Scientific Narrative

Human experience is fundamentally attributable to consciousness. Everything we see, hear, feel, do, learn, and understand builds upon individual experiences of consciousness, creating unique forms of consciousness for everyone. The ancient question of how we navigate and make sense of the world around has puzzled philosophers, psychologists, and neuroscientists alike, and there are  debates on the rather ambiguous definition of consciousness to this day. However, from a scientific perspective, the study of consciousness runs into an obstacle called the “hard problem of consciousness”, facing challenges in investigating and explaining subjective experiences by objective methods and data (Chalmers, 2015). Scientists are still trying to address the ongoing question of how to quantify and explain consciousness through scientific methodologies and numbers by developing new concepts and tools to better understand the neural workings that constitute consciousness.

To find quantifiable answers to the “hard problem”, research of the Neural Correlate of Consciousness (NCC) investigates the “minimum neuronal mechanisms jointly sufficient for any one specific conscious experience” (Koch, 2016). A theoretical concept developed by scientists incluing Francis Crick and Christof Koch in the 1990s, related programs establish NCC as a prerequisite condition for any perceptive experience of consciousness. NCC research investigates the correlation between neuronal events and empirical evidence of mental phenomena, researchers (Chalmers, 2015). Through brain imaging techniques such as EEG, ERP, and fMRI, recent NCC research uses neuroimaging signals and data to predict the conscious experience of individuals (Friedman, 2023). Hypothesizing the workings of consciousness to be found in neural activities acting in accordance with classical, or even quantum physics, the framework aims to both measure the holistic state of consciousness or content-specific approaches, such as identifying faces. Based on the observations of neuronal activities in areas of the brain with prominent neural activity related to conscious phenomena, such as the posterior cerebral cortex within the temporo-parietal-occipital hot zone (Koch, 2016), neuroscientists use “reverse inference”, where certain patterns of brain activity can be attributed to specific cognitive processes (Poldrack, 2005).

Despite active research, Neural Correlates of Consciousness still poses unresolved problems, both theoretically and experimentally. Conceptually, matters of how different mental activities should be classified remains ambiguous. For instance, upon processing/interpreting the visual perception of the same red apple, it is difficult to prove that the red that one person sees will be the exact same shade that another sees. Although scientists have successfully developed classifications of memory, such as short-term, long-term, episodic, classifications for language are deemed virtually impossible, for its unfathomable complexity (Nani, 2019). In experimental designs, the commonly-used “reverse inference” practice has limitations in how it fails to wholly capture the correlation when applied to cognitive processes of which their occurrences and activities have weaker correlations to specific areas of the brain (Poldrack, 2005).

Although the exploration of Neural Correlates of Consciousness cannot provide a direct answer to the “hard problem”, it provides a framework where the relationship between neural activities and our conscious experiences can be explored empirically. Research of consciousness stands in the junction of neuroscience and philosophy, where objective measurements aim to explain individuals’ subjective understandings of the world around them. We must approach the “hard problem” with multidisciplinary insights, as cognitive functions are based on neural activities, but they are ultimately inextricable from environmental factors that add an even more complex, contextual depth to the workings of the brain.

References

Chalmers, D. (2015). The Hard Problem of Consciousness. In G. Rosen, A. Byrne, J. Cohen, E. Harman, & S. V. Shiffrin (Eds.), The Norton Introduction to Philosophy.

Friedman, G., Turk, K. W., & Budson, A. E. (2023). The Current of Consciousness: Neural Correlates and Clinical Aspects. Current neurology and neuroscience reports, 23(7), 345–352. https://doi.org/10.1007/s11910-023-01276-0

Koch, C., Massimini, M., Boly, M., & Tononi, G. (2016). Neural correlates of consciousness: Progress and problems. Nature Reviews Neuroscience, 17(5), 307-321. https://doi.org/10.1038/nrn.2016.22

Nani, A., Manuello, J., Mancuso, L., Liloia, D., Costa, T., & Cauda, F. (2019). The Neural Correlates of Consciousness and Attention: Two Sister Processes of the Brain. Frontiers in neuroscience, 13, 1169. https://doi.org/10.3389/fnins.2019.01169

Poldrack, R. A. (2005). Can cognitive processes be inferred from neuroimaging data? Trends in Cognitive Sciences, Volume 10, Issue 2, 59 – 63. https://doi.org/10.1016/j.tics.2005.12.004