Visual cortex damage or lesions may often lead to blindness which in many patients’ cases, is difficult to treat. After damage happens in the cortex, another peculiarity occurs in the human occipital lobe (Bagins et al., 2019). The patients may locate visual stimuli being unaware of position, shape, colour, and size. This phenomenon is called blindsight and is associated with the sight pathways (Koch et al., 2017). The fact that this process allows blind patients to locate stimuli contributes to the factor that this process may be vital in developing treatment opportunities. Regardless, blindsight can be applied to sustaining visual awareness in patients with cortical lesions. Thus, the exploration of blindsight in patients with cortical damage requires scientific consideration. The striate cortex retro-geniculate lesions caused by various aspects such as mechanical damage can lead to the blindsight phenomenon during which patients can locate the visual stimuli even with a damaged vision system.
The striate cortex is vital in ensuring neurologically healthy vision (Bagins et al., 2019). The blindsight phenomenon raised questions within scientists. Several studies experimentally examine the patients’ awareness of visual stimuli and their role in blindsight (Bagins et al., 2019). Researchers believe that exploration of the neurological process ensuring the accurate unconsciousness locating visual stimuli in the damaged cortex and occipital lobe can contribute to developing treatment opportunities (Koch et al., 2017). The blindsight phenomenon is described by the fact that human vision has both main and subsidiary pathways. Lesions usually harms one of them, in most cases, the main one is connected with the visual cortex and causes cerebral visual impairment (Koch et al., 2017). The additional pathway makes the unconscious location of visual stimuli possible.
Blindsight may also be used to find treatment opportunities for other visual lesions. For example, after treating the optic chiasm damage caused by homonymous hemianopia, scientists applied the transcranial direct current stimulation to estimate the role of blindsight rehabilitation (Cerri et al., 2017). According to the research, the patients showed better orientation results after blindsight training (Cerri et al., 2017). Thus, due to the conscious development of the subsidiary pathway, the patients can compensate for vision loss or improve the operational results. The blindsight phenomenon was also successfully used to treat unilateral occipital damage (Chokron et al., 2008). Damaged neurons can be restored in the blind visual field using unconscious visual capacities (Chokron et al., 2008). Therefore, there is a possibility to intervene in the two visual pathways to find possible treatment opportunities.
These discoveries allowed scientists to develop possible blindness treatment opportunities. The visual cortex system functioning was examined using transcranial magnetic stimulation (Hurme & Railo, 2021). Scientists manage to imitate the blindsight in the undamaged visual cortex by sending rapid impulses to the particular neurons in the brain of the occipital lobe (Hurme & Railo, 2021). Therefore, they proved that the subsidiary pathway has the neurologically conditioned perception of visual stimuli. As far as blindsight is proven to be the normal functioning of the human brain, the fact that the exploration of the specificities of this process can contribute to using the subsidiary visual pathway to reconstruct the damaged cortex or occipital lobe through using surgery or apparatus interventions. Monkeys and humans are considered to have similar brain functioning and neurological structure.
Various experiments prove the correlations between the monkey’s and human’s neurological blindsight and the striate cortex functioning (Cowey et al., 2002). In order to explore the blindsight phenomenon, researchers held experiments, including the ablation of the primary visual cortex in monkeys (Cowey et al., 2002). Primates responded to the visual stimuli even without conscious sight, which resembled patients with blindsight (Cowey et al., 2002). Thus, the importance of the subsidiary vision pathway was established. Such an experiment shows that the monkey’s brain befits perfectly for the exploration aimed at sight restoration.
Therefore, from a long-term perspective, blindsight can be used to identify conscious vision peculiarities and explore the methods to treat cerebral visual impairment caused by visual cortex damage. A problem under discussion in the current paper is the possibility to use vast empirical scientific research results uncovering the correlation between the monkeys’ and humans’ striate cortical functioning to provoke the blindness treatment testing and development.
Aim and Goals
The current research aims to suggest possible blindness treatment opportunities based on existing scientific papers on visual cortex damage and its blindsight contributions analysis. The long-established aim to develop blindness treatment opportunities requires preliminary research and summarizing the results of the existing experiments. This procedure is necessary to ensure the theoretical foundation for the subsequent valuable experiments. To achieve the aim of the study, three particular goals are set. The first goal will require collecting and analyzing the information collected and preliminary exploration. The second goal will be assessing, comparing and critically analyzing the research results and concisely presenting the findings. The third will include the suggestion of the blindness treatment testing opportunities based on the research findings concerning the monkey and human stimuli reaction.
Methods
During the research, the method of the survey of the literature will be used to explore the correlation between the two variables of the study: the striate cortex stimuli activities of the human and monkey. The process will focus on recent research within the specified area. More specifically, it is envisaged to rely on the peer-reviewed articles and study reports published within the past 15 years. This way, the review is expected to reflect the current body of knowledge with its modernized methods of research and evaluation. In order to summarize and compare the experiments on the neurologically-conditioned vision damage and blindsight peculiarities in monkeys and humans, the method of comparative analysis will be used. In this regard, various experimental datasets will be compared, revealing statistically prevalent trends, as well as non-significant variables.
