Functional neuroimaging of self-referential encoding with age

Department of Psychology, Brandeis University, Waltham, MA 02454-9110, USA.
Neuropsychologia (Impact Factor: 3.3). 09/2009; 48(1):211-9. DOI: 10.1016/j.neuropsychologia.2009.09.006
Source: PubMed


Aging impacts memory formation and the engagement of frontal and medial temporal regions. However, much of the research to date has focused on the encoding of neutral verbal and visual information. The present fMRI study investigated age differences in a social encoding task while participants made judgments about the self or another person. Although previous studies identified an intact self-reference effect with age, subserved by robust engagement of medial prefrontal cortex (mPFC) by both young and older adults, we identified a number of age differences. In regions including superior mPFC, inferior prefrontal cortex, and anterior and posterior cingulate cortex, young and older adults exhibited reversals in the pattern of activity for self and other conditions. Whereas young primarily evidenced subsequent forgetting effects in the self-reference condition, older adults demonstrated subsequent memory effects in the other-reference condition. These results indicate fundamental differences across the age groups in the engagement of elaborative encoding processes. We suggest that older adults may encode information about the self in a more normative manner, whereas young adults focus on encoding the unique aspects of the self and distinguishing the self from others.

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Available from: Daniel L Schacter, Feb 06, 2014
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    • "However, because MPFC lesions in patients would affect throughout the task (from encoding to the retrieval phase), it is difficult to determine in which phase (encoding, retrieval, or both) MPFC plays an important role for SRE. Few previous studies that investigated the neural correlates of SRE during encoding or retrieval (Fossati et al., 2004; Macrae et al., 2004; Benoit et al., 2010; Gutchess et al., 2010; Leshikar and Duarte, 2012, 2014) recognized the involvement of the ventral part of MPFC. For example, Macrae et al. (2004) examined normal subjects using the self-reference task in an event-related functional magnetic resonance imaging (fMRI) and set the contrast according to whether the referenced word was later remembered or forgotten and whether the item was judged as self-relevant. "
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    ABSTRACT: The self-reference effect (SRE) is defined as better recall or recognition performance when the memorized materials refer to the self. Recently, a number of neuroimaging studies using self-referential and other-referential tasks have reported that self- and other-referential judgments basically show greater activation in common brain regions, specifically in the medial prefrontal cortex (MPFC) when compared with nonmentalizing judgments, but that a ventral-to-dorsal gradient in MPFC emerges from a direct comparison between self- and other-judgments. However, most of these previous studies could not provide an adequate explanation for the neural basis of SRE because they did not directly compare brain activation for recognition/recall of the words referenced to the self with another person. Here, we used an event-related functional magnetic resonance imaging (fMRI) that measured brain activity during processing of references to the self and another, and for recognition of self and other referenced words. Results from the fMRI evaluation task indicated greater activation in ventromedial prefrontal cortex (VMPFC) in the self-referential condition. While in the recognition task, VMPFC, posterior cingulate cortex (PCC) and bilateral angular gyrus (AG) showed greater activation when participants correctly recognized self-referenced words versus other-referenced words. These data provide evidence that the self-referenced words evoked greater activation in the self-related region (VMPFC) and memory-related regions (PCC and AG) relative to another person in the retrieval phase, and that the words remained as a stronger memory trace that supports recognition.
    Frontiers in Human Neuroscience 06/2015; 9:383. DOI:10.3389/fnhum.2015.00383 · 2.99 Impact Factor
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    • "In particular, based on previous results, we assumed that activity in the MPFC should contribute to the source memory benefit for self-referenced information in older adults, as previously found in young adults (Leshikar and Duarte, 2012). Nevertheless, if there is a loss of specificity in areas related to successful encoding of self-referenced information in aging (i.e., reduction of specificity in the MPFC), we hypothesized that additional agerelated correlations would be found between subsequent selfreferenced memory effects and extra CMS regions (Gutchess et al., 2010). "
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    ABSTRACT: Self-referential processing relies mainly on the medial prefrontal cortex (MPFC) and enhances memory encoding (i.e., Self-Reference Effect, SRE) as it improves the accuracy and richness of remembering in both young and older adults. However, studies on age-related changes in the neural correlates of the SRE on the subjective (i.e., autonoetic consciousness) and the objective (i.e., source memory) qualitative features of episodic memory are lacking. In the present fMRI study, we compared the effects of a self-related (semantic autobiographical memory task) and a non self-related (general semantic memory task) encoding condition on subsequent episodic memory retrieval. We investigated encoding-related activity during each condition in two groups of 19 younger and 16 older adults. Behaviorally, the SRE improved subjective memory performance in both groups but objective memory only in young adults. At the neural level, a direct comparison between self-related and non self-related conditions revealed that SRE mainly activated the cortical midline system, especially the MPFC, in both groups. Additionally, in older adults and regardless of the condition, greater activity was found in a fronto-parietal network. Overall, correlations were noted between source memory performance and activity in the MPFC (irrespective of age) and visual areas (mediated by age). Thus, the present findings expand evidence of the role of the MPFC in self-referential processing in the context of source memory benefit in both young and older adults using incidental encoding via semantic autobiographical memory. However, our finding suggests that its role is less effective in aging.
    Frontiers in Behavioral Neuroscience 01/2015; DOI:10.3389/fnbeh.2014.00449 · 3.27 Impact Factor
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    • "The present findings confirmed previous studies [14] [22] [23] [52] reporting that Self-reference processing enhances memory performance more than a semantic deep processing in aging. We additionally demonstrated for the first time that the effects of depth of processing and Self-reference processing are preserved and robust in long-term episodic memory. "
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    ABSTRACT: The Self-reference effect (SRE) on long-term episodic memory and autonoetic consciousness has been investigated in normal young adults, scarcely in old adults, but never in Alzheimer’s patients. Is the functional influence of Self-reference still present when the individual’s memory and identity are impaired? We investigated this issue in 60 young subjects, 41 elderly subjects, and 28 patients with Alzheimer’s disease, by using 1) an incidental-learning task of personality traits in three encoding conditions, inducing variable degrees of depth of processing and personal involvement, 2) a 2-minutes retention interval free recall task, and 3) a 20-minutes retention interval recognition task, combined with a remember-know paradigm. Each score recorded was corrected for errors (intrusions in free recall, false alarms in recognition, and false source memory in remember responses). The Self-reference, compared with alternative encodings, significantly enhanced performance on the free recall task in the young group, and on the recognition task both in the young and elder groups but not in the Alzheimer group. The most important finding is that the Self-reference led more often to a subjective sense of remembering with the retrieval of the correct encoding source in the Alzheimer group. This Self-reference recollection effect in patients was related to independent subjective measures of a positive and definite sense of Self (measured by the Tennessee Self Concept Scale), and to memory complaints in daily life. In conclusion, these results demonstrated the power and robustness of the Self-reference effect on the recollection in long-term episodic memory in Alzheimer’s disease albeit the retrieval is considerably reduced. These results should open new perspectives for the development of rehabilitation programs for memory deficits.
    Current Alzheimer research 01/2014; 10(10):1107-1117. DOI:10.2174/15672050113106660175 · 3.89 Impact Factor
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