On the Processing of Semantic Aspects of Experience in the Anterior Medial Temporal Lobe: An Event-related fMRI Study

2010 ◽  
Vol 22 (3) ◽  
pp. 590-601 ◽  
Author(s):  
Patric Meyer ◽  
Axel Mecklinger ◽  
Angela D. Friederici
Keyword(s):  
Recognition Memory ◽  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Semantic Processing ◽  
Sentence Comprehension ◽  
Declarative Memory ◽  
Specific Information ◽  
New Words ◽  
Subsequent Test ◽  
Fmri Study

Recognition memory based on familiarity judgments is a form of declarative memory that has been repeatedly associated with the anterior medial temporal lobe. It has been argued that this region sustains familiarity-based recognition not only by retrieving item-specific information but also by coding for those semantic aspects of an event that support later familiarity-based recognition. Here, we used event-related fMRI to directly examine whether the contribution of anterior medial temporal lobe to declarative memory indeed results from its role in processing semantic aspects of an event. For this purpose, a sentence comprehension task was employed which varied the demands of semantic and syntactic processing of the sentence-final word. By presenting those sentence-final words together with new words in a subsequent incidental recognition memory test, we were able to determine the mnemonic consequences of presenting words in different sentential contexts. Results showed that enhanced semantic processing during comprehension activates regions in medial temporal lobe cortex and leads to response suppression in partly overlapping regions when the word is successfully retrieved. Data from a behavioral follow-up study support the view that enhanced semantic processing at study enhances familiarity-based remembering in a subsequent test phase.

scholarly journals Differences in Mnemonic Processing by Neurons in the Human Hippocampus and Parahippocampal Regions

2006 ◽  
Vol 18 (10) ◽  
pp. 1654-1662 ◽  
Author(s):  
Indre V. Viskontas ◽  
Barbara J. Knowlton ◽  
Peter N. Steinmetz ◽  
Itzhak Fried
Keyword(s):  
Recognition Memory ◽  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Computational Models ◽  
Systems Approach ◽  
Declarative Memory ◽  
Neuronal Firing ◽  
Psychological Review ◽  
Firing Patterns ◽  
Human Hippocampus

Different structures within the medial-temporal lobe likely make distinct contributions to declarative memory. In particular, several current psychological and computational models of memory predict that the hippocampus and parahippocampal regions play different roles in the formation and retrieval of declarative memories [e.g., Norman, K. A., & O'Reilly, R. C. Modeling hippocampal and neocortical contributions to recognition memory: A complementary-learning systems approach. Psychological Review, 110, 611–646, 2003]. Here, we examined the neuronal firing patterns in these two regions during recognition memory. Recording directly from neurons in humans, we find that cells in both regions respond to novel stimuli with an increase in firing (excitation). However, already on the second presentation of a stimulus, neurons in these regions show very different firing patterns. In the parahippocampal region there is dramatic decrease in the number of cells responding to the stimuli, whereas in the hippocampus there is recruitment of a large subset of neurons showing inhibitory (decrease from baseline firing) responses. These results suggest that inhibition is a mechanism used by cells in the human hippocampus to support sparse coding in mnemonic processing. The findings also provide further evidence for the division of labor in the medial-temporal lobe with respect to declarative memory processes.

scholarly journals Semantic Processing Impairment in Patients with Temporal Lobe Epilepsy

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Amanda G. Jaimes-Bautista ◽  
Mario Rodríguez-Camacho ◽  
Iris E. Martínez-Juárez ◽  
Yaneth Rodríguez-Agudelo
Keyword(s):  
Episodic Memory ◽  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Semantic Processing ◽  
Functional Neuroimaging ◽  
Declarative Memory ◽  
Semantic Networks ◽  
N400 Effect ◽  
Functional Reorganization ◽  
Electrophysiological Studies

