Laminar Computing by Cerebral Cortex

2021 ◽  
pp. 353-369
Author(s):  
Stephen Grossberg
Keyword(s):  
Cerebral Cortex ◽  
Adaptive Algorithms ◽  
General Purpose ◽  
Cortical Layers ◽  
Top Down ◽  
Bottom Up ◽  
Feedback Processing ◽  
Laminar Organization ◽  
Intelligent Behavior ◽  
Language And Cognition

The cerebral cortex computes the highest forms of biological intelligence in all sensory and cognitive modalities. Neocortical cells are organized into circuits that form six cortical layers in all cortical areas that carry out perception and cognition. Variations in cell properties within these layers and their connections have been used to classify the cerebral cortex into more than fifty divisions, or areas, to which distinct functions have been attributed. Why the cortex has a laminar organization for the control of behavior has, however, remained a mystery until recently. Also mysterious has been how variations on this ubiquitous laminar cortical design can give rise to so many different types of intelligent behavior. This chapter explains how Laminar Computing contributes to biological intelligence, and how layered circuits of neocortical cells support all the various kinds of higher-order biological intelligence, including vision, language, and cognition, using variations of the same canonical laminar circuit. This canonical circuit can be used in general-purpose VLSI chips that can be specialized to carry out different kinds of biological intelligence, and seamlessly joined together to control autonomous adaptive algorithms and mobile robots. These circuits show how preattentive automatic bottom-up processing and attentive task-selective top-down processing are joined together in the deeper cortical layers to form a decision interface. Here, bottom-up and top-down constraints cooperate and compete to generate the best decisions, by combining properties of fast feedforward and feedback processing, analog and digital computing, and preattentive and attentive learning, including laminar ART properties such as analog coherence.

scholarly journals A Canonical Laminar Neocortical Circuit Whose Bottom-Up, Horizontal, and Top-Down Pathways Control Attention, Learning, and Prediction

2021 ◽  
Vol 15 ◽  
Author(s):  
Stephen Grossberg
Keyword(s):  
Decision Making ◽  
Working Memory ◽  
Cerebral Cortex ◽  
Speech Perception ◽  
Category Learning ◽  
Top Down ◽  
Human Cerebral Cortex ◽  
Bottom Up ◽  
3D Vision

All perceptual and cognitive circuits in the human cerebral cortex are organized into layers. Specializations of a canonical laminar network of bottom-up, horizontal, and top-down pathways carry out multiple kinds of biological intelligence across different neocortical areas. This article describes what this canonical network is and notes that it can support processes as different as 3D vision and figure-ground perception; attentive category learning and decision-making; speech perception; and cognitive working memory (WM), planning, and prediction. These processes take place within and between multiple parallel cortical streams that obey computationally complementary laws. The interstream interactions that are needed to overcome these complementary deficiencies mix cell properties so thoroughly that some authors have noted the difficulty of determining what exactly constitutes a cortical stream and the differences between streams. The models summarized herein explain how these complementary properties arise, and how their interstream interactions overcome their computational deficiencies to support effective goal-oriented behaviors.

scholarly journals Dissociable laminar profiles of concurrent bottom-up and top-down modulation in the human visual cortex

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Samuel JD Lawrence ◽  
David G Norris ◽  
Floris P de Lange
Keyword(s):  
Cortical Layer ◽  
Stimulus Contrast ◽  
Cortical Layers ◽  
Top Down ◽  
Brain Areas ◽  
Bottom Up ◽  
Bold Responses ◽  
Recent Developments ◽  
Feature Based ◽  
Human Neuroimaging

Recent developments in human neuroimaging make it possible to non-invasively measure neural activity from different cortical layers. This can potentially reveal not only which brain areas are engaged by a task, but also how. Specifically, bottom-up and top-down responses are associated with distinct laminar profiles. Here, we measured lamina-resolved fMRI responses during a visual task designed to induce concurrent bottom-up and top-down modulations via orthogonal manipulations of stimulus contrast and feature-based attention. BOLD responses were modulated by both stimulus contrast (bottom-up) and by engaging feature-based attention (top-down). Crucially, these effects operated at different cortical depths: Bottom-up modulations were strongest in the middle cortical layer and weaker in deep and superficial layers, while top-down modulations were strongest in the superficial layers. As such, we demonstrate that laminar activity profiles can discriminate between concurrent top-down and bottom-up processing, and are diagnostic of how a brain region is activated.

