Role of the Hippocampus in Distinct Memory Traces: Timing of Match and Mismatch Enhancement Revealed by Intracranial Recording

Role of the Hippocampus in Distinct Memory Traces: Timing of Match and Mismatch Enhancement Revealed by Intracranial Recording Ni Wu Yu Zhu Li Liu

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Role of the Hippocampus in Distinct Memory Traces: Timing of Match and Mismatch Enhancement Revealed by Intracranial Recording 2017 Neuroscience Bulletin 10.1007/s12264-017-0172-8 Ni2017-role-of-the-hippocampus-in-distinct-memory-t Ni2017-role-of-the-hippocampus-in-distinct-memory-t.txt, the project's staged copy 775d67cad7bec29513517bd2e077bcf7622af9b9 not-redistributable neuroscience

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0 spans located by searching the stored text for the quote's exact words, allowing any whitespace between them the timing of goal-match and perceptual-mismatch signals in the human hippocampus during a working memory task Quotation withheld because this record is not cleared for redistribution. if and how the hippocampus is involved in working memory, and whether its components separate in time Quotation withheld because this record is not cleared for redistribution. separates goal-match from perceptual-mismatch enhancement within identical stimuli and times them, finding mismatch about 150 ms earlier and localised bilaterally where match is left posterior Quotation withheld because this record is not cleared for redistribution. existence Quotation withheld because this record is not cleared for redistribution. hippocampal match and mismatch enhancement in working memory Quotation withheld because this record is not cleared for redistribution. electrophysiology electrophysiology Quotation withheld because this record is not cleared for redistribution. mechanisms whether an incoming event matches or mismatches expectation drives the hippocampus to switch between memory encoding and memory retrieval modes Quotation withheld because this record is not cleared for redistribution. mechanisms decoding of task demand was degraded because participants defaulted to maintaining the sample in both tasks instead of simulating a new scene on switch trials, so the two tasks engaged more similar mental operations than the design intended Quotation withheld because this record is not cleared for redistribution. the same probe display is a goal match or a perceptual match depending only on a verbal instruction, which dissociates the two within identical stimuli Quotation withheld because this record is not cleared for redistribution. this is exactly what the earlier imaging work could not do, and the paper says why Quotation withheld because this record is not cleared for redistribution. a two-step contrast is used: first find where the two instruction conditions differ, then ask within that window which of the two enhancement patterns holds Quotation withheld because this record is not cleared for redistribution. latencies are validated against 1000 label permutations rather than taken from the contrast alone Quotation withheld because this record is not cleared for redistribution. the identical electrode configuration across patients is what makes grand averaging across individuals defensible Quotation withheld because this record is not cleared for redistribution. patients with hippocampal sclerosis are excluded so that the recorded tissue is morphologically intact Quotation withheld because this record is not cleared for redistribution. display timings were shortened because the constraint that set them belonged to a method this study does not use Quotation withheld because this record is not cleared for redistribution. the task was modified to fit the patients rather than the patients excluded to fit the task, which is disclosed Quotation withheld because this record is not cleared for redistribution. the single-participant threshold is loosened relative to the group analysis, and the loosening is stated Quotation withheld because this record is not cleared for redistribution. single-trial decoding is used to ask whether task demand is recoverable at all, independently of the averaged contrasts Quotation withheld because this record is not cleared for redistribution. the decoding result is then argued to be an underestimate, because subjects probably maintained the sample regardless of instruction Quotation withheld because this record is not cleared for redistribution. The single-trial decoding result may be weakened because participants tended to maintain the sample regardless of which task was instructed. what this limits: the single-trial decoding result: THE RESULT OF THE DECODING MIGHT BE COMPROMISED, BECAUSE THE DISSOCIATION BETWEEN THE SWITCH AND MATCH TASK RELIES ON A DIFFERENT MENTAL MANIPULATION Quotation withheld because this record is not cleared for redistribution. The task had to be modified from the original because the epilepsy patients' memory performance was impaired relative to healthy participants. what this limits: any comparison with the original task or with unimpaired participants: THIS MODIFICATION WAS IMPLEMENTED TO AID PATIENT PERFORMANCE BECAUSE ... THEIR MEMORY PERFORMANCE WAS IMPAIRED COMPARED TO NORMAL PARTICIPANTS Quotation withheld because this record is not cleared for redistribution. the decoding may understate the effect because participants likely maintained the sample whatever