Conscious and Unconscious State of Human Mind

Human mind has always been a mystery for the researchers and scientist. The mind can either be in consciousness state or unconsciousness state. Consciousness is the state where the entity is aware of its surrounding, thoughts, memories and the feelings; while Unconsciousness is the state where human process some thought in mind, automatically which he is not aware of. Scientists have been trying to find answers about how it works, till date. The main debate of research is the mind-body problem, that is how the conscious state of mind is related to the unconscious state (some call it imagination, thoughts, or memory).  

The purpose of the paper is to give information about how the brain recovers memory, how it reasons, and gives logics, speed of processing to think and how the neurobehavioral function display invariant sequence of return across individuals.

In the paper, the researchers are trying to detect the covert consciousness in the patients who are unresponsive, by using brain neuroimaging and then comparing it with a healthy patient by sedating them (Huang, Z. et al., 2018). Another experiment is to identify the consciousness- specific patterns of brain and comparing them; in awake volunteers, propofol-anaesthetised volunteers, and patients with disorders. The main outcome was that it tells human consciousness depends on the spatio-temporal interaction between brain integration and functional diversity.    What interest me the most to take this topic, are the factors, on which our mind works in unconscious state as compared to the conscious state, and how with increasing age, human minds tends to not remember things easily as it used to remember in when humans are young. However the question that how the mind reacts to our changing mental and emotional state is still unanswered.    

The paper aims to give information about the human mind, and the concept behind its working. Brain can be defined as the heart and the soul of the body, if brain is conscious then the body will work tend to work fine. Consciousness is defined as the state where the entity is aware of its surrounding, thoughts, memories and the feelings; often the term consciousness have been used in different topics like knowledge in general, intentionality, introspection and phenomenal experience; introspection is the knowledge that one hold inside his mind. Often the term Consciousness is confused with the term Self- Consciousness; as said by philosophers, Consciousness is a fascinating but elusive phenomenon. One has to be aware of its surrounding to be in conscious state of mind. There is a debate going on since centuries about the exact meaning of the word; because the mind is vast that there is no common meaning for the same. The reason that I chose this topic for my paper is because of the main problem related to human mind that often philosophers talk is the ‘Mind-Body Problem’. Mind Body Problem where mental process is correlated to physical process. I was always curious on how what we think internally comes out it in form of writing or any other way of expression; how we tend to remember things, how we learn things easily as a kid when compared to grown-ups; this reason made me curious to study about the concept of human mind. Many says experience is the essence of consciousness and believe it is only from inside subjectively. But there is not answer to why only humans are conscious and not rocks or any other thing. And because of these questions I personally wanted to know more and hence I have gone to many workshops and have been a part of someone’s study as a subject also. The paper that I have chosen gives a an idea about how the integration and diversity of information processing takes place in brain, on volunteers. In this paper an experiment was carried out on volunteers who were awake, propofol-anaesthetised volunteers (propofol is a drug or a short-acting medication that results in a decreased level of consciousness and lack of memory for events) and volunteers with some disorders and MRI data was chosen to identify consciousness specific pattern in their brain.    

For the propofol patients the data was collected from Robarts Research Institute in London, Ontario (Canada) between May and November 2014. A total of 19 participants in which 13 were males and others are unknown and the age group is 19-40 years. After this fMRI data with no sedation (AWAKE volunteers) and Deep sedated (propofol anaesthetised) were collected, and post this the volunteers have to undergo 2 tests a computerised auditory target- detection task and a memory test of verbal recall, to evaluate their level of wakefulness independently of the assessors. For the propofol sedated volunteer a Ramsay score was given, and was administered intravenously using an AS50 auto syringe infusion Pump. There were 71 patients with disorders and they should have written consent from the doctor, inorder to be a part of the study. Post this underwent clinical and neuroimaging testing. The main focus was on the graph theoretical properties of the brain. Each patient was scanned and computed for the static integrated and segregated functional connectivity matrix of each subject, for each scanning session. Now the quantification of the nearby distribution of unconsciousness-related modifications in the metrics throughout the brain was done and it was investigated that how much loss of cognizance affected the connectivity of the area with relaxation of the brain. There was sudden localised decrease and increase in ICC (Intrinsic Connectivity Contrast) for those who were sedated and analogous findings were found when comparing it with the healthy patients and patients with disorders when they were awake. To identify the temporal states of high integration and high segregation, and to investigate how loss of consciousness influenced the probability of occurrence and functional diversity for the patients, the dynamic functional connectivity analysis was applied to achieve the above. And the result shows that the human consciousness is dependent on spatio temporal interaction between brain integration and functional diversity, the deterioration of which may be generalizable loss of consciousness. However the paper lacks in providing some of the information like the amount of propofol given to sedate the patients, it is only mentioned that the concentration of propofol is 0.6 μg mL−1, Sedating a patient with access propofol can lead to critical health issues and death also.    

