004; Martinussen et al., 2005; Kibby and Cohen, 2008; Kibby, 2012).”

“Although there have been several studies examining memory functioning using the CMS (Hawley et al, 2004 ) in other clinical populations such as reading disability (Kibby & Cohen, 2008 ) and specific language impairment (Riccio, Cash, & Cohen, 2007 ), very few studies have examined the pattern of memory deficits noted…”

“In contrast, phonological STM was impaired in dyslexia in Study 1, consistent with prior research (Kibby, in press; Kibby & Cohen, 2008; Rack et al., 1992; Wagner et al., 1994).”

“In terms of the phonological loop, Kibby and Cohen (2008) showed children with RD and ADHD had impaired performance on forward digit span, and the RD/ADHD interaction term was not significant.”

“…children may present impairment in tasks involving the phonological loop ,even though most of these individuals have within average performances in skills that involve the visuo-spatial sketchpad, central executive and/or episodic buffer subcomponents (Kibby & Cohen, 2008; Kibby et al., 2004).”

“…for a wide range of cognitive skills such as language comprehension, learning and reasoning (Baddeley, 1992) and individuals with working memory deficits are at an Page 5 of 44 Ac ce pt ed M an us cr ip t 5 increased risk for reading difficulties (Gathercole et al., 2006; Kibby and Cohen, 2008).”

“These include: problems with peer relations including peer victimisation [45], sleep problems [46], irritability [47], cognitive problems [41, 48, 49], working memory issues [49, 50], substance use [51] and delinquency [52], which are all likely to be risk factors for an unsuccessful high school transition.”

“Similar inconsistencies have been found in the verbal domain, with preserved [31] or impaired [30] long-term verbal abilities in children with DD.”

“Whereas the deficits in PL and CE tasks exhibited by children with DD have been reported extensively (Schuchardt et al., 2008; Smith-Spark & Fisk, 2007; Swanson et al., 2009), the findings regarding VSSP have been inconsistent (Bacon et al., 2013; Kibby & Cohen, 2008; Menghini et al., 2011).”

“Impairments on such tasks in children with dyslexia are typically observed in comparison with age‐matched typically developing children (Kibby & Cohen, 2008; Menghini, Carlesimo, Marotta, Finzi, & Vicari, 2010; Vellutino & Scanlon, 1985).”

“While EF may be spared in some children with ADHD (Castellanos, Sonuga-Barke, Milham, & Tannock, 2006; Kibby & Cohen, 2008; Nigg, Willcutt, Doyle, & Sonuga-Barke, 2005; Willcutt, Doyle, Nigg, Faraone, & Pennington, 2005), a large body of research suggests that children with ADHD typically have…”

“One the other hand, some studies have found a relationship between working memory and word decoding (e.g., Christopher et al., 2012; Kibby & Cohen, 2008; Kibby et al., 2014; but see Keresteš et al., 2019).”

“The latter fi nding is critical because children and adolescents with LD tend to experience memory problems including working memory and long-term memory (Kibby & Cohen, 2008; Maehler & Schu-chardt, 2009), which can result in learning di ffi culties.”

“…resource is often discussed in the literature, and processing capacity has been found to be deficient in children with learning disabilities (Kibby & Cohen, 2008; Malstädt, Hasselhorn, & Lehmann, 2012), including those with language impairment (Hanson & Montgomery, 2002; Montgomery, 2002a;…”

“Notwithstanding, and consistent with previous research findings (Bental & Tirosh, 2007; Bolden, Rapport, Raiker, Sarver, & Kofler, 2012; Kibby & Cohen, 2008; Tiffin-Richards, Hasselhorn, Woerner, Rothenberger, & Banaschewski, 2008; Van De Voorde, Roeyers, Verté, & Wiersema, 2011), these results…”

“…difficulties, such as slowed information processing, have been the subject of a growing number of studies (Katz, Brown, Roth, & Beers, 2011; Kibby & Cohen, 2008; McGrath et al., 2011; Willcutt, Pennington, Olson, Chhabildas, & Hulslander, 2005), the observation that both dyslexia and ADHD…”

“…Tannock, 2009; Johnson et al., 2001; Muller et al., 2007; Shang and Gau, 2011) were confounded by skills typically problematic among ADHD samples such as fine motor control (Johnson et al., 2010; Lavasani and Stagnitti, 2011) and working memory demands (Barnett et al., 2009; Kibby and Cohen, 2008).”

“However, these findings are contrary to the view that only visual memory or auditory memory would be relevant for RP [8, 43].”

“…in relation to reading research, some findings propose contradictory patterns of results with respect to memory in poor reading (i.e. intact [e.g. Kibby & Cohen, 2008; Li, Shu, McBride-Chang, Liu, & Xue, 2009; Messbauer & de Jong, 2003], deficient episodic memory [e.g. Menghini, Carlesimo,…”

“More specifically, visual/non-spatial short-term memory performance may be intact (French, Zentall, & Bennett, 2001; Karatekin, 2004; Kibby & Cohen, 2008; McInnes et al., 2003; Rucklidge & Tannock, 2002; Willcutt et al., 2001), but visual-spatial short-term memory performance is frequently poor…”

“CMS correlates well with other measures of cognitive and intellectual ability, demonstrating at least a moderate relationship between the CMS subtests and other memory measures (Kibby & Cohen, 2008).”

“As part of the current study, participants repeated verbally presented digits in the digit span backward task, supporting past research that verbal working memory deficits in RD are a consequence of phonological loop deficits [102– 104].”

“This finding is consistent with previous studies that found that children with ADHD tend to display intact LTM if the material is encoded successfully (122, 123), suggesting that if children with ADHD have encoded information into long-term memory, they have no difficulties in retaining and retrieving that information…”

“2024 , 14 , 435 3 of 20 these studies have found that children with co-occurring dyslexia and ADHD have both a phonological processing and an inhibition deficit [12,45,46].”

“The results indicated that the groups did not differ on the learning trials or primary delayed memory scores (Brown et al., 2010), whereas prior studies found that single-exposure, drawing based visual memory tests were often lower among AD/HD patients (Kibby & Cohen, 2008; Shang & Gau, 2011).”

“Almost all studies investigating phonological loop capacity have documented reductions in verbal span in children with developmental dyslexia (Kibby & Cohen, 2008; Menghini et al., 2011; Swanson et al., 2009; Willcutt et al., 2005).”

“However, the ability to decode and store verbal information by relying on its meaning may be intact in dyslexia (Kibby, 2009; Kibby and Cohen, 2008; McDougall and Donohoe, 2002).”

“These results are consistent with the results of previous studies (34,35).”

“Typical cognitive weaknesses in school-aged children with MMC include attention impairments, executive dysfunction, slower processing speed, and deficits in memory and novel problem-solving, often accompanied by relative strengths in rote learning or vocabulary [1, 26].”

“One possible explanation for this result is that the executive load in updating tasks may be greater than in classic working memory tasks (Kibby and Cohen 2008).”

“Looking at broader memory functions, Kibby et al. (2021) found intact short-and long-term verbal memory but inconsistent visual memory on the Children’s Memory Scale (Cohen, 1997).”

“CMS Dots Locations Learning and Dot Locations Short Delay were sensitive to differences between children with reading disabilities and ADHD (Kibby & Cohen, 2008).”

“…have argued that individuals with developmental reading disorders do not exhibit impairment in the central executive component of their WM (Kibby & Cohen, 2008), findings from recent studies involving this population suggest impairment in both the phonological store and central executive…”