the task what this limits: the same scope as limitations[0], with the direction given: THE PARTICIPANT TENDED TO MAINTAIN THE SAMPLE NO MATTER WHAT THE TASK WAS, WHICH MAY LEAD TO A POOR PERFORMANCE IN DECODING Quotation withheld because this record is not cleared for redistribution. the paradigm was altered from the original to make it performable by patients what this limits: the same scope as limitations[1] - the paradigm is a modified one, with THE REPEATED PRESENTATION OF THE SAMPLE AFTER THE AUDITORY INSTRUCTION added Quotation withheld because this record is not cleared for redistribution. electrode placement was dictated entirely by clinical need what this limits: which structures could be observed at all: THE ELECTRODE LOCATIONS WERE BASED EXCLUSIVELY ON CLINICAL CRITERIA Quotation withheld because this record is not cleared for redistribution. the task inseparably combines object identity with location, so the hippocampal involvement cannot be attributed to either alone what this limits: any attribution of the hippocampal signal to one factor: A COMBINATION OF TWO STREAMS OF INFORMATION, OBJECT IDENTITY AND POSITION, ARE INVOLVED IN THE TASK Quotation withheld because this record is not cleared for redistribution. the supporting spatial-memory literature comes mostly from animal models what this limits: the convergent-evidence argument: the spatial-memory role is well understood, THOUGH ANIMAL MODELS WERE USED IN MOST OF THE STUDIES Quotation withheld because this record is not cleared for redistribution. testing patients before and after resection is proposed as the missing comparison what this limits: the causal question the recordings cannot reach: IT WILL BE OF INTEREST TO TEST THE RESULTS FROM THE ANIMAL MODELS ON EPILEPSY PATIENTS BEFORE AND AFTER RESECTION Quotation withheld because this record is not cleared for redistribution. the dissociation between repetition suppression and sample-matched enhancement, imported as the template for what to look for in human hippocampus Quotation withheld because this record is not cleared for redistribution. linear discriminant analysis after principal component reduction, used to ask whether the task instruction is recoverable from a single trial Quotation withheld because this record is not cleared for redistribution. trials with potential artifacts rejected on the amplitude of the data from 1 to 700 ms, per participant, after baseline correction eliminates: movement and electrical artifacts entering an averaged evoked response, with the threshold applied per participant rather than globally · outcome (stated by the tagger, no quotation): held Quotation withheld because this record is not cleared for redistribution. working memory - as measured by a digit span, where these patients are intact, versus as measured by feature integration, where they are impaired; the same patients on two tests Quotation withheld because this record is not cleared for redistribution. match enhancement - as a response to a goal state versus as a response to a previously perceived stimulus; the paradigm separates them within identical displays Quotation withheld because this record is not cleared for redistribution. the same probe display - counting as GOAL or PERCEPT depending only on the verbal instruction that preceded it Quotation withheld because this record is not cleared for redistribution. enhancement - a match effect where BOTH exceeds NEITHER, against a mismatch effect where NEITHER exceeds BOTH; two opposite orderings of the same four conditions Quotation withheld because this record is not cleared for redistribution. a late perceptual match effect that fits neither pattern cleanly, with BOTH above NEITHER but GOAL below PERCEPT Quotation withheld because this record is not cleared for redistribution. hippocampal role - as long-term declarative memory only, versus as also serving working memory encoding and retrieval Quotation withheld because this record is not cleared for redistribution. claim_type: existence a second reading reaching the same value. Recorded: existence — note: a second reading reaching the same value from a different sentence. Not applied - a person decides. Quotation withheld because this record is not cleared for redistribution. method: intracranial field potentials from depth electrodes along the hippocampal axis during a modified delayed-match-to-sample task in which a verbal instruction determines whether a display counts as a goal match or a perceptual match a second reading DIFFERING from the recorded value. Recorded: electrophysiology — note: a second reading, verbatim-verified, disagreeing with the value on the record. Not applied - a person decides. Quotation withheld because this record is not cleared for redistribution. phenomenon: match and mismatch signals in the hippocampus during working memory maintenance a second reading DIFFERING from the recorded value. Recorded: hippocampal match and mismatch enhancement in working memory — note: a second reading, verbatim-verified, disagreeing with the value on the record. Not applied - a person decides. Quotation withheld because this record is not cleared for redistribution. replicates → Duncan et al.'s fMRI dissociation of goal match and perceptual mismatch enhancement (reference [29]) Quotation withheld because this record is not cleared for redistribution. builds-on → Duncan (reference [29]) - stimuli and task design reused Quotation withheld