Spatial memory impairments in amnestic mild cognitive impairment in a virtual radial arm maze

Figures & data

Table 1 Mean demographic data and scores (SD) of the Mini-Mental State Examination of the normal control, amnestic mild cognitive impairment, and Alzheimer’s disease groups

	NC (n=20)	aMCI (n=20)	AD (n=20)
Age, years (SD)	70.8 (5.2)	70.7 (5.0)	72.4 (5.6)
Female, n (%)	11 (55%)	9 (45%)	10 (50%)
Years of education (SD)	11.2 (4.7)	11.0 (4.2)	7.0 (4.2)*
MMSE scores (SD)	27.6 (2.0)	25.6 (2.4)	20.5 (3.4)*
MMSE range (min, max)	23, 30	20, 29	13, 24

Note:

* P<0.05, significantly different from normal controls and amnestic mild cognitive impaired patients in Bonferroni post hoc analysis.

Abbreviations: AD, Alzheimer’s disease; aMCI, amnestic mild cognitive impairment; NC, normal control; MMSE, Mini-Mental State Examination; min, minimum; max, maximum; SD, standard deviation.

Figure 1 Virtual radial arm maze test.

Notes: (A) Virtual radial arm maze with six arms in virtual environment. (B) View of virtual radial arm maze from above.

Figure 2 Results of virtual radial arm maze test for the normal control, amnestic mild cognitive impairment, and Alzheimer’s disease groups.

Notes: (A) Mean working memory errors ± standard error (SE); (B) mean reference memory errors ± SE; (C) mean distance ± SE; and (D) mean time latency ± SE to find the hidden rewards across trials in the normal control, amnestic mild cognitive impaired, and Alzheimer’s disease groups for five trials.
Abbreviations: AD, Alzheimer’s disease; aMCI, amnestic mild cognitive impairment; NC, normal control; sec, seconds.

Figure 3 Results of virtual radial arm maze test for the converted and nonconverted amnestic mild cognitive impaired groups.

Notes: (A) Mean working memory errors ± standard error (SE); (B) mean reference memory errors ± SE (significant group effect of P<0.05); (C) mean distance ± SE; and (D) mean time latency ± SE to find the hidden rewards across five trials in converted amnestic mild cognitive impaired (aMCI) and nonconverted aMCI groups within original aMCI group followed-up for 5 years.
Abbreviations: AD, Alzheimer’s disease; aMCI, amnestic mild cognitive impairment; sec, seconds.

Table 2 Correlations between virtual radial arm maze and neuropsychological tests after controlling for years of education

	WM errors	RM errors	Time	Distance
Spatial Span Forward	−0.169	−0.172	−0.165	−0.155
Spatial Span Backward	−0.286†	−0.334†	−0.251†	−0.307†
SRFT copy	−0.356†	−0.369†	−0.371†	−0.403†
SRFT immediate recall	−0.373†	−0.443†	−0.368†	−0.408†
SRFT delayed recall	−0.389†	−0.451†	−0.418†	−0.410†

Note:

† Indicates that the correlation was significant at the 0.05 level.

Abbreviations: RM, reference memory; SRFT, simplified Rey complex figure test; WM, working memory.