scholarly journals A precise and adaptive neural mechanism for predictive temporal processing in the frontal cortex

Neuron ◽  
2021 ◽  
Vol 109 (18) ◽  
pp. 2995-3011.e5
Author(s):  
Nicolas Meirhaeghe ◽  
Hansem Sohn ◽  
Mehrdad Jazayeri
2021 ◽  
Author(s):  
Nicolas Meirhaeghe ◽  
Hansem Sohn ◽  
Mehrdad Jazayeri

AbstractThe theory of predictive processing posits that the nervous system uses expectations to process information predictively. Direct empirical evidence in support of this theory however has been scarce and largely limited to sensory areas. Here, we report a precise and adaptive neural mechanism in the frontal cortex of non-human primates consistent with predictive processing of temporal events. We found that the speed at which neural states evolve over time is inversely proportional to the statistical mean of the temporal distribution of an expected stimulus. This lawful relationship was evident across multiple experiments and held true during learning: when temporal statistics underwent covert changes, neural responses underwent predictable changes that reflected the new mean. Together, these results highlight a precise mathematical relationship between temporal statistics in the environment and neural activity in the frontal cortex that could serve as a mechanistic foundation for predictive temporal processing.


1989 ◽  
Vol 155 (S7) ◽  
pp. 93-98 ◽  
Author(s):  
Nancy C. Andreasen

When Kraepelin originally defined and described dementia praecox, he assumed that it was due to some type of neural mechanism. He hypothesised that abnormalities could occur in a variety of brain regions, including the prefrontal, auditory, and language regions of the cortex. Many members of his department, including Alzheimer and Nissl, were actively involved in the search for the neuropathological lesions that would characterise schizophrenia. Although Kraepelin did not use the term ‘negative symptoms', he describes them comprehensively and states explicitly that he believes the symptoms of schizophrenia can be explained in terms of brain dysfunction:“If it should be confirmed that the disease attacks by preference the frontal areas of the brain, the central convolutions and central lobes, this distribution would in a certain measure agree with our present views about the site of the psychic mechanisms which are principally injured by the disease. On various grounds, it is easy to believe that the frontal cortex, which is specially well developed in man, stands in closer relation to his higher intellectual abilities, and these are the faculties which in our patients invariably suffer profound loss in contrast to memory and acquired ability.” Kraepelin (1919, p. 219)


2019 ◽  
Author(s):  
Qiang Zhang ◽  
Dennis Jung ◽  
Travis Larson ◽  
Youngcho Kim ◽  
Nandakumar S. Narayanan

AbstractNeurodegenerative diseases such as Parkinson’s disease (PD), dementia with Lewy Bodies (DLB), and Alzheimer’s disease (AD) involve loss of cholinergic neurons in the basal forebrain. Here, we investigate how cholinergic dysfunction impacts the frontal cortex during interval timing, a process that can be impaired in PD and AD patients. Interval timing requires participants to estimate an interval of several seconds by making a motor response, and depends on the medial frontal cortex (MFC), which is richly innervated by basal forebrain cholinergic projections. Past work has shown that scopolamine, a muscarinic cholinergic receptor antagonist, reliably impairs interval timing. We tested the hypothesis that scopolamine would attenuate time-related ramping, a key form of temporal processing in the MFC. We recorded neuronal ensembles from 8 mice during performance of a 12-s fixed-interval timing task, which was impaired by the administration of scopolamine. Consistent with past work, scopolamine impaired timing. To our surprise, we found that time-related ramping was unchanged, but stimulus-related activity was enhanced in the MFC. Principal component analyses revealed no consistent changes in time-related ramping components, but did reveal changes in higher components. Taken together, these data indicate that scopolamine changes stimulus-processing rather than temporal processing in the MFC. These data could help understand how cholinergic dysfunction affects cortical circuits in diseases such as PD, DLB, and AD.HighlightsThe cholinergic muscarinic inhibitor scopolamine impairs interval timing behavior.Scopolamine does not change time-related ramping activity in the medial frontal cortex.Medial prefrontal stimulus-related modulation increased


1988 ◽  
Vol 26 (2) ◽  
pp. 307-318 ◽  
Author(s):  
David S. Olton ◽  
Gary L. Wenk ◽  
Russell M. Church ◽  
Warren H. Meck

2017 ◽  
Author(s):  
Y Yeshurun ◽  
M Nguyen ◽  
U. Hasson

AbstractChanging just a few words in a story can induce a substantial change in the overall narrative. How does the brain accumulate and process local and sparse changes, creating a unique situation model of the story, over the course of a real-life narrative? Recently, we mapped a hierarchy of processing timescales in the brain: from early sensory areas that integrate information over 10s-100s ms, to high-order areas that integrate information over many seconds to minutes. Based on this hierarchy, we hypothesize that early sensory areas would be sensitive to local changes in word use, but that there will be increasingly divergent neural responses along the processing hierarchy as higher-order areas accumulate and amplify these local changes. To test this hypothesis, we created two structurally related but interpretively distinct narratives by changing some individual words. We found that the neural response distance between the stories was amplified as story information is transferred from low-level regions (e.g. early auditory cortex) to high-level regions (e.g precuneus and prefrontal cortex) and that the neural difference between stories is highly correlated with an area’s ability to integrate information over time. Our results suggest a neural mechanism by which two similar situations become easy to distinguish.


2008 ◽  
Vol 31 (1) ◽  
pp. 30-30 ◽  
Author(s):  
Marco Iacoboni

AbstractDepth electrode recordings in the human mesial frontal cortex have revealed individual neurons with mirror properties. A third of these cells have excitatory properties during action execution and inhibitory properties during action observation. These cells – which we call super mirror neurons – provide the neural mechanism that implements the functions of layers 3+4 of the shared circuits model (SCM).


Author(s):  
MB. Tank Buschmann

Development of oligodendrocytes in rat corpus callosum was described as a sequential change in cytoplasmic density which progressed from light to medium to dark (1). In rat optic nerve, changes in cytoplasmic density were not observed, but significant changes in morphology occurred just prior to and during myelination (2). In our study, the ultrastructural development of oligodendrocytes was studied in newborn, 5-, 10-, 15-, 20-day and adult frontal cortex of the golden hamster (Mesocricetus auratus).Young and adult hamster brains were perfused with paraformaldehyde-glutaraldehyde in sodium cacodylate buffer at pH 7.3 according to the method of Peters (3). Tissue samples of layer V of the frontal cortex were post-fixed in 2% osmium tetroxide, dehydrated in acetone and embedded in Epon-Araldite resin.


2019 ◽  
Vol 28 (2) ◽  
pp. 322-332 ◽  
Author(s):  
Aurora J. Weaver ◽  
Jeffrey J. DiGiovanni ◽  
Dennis T. Ries
Keyword(s):  

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