The impairment in episodic memory system is the best-known cognitive deficit in patients with temporal lobe epilepsy (TLE). Recent studies have shown evidence of semantic disorders, but they have been less studied than episodic memory. The semantic dysfunction in TLE has various cognitive manifestations, such as the presence of language disorders characterized by defects in naming, verbal fluency, or remote semantic information retrieval, which affects the ability of patients to interact with their surroundings. This paper is a review of recent research about the consequences of TLE on semantic processing, considering neuropsychological, electrophysiological, and neuroimaging findings, as well as the functional role of the hippocampus in semantic processing. The evidence from these studies shows disturbance of semantic memory in patients with TLE and supports the theory of declarative memory of the hippocampus. Functional neuroimaging studies show an inefficient compensatory functional reorganization of semantic networks and electrophysiological studies show a lack of N400 effect that could indicate that the deficit in semantic processing in patients with TLE could be due to a failure in the mechanisms of automatic access to lexicon.

scholarly journals Localization of Syntactic and Semantic Brain Responses using Magnetoencephalography

2007 ◽  
Vol 19 (7) ◽  
pp. 1193-1205 ◽  
Author(s):  
Elisabet Service ◽  
Päivi Helenius ◽  
Sini Maury ◽  
Riitta Salmelin
Keyword(s):  
Temporal Lobe ◽  
Semantic Processing ◽  
Sentence Comprehension ◽  
Right Hemisphere ◽  
Temporal Cortex ◽  
Word Class ◽  
Sentence Reading ◽  
Word Onset ◽  
Semantic Errors ◽  
The Right

Electrophysiological methods have been used to study the temporal sequence of syntactic and semantic processing during sentence comprehension. Two responses associated with syntactic violations are the left anterior negativity (LAN) and the P600. A response to semantic violation is the N400. Although the sources of the N400 response have been identified in the left (and right) temporal lobe, the neural signatures of the LAN and P600 have not been revealed. The present study used magnetoencephalography to localize sources of syntactic and semantic activation in Finnish sentence reading. Participants were presented with sentences that ended in normally inf lected nouns, nouns in an unacceptable case, verbs instead of nouns, or nouns that were correctly inflected but made no sense in the context. Around 400 msec, semantically anomalous last words evoked strong activation in the left superior temporal lobe with significant activation also for word class errors (N400). Weaker activation was seen for the semantic errors in the right hemisphere. Later, 600-800 msec after word onset, the strongest activation was seen to word class and morphosyntactic errors (P600). Activation was significantly weaker to semantically anomalous and correct words. The P600 syntactic activation was localized to bilateral sources in the temporal lobe, posterior to the N400 sources. The results suggest that the same general region of the superior temporal cortex gives rise to both LAN and N400 with bilateral reactivity to semantic manipulation and a left hemisphere effect to syntactic manipulation. The bilateral P600 response was sensitive to syntactic but not semantic factors.

P3-373: STRUCTURAL INTEGRITY OF THE MEDIAL TEMPORAL LOBE AND RECOGNITION MEMORY FOLLOWING NATURAL AND SURGICAL MENOPAUSE

2006 ◽  
Vol 14 (7S_Part_23) ◽  
pp. P1234-P1234
Author(s):  
Nicole J. Gervais ◽  
Elizabeth Baker-Sullivan ◽  
Cheryl Grady ◽  
Rosanna Olsen ◽  
Laura Gravelsins ◽  
...  
Keyword(s):  
Recognition Memory ◽  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Structural Integrity ◽  
Surgical Menopause

scholarly journals Syntactic and Semantic Modulation of Neural Activity during Auditory Sentence Comprehension

2006 ◽  
Vol 18 (4) ◽  
pp. 665-679 ◽  
Author(s):  
Colin Humphries ◽  
Jeffrey R. Binder ◽  
David A. Medler ◽  
Einat Liebenthal
Keyword(s):  
Temporal Lobe ◽  
Word Order ◽  
Semantic Processing ◽  
Sentence Comprehension ◽  
Functional Neuroimaging ◽  
Syntactic Structure ◽  
Imaging Study ◽  
Angular Gyrus ◽  
Semantic Structure ◽  
Word Lists

