Figures & data
Table 1. Sample characteristics by age group (young adults, older adults).
Figure 1. Schematic illustration of the task. The task was composed of two main phases separated by a short distractor task: the encoding phase and the recognition phase. In the encoding phase, participants were presented with images depicting real faces together with the names of professions. They had to decide whether or not the professions fitted the faces displayed. In the recognition face, participants were again presented with face-profession pairs. These pairs could be the same as the ones presented in the encoding face (target pairs) or could be presented in a recombined order (rearranged pairs). In addition, never-seen-before pairs were also presented (new pairs). Participants had to decide whether they had seen each pair before (“old”) or not (“new”). Additionally, for each pair they were asked to indicate their level of confidence on a scale from 1 (“not sure”) to 3 (“very sure”).
Figure 2. Schematic description of PLSC. looked for latent variables that maximised the amount of information that was common to the behavioural and brain measures, computing latent variables with maximal covariance. The relationship between a matrix X containing participants’ measures of all ROIs (e.g., pmFC and IFG) and a matrix Y containing participants’ behavioural measures (e.g., meta-d’/d’ for new or for rearranged pairs) is stored in a cross-product matrix R. R is a matrix of correlations between the normalised values of X and Y, which is then decomposed through single values decomposition (SVD) into a vector of saliences V, representing the brain measures that best characterise R. The original matrix X is finally projected onto the vector of saliences V to create the matrix of latent variables of X, Lx, which is called “brain scores”. Note: pmPFC – posteromedial prefrontal cortex; IFG – inferior frontal gyrus.
Figure 3. Response rates as a function of response type and age group. Note: YA – young adults; OA – older adults.
Figure 4. Confidence ratings as a function of stimulus type and accuracy. Note: YA – young adults; OA – older adults.
Figure 5. Meta-d’/d’ as a function of lure type and age group. Note: YA – young adults; OA – older adults.
Figure 6. Results of PLSC analyses for Meta-d’/d’. Multivariate brain profile associated with metacognitive efficiency for rearranged pairs (top-left) and new pairs (bottom-left). The bars represent the stability of the saliencies (z-score), and the dotted red lines represent the cut-off values used to evaluate the reliability of the saliencies (± 1.96). Top-left and bottom-left show the correlations between brain scores and age and brain score and meta-d’/d’ for rearranged and new pairs, respectively. Note: pmPFC – posteromedial prefrontal cortex; IFG – inferior frontal gyrus; dlPFC – dorsolateral prefrontal cortex; vmPFC-ventromedial prefrontal cortex; LPC – lateral parietal; parHCgyrus – parahippocampal gyrus; HC sub – subiculum; HC ERC – entorhinal cortex.
Figure 7. Results of PLSC analyses for d’. Multivariate brain profile associated with metacognitive efficiency for rearranged pairs (top-left) and new pairs (bottom-left). The bars represent the stability of the saliencies (z-score), and the dotted red lines represent the cut-off values used to evaluate the reliability of the saliencies (± 1.96). Top-left and bottom-left show the correlations between brain scores and age and brain score and meta-d’/d’ for rearranged and new pairs, respectively. Note: pmPFC – posteromedial prefrontal cortex; IFG – inferior frontal gyrus; dlPFC – dorsolateral prefrontal cortex; vmPFC-ventromedial prefrontal cortex; LPC – lateral parietal; parHCgyrus – parahippocampal gyrus; HC sub – subiculum; HC ERC – entorhinal cortex.
Figure 8. Confidence ratings as a function of lure type and age group.
Supplemental Material
Download MS Word (194.6 KB)Data availability statement
The data that support the findings of this study are available from the corresponding author, FP, upon reasonable request.