The Neurophysiology of Memory

The Neurophysiology of Memory Suzuki Eichenbaum

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The Neurophysiology of Memory 2000 Annals of the New York Academy of Sciences 10.1111/j.1749-6632.2000.tb06726.x Suzuki2000-the-neurophysiology-of-memory Suzuki2000-the-neurophysiology-of-memory.txt, the project's staged copy 832961790eeaeb6d583799e2fe0df6c47bc2a3a0 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 existence Quotation withheld because this record is not cleared for redistribution. medial temporal lobe neuronal correlates of recognition and associative memory Quotation withheld because this record is not cleared for redistribution. review review Quotation withheld because this record is not cleared for redistribution. mechanisms Because the hippocampus receives polymodal rather than unimodal input, it is positioned to combine the cortex's stimulus-selective signals into complex conjunctions or to abstract a general output signal from them, which is why its mnemonic code is abstracted rather than stimulus-specific Quotation withheld because this record is not cleared for redistribution. mechanisms The occasional stimulus-selective, cortex-type recognition signals seen in the hippocampus are inherited through the direct anatomical projections from perirhinal and entorhinal cortex to area CA1 Quotation withheld because this record is not cleared for redistribution. mechanisms At long delays interference builds up, so contextual/episodic conjunctive information becomes the useful cue for recognition, which is why hippocampal damage bites hardest at long delays Quotation withheld because this record is not cleared for redistribution. mechanisms Cortical stimulus-stimulus association works by a cue acquiring the capacity to generate the neural representation of the stimulus it was paired with, producing pair-coding and pair-recall firing Quotation withheld because this record is not cleared for redistribution. The parahippocampal/postrhinal cortex is excluded from the review because too little is known about its mnemonic activity. what this limits: the anatomical coverage of the review, and the field's coverage it reflects: MUCH LESS IS KNOWN ABOUT THE PATTERNS OF MNEMONIC ACTIVITY IN THE PARAHIPPOCAMPAL/POSTRHINAL CORTEX, AND THEREFORE THIS REGION WILL NOT BE DISCUSSED Quotation withheld because this record is not cleared for redistribution. No direct comparison exists that would identify which testing conditions produce similar versus different coding in cortex and hippocampus. what this limits: any comparison across testing conditions: A COMPELLING DIRECT COMPARISON THAT REVEALS THE CRITICAL ASPECTS OF THESE DIFFERENT TESTING CONDITIONS HAS YET TO BE MADE Quotation withheld because this record is not cleared for redistribution. The scope of associative-memory signals across the medial temporal lobe is not yet established. what this limits: the reach of the associative-memory account: ADDITIONAL COMPARATIVE STUDIES ARE NEEDED TO DETERMINE THE FULL SCOPE OF NEURAL SIGNALS UNDERLYING ASSOCIATIVE MEMORY ACROSS THE MEDIAL TEMPORAL LOBE Quotation withheld because this record is not cleared for redistribution. A specific empirical gap: intervening stimuli have not been tested against selective delay activity in rat perirhinal/entorhinal cortex. what this limits: the rat delay-activity literature specifically: THE EFFECT OF INTERVENING STIMULI ON THE SELECTIVE DELAY ACTIVITY IN THE PERIRHINAL OR ENTORHINAL CORTICES OF RATS HAS NOT BEEN EXAMINED Quotation withheld because this record is not cleared for redistribution. The anatomy is used to support two opposite expectations, both stated in the same passage. what this limits: any finding of regional difference in the medial temporal lobe: the review argues from differing convergent cortical input that each area may be characterised by distinct patterns of mnemonic activity, and separately argues from parallel projections that all these regions access similar information Quotation withheld because this record is not cleared for redistribution. How many neurons show the effect depends on which version of the task was run. what this limits: any proportion of match-enhancement neurons quoted from this work: the proportion was substantially higher during the ABBA version of the task than during the standard version Quotation withheld because this record is not cleared for redistribution. The neuropsychological literature is stated to give only indirect insight into neural activity. what this limits: any inference from lesion studies to patterns of neural activity: the authors state that neuropsychological studies of brain-damaged patients or experimental animals provide only indirect insights into the specific patterns of activity underlying declarative memory Quotation withheld because this record is not cleared for redistribution. match enhancement match enhancement Quotation withheld because this record is not cleared for redistribution. ABBA version ABBA version Quotation withheld because this record is not cleared for redistribution. convergent cortical input convergent cortical input Quotation withheld because this record is not cleared for redistribution. parallel projections parallel projections Quotation withheld because this record is not cleared for redistribution. declarative memories declarative memories Quotation withheld because this record is not cleared for redistribution. the anatomical argument - TWO OPPOSITE PREDICTIONS FROM THE SAME STRUCTURES: differing convergent cortical input is read as predicting distinct mnemonic patterns per area, and strong parallel projections as predicting shared access to similar information; both are stated, so neither a difference nor a similarity result can discriminate between them