32.6K
views
31
authors
8
articles
Editors
3
Impact
Loading...
8,735 views
4 citations
3,687 views
8 citations

In most neuroscience textbooks, the thalamus is presented as a structure that relays sensory signals from visual, auditory, somatosensory, and gustatory receptors to the cerebral cortex. But the function of the thalamic nuclei goes beyond the simple transfer of information. This is especially true for the second-order nuclei, but also applies to first-order nuclei. First order thalamic nuclei receive information from the periphery, like the dorsal lateral geniculate nucleus (dLGN), which receives a direct input from the retina. In contrast, second order thalamic nuclei, like the pulvinar, receive minor or no input from the periphery, with the bulk of their input derived from cortical areas. The dLGN refines the information received from the retina by temporal decorrelation, thereby transmitting the most “relevant” signals to the visual cortex. The pulvinar is closely linked to virtually all visual cortical areas, and there is growing evidence that it is necessary for normal cortical processing and for aspects of visual cognition. In this article, we will discuss what we know and do not know about these structures and propose some thoughts based on the knowledge gained during the course of our careers. We hope that these thoughts will arouse curiosity about the visual thalamus and its important role, especially for the next generation of neuroscientists.

4,330 views
8 citations
Review
02 March 2023

Objective: Multiple studies have explored the use of visual cortex non-invasive brain stimulation (NIBS) to enhance visual function. These studies vary in sample size, outcome measures, and methodology. We conducted a systematic review and meta-analyses to assess the effects of NIBS on visual functions in human participants with normal vision.

Methods: We followed the PRISMA guidelines, and a review protocol was registered with PROSPERO before study commencement (CRD42021255882). We searched Embase, Medline, PsychInfo, PubMed, OpenGrey and Web of Science using relevant keywords. The search covered the period from 1st January 2000 until 1st September 2021. Comprehensive meta-analysis (CMA) software was used for quantitative analysis.

Results: Fifty studies were included in the systematic review. Only five studies utilized transcranial magnetic stimulation (TMS) and no TMS studies met our pre-specified criteria for meta-analysis. Nineteen transcranial electrical stimulation studies (tES, 38%) met the criteria for meta-analysis and were the focus of our review. Meta-analysis indicated acute effects (Hedges’s g = 0.232, 95% CI: 0.023–0.442, p = 0.029) and aftereffects (0.590, 95% CI: 0.182–0.998, p = 0.005) of tES on contrast sensitivity. Visual evoked potential (VEP) amplitudes were significantly enhanced immediately after tES (0.383, 95% CI: 0.110–0.665, p = 0.006). Both tES (0.563, 95% CI: 0.230–0.896, p = 0.001) and anodal-transcranial direct current stimulation (a-tDCS) alone (0.655, 95% CI: 0.273–1.038, p = 0.001) reduced crowding in peripheral vision. The effects of tES on visual acuity, motion perception and reaction time were not statistically significant.

Conclusion: There are significant effects of visual cortex tES on contrast sensitivity, VEP amplitude, an index of cortical excitability, and crowding among normally sighted individuals. Additional studies are required to enable a comparable meta-analysis of TMS effects. Future studies with robust experimental designs are needed to extend these findings to populations with vision loss.

Clinical trial registration: ClinicalTrials.gov/, identifier CRD42021255882.

5,941 views
15 citations
Open for submission
Frontiers Logo

Frontiers in Psychology

At the Borders of Movement, Art, and Neurosciences- Volume II
Edited by Guy Cheron, Bernard Andrieu, Carlos Enrique Cevallos, Ana-Maria Cebolla, Jan De Maere
Deadline
13 September 2025
Submit a paper
Recommended Research Topics
Frontiers Logo

Frontiers in Neuroscience

Neuroscience-Inspired Visual Sensing and Understanding
Edited by Qingbo Wu, King Ngi Ngan, Lei Bai, Weisi Lin
18.3K
views
33
authors
7
articles
Frontiers Logo

Frontiers in Neuroscience

Cognitive mechanisms of visual attention, working memory, emotion, and their interactions
Edited by Chaoxiong Ye, Qiang Liu, Qianru Xu
61.9K
views
73
authors
15
articles
Frontiers Logo

Frontiers in Neuroscience

Ocular Neurodegenerative Diseases: Novel Mechanisms, Diagnosis, and Therapeutic Strategies
Edited by Dan Wen, Hetian Lei, Wensi Tao
58.9K
views
111
authors
18
articles
Frontiers Logo

Frontiers in Neuroscience

Animal Models and Diagnostic Tools for Retinal Disease and Optic Neuropathy
Edited by Haohua Qian, Yikui Zhang
16.5K
views
36
authors
5
articles
Frontiers Logo

Frontiers in Psychology

Visual Perception and Mental Imagery in Aging, Health and Disease
Edited by Anna Maria BERARDI, Renaud F Cohen
13.9K
views
30
authors
5
articles