The data collection method will be applied to choose relevant papers and practical experiments. For the validity of research, it appears essential to focus on the up-to-date, objective findings that reflect the current state of research. The most pertinent for the research technique of data collection will be the scientific documents and records exploration which reflects the results of the experiments and surgeries on the monkeys’ visual cortex. This quantitative method will help overview the vast number of empirical information and collect the relevant topic data. The data is to be categorized in relevant groups, attributing quantifiable values when applicable. This method is expected to yield more objective results that will make a contribution to the current body of knowledge. Moreover, the text analysis will enable the valuable scientists’ insights on the possibility of surgery testing on the monkey’s brain to improve blindness treatment opportunities.
As far as current research is oriented on the theoretical exploration of the previous study, the different data analysis methods will be applied (Bergin, 2018). The descriptive analysis will be used to select and structure the vast volume of information on visual cortex lesions. The exploratory analysis will be applied to find the connection between the studies and different approaches to the issue of interest. Predictive analysis will enable the offering of possible future discussions regarding the topic. The prescriptive analysis will contribute to the theoretical blindness treatment and monkey testing suggestions based on the analyzed material.
The data collection will rely on four inclusion criteria and three exclusion criteria. The inclusion requires that studies must be experimental; published within the last 15 years; contain the practical experiment analytical data regarding the human or/and monkey visual cortex; address the blindsight phenomenon and visual stimuli reactions of human or/and monkey rates. The exclusion criteria include the following aspects: observational study design; vision cortex blindness treatment disregarding blindsight; study presented as a systematic review.
The procedure of research follows a five-step paradigm. First, find relevant experimental papers on the correlation between the striate cortex of monkeys and humans. Second, analyze the stimuli similarities of the species under the condition of blindsight. Third, compare the scientific research results and highlight the relevance for the neurological blindness treatment. Fourth, compare the retro-geniculate lesion of the monkey’s striate cortex and human according to the literature. Fifth, propose the possible theoretical opportunities for the blindness treatment or minimizing the negative consequences of the striate cortex damage.
Significance
This project is interesting in the context of consciousness research because it reveals the neurological aspect of brain activity related to the after cortex damage blindsight. Consciousness exploration can help blind people to sustain visual awareness when the treatment is inconclusive. Moreover, if this topic will be discussed after current research, the consciousness neurological aspects may contribute to blindness treatment opportunities. The consciousness can be used productively in medicine to help many people cope with fatal illnesses.
If the aim of the research is achieved, the theoretical results can be a sound basis for medical consideration and experiments. Thanks to the data collection and analysis of the various scientific experiments and articles, the role of consciousness in the vision may be highlighted. If the research aim will not be achieved and there is not enough experimental information to suggest possible treatment opportunities, the topic of blindsight and the role of consciousness in vision should be reconciled first. The lack of information does not state the insignificance of the issue for medicine and social science. Conversely, it will attract scholarly attention to the lack of the experiment and contribute to the research development.
References
Celeghin, A., Bagnis, A., Diano, M., Méndez, C., Costa, T., & Tamietto, M. (2019). Functional neuroanatomy of blindsight revealed by activation likelihood estimation meta-analysis. Neuropsychologia, 128, 109-118. doi: 10.1016/j.neuropsychologia.
A recent literature review of evidence for the existence of the pathways to the cerebral cortex: Rabbo, F. A., Koch, G., Lefevre, C., & Seizeur, R. (2015). Direct geniculo-extrastriate pathways: A review of the literature. Surgical and Radiologic Anatomy, 37(8), 891-899.
Bagnisa, A., Celeghina, A., Dianoa, M., Tamietto, M., & Tommaso, C. (2019). Functional neuroanatomy of blindsight revealed by activation likelihood estimation meta-analysis. Neuropsychologia, 128, 109–118.
Bergin, T. (2018). Data analysis: Quantitative, qualitative and mixed methods. London, England: SAGE Publications.
Cerri, C., Cornaggia, M., Matteo, B., Meroni, R., Perin, C., & Vigano, B. (2017). Transcranial direct current stimulation (tDCS) combined with blindsight rehabilitation for the treatment of homonymous hemianopia: a report of two-cases. Journal of Physical Therapy Science, 29(9), 1700–1705.
Cowey, A., Stoerig, P., & Zontanou, A. (2002). Aware or unaware: Assessment of cortical blindness in four men and a monkey. Cerebral Cortex Journal, 12, 567–574.
Chokron, S., Gaudry, I., Gout, O., Laloum, L., Perez, C., & Obadia, M. (2008). From blindsight to sight: Cognitive rehabilitation of visual field defects. Restor Neurol Neurosci., 26(4), 305–320.
Hurme, M., & Railo, H. (2021). Is the primary visual cortex necessary for blindsight-like behavior? Review of transcranial magnetic stimulation studies in neurologically healthy individuals. Neuroscience & Biobehavioral Reviews, 127, 353–364.
Koch, G., Lefevre, C., Rabbo, F., & Seizeur, R. (2017). A recent literature review of evidence for the existence of the pathways to the cerebral cortex. Surgical and Radiologic Anatomy, 37(8), 891–899.