Rapid Sequential Implication of the Human Medial Temporal Lobe in Memory Encoding and Recognition

The medial temporal lobe (MTL) is crucial for memory encoding and recognition. The time course of these processes is unknown. The present study juxtaposed encoding and recognition in a single paradigm. Twenty healthy subjects performed a continuous recognition task as brain activity was monitored with a high-density electroencephalography. The task presented New pictures thought to evoke encoding. The stimuli were then repeated up to 4 consecutive times to produce over-familiarity. These repeated stimuli served as “baseline” for comparison with the other stimuli. Stimuli later reappeared after 9–15 intervening items, presumably associated with new encoding and recognition. Encoding-related differences in evoked response potential amplitudes and in spatiotemporal analysis were observed at 145–300 ms, whereby source estimation indicated MTL and orbitofrontal activity from 145 to 205 ms. Recognition-related activity evoked by late repetitions occurred at 405–470 ms, implicating the MTL and neocortical structures. These findings indicate that encoding of information is initiated before it is recognized. The result helps to explain modifications of memories over time, including false memories, confabulation, and consolidation.

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Study–Test Congruency Affects Encoding-related Brain Activity for Some but Not All Stimulus Materials

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_00070 ◽

2012 ◽

Vol 24 (1) ◽

pp. 183-195 ◽

Cited By ~ 8

Author(s):

Eva M. Bauch ◽

Leun J. Otten

Keyword(s):

Time Course ◽

Incidental Learning ◽

Brain Activity ◽

Recognition Task ◽

Long Term Memory ◽

Related Activity ◽

Alternative Mode ◽

Electrical Brain Activity ◽

Mode Of Presentation ◽

Study Test

Memory improves when encoding and retrieval processes overlap. Here, we investigated how the neural bases of long-term memory encoding vary as a function of the degree to which functional processes engaged at study are engaged again at test. In an incidental learning paradigm, electrical brain activity was recorded from the scalps of healthy adults while they made size judgments on intermixed series of pictures and words. After a 1-hr delay, memory for the items was tested with a recognition task incorporating remember/know judgments. In different groups of participants, studied items were either probed in the same mode of presentation (word–word; picture–picture) or in the alternative mode of presentation (word–picture; picture–word). Activity over anterior scalp sites predicted later memory of words, irrespective of type of test probe. Encoding-related activity for pictures, by contrast, differed qualitatively depending on how an item was cued at test. When a picture was probed with a picture, activity over anterior scalp sites predicted encoding success. When a picture was probed with a word, encoding-related activity was instead maximal over posterior sites. Activity differed according to study–test congruency from around 100 msec after picture onset. These findings indicate that electrophysiological correlates of encoding are sensitive to the similarity between processes engaged at study and test. The time course supports a direct and not merely consequential role of encoding–retrieval overlap in encoding. However, because congruency only affected one type of stimulus material, encoding–retrieval overlap may not be a universal organizing principle of neural correlates of memory.

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A Neurobiological Account of False Memories

10.1093/oso/9780190612016.003.0005 ◽

2017 ◽

Author(s):

Vincent van de Ven ◽

Henry Otgaar ◽

Mark L. Howe

Keyword(s):

Executive Functioning ◽

Medial Temporal Lobe ◽

Functional Neuroimaging ◽

Brain Activity ◽

False Memories ◽

Mental States ◽

Memory Formation ◽

Memory Encoding ◽

Associative Account ◽

The Brain

This chapter discusses human functional neuroimaging findings about how the brain creates true and false memories. These studies have shown that different brain systems contribute to the creation and retrieval of false memories, including systems for sensory perception, executive functioning and cognitive control, and the medial temporal lobe, which has long been associated with episodic and autobiographical memory formation. Many neuroimaging findings provide support for an associative account of false memories, which proposes that false memories arise from associating unrelated mental experiences in memory. At the same time, other neuroimaging findings suggest that false memory creation may depend on states of brain activity during memory encoding. Finally, the chapter briefly provides cautionary notes about using functional neuroimaging as a tool to assess private mental states in individual cases in the courtroom.

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Developmental Differences in Medial Temporal Lobe Function during Memory Encoding

Journal of Neuroscience ◽

10.1523/jneurosci.3500-09.2010 ◽

2010 ◽

Vol 30 (28) ◽

pp. 9548-9556 ◽

Cited By ~ 128

Author(s):

S. Ghetti ◽

D. M. DeMaster ◽

A. P. Yonelinas ◽

S. A. Bunge

Keyword(s):

Temporal Lobe ◽

Medial Temporal Lobe ◽

Developmental Differences ◽

Memory Encoding

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Modulation of medial temporal lobe activity in epilepsy patients with hippocampal sclerosis during verbal working memory

Journal of the International Neuropsychological Society ◽

10.1017/s135561770909078x ◽

2009 ◽

Vol 15 (4) ◽

pp. 536-546 ◽

Cited By ~ 10

Author(s):

PABLO CAMPO ◽

FERNANDO MAESTÚ ◽

IRENE GARCÍA-MORALES ◽

ANTONIO GIL-NAGEL ◽

BRYAN STRANGE ◽

...

