Functional cross‐hemispheric shift between object‐place paired associate memory and spatial memory in the human hippocampus

Lee, Choong-Hee; Ryu, Jiho; Lee, Sang-Hun; Kim, Hak-Jin; Lee, Inah

doi:10.1002/hipo.22614

Cited by 3 publications

(3 citation statements)

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“…We then grand‐averaged the P1w peak amplitude for EC and FG stimulation separately in each individual patient, when the stimulation is delivered to more than one electrode pair in each region. Recently, Lee, Ryu, Lee, Kim, and Lee () showed in human fMRI study that the efficient retrieval of object–place paired associate memory was correlated with the BOLD response of the left hippocampus, whereas the efficient retrieval of relatively pure spatial memory was correlated with the right hippocampal BOLD response, suggesting that the left and right hippocampus process qualitatively different information for remembering episodic events in space. Thus, we expect that both the left and right hippocampus may have an important role in episodic memory function.…”

Section: Methodsmentioning

confidence: 99%

Human entorhinal cortex electrical stimulation evoked short‐latency potentials in the broad neocortical regions: Evidence from cortico‐cortical evoked potential recordings

et al. 2019

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Objective We aimed at clarifying the clinical significance of the responses evoked by human entorhinal cortex (EC) electrical stimulation by means of cortico‐cortical evoked potentials (CCEPs). Methods We enrolled nine patients with medically intractable medial temporal lobe epilepsy who underwent invasive presurgical evaluations with subdural or depth electrodes. Single‐pulse electrical stimulation was delivered to the EC and fusiform gyrus (FG), and their evoked potentials were compared. The correlation between the evoked potentials and Wechsler Memory Scale‐Revised (WMS‐R) score was analyzed to investigate whether memory circuit was involved in the generation of the evoked potentials. Results In most electrodes placed on the neocortex, EC stimulation induced unique evoked potentials with positive polarity, termed as “widespread P1” (P1w). Compared with FG stimulation, P1w induced by EC stimulation were distinguished by their high occurrence rate, short peak latency (mean: 20.1 ms), small peak amplitude, and waveform uniformity among different recording sites. A stimulation of more posterior parts of the EC induced P1w with shorter latency and larger amplitude. P1w peak amplitude had a positive correlation (r = .69) with the visual memory score of the WMS‐R. In one patient, with depth electrode implanted into the hippocampus, the giant evoked potentials were recorded in the electrodes of the anterior hippocampus and EC near the stimulus site. Conclusions The human EC electrical stimulation evoked the short‐latency potentials in the broad neocortical regions. The origin of P1w remains unclear, although the limited evidence suggests that P1w is the far‐field potential by the volume conduction of giant evoked potential from the EC itself and hippocampus. The significance of the present study is that those evoked potentials may be a potential biomarker of memory impairment in various neurological diseases, and we provided direct evidence for the functional subdivisions along the anterior–posterior axis in the human EC.

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Section: Methodsmentioning

confidence: 99%

Human entorhinal cortex electrical stimulation evoked short‐latency potentials in the broad neocortical regions: Evidence from cortico‐cortical evoked potential recordings

et al. 2019

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“…Prior volumetric and functional neuroimaging studies revealed that the hippocampus was structurally and functionally asymmetric, suggesting that the left and right hippocampi are involved in qualitatively different aspects of memory formation. The right hippocampus is thought to be involved in processing of spatial memory, and the left hippocampus in the processing of verbal memory . Our current study supports the idea that the right hippocampus is involved in visuospatial memory.…”

Section: Discussionmentioning

confidence: 99%

Association between delayed recall and T2* relaxation time of the subiculum in adolescents: Implications for ultra‐high‐field magnetic resonance imaging

Jeon

Hwang

Son

et al. 2019

Psychiatry Clin Neurosci

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Aim The aim of this study was to assess neuropsychological correlations with the T2* relaxation time (T2*‐RT) of hippocampal subregions in adolescents using ultra‐high‐field (UHF) 7.0‐T magnetic resonance imaging (MRI). Methods We assessed the T2*‐RT of hippocampal subregions in 31 healthy 11th‐ or 12th‐grade high school students using an UHF 7.0‐T MRI system. T2*‐RT of the cornu ammonis (CA) 1, CA2, CA3, and CA4 subregions and the subiculum were calculated for both the left and right hippocampus. Seven subtests of the Cambridge Neuropsychological Test Automated Battery were administered to the subjects to assess visuospatial memory. Results Poor performances in delayed recall in the pattern‐recognition test were significantly correlated with longer T2*‐RT in the bilateral subiculum (right, r = −0.480, P = 0.006; left, r = −0.648, P < 0.001) and the left CA2 (r = −0.480, P = 0.006). Conclusion This study showed that longer T2*‐RT in the subiculum were associated with poorer performances in delayed recall in the visual memory tasks. This finding suggests that the subiculum might play a predominant role in delayed recall in adolescents.

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“…There may be differences in hemispheric specialization in the primate hippocampus. Human studies indicate that exploration and recognition show laterality, with the right hippocampus preferentially activating during exploration of new scenes and the left hippocampus preferentially activating during repeated scenes (Lee et al, 2016). The right hippocampus also seems to be preferentially recruited for large-scale, allocentric navigation whereas the left hippocampus is recruited for temporal sequence memory, egocentric navigation, autobiographical experience memory and match-mismatch associative memory (Iglói et al, 2010;Kumaran & Maguire, 2007;Lehn et al, 2009;Maguire & Frith, 2003).…”

Section: Limitationsmentioning

confidence: 99%

Unexpected changes in learned task contingencies trigger sharp wave ripples in the primate hippocampus during virtual navigation

McIntosh¹,

Corrigan²,

Gulli³

et al. 2020

Preprint

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The hippocampi and mesial temporal lobes play a central role in episodic memory and associative learning. It is unclear how unexpected experience influences learning. Hippocampal sharp wave ripples (SWR) are an electrical biomarker of memory consolidation. We tracked when and where SWR occur during 2 tasks. Local field potentials were recorded in the hippocampi, entorhinal cortices and amygdalae of non-human primates (NHP; n=3) performing reversal and associative learning tasks in a 3D virtual environment. Our results show hippocampal SWR occurred when learned task contingencies were unexpectedly altered. Surprise rewards and reward denial were associated with SWR rates 9.8x and 8.0x greater than expected rewards. The highest density of SWR occurred in zones where errors were made. SWR were preceded by event-related potentials in the amygdala but not entorhinal cortex. Our results suggest that SWR generation in primates may prioritize behaviourally relevant experience for commitment to memory to allow flexible learning.

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Functional cross‐hemispheric shift between object‐place paired associate memory and spatial memory in the human hippocampus

Cited by 3 publications

References 0 publications

Human entorhinal cortex electrical stimulation evoked short‐latency potentials in the broad neocortical regions: Evidence from cortico‐cortical evoked potential recordings

Human entorhinal cortex electrical stimulation evoked short‐latency potentials in the broad neocortical regions: Evidence from cortico‐cortical evoked potential recordings

Association between delayed recall and T2* relaxation time of the subiculum in adolescents: Implications for ultra‐high‐field magnetic resonance imaging

Unexpected changes in learned task contingencies trigger sharp wave ripples in the primate hippocampus during virtual navigation

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