Memory and cognition in schizophrenia

Abstract

Episodic memory deficits are consistently documented as a core aspect of cognitive dysfunction in schizophrenia patients, present from the onset of the illness and strongly associated with functional disability. Over the past decade research using approaches from experimental cognitive neuroscience revealed disproportionate episodic memory impairments in schizophrenia (Sz) under high cognitive demand relational encoding conditions and relatively unimpaired performance under item-specific encoding conditions. These specific deficits in component processes of episodic memory reflect impaired activation and connectivity within specific elements of frontal-medial temporal lobe circuits, with a central role for the dorsolateral prefrontal cortex (DLPFC), relatively intact function of ventrolateral prefrontal cortex and variable results in the hippocampus. We propose that memory deficits can be understood within the broader context of cognitive deficits in Sz, where impaired DLPFC related cognitive control has a broad impact across multiple cognitive domains. The therapeutic implications of these findings are discussed.

On the relationship of first-episode psychosis to the amphetamine-sensitized state: a dopamine D2/3 receptor agonist radioligand study

“…Since psychotic patients show elevated responses to AMPH without any prior drug exposure 1 , psychosis has been conceptualized as a state of "endogenous sensitization" 10,17,18 . The prefrontal cortex (PFC), origin of reciprocal regulatory connections to subcortical DA neurons 19 , has often been found to be structurally and functionally impaired in SCZ 20,21 . Earlier studies have shown particularly strong relationships between subcortical DA metabolism and the lefthemispheric dorso-lateral PFC (DLPFC) and inferior frontal gyrus (IFG) in SCZ and subjects at-risk mental state for SCZ 22,23 .…”

Key role for lipids in cognitive symptoms of schizophrenia

“…The various subregions of the PFC are involved in deficits in specific cognitive domains 16 . For example, although ventro-lateral PFC functioning remains largely unaffected, impaired dorsolateral (dl)PFC-dependent processes are thought to underlie a range of cognitive deficits in SZ [17][18][19] . In addition, dlPFC activation during the performance of cognitive tasks is decreased in SZ patients 18,20,21 .…”

Neuroprotective Effect of Optogenetics Varies With Distance From Channelrhodopsin-2 Expression in an Amyloid-β-Injected Mouse Model of Alzheimer’s Disease

“…Various regions of the brain are involved in executive memory. The medial temporal lobe (hippocampal system), prefrontal cortex, diencephalon (papillary body and thalamus), and amygdala are reciprocally connected and associated with learning and memory ( Naya et al, 2017 ; Shirayama et al, 2017 ; Guo et al, 2019 ). Short-term memory (including working memory) and long-term memory are separate systems.…”