Table 3.

Prognostic factors for training improvement in verbal short-term memory

Study	Test for outcome assessment	Dependent variable	Prognostic factor
Multiple regression
			Age	Education	Sex	Neuropsychology	Imaging	Others
de Lange et al., [32]	Word list	Standardized residuals					White matter microstructure →
McDougall et al. [40]	HVLT RBMT	Relative gains	↑			Pre-test score ↑		Ethnicity →
Neely and Bäckman [42]	Immediate recall of word list	Post-test scores	↓	↑		MMSE ↑ Pre-test score ↑ *
Rosi et al. [44]	Immediate recall of word list	Post-test scores	↓			Pre-test ↑* Working memory ↓ Fluid ability ↓ Crystallized ability ↑* Processing speed ↑ Short-term memory ↓
Sandberg et al. [45]	Number recall	Post-test scores	↓*			Episodic memory ↑* Processing speed ↓ Working memory ↑* Verbal knowledge ↑
Brooks et al. [8]	Name recall	Post-test scores	↑*			Pre-test score*		Pretraining x mnemonic training →
Correlation analysis
Mohs et al. [21]	HVLT	Post-test scores	→	→	→			Subjective reported memory →
Kirchhoff, Anderson, Smith, Barch et al., [22]	Recognition memory decisions	Change score					Activity in frontal cortex ↑
Kirchhoff, Anderson, Smith et al., [22]	Recognition memory decisions	Change score					Activity in hippocampus ↑
Andrewes et al. [26]	Face-name test	Change score				NART → RAVT → Warrington Forced Choice Recognition ↑		Depression → Mattis dementia scale →
Bråthen et al. [29]	Immediate recall of word list	n.a.					Hippocampal volume ↑* Amplitude of low frequency fluctuation ↓ Fractional amplitude of low frequency fluctuation ↓*
Finkel and Yesavage [35]	Immediate recall of word list	Gain scores	x	x		MMSE x		Openness of experience ↑* Depression x Extraversion x Neuroticism x
Hill et al. [37]	Face-name recall	Standardized residual scores						Rated confidence ↑
Hill et al. [38]	Face-name recall	Performance changes				MMSE ↑
Group comparisons (ANOVA, t test)
Clark, Xu, Callahan et al., [30]	HVLT RAVL RBMT	Relative mean improvement						Obesity ↓*
Clark, Xu, Unverzagtet al., [31]	HVLT RAVL RBMT	Relative mean improvement		→
McDougall et al. [40]	HVLT RBMT	n.a.		↓				Ethnicity (Blacks and Hispanics scored lower than Whites)
Mixed models
Tomaszewski Farias et al. [34]	HVLT RAVL RBMT	Normalized residuals						Activities of daily living ↑
López-Higes et al. [39]	Word list recall Logical memory test	n.a.						Apolipoprotein E4 →
No clear reporting
Bissig and Lustig [28]	Rank-test	n.a.	↓			Crystallized intelligence ↑
de Lange et al., [33]	Word list	Standardized residuals					White matter microstructure ↑

Studies are sorted according to the statistical method used for obtaining the prognostic factors

HVLT Hopkins Verbal learning Task, MMSE Mini Mental State Examination, NART National Adult Reading Test, RAVL Rey Auditory Verbal Learning Test, RBMT Rivermead Behavioral Memory Test, ↑ the higher the prognostic factor, the higher the improvement/positive correlation, ↓ the lower the prognostic factor, the higher the improvement/negative correlation, → no direction of effect reported, * significant, x unclear reporting