Differential Contributions of Default and Dorsal Attention Networks to Remembering Thoughts and External Stimuli From Real-Life Events

Abstract

Episodic memories are typically composed of perceptual information derived from the external environment and representations of internal states (e.g., one's thoughts during prior episodes). To date, however, research has mostly focused on the remembrance of external stimuli, such that little is known about how internal mentation is represented within episodic memory. In the present fMRI study, we examined the neural correlates of these 2 components of episodic memories using a novel method of cuing memories from photographs taken during real-life events. We found that, compared with corresponding semantic memory tasks, memories for internal thoughts and external elements were associated with activity in brain areas supporting episodic recollection. Most importantly, however, the 2 kinds of memories also showed differential activation in large-scale brain networks: the remembrance of external elements was associated with greater activity in the dorsal attention network, whereas memories of internal thoughts mainly recruited default network areas. These findings shed new light on the representation of internal and external aspects of prior experience within episodic memory. The default network may contribute to the reinstatement of thoughts experienced during past events, whereas the dorsal attention network may support the allocation of attention to visuospatial features within episodic memory representations.

Activation‐based association profiles differentiate network roles across cognitive loads

“…Recent studies have also reported that the entire FPN is composed of three heterogeneous modules (namely, DMN aligned, DAN aligned, and dual aligned) that dissociably mediate global communication (Dixon et al, ; Spreng et al, ). This accords with the concept that the DAN globally regulates the positive networks by overseeing visuospatial encoding/planning (Spreng et al, ; Stawarczyk, Jeunehomme, & D'Argembeau, ), episodic retrieval, and WM (Luckmann, Jacobs, & Sack, ; Nee & Jonides, ). This function of the DAN has also been confirmed in studies comparing normal controls with participants exhibiting spatial neglect (Ptak & Schnider, ) and aging (Amer et al, ; Kurth et al, ).…”

The dynamics of memory retrieval for internal mentation

“…Participants undertook a walk on the campus of the University of Liège while wearing an Autographer (OMG Life Ltd), a lifelogging camera that automatically, silently, and continuously takes pictures from the first person perspective 36,41 (for an illustration of the experimental procedure, see Fig. 1 ) .…”

“…Our second aim was to identify thought features that predict their accessibility in memory. To address this question, a cued recall task was presented following the free recall task, in which participants reviewed the pictures that had been taken during their walk and described all additional thoughts (i.e., not reported during free recall) that the pictures reminded them of; a previous study indeed showed that such pictures are particularly effective cues to help the retrieval of internal mentation 41 . Thoughts produced during the free recall and cued recall tasks were then rated on various dimensions (e.g., visual imagery, personal importance, affective valence; see Table 1), which allowed us to identify features that differentiated between thoughts that were accessible without the help of cues (i.e., thoughts produced in the free recall task) and thoughts that were only accessed when retrieval cues were presented (i.e., thoughts produced in the cued recall task).…”

The Effect of Traditional Chinese Mind-Body Exercise (Baduanjin) and Brisk Walking on the Dorsal Attention Network in Older Adults With Mild Cognitive Impairment

“…Brain function, as measured by functional magnetic resonance imaging (fMRI), has shown that physical activity is associated with increased activity in left dorsolateral prefrontal, posterior parietal, and anterior cingulate cortices (Rosano et al, 2010), which are important components of the core region of the dorsal attention network (DAN) (Kim, 2014). The DAN is consistently involved in attention and has been associated with working memory and episodic memory encoding (Majerus et al, 2018; Stawarczyk et al, 2018). Recent studies have found intranetwork and internetwork functional disruptions in the DAN in MCI patients (Qian et al, 2015; Bi et al, 2018).…”