"In the final stage of ego-lessness there is an 'obscure knowledge' that All is In all - that All is actually each. This is as near, I take it, as a finite mind can ever come to 'perceiving everything that is happening everywhere in the universe'.”- Aldous Huxley, The doors of perception
Ever wondered how the brain is affected by psychedelics?
Exploring the profound concept of ego death through a scientific lens, this article delves into the intricate relationship between psychedelics and the brain. By combining research findings and studies, we aim to shed light on the brain regions associated with ego dissolution, their functions, and the theories connecting them to the psychedelic experience.
What is the Ego, and why would it ‘die’?
Our sense of self: Our ego
Simply put the ego is our sense of self, the feeling of having an identity or personality. Delving deeper, we could identify two primary aspects: the minimal or embodied sense of self rooted in first-person perspective and grounded in tangible bodily experiences, and the narrative or autobiographical self shaped by our memories, constructing a conceptualized identity of self. In Freudian metapsychology, the ego, however, was defined as more than merely our sense of self-hood. It is a foundational mechanism that collaborates and competes with other mental processes to assess the quality of consciousness.
Ego Death
The distortion or dissolution of the sense of self has been termed ego-death or ego-dissolution and is integral to the psychedelic experience. Looking at this from a psychoanalytical point of view it can be seen as the blurring of self-representation and object-representation resulting in a sense of unity with all. While, based on the experiences of participants it is often described as a blissful and mythical feeling as one dissolves into and becomes the whole. Although this reduction in sense of self is often associated with heroic dose psychedelic experiences, it is said to be experienced by practitioners of ‘non dual-awareness’ meditation. When it comes to ‘practicality’, the experience of ego death has been speculated to be rather therapeutic as it could provide a new perspective on personal struggles by creating a sense of distance and objectivity.
Let’s take a look inside our heads: The Default Mode Network (DMN)
Now, exploring the inner workings of our mind, we’ll focus on the Default Mode Network (DMN), a part of the brain associated with, among many things, awareness of self, social thinking, the ability to differentiate self from ‘not self’, and autobiographical memories. A replication study, utilizing two different brain imaging techniques, found similar results revealing that there was a reduced activity in the DMN during the psychedelic state induced by large doses of psilocybin. Since this brain area is associated with the aforementioned aspects the conclusion that reduced activity and disintegration of this network leads to ego-dissolution is often made. However it is a tad more complex than this, so let’s take a further look…
How did this claim come about?
Reverse inference is a rather problematic way of concluding the field of neuroscience. It is basically the assumption, that if a specific part of the brain is active during a certain task, and we know a cognitive function linked to that brain area, then that task must always involve that cognitive function. So in this case, since we know what cognitive functions are associated with the DMN, and during psychedelic experiences the DMN shows reduced activity, the conclusion is drawn that ego dissolution is the result of DMN disintegration. However as our brains are very complex and multifaceted often, like in the case of the DMN, many cognitive functions can correspond to one brain area. On top of this disintegration or reduced activity of this network can be seen in other contexts as well, thus making such claims is not this straightforward.
In the previously mentioned study, reduced brain blood flow and reduction in connectivity between two core areas of the DMN were measured, namely the medial Prefrontal Cortex (mPFC) and the Posterior Cingulate Cortex (PCC). These parts are the most connected to the rest of the DMN and the whole brain. Under normal circumstances they are very active, the PCC alone consumes 20% more energy than any other brain area. Due to its substantial size and energy consumption, and the observed capability of psilocybin to reduce its activation by 20%, exploring the significance of this area is certainly a topic worth investigating. In this particular study a correlation was found between the deactivation of this region and the reported psychedelic experience of the patients, meaning the more intensely the ‘journey’ was felt, the more deactivation was observed. As this part of the brain has been particularly associated with its role in consciousness and self-construction the reduction of its activity through the previously mentioned reversed inference could be linked to ego death, however, this is just not yet enough to make such a conclusion.