because this record is not cleared for redistribution. extends → previous electrophysiological research on match and mismatch enhancement (references [18], [19]) Quotation withheld because this record is not cleared for redistribution. extends → the fMRI study proposing parallel goal-match and perceptual-mismatch traces, by adding the timing it could not resolve Quotation withheld because this record is not cleared for redistribution. critiques → earlier imaging designs in which perceptual mismatches and goal matches are unavoidably mixed Quotation withheld because this record is not cleared for redistribution. contradicts → the traditional view that the hippocampus subserves long-term declarative memory only Quotation withheld because this record is not cleared for redistribution. builds-on → Miller and Desimone, who dissociated repetition suppression from sample-specific match enhancement in perirhinal cortex Quotation withheld because this record is not cleared for redistribution. supports → evidence that the hippocampus is engaged when features must be bound to location but not for single features Quotation withheld because this record is not cleared for redistribution. extends → fMRI work that found only a subtle perceptual mismatch effect, by resolving it with intracranial timing Quotation withheld because this record is not cleared for redistribution. goal match enhancement —contrasted-with→ perceptual mismatch enhancement goal match enhancement perceptual mismatch enhancement strength of the relation: 1 Audit 2026-09-28: DOUBTFUL - read against its full span and kept, but endpoint by anaphora: 'this effect' = the goal match enhancement effect (previous sentence). Quotation withheld because this record is not cleared for redistribution. match enhancement —contrasted-with→ mismatch enhancement match enhancement mismatch enhancement strength of the relation: 1 Quotation withheld because this record is not cleared for redistribution. paired t-test paired t-test Quotation withheld because this record is not cleared for redistribution. t-test (sample-by-sample, time-resolved) t-test (sample-by-sample, time-resolved) Quotation withheld because this record is not cleared for redistribution. ANOVA (two-way) ANOVA (two-way) Quotation withheld because this record is not cleared for redistribution. permutation test permutation test Quotation withheld because this record is not cleared for redistribution. ANOVA (three-way) with Bonferroni correction for multiple comparisons ANOVA (three-way) with Bonferroni correction for multiple comparisons Quotation withheld because this record is not cleared for redistribution. correlation correlation Quotation withheld because this record is not cleared for redistribution. linear discriminant analysis with principal component analysis linear discriminant analysis with principal component analysis Quotation withheld because this record is not cleared for redistribution. standard error of the mean standard error of the mean Quotation withheld because this record is not cleared for redistribution. p-value p-value Quotation withheld because this record is not cleared for redistribution. sample-by-sample t -test sample-by-sample t -test Quotation withheld because this record is not cleared for redistribution. Monte Carlo permutations Monte Carlo permutations Quotation withheld because this record is not cleared for redistribution. linear discriminant analysis linear discriminant analysis Quotation withheld because this record is not cleared for redistribution. Bonferroni confidence interval adjustment Bonferroni confidence interval adjustment Quotation withheld because this record is not cleared for redistribution. Goal match enhancement appeared only at contacts in the left posterior hippocampus, whereas perceptual mismatch enhancement appeared bilaterally across both anterior and posterior hippocampus. Quotation withheld because this record is not cleared for redistribution. The perceptual mismatch signal began before the goal match signal in every one of the eight participants. Quotation withheld because this record is not cleared for redistribution. The two hippocampal signals divide by content: match enhancement tracks the match to the maintained goal while mismatch enhancement tracks perceptual mismatch, dissociating components of working memory within the hippocampus. Quotation withheld because this record is not cleared for redistribution. Participants whose right posterior hippocampus produced a later perceptual mismatch enhancement were more accurate, a positive correlation between latency and memory performance. Quotation withheld because this record is not cleared for redistribution. That latency-accuracy link is read as evidence that the right posterior hippocampal mismatch latency indexes the quality of memory retrieval. Quotation withheld because this record is not cleared for redistribution. In six of the eight patients, single-trial intracranial field potentials from the right hippocampus were sufficient to classify whether the trial was a match task or a switch task. Quotation withheld because this record is not cleared for redistribution. Behaviourally, responses were faster in the match task than in the switch task. Quotation withheld because this record is not cleared for redistribution. Hippocampal engagement here is attributed to the task requiring object identity and location to be bound together, in both