scholarly journals Dissociable laminar profiles of concurrent bottom-up and top-down modulation in the human visual cortex

2018 ◽  
Author(s):  
Samuel J. D. Lawrence ◽  
David G. Norris ◽  
Floris P. de Lange
Keyword(s):  
Cortical Layer ◽  
Stimulus Contrast ◽  
Cortical Layers ◽  
Top Down ◽  
Brain Areas ◽  
Bottom Up ◽  
Bold Responses ◽  
Recent Developments ◽  
Feature Based ◽  
Human Neuroimaging

AbstractRecent developments in human neuroimaging make it possible to non-invasively measure neural activity from different cortical layers. This can potentially reveal not only which brain areas are engaged by a task, but also how. Specifically, bottom-up and top-down responses are associated with distinct laminar profiles. Here, we measured lamina-resolved fMRI responses during a visual task designed to induce concurrent bottom-up and top-down modulations via orthogonal manipulations of stimulus contrast and feature-based attention. BOLD responses were modulated by both stimulus contrast (bottom-up) and by engaging feature-based attention (top-down). Crucially, these effects operated at different cortical depths: Bottom-up modulations were strongest in the middle cortical layer, while top-down modulations were strong at all depths, being significantly stronger in deep and superficial layers compared to bottom-up effects. As such, we demonstrate that laminar activity profiles can discriminate between concurrent top-down and bottom-up processing, and are diagnostic of how a brain region is activated.

scholarly journals English and Arabic Inscriptions in the Linguistic Landscape of Yemen: A Multilingual Writing Approach

2017 ◽  
Vol 6 (4) ◽  
pp. 149 ◽  
Author(s):  
Anwar A. H. Al-Athwary
Keyword(s):  
Public Space ◽  
Low Frequency ◽  
Salient Feature ◽  
General Purpose ◽  
Linguistic Landscape ◽  
Top Down ◽  
Bottom Up ◽  
The Public ◽  
Standard Arabic ◽  
Multilingual Writing

The present paper investigates the multilingual written texts of the signboards in the public space of Yemen. It attempts to apply Reh's (2004) typology of multilingual writing. Reh introduces four strategies of multilingualism: duplicating, fragmentary, overlapping, and complementary. They refer to the arrangement of information in the inscriptions of multilingual signs in a given linguistic landscape (LL). To achieve this purpose, a data corpus of 755 multilingual signs in the LL of Yemen has been used, the majority of which are bilingual in Arabic and English. The analysis showed that all four strategies of duplicating, fragmentary, overlapping, and complementary multilingual writings were generally employed in Sana'a's LL. While overlapping and complementary multilingualism were totally absent in the top-down signs, duplicating and fragmentary multilingualism had much higher frequency over overlapping and complementary ones in bottom-up signs. Keeping in mind that speech community in Yemen is monolingual in Arabic, the absence or low frequency of overlapping, and complementary signs in both top-down and bottom-up levels can be explained by the fact that these two types of texts presuppose multilingual readers since knowledge of all the languages involved is necessary to understand the whole message. The model of writing mimicry system proposed by Sutherland (2015) is also examined. Writing mimicry system was found to be a salient feature of the public space of Yemen performing some specific functions; it is only used for advertising and promotional purposes rather than expressing the identity of ethnolinguistic minorities. The study also revealed that Sana'a multilingual LL is characterized by the use of Arabicised English, glocalisation and multifunctional signs, all of which are employed to serve a general purpose of promoting, and advertising commodities and showing modernity and success. Standard Arabic appears on almost all of both top-down and bottom-up signs. The scarce use of Yemeni Arabic is indicative of the notion of Arab nationalism. Linguistic nationalism refers to the communicative and symbolic functions of Standard Arabic in articulating national identity in the LL of Yemen. 

Psychology and Culture: Top Down Versus Bottom Up?

PsycCRITIQUES ◽  
2005 ◽  
Vol 50 (19) ◽  
Author(s):  
Michael Cole
Keyword(s):  
Top Down ◽  
Bottom Up
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