Quotation withheld because this record is not cleared for redistribution. match enhancement - A PROPORTION THAT MOVES WITH THE PROTOCOL: substantially more neurons show it in the ABBA version of the task than in the standard version, so 'how many neurons do X' is a fact about the task that was run as much as about the tissue Quotation withheld because this record is not cleared for redistribution. neuropsychological evidence - INDIRECT BY THE AUTHORS' OWN DESCRIPTION: lesion work on patients and animals is said to provide only indirect insight into the specific patterns of neural activity, which is why the review turns to recording Quotation withheld because this record is not cleared for redistribution. builds-on → Sakai and Miyashita (ref. 52), pair-coding neurons; and Wood et al. (ref. 37), conjunctive coding neurons Quotation withheld because this record is not cleared for redistribution. ABBA version —causes→ match enhancement ABBA version match enhancement direction on the measure: increases · strength of the relation: 1 Quotation withheld because this record is not cleared for redistribution. Across humans, monkeys and rats the patterns of memory-related firing in the medial temporal lobe are largely the same, so mnemonic signals are conserved across species. Quotation withheld because this record is not cleared for redistribution. Unlike the stimulus-selective recognition signals of cortex, hippocampal-formation neurons convey abstracted recognition memory signals. Quotation withheld because this record is not cleared for redistribution. Selective delay activity in perirhinal cortex was disrupted by even a single intervening stimulus. Quotation withheld because this record is not cleared for redistribution. Match-enhancement neurons were enhanced only when the behaviourally relevant stimulus was repeated. Quotation withheld because this record is not cleared for redistribution. Match suppression is not sensory fatigue or habituation, because the suppression is abolished when the same stimulus reappears as the sample on the next trial. Quotation withheld because this record is not cleared for redistribution. Hippocampal neurons nearly always showed different, independent spatial firing patterns in the two environments. Quotation withheld because this record is not cleared for redistribution. Damage limited to the hippocampus produces the most striking recognition impairments at long delays of many minutes to hours. Quotation withheld because this record is not cleared for redistribution. About a third to two fifths of human hippocampal (35%) and entorhinal (40%) neurons recorded at retrieval were influenced by whether the item was new or old. Quotation withheld because this record is not cleared for redistribution. Pair-recall neurons increased firing during the delay after the associate of their optimal cue, leading up to a robust response to that cue. Quotation withheld because this record is not cleared for redistribution. associative memory associative memory Quotation withheld because this record is not cleared for redistribution. priming priming Quotation withheld because this record is not cleared for redistribution. hippocampal formation hippocampal formation Quotation withheld because this record is not cleared for redistribution. "abstracted" recognition signal "abstracted" recognition signal Quotation withheld because this record is not cleared for redistribution. conjunctive coding conjunctive coding Quotation withheld because this record is not cleared for redistribution. familiarity effect familiarity effect Quotation withheld because this record is not cleared for redistribution. physical characteristics physical characteristics Quotation withheld because this record is not cleared for redistribution. location of the odor presentation location of the odor presentation Quotation withheld because this record is not cleared for redistribution. 47% ... 94% — proportion of visually responsive monkey entorhinal (47%) versus perirhinal (94%) neurons that respond selectively to particular visual stimuli Quotation withheld because this record is not cleared for redistribution. 35% ... 11% — proportion of sampled rat lateral entorhinal (35%) versus perirhinal (11%) neurons with odor-specific firing Quotation withheld because this record is not cleared for redistribution. 15 of 120 or 12.5% — share of responsive hippocampal neurons that differentiated match from nonmatch presentations Quotation withheld because this record is not cleared for redistribution. 13 of 91 or 14% — share of responsive rat hippocampal neurons carrying an abstracted match-nonmatch signal independent of odor identity Quotation withheld because this record is not cleared for redistribution. 18 of 91 or 20% ... 4 of 91 or 4% — share of responsive hippocampal neurons coding match-nonmatch status conjointly with position (20%), or with both position and odor identity (4%) Quotation withheld because this record is not cleared for redistribution. 24 hours — longest delay across which repetition suppression to a once-novel stimulus persists Quotation withheld because this record is not cleared for redistribution. 74 neurons in 3 regions — size of the human single-unit sample in the recognition study whose results matched the animal cortical pattern Quotation withheld because this record is not cleared for redistribution. 24 — number of fractal stimulus patterns used in the paired-associate study of inferotemporal and perirhinal neurons Quotation withheld because this record is not cleared for redistribution. between 1 and 10 hours — encoding-to-retrieval interval in the human single-unit recognition task, a delay known to challenge amnesic patients 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/10.1111/j.1749-6632.2000.tb06726.x.