the match and the switch task. Quotation withheld because this record is not cleared for redistribution. goal match enhancement appeared in the left posterior hippocampus between about 520 and 735 ms after probe onset Quotation withheld because this record is not cleared for redistribution. perceptual mismatch enhancement appeared bilaterally in anterior and posterior hippocampus, averaging 376 to 555 ms Quotation withheld because this record is not cleared for redistribution. mismatch enhancement began earlier than match enhancement in every participant Quotation withheld because this record is not cleared for redistribution. region latencies were 524 ms for goal match and about 405 to 430 ms for perceptual mismatch across the four subdivisions Quotation withheld because this record is not cleared for redistribution. a late perceptual match effect appeared on two electrodes at 717 and 900 ms Quotation withheld because this record is not cleared for redistribution. for each electrode and effect, the probability of the observed latency was below 0.05 Quotation withheld because this record is not cleared for redistribution. mismatch latency in the right posterior hippocampus correlated positively with memory accuracy Quotation withheld because this record is not cleared for redistribution. task demand was decodable from single trials in 6 of 8 patients, always from the right hippocampus Quotation withheld because this record is not cleared for redistribution. responses were faster in the match task than in the switch task Quotation withheld because this record is not cleared for redistribution. over 80% of trials survived artifact rejection Quotation withheld because this record is not cleared for redistribution. mismatch enhancement mismatch enhancement Quotation withheld because this record is not cleared for redistribution. latency of the enhancement effect latency of the enhancement effect Quotation withheld because this record is not cleared for redistribution. match enhancement match enhancement Quotation withheld because this record is not cleared for redistribution. delayed-match-to-sample delayed-match-to-sample Quotation withheld because this record is not cleared for redistribution. intracranial field potential intracranial field potential Quotation withheld because this record is not cleared for redistribution. object configuration object configuration Quotation withheld because this record is not cleared for redistribution. local field potential local field potential Quotation withheld because this record is not cleared for redistribution. latency of the enhancement effect latency of the enhancement effect Quotation withheld because this record is not cleared for redistribution. reaction time and accuracy reaction time and accuracy Quotation withheld because this record is not cleared for redistribution. electrode configuration electrode configuration Quotation withheld because this record is not cleared for redistribution. latency latency Quotation withheld because this record is not cleared for redistribution. task demand task demand Quotation withheld because this record is not cleared for redistribution. correct percentage correct percentage Quotation withheld because this record is not cleared for redistribution. 120 ... 8 — depth electrode contacts recorded, and epilepsy patients implanted Quotation withheld because this record is not cleared for redistribution. 126 — trials per experimental run Quotation withheld because this record is not cleared for redistribution. >80% — proportion of trials retained after artifact rejection Quotation withheld because this record is not cleared for redistribution. 1000 — random permutations computed per electrode to test the observed enhancement latencies Quotation withheld because this record is not cleared for redistribution. <0.05 — permutation probability of the observed latency, for every electrode and every significant effect Quotation withheld because this record is not cleared for redistribution. 6 out of 8 — patients whose hippocampal field potentials reliably represented the task demand in single-trial decoding Quotation withheld because this record is not cleared for redistribution. 120 depth electrode contacts in 8 patients — the sample Quotation withheld because this record is not cleared for redistribution. 520 ms to 735 ms — window of goal match enhancement after probe onset Quotation withheld because this record is not cleared for redistribution. 376 ms to 555 ms — window of perceptual mismatch enhancement Quotation withheld because this record is not cleared for redistribution. ~150 ms — how much earlier mismatch precedes match Quotation withheld because this record is not cleared for redistribution. ρ = 0.74 — correlation between right posterior mismatch latency and accuracy Quotation withheld because this record is not cleared for redistribution. 126 trials per run, 3 to 5 runs — to obtain at least 80 correct trials per participant Quotation withheld because this record is not cleared for redistribution. 6 out of 8 — patients whose task demand was decodable from hippocampal signal Quotation withheld because this record is not cleared for redistribution.

The full text of this article is not redistributable, so it is not included here. The evidence sentences are withheld with it; the tag layer and its grounding status remain. The article itself is at https://doi.org/10.1007/s12264-017-0172-8.