scholarly journals Cognitive Control of Episodic Memory in Schizophrenia: Differential Role of Dorsolateral and Ventrolateral Prefrontal Cortex

2015 ◽  
Vol 9 ◽  
Author(s):  
John D. Ragland ◽  
Charan Ranganath ◽  
Joshua Phillips ◽  
Megan A. Boudewyn ◽  
Ann M. Kring ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Cognitive Control ◽  
Episodic Memory ◽  
Ventrolateral Prefrontal Cortex

Acoustic Features of Rhesus Vocalizations and Their Representation in the Ventrolateral Prefrontal Cortex

2007 ◽  
Vol 97 (2) ◽  
pp. 1470-1484 ◽  
Author(s):  
Yale E. Cohen ◽  
Frédéric Theunissen ◽  
Brian E. Russ ◽  
Patrick Gill
Keyword(s):  
Prefrontal Cortex ◽  
Acoustic Properties ◽  
Acoustic Features ◽  
Ventrolateral Prefrontal Cortex ◽  
Communication Signals ◽  
First Order ◽  
Natural Stimuli ◽  
Spectrotemporal Receptive Field ◽  
Auditory Objects

Communication is one of the fundamental components of both human and nonhuman animal behavior. Auditory communication signals (i.e., vocalizations) are especially important in the socioecology of several species of nonhuman primates such as rhesus monkeys. In rhesus, the ventrolateral prefrontal cortex (vPFC) is thought to be part of a circuit involved in representing vocalizations and other auditory objects. To further our understanding of the role of the vPFC in processing vocalizations, we characterized the spectrotemporal features of rhesus vocalizations, compared these features with other classes of natural stimuli, and then related the rhesus-vocalization acoustic features to neural activity. We found that the range of these spectrotemporal features was similar to that found in other ensembles of natural stimuli, including human speech, and identified the subspace of these features that would be particularly informative to discriminate between different vocalizations. In a first neural study, however, we found that the tuning properties of vPFC neurons did not emphasize these particularly informative spectrotemporal features. In a second neural study, we found that a first-order linear model (the spectrotemporal receptive field) is not a good predictor of vPFC activity. The results of these two neural studies are consistent with the hypothesis that the vPFC is not involved in coding the first-order acoustic properties of a stimulus but is involved in processing the higher-order information needed to form representations of auditory objects.

Transient Disruption of Ventrolateral Prefrontal Cortex During Verbal Encoding Affects Subsequent Memory Performance

2005 ◽  
Vol 94 (1) ◽  
pp. 688-698 ◽  
Author(s):  
Itamar Kahn ◽  
Alvaro Pascual-Leone ◽  
Hugo Theoret ◽  
Felipe Fregni ◽  
Dav Clark ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Episodic Memory ◽  
Phonological Processing ◽  
Functional Neuroimaging ◽  
Memory Performance ◽  
Single Pulse ◽  
Stimulus Onset ◽  
Ventrolateral Prefrontal Cortex ◽  
Episodic Encoding ◽  
Functional Shift

Episodic memory supports conscious remembrance of everyday experience. Prior functional neuroimaging data indicate that episodic encoding during phonological task performance is correlated with activation in bilateral posterior ventrolateral prefrontal cortex (pVLPFC), although uncertainty remains regarding whether these prefrontal regions make necessary contributions to episodic memory formation. Using functional MRI data to guide application of single-pulse transcranial magnetic stimulation (spTMS), this study examined the necessity of left and right pVLPFC for episodic encoding (as expressed through subsequent memory performance). To assess the timing of critical computations, pVLPFC function was transiently disrupted at different poststimulus onset times while subjects made syllable decisions about visually presented familiar and unfamiliar words; subsequent memory for these stimuli was measured. Results revealed that left pVLPFC disruption during encoding of familiar words impaired subsequent memory, expressed as a decline in recognition confidence, with disruption being maximal at 380 ms after stimulus onset. In contrast, right pVLPFC disruption facilitated subsequent memory for familiar words, expressed as an increase in medium confidence recognition, with this facilitation being maximal at 380 ms. Finally, phonological (syllable) decision accuracy was facilitated by right pVLPFC disruption, with this effect being maximal at 340 ms, but was unaffected by left pVLPFC disruption. These findings suggest that left pVLPFC mechanisms onset between 300 and 400 ms during phonological processing of words, with these mechanisms appearing necessary for effective episodic encoding. In contrast, disruption of correlated mechanisms in right pVLPFC facilitates encoding, perhaps by inducing a functional shift in the mechanisms engaged during learning.

scholarly journals Similar or Different? The Role of the Ventrolateral Prefrontal Cortex in Similarity Detection

PLoS ONE ◽  
2012 ◽  
Vol 7 (3) ◽  
pp. e34164 ◽  
Author(s):  
Béatrice Garcin ◽  
Emmanuelle Volle ◽  
Bruno Dubois ◽  
Richard Levy
Keyword(s):  
Prefrontal Cortex ◽  
Ventrolateral Prefrontal Cortex ◽  
Similarity Detection
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