Moving forward, in a follow-up study the DMN was shown to be more connected to the Dorsal Attention Network (DAN) which is involved in the perception of the external world. Typically, these two networks compete since the DMN is engaged in self-related activities and the DAN is focused on processing sensory information from the external world. During the psychedelic experience, the increased connectivity of these two regions could be associated with the blurring effect of the internal and external experiences and thus can be connected to the ‘becoming one with everything’ aspect of ego death.
‘Who I am’ rests in my memories
Aldous Huxley, along with many exploring the field of psychedelics, describes the psychedelic state as a "mind-revealing state." In this state, latent ideas can come to the surface, and new connections between ideas can be formed.
Could it then be that as we are letting go of our self-constructed identity we are remembering more of who ‘we really are’?
In a recent study the hippocampus, our memory region which is also part of the DMN, showed greater levels of variance during psychedelic experiences, indicating higher levels of activity. Interestingly these were also observed during psychotic states and REM sleep. Could there be a connection between psychosis, psychedelic experiences, and dreaming? While it is very speculative these findings would support such theories and explain the revelations people seem to be experiencing during psychedelic experience.
Surrounding the hippocampus are our parahippocampal gray matter areas. Their function is to convey memory-related information from the hippocampus to the rest of the brain. As previously noted, a significant aspect of our self-identity is grounded in our autobiographical memories, residing in the hippocampus. Interestingly, a study utilizing psilocybin revealed connections between the occurrence of ego dissolution and a decrease in parahippocampal activity. This suggests that there is a reduced sharing of information about our identity with the brain, potentially contributing further to the sensation of self-dissolution. Further support for this comes from a study conducted with LSD yielding similar results. This study additionally noted that there was reduced connectivity between the parahippocampus and another part of the DMN, the retrosplenial cortex. This again shows that during psychedelic experiences the DMN exhibits reduced connectivity within its components such as the parahippocampal areas, which inhibit access to our constructed sense of self, formed through our past experiences.
‘Who I am’ rests on the awareness of my body
Part of a network known as the salience network is the insula, which plays a crucial role in integrating bodily sensations with our cortex. This integration makes the information available for appraisal, allowing us to make judgments based on bodily sensations. Studies using psilocybin have found that ego dissolution corresponded with the disintegration of the salience network which can thus explain a reduced sense of awareness of our bodies. Backing this up, a different study using LSD discovered a correlation between the degree to which two brain regions increased their connectivity with the rest of the brain and the occurrence of ego death. These two regions were the already mentioned insula, and the Temporal Parietal Junction(TPJ), which, similarly to the insula, is involved in integrating sensory information. It is particularly involved in integrating visual information with somatic information, so it is responsible for our coherent bodily representation and sensing our location in space. Interestingly, a link has been associated between the TPJ and out-of-body experiences, supporting its crucial role in waking consciousness.
Putting it all together
Exploring the connection between psychedelics and ego dissolution, the current studies highlighted the key role of the DMN during psychedelic experiences, while showing how complex and multifaceted this area is. The observed correlations suggest that experienced ego dissolution is linked to DMN disconnectivity, notably marked by reduced activity while highlighting other areas and their contributions.
Notable is the normally competing DAN and DMN connection contributing to the blending of realities. The hippocampus emerges as a key player as well, hyperactivating during these experiences and potentially influencing the influx of latent information. Simultaneously, the parahippocampus appears to inhibit the conveyance of autobiographical memories. When it comes to our awareness in space and the integration of sensory information the insula and the TPJ play crucial roles, these are also affected regions when one is on a psychedelic ‘journey’. These correlations, while not establishing causation, collectively offer insights into the intricate interplay of brain regions during ego dissolution, laying the foundation for a comprehensive understanding of this phenomenon.
While this article’s focus was on studies utilizing large, macro-doses of psychedelics, the observed effects and theories could relate to microdosing as well. It is possible that underlying the therapeutic effects of microdosing are similar mechanisms involving the same brain areas. Hopefully, as neuroscience advances and psychedelic research receives more attention, even more light will be shed on this topic.