In previous functional neuroimaging studies, left anterior temporal and temporal-parietal areas responded more strongly to sentences than to randomly ordered lists of words. The smaller response for word lists could be explained by either (1) less activation of syntactic processes due to the absence of syntactic structure in the random word lists or (2) less activation of semantic processes resulting from failure to combine the content words into a global meaning. To test these two explanations, we conducted a functional magnetic resonance imaging study in which word order and combinatorial word meaning were independently manipulated during auditory comprehension. Subjects heard six different stimuli: normal sentences, semantically incongruent sentences in which content words were randomly replaced with other content words, pseudoword sentences, and versions of these three sentence types in which word order was randomized to remove syntactic structure. Effects of syntactic structure (greater activation to sentences than to word lists) were observed in the left anterior superior temporal sulcus and left angular gyrus. Semantic effects (greater activation to semantically congruent stimuli than either incongruent or pseudoword stimuli) were seen in widespread, bilateral temporal lobe areas and the angular gyrus. Of the two regions that responded to syntactic structure, the angular gyrus showed a greater response to semantic structure, suggesting that reduced activation for word lists in this area is related to a disruption in semantic processing. The anterior temporal lobe, on the other hand, was relatively insensitive to manipulations of semantic structure, suggesting that syntactic information plays a greater role in driving activation in this area.

scholarly journals Patterns of single-neuron activity during associative recognition memory in the human medial temporal lobe

NeuroImage ◽  
2020 ◽  
Vol 221 ◽  
pp. 117214
Author(s):  
M. Derner ◽  
G. Dehnen ◽  
L. Chaieb ◽  
T.P. Reber ◽  
V. Borger ◽  
...  
Keyword(s):  
Recognition Memory ◽  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Single Neuron ◽  
Associative Recognition ◽  
Neuron Activity ◽  
Single Neuron Activity

scholarly journals An Exploratory Study of the Relationship between Face Recognition Memory and the Volume of Medial Temporal Lobe Structures in Healthy Young Males

1998 ◽  
Vol 11 (1) ◽  
pp. 3-20 ◽  
Author(s):  
Clare E. Mackay ◽  
Neil Roberts ◽  
Andrew R. Mayes ◽  
John J. Downes ◽  
Jonathan K. Foster ◽  
...  
Keyword(s):  
Face Recognition ◽  
Recognition Memory ◽  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Multiple Comparisons ◽  
Cerebral Hemispheres ◽  
Parahippocampal Gyrus ◽  
Bonferroni Correction ◽  
Temporal Pole ◽  
The Right

A rigorous new methodology was applied to the study of structure function relationships in the living human brain. Face recognition memory (FRM) and other cognitive measures were made in 29 healthy young male subjects (mean age = 21.7 years) and related to volumetric measurements of their cerebral hemispheres and of structures in their medial temporal lobes, obtained using the Cavalieri method in combination with high resolution Magnetic Resonance Imaging (MRI. Greatest proportional variability in volumes was found for the lateral ventricles (57%) for the cerebral hemispheres (8%) in the mean volumes of the hippocampus, parahippocampal gyrus, amygdala, caudate nucleus, temporal pole and temporal lobe on the right and left sides of the brain. The volumes of the right and left parahippocampal gyrus, temporal pole, temporal lobe, and left hippocampus were, prior to application of the Bonferroni correction to take account of 12 multiple comparisons, significantly correlated with the volume of the corresponding hemisphere (p< 0.05). The volumes of all structures were highly correlated (p< 0.0002 for all comparisons) between the two cerebral hemispheres. There were no positive relationships between structure volumes and FRM score. However, the volume of the right amygdala was, prior to application of the Bonferroni correction to take account of 38~multiple comparisons, found to be significantly smaller in the five most consistent high scorers compared to the five most consistent low scorers (t= 2.77,p= 0.025). The implications for possible relationships between healthy medial temporal lobe structures and memory are discussed.

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