Keyword(s):

Working Memory ◽

Episodic Memory ◽

Temporal Lobe ◽

Medial Temporal Lobe ◽

Time Course ◽

Hippocampal Sclerosis ◽

Stimulus Presentation ◽

Verbal Working Memory ◽

Compelling Evidence ◽

Electrophysiological Studies

AbstractIt has been traditionally assumed that medial temporal lobe (MTL) is not required for working memory (WM). However, animal lesion and electrophysiological studies and human neuropsychological and neuroimaging studies have provided increasing evidences of a critical involvement of MTL in WM. Based on previous findings, the central aim of this study was to investigate the contribution of the MTL to verbal WM encoding. Here, we used magnetoencephalography (MEG) to compare the patterns of MTL activation of 9 epilepsy patients suffering from left hippocampal sclerosis with those of 10 healthy matched controls while they performed a verbal WM task. MEG recordings allow detailed tracking of the time course of MTL activation. We observed impaired WM performance associated with changes in the dynamics of MTL activity in epilepsy patients. Specifically, whereas patients showed decreased activity in damaged MTL, activity in the contralateral MTL was enhanced, an effect that became significant in the 600- to 700-ms interval after stimulus presentation. These findings strongly support the crucial contribution of MTL to verbal WM encoding and provide compelling evidence for the proposal that MTL contributes to both episodic memory and WM. Whether this pattern is signaling reorganization or a normal use of a damaged structure is discussed. (JINS, 2009, 15, 536–546.)

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Relating Medial Temporal Lobe Volume to Frontal fMRI Activation for Memory Encoding in Older Adults

Cortex ◽

10.1016/s0010-9452(08)70199-0 ◽

2005 ◽

Vol 41 (4) ◽

pp. 595-602 ◽

Cited By ~ 20

Author(s):

A ROSEN ◽

J GABRIELI ◽

T STOUB ◽

M PRULL ◽

R OHARA ◽

...

Keyword(s):

Older Adults ◽

Temporal Lobe ◽

Medial Temporal Lobe ◽

Memory Encoding

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A putative high risk diplotype of the G72 gene is in healthy individuals associated with better performance in working memory functions and altered brain activity in the medial temporal lobe

NeuroImage ◽

10.1016/j.neuroimage.2008.12.054 ◽

2009 ◽

Vol 45 (3) ◽

pp. 1002-1008 ◽

Cited By ~ 29

Author(s):

Andreas Jansen ◽

Sören Krach ◽

Axel Krug ◽

Valentin Markov ◽

Thomas Eggermann ◽

...

Keyword(s):

Working Memory ◽

High Risk ◽

Temporal Lobe ◽

Medial Temporal Lobe ◽

Brain Activity ◽

Healthy Individuals ◽

Memory Functions

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Medial temporal lobe activations during associative memory encoding for arbitrary and semantically related object pairs

Brain Research ◽

10.1016/j.brainres.2007.05.046 ◽

2007 ◽

Vol 1161 ◽

pp. 46-55 ◽

Cited By ~ 22

Author(s):

Amélie M. Achim ◽

Marie-Claude Bertrand ◽

Alonso Montoya ◽

Ashok K. Malla ◽

Martin Lepage

Keyword(s):

Associative Memory ◽

Temporal Lobe ◽

Medial Temporal Lobe ◽

Memory Encoding ◽

Related Object

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Studying Memory Encoding to Promote Reliable Engagement of the Medial Temporal Lobe at the Single-Subject Level

PLoS ONE ◽

10.1371/journal.pone.0119159 ◽

2015 ◽

Vol 10 (3) ◽

pp. e0119159 ◽

Cited By ~ 6

Author(s):

Marta Simó ◽

Pablo Ripollés ◽

Lluís Fuentemilla ◽

Lucía Vaquero ◽

Jordi Bruna ◽

...

Keyword(s):

Temporal Lobe ◽

Medial Temporal Lobe ◽

Single Subject ◽

Memory Encoding

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Differential impact of reward and punishment on functional connectivity after skill learning

10.1101/243899 ◽

2018 ◽

Author(s):

Adam Steel ◽

Edward H. Silson ◽

Charlotte J. Stagg ◽

Chris I. Baker

Keyword(s):

Functional Connectivity ◽

Temporal Lobe ◽

Medial Temporal Lobe ◽

Brain Activity ◽

Premotor Cortex ◽

Reaction Time Task ◽

Resting State Fmri ◽

Skill Learning ◽

Control Feedback ◽

Reward And Punishment

AbstractReward and punishment shape behavior, but the mechanisms underlying their effect on skill learning are not well understood. Here, we tested whether the functional connectivity of premotor cortex (PMC), a region known to be critical for learning of sequencing skills, is altered after training by reward or punishment given during training. Resting-state fMRI was collected in two experiments before and after participants trained on either a serial reaction time task (SRTT; n = 36) or force-tracking task (FTT; n = 36) with reward, punishment, or control feedback. In each experiment, training-related change in PMC functional connectivity was compared across feedback groups. In both tasks, reward and punishment differentially affected PMC functional connectivity. On the SRTT, participants trained with reward showed an increase in functional connectivity between PMC and cerebellum as well as PMC and striatum, while participants trained with punishment showed an increase in functional connectivity between PMC and medial temporal lobe connectivity. After training on the FTT, subjects trained with control and reward showed increases in PMC connectivity with parietal and temporal cortices after training, while subjects trained with punishment showed increased PMC connectivity with ventral striatum. While the results from the two experiments overlapped in some areas, including ventral pallidum, temporal lobe, and cerebellum, these regions showed diverging patterns of results across the two tasks for the different feedback conditions. These findings suggest that reward and punishment strongly influence spontaneous brain activity after training, and that the regions implicated depend on the task learned.

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