Another experiment was carried out where Covert Consciousness was detected for those sedated with propofol, with the help of brain imaging (Huang, Z. et al., 2018). The results of reveals a model that can help to accelerate the development of the new approaches to detect covert consciousness for those patients who are unstable and have heterogeneous neuropathology. For the experiment 7 candidates (4 males and 3 females, 22-30 age group) were recruited, who were good in English and did not had any contradiction to MRI scanning like for females pregnancy, claustrophobia and more. Propofol was used as Anaesthetic agent. The experiment was carried out before and after sedation of propofol to compare the results. The subjects fasted for 8 hours before the experiment and 2.4 μg ML-1 propofol in total was given. The volunteers were asked to perform Mental imagery (tennis – imagine standing on a tennis court and to swing the arm to hit the ball; navigation – to imagine navigating to a known city or place to visualise what the see and hand squeeze - imagine squeezing a MRI compatible grip dynamometer) task and motor response (actual hand squeeze – to squeeze an actual rubber ball) task. The instruction were given by E-Prime 3.0. The fMRI data was processed in AFNI that includes (1) slice timing correction; (2) rigid body correction/realignment within and across runs; and more. Apart from this another paper that I chose gives information about how human brain reconstruct consciousness and cognition stud. 60 participants were recruited and were sedated between the recovery time in range of 30 min to 90 min on the study day and were fitted with EEG head cap to their scalp capnography will be measured and EEG recordings will be taken. Post this they were pre-oxygenated before getting infused again by increased propofol rat. The main aim of this experiment was to analyse the brain network recovery when humans recovers and emerge from coma or anaesthetic state. However based on the information the paper lacks in some points like what was the age of group on the participants and were they male or female. Also it lacks to inform whether the volunteers had any health issues because it can affect the results of the case study.    

Another study however states that unconscious control of mind can lead to memory retrieval and forgetting (Salvador, A. et al., 2018). In this 44 participants out which 25 were females and 19 were males, age group range 21-33 year old). 2 Experiments were conducted and no participants were allowed to participate in both experiments. The experiment was carried out in 3 phases- learning phase, a Think / No-Think phase and final recall test. For learning phase the participants were asked to learn 30 words pairs (Hint and response word) example – wood –knife. Each word were shown for 4 sec where hind word was for 200ms followed by response word for 500ms interval gap. After all the participants were asked to recall the response words where only hint words were shown for 4sec. The Think / No-Think phase hint word was shown followed by Think / No-Think cues. For Think cues the participants had to tell the response word without saying loud and for No-Think cues they had to tell categorise the words based on the gender. The final recall test is to now recall the word pairs as done in the learning phase.    

The result of this was that there was a decrease of recall performance (76% versus 79%) in the initial phase and Think / No-Think phase. For the 2nd experiment the same procedure was carried out but with a twist that the response word was shown before the hint word; the idea behind this was to extend experiment 1 outcomes, but there were 31 participants in this experiment where 23 were female and 8 were males. For this task the memory recall results was reduced drastically 67% to 78%, the reason for this was that it was tough to remember the response word because it was shown before the hint with extra instruction. Overall the results of the experiment concludes that when there is a control, people tend to not remember things and suppress memory outside the individual’s awareness. It is fact that Sleep and Anesthesia provoke modification in conscious experience. Some recent study found the reason that cortical activity distinguish between conscious and unconscious state. However there is no proper evidence to proof it. An experiment was conducted to test this fact (Darracq, M. et al., 2018), where transcranial magnetic stimulation – electroencephalography (TMS–EEG) were employed over parietal region of anaesthesia and sleep to check whether brain activity is different in disconnected or unconscious states. The brain activity was recorded using a TMS amplifier channel which was of 60 channels, which was sampled at 1450 Hz. The TMS pulse were delivered every 2-3sec intervals. This was carried out to check the alpha-band responses and low-gamma power in disconnected conscious and unconscious state. It was found that alpha activity, which is the reason of sensory stimuli to regulate perception is altered in the disconnected states of rapid eye movement (REM) sleep and ketamine anesthesia and there is reduction of evoked low gamma power (30-40Hz) when compared to wakefulness. The paper also throws some light stating that alpha oscillations can easily guide the neurons to synchronize which can be important aspect for conscious experience.    

To conclude, the paper and study shows different aspects of human mind in conscious and unconscious state. Experiments proof the hypothesis in paper, although there is always a scope of improvement and future scope. In Salvador, A. et al., 2018, study, the cues were in French, but it fails to tell the readers whether the volunteer knows French language or not. Readers cannot assume that the volunteers know the language. Also to cross verify the results, if cross- culture volunteers were recruited, for instance a native French speaker were shown English noun, or native English speaker were shown German nouns, and then if they were asked to perform the 3 phases, will they reflect the same result as mentioned in paper or there will be a huge difference. It is a known fact, it is tough to remember things if they are not in your native language. So the results would have changed. Also kids tends to remember things easily and they learn things quickly, trying the same experiments on kids and then comparing the results would be extension of what is performed. Another scenario could be replacing the phrase with an image, because it is easier to remember a pictorial view and then memorising a phrase, and then performing the same experiment with altering the time of display. In Luppi, A.I. et al., 2019, study it is not mentioned what kind disorder was taken into consideration, and exposing the volunteers to some music or playing music when the experiment is being performed can be another factor that can be taken into consideration, because music can change the wavelength and the thinking process of human mind.    

References 

1. Huang, Z. et al., (2018). Brain imaging reveals covert consciousness during behavioral unresponsiveness induced by propofol. Science Report, 8, 1, 13195. 
2. Luppi, A.I. et al., (2019). Consciousness-specific dynamic interactions of brain integration and functional diversity. Nature Communication, 10, 1, 4616. 
3. Salvador, A. et al., (2018). Unconscious memory suppression. Science Direct, 180, 191-199. 
4. Maier, K.L. et al., (2017). Protocol for the Reconstructing Consciousness and Cognition (ReC Cognition) Study. Frontiers in Human Neuroscience, 11, 28. 
5. Darracq, M. et al., (2018). Evoked Alpha Power is reduced in Disconnected Consciousness during Sleep and Anesthesia. Science Report, 8, 16664.