Table 3 Studies Examining WM Skills in Individuals with DS Organized by Age Group and Presented Chronologically
| Study | Comparison Group | Matching Assessment | DS Group CA | DS Group MA | Tasks | Findings |
|---|---|---|---|---|---|---|
| School Age and Adolescent studies (6 to 17 years old) | ||||||
| Vicari 1995 [118] |
NVMA-matched TD ID group | Leiter | M=16.6 | M=5.2 |
Verbal & Spatial WM
Backwards Digit Span Backwards Corsi Span |
DS< TD-NVMA & ID DS< TD-NVMA & ID |
| Munir 2000 [58] |
MA-matched TD, CA-matched TD, & FXS | BPVS | M= 11.17 | M=6.09 |
Verbal WM
WISC-III Backward Digit Span | DS > FXS; DS < TD-MA & TD-CA |
| Pennington 2003 [9] | MA-matched TD | DAS |
M=14 (Range=11-19) | M=4.5 |
Verbal & Spatial WM
Counting Span CANTAB Spatial WM |
DS ~ TD-MA DS ~ TD-MA |
| Lanfranchi 2004 Study 1 [115] | MA-matched TD | Logical Operations Test |
M=11.75 (Range=7-16) | M=5.42 |
Verbal WM
Backward Word Span Selective Word Recall Dual Request Word Recall |
DS < TD-MA DS < TD-MA DS < TD-MA *As cognitive control required for each task increased, the deficit in DS performance increased as well |
| Lanfranchi 2004 Study 2 [115] | MA-matched TD | Logical Operations Test |
M=14.5 (Range=11-18) | M=4.5 |
Visual WM
Pathway Backwards Starting Position Selection Dual Request Selective Task |
DS ~ TD-MA DS < TD-MA DS < TD-MA |
| Visu-Petra 2007 [120] | MA-matched TD | SB |
M=14.4 (Range=8-21) | M=5.75 |
Spatial WM
CANTAB Visual Spatial Working Memory (recalling hidden items in sequence) |
DS ~ TD-MA on strategyTotal Between Errors: DS> TD- MA 4-Box Between Errors: DS~ TD-MA |
| Lanfranchi 2009 [117] |
VMA-matched TD Verbal MA-matched TD |
PPVT-R WPPSI Verbal Scales |
M=13.0 (Range=8-19) | M=4.10 |
Verbal & Spatial WM
Selective Span Verbal Double Task Starting Position Selection Visuospatial Double task |
DS< TD-Verbal & TD-VMA DS< TD-Verbal & TD-VMA DS~ TD-Verbal & TD-VMA DS< TD-Verbal & TD-VMA |
| Lanfranchi, 2009 [142] | MA-matched TD |
PPVT-R and RCM |
M=12.6 (Range=7-17) | M=6.0 |
Spatial WM
Selective Position Recall Selective Pathway Recall |
DS<TD-MA DS~TD-MA |
| Edgin 2010 [25] |
IQ-matched WS group | WASI |
M=17.4 (Range=13-23) | -- |
Verbal & Spatial WM
Backwards Digit Span Backward Corsi Span |
DS ~ WS DS ~ WS |
| Lanfranchi 2010 [116] | MA-matched TD | Logical Operations Test |
M=15.1 (Range=11-18) | M=5.75 |
Verbal & Spatial WM
Verbal Dual task Visuospatial Dual task |
DS< TD-MA DS< TD-MA |
| Nash 2011 [194] | Comprehension Ability Matched (CAM) TD |
BAS-II Single Word Reading Test (RA group) Neale Analysis of Reading Ability II (CAM group) | M=15.5 |
Reading age=5.2 Rec. Vocab age=7.0 |
Verbal WM
Working Memory Test Battery for Children | DS < TD-CAM |
| Lanfranchi 2012 [119] | VMA-matched TD | PPVT-Revised |
M=13.7 (Range=8-23) | M=5.25 |
Verbal & Spatial WM
Selective Word Recall Verbal Dual task Verbal/Visuospatial Task Selective Pathways Recall Visuospatial Dual Task Visuospatial/Verbal Task |
DS < TD-VMA DS < TD-VMA DS < TD-VMA DS ~ TD-VMA DS < TD-VMA DS < TD-VMA |
| Borella 2013 [114] | VMA- matched TD | PPVT- Revised |
M=14.6 (Range=10-19) | M=5.58 |
Verbal WM
Verbal Dual Task | DS < TD-VMA |
| Costanzo 2013 [90] |
WS group & NVMA-matched TD |
Leiter-Revised (for all but 1 participant who received SB) |
M= 14.5 (Range=8-21) | M=6.2 |
Verbal & Spatial WM
Backward Digit Span Backward Corsi Span |
DS< TD-NVMA: DS<WS DS< TD-NVMA; DS~WS |
| Carney 2013 [92] | TD participants with similar MA | SB Abbreviated Battery |
M=13.6 (Range=10 –18) | M=6.0 |
Verbal & Spatial WM
Listening Span Odd One Out - determining odd figure out of 3 figures, then recalling figure position |
DS < TD DS < TD |
| Trezise 2014 [121] |
CA and NVMA-matched ASD+ID and Nonspecific ID | Wechsler Nonverbal Scale of Ability: Spatial Span MA score |
M=14.84 (Range=10-18) | M=8.19 |
Verbal & Visual WM
Word Repetition Recognition Line Drawing Recognition |
DS < ID; DS~ASD+ID DS < ID; DS~ASD+ID |
| Adult and Older adult studies (18 years and older) | ||||||
| Numminen 2001 [123] | NV IQ-matched ID group | RCM |
M=41.8 (Range=38-48) | M=5.03 |
Verbal & Spatial WM
Digit Span Backward Visuospatial Test (recall of patterns) |
DS~ID DS~ID |
| Roch 2012 [122] | Reading comprehension matched TD (CAM) | Standardized test of reading comprehension (administered collectively) |
M~18.5 (Range=11-26) | -- |
Verbal WM
Backward Word Recall Backward word recall with visual support |
DS < TD-CAM DS ~ TD-CAM |
| Belacchi 2014 [108] | NVMA and SES matched TD | RCM |
M=18.8 (Range=15-29) | MA~5.5 |
Verbal & Visual WM
First Word List Recall First Stop Position Recall |
DS < TD-NVMA DS = TD-NVMA |
| Reid 2017 [105] | Cornelia de Lange Snydrome group (CdLS) | -- | M= 24.38 (SD=5.82) |
M=6.29 (BPVS) |
Verbal & Visual WM
Digits Span Backwards Corsi Backwards |
DS~CdLS DS~CdLS |