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. 2006 Oct 18;92(3):213–218. doi: 10.1136/adc.2006.104786

Table 3 Mean scores and standard deviations for the cognitive measures.

Variables Group p Value
Controls (n = 45) PKU off diet (n = 25) PKU on diet* (n = 25)
Mean (SD) Mean (SD) Mean (SD)
n‐back percentage accuracy **
 0‐back 98.01 (1.52) 97.08 (2.46) 98.83 (1.09)
 1‐back 97.13 (2.34) 95.65 (3.24) 97.78 (1.53)
 2‐back 86.51 (7.95) 84.55 (7.62) 88.93 (5.69)
n‐back speed per item (s) **
 0‐back 0.39 (0.04) 0.43 (0.05) 0.45 (0.08)
 1‐back 0.50 (0.13) 0.60 (0.15) 0.55 (0.13)
 2‐back 1.01 (0.43) 1.54 (1.17) 1.34 (0.67)
Flanker percentage accuracy
 Compatible trials 99.28 (1.59) 98 (1.57) 99.35 (1.03)
 Incompatible trials 97.22 (2.82) 97.05 (2.28) 97.65 (3.41)
Flanker speed per item (s) **
 Compatible trials 0.43 (0.06) 0.49 (0.07) 0.45 (0.06)
 Incompatible trials 0.46 (0.06) 0.52 (0.08) 0.47 (0.05)
Object alternation
 10 consecutive correct trials (%) 51 28 48
 Percentage of trials correct 66.04 (16.14) 60.24 (17.75) 66.48 (15.75)
 Speed per item in s 0.76 (0.4) 0.92 (0.35) 0.88 (0.3)
Perceptual judgement percentage accuracy
 Shape matching 98.6 (2.02) 98.2 (2.84) 99.4 (1.66)
 Function matching 98 (2.61) 97 (5.95) 97.4 (3.85)
Perceptual judgement speed per item (s)
 Shape matching 0.82 (0.26) 0.87 (0.2) 0.99 (0.35)
 Function matching 1 (0.32) 0.98 (0.24) 1.13 (0.34)

PKU, phenylketonuria.

*PKU on‐diet group from Channon et al.23

**p<0.01.