Lateral prefrontal cortex lesion impairs regulation of internally and externally directed attention

Abstract

Our capacity to flexibly shift between internally and externally directed attention is crucial for successful performance of activities in our daily lives. Neuroimaging studies have implicated the lateral prefrontal cortex (LPFC) in both internally directed processes, including autobiographical memory retrieval and future planning, and externally directed processes, including cognitive control and selective attention. However, the causal involvement of the LPFC in regulating internally directed attention states is unknown. The current study recorded scalp EEG from patients with LPFC lesions and healthy controls as they performed an attention task that instructed them to direct their attention either to the external environment or their internal milieu. We compared frontocentral midline theta and posterior alpha between externally and internally directed attention states. While healthy controls showed increased theta power during externally directed attention and increased alpha power during internally directed attention, LPFC patients revealed no differences between the two attention states in either electrophysiological measure in the analyzed time windows. These findings provide evidence that damage to the LPFC leads to dysregulation of both types of attention, establishing the important role of LPFC in supporting sustained periods of internally and externally directed attention.

Left dorsolateral prefrontal cortex supports context-dependent prioritisation of off-task thought

“…Our neural evidence suggests that these are complementary 41 , rather than contradictory accounts, since we found that focusing on a task, or imagining different people, times, and places, depends on shared neural processes in left DLPFC. Our individual difference analysis suggests DLPFC helps prioritise off-task thought via reductions in the processing of external task-relevant signals 14 , a position supported by evidence that lesions to this region prevent patients ignoring external sensory input 42 . In mechanistic terms, therefore, our data suggests DLPFC may contribute to the decoupling of attention from external input that is thought to be necessary for efficient processing of self-generated information 21 .…”

“…Altogether, this emerging literature provides the basis for a hypothesis of the contribution of the DMN in patterns of ongoing thought that future studies could explore. In particular, it will be helpful to use measures of neural function and experience across a wide range of situations to identify how broadly this relationship holds and identifying the causal role of DMN regions by studying populations with deficits within this system (such as Alzheimer’s Disease) and by creating virtual lesions within this system in normal populations using techniques like transcranial stimulation 42 .…”

Selective Estrogen Receptor β Agonists: a Therapeutic Approach for HIV-1 Associated Neurocognitive Disorders

“…When HIV-1 Tg animals were treated with SE at a more advanced age (i.e., 6 to 8 months), the enhancement in sustained attention occurred in a smaller subset (i.e., 40%) of animals and was localized to misses at the shortest signal duration (i.e., 100 msec; Moran et al 2019). Notably, the assessment of two attentional domains in the present study tapped multiple regions of the prefrontal cortex (PFC), with the medial PFC (mPFC) having a primary role in sustained attention (Kim et al 2016), whereas the lateral PFC plays a more prominent role in selective attention (Kam et al 2018). SE treatment relatively early in the course of viral protein exposure (i.e., 2 to 3 months), therefore, enhances sustained and selective attention in a global manner, targeting both hits and misses across signal durations.…”

Learning in Infancy Is Active, Endogenously Motivated, and Depends on the Prefrontal Cortices

“…Classical accounts of lateral PFC emphasize its role in high-level regulatory processes, such as executive control and working memory (Barbey et al 2013;Miller & Cohen 2001). Human patients with focal lesions in lateral PFC show marked deficits in these domains (Kam et al 2018). More recent approaches have parcellated lateral PFC into distinct subcomponents which manage hierarchical generation, planning and execution of goals together with other PFC regions (Pezzulo et al 2018).…”