This Side of Self: Mind, Brain and Identity
Our selves. The expression is universal, and for majority merely alludes to ‘me’—a collection of one’s thoughts, emotions, desires, and experiences. But do these attributes constitute a sufficient definition of self? Could it be nothing more than a series of fleeting perceptions? What distinguishes a unique self from the multitude of other different selves existing in the world?
Despite dissimilar conjectures, sages and philosophers have concurred that the mind or reasoning is essential to identity. Plato called it the rational soul, a third of his three–part soul model. For Descartes, it was a thinking thing (Chaffee, 2014: 111–112; 115–118). Others cited consciousness, memories, experiences, and even brain states.
This hub explores the concept of mind and self by looking at two important philosophical frameworks: David Hume’s “bundle” theory and Immanuel Kant’s metaphysical model. It attempts to evaluate both accounts in light of current research findings in neuroscience. The first section will identify a few puzzles that arise from adopting Hume’s naturalistic approach, while the second takes a primarily Kantian outlook on thinking about self.
2 A Naturalistic Account
2.1 The “bundle” theory
We begin with a brief summary of the “bundle” theory posited by empiricist David Hume. Based on his belief that all knowledge arise from experience, Hume regarded the contents of our minds1 as embodied experiences, which are further classified as impressions and ideas. Impressions are the elementary data, basic sensations, while ideas are faint copies of impressions, such as memories and dreams. To Hume, an idea that does not correspond to a previous impression is false and meaningless. Examining the self, he is unable to trace the idea of self to a constant impression in time.
There are instead “bundles” of perceptions that “pass, repass, glide away” in the theatre of one’s mind. With no direct experience of self, there can be no knowledge of it (Chaffee, 2014: 127–130). To specify, the mind records perceptions gained from external and internal stimuli when one is conscious. An individual is likened to a passive observer whose cognition may be switch on or off depending on his state of consciousness (Nollmeyer, n.d.). Should one hold to this naturalistic view, the following statements may be asserted:
- An impression that cannot be remembered is meaningless as there are copies of it.
- Apart from “bundles” of perception, there is no sense of identity in the mind
Assuming these statements as true, let us attempt to apply them to a few neuroscience studies.
2.2 Some neurolinguistic studies on mind and identity
Several cognitive studies on brain-injured persons have indicated that a strong sense of identity is retained despite limited memory and level of consciousness (Kihlstrom, 2012). Patients with severe amnesia provide a case in point.
The first concerns Henry Molaison (H.M), a walking lesson to the neuropsychological community in the early 1950s. Suffering from severe epilepsy, H.M’s hippocampus was experimentally removed in a brain surgery which cured his epilepsy. However the removal prevented H.M. from forming both short and long term memories. While, he could recall past events, concepts, and people before the surgery, little or no events were perceived after the surgery (The Many Lives of Memory, 2012). Living became a daily process of re-learning, for experiences once recorded, faded away in seconds. “It’s like waking up, sort of like waking up in the world. . . trying to push things together yourself, reaching back. And you wonder at times just, well, what it is and what it isn’t.” Yet in the midst of forgetting almost everything, H.M. evidently preserved a concept of self, as a humorous and cheerful personality (Bornstein, 1998).
More recent examples include K.C and W.J, persons with severe amnesia due to head trauma. Both possessed an idea of who they were even with a significant loss of memories. For K.C., the trauma led to an altered personality, which he was still able to identify with by integrating new knowledge about himself from daily life even when the experiences could not be consciously retrieved (Kihlstrom, 2012; Rosenbaum et al., 2004).
The second example involves an anonymous Hispanic lady, aged 30, who suffered from bouts of psychogenic amnesia. During such times, all prior memories, personal or otherwise, were forgotten, and her personality underwent a drastic change. The patient was conscious of what she called her true self divorced from her perceptions. In attempt to explain the disembodied identity, she stated a desire to “travel back” to the time when she was her self (Arzy et al., 2011).
The examples do not conform to the earlier statements put forth in accordance with Hume’s account of self. We now consider a number of challenges posed:
- Fleeting impressions captured in the minds of amnesic patients cannot be traced to corresponding ideas, i.e. there are no memories. Are these impressions then false?
- If unmatched impressions are meaningless, it would not be possible for K.C. to use experiences to update himself on his identity—a feat he accomplished.
- More importantly, the patients maintained an identity separate from their perceptions, clearly shown in the case of the Hispanic lady. How was it that they thought of self as distinct, and why? What then defines it?
3 A Metaphysical Account
Emmanuel Kant advanced the notion that self may be discovered through knowledge, which is not necessarily dependent on experiences alone. The mind possesses in-built a priori organizational rules used to categorize sense data and objects of experiences. This is done by acts of synthesis, where the mind pieces representations into a coherent construct. Disconnected fragments of information and sensations are related and weaved into a unified perspective of the world (Nollmeyer, n.d). And what is self? It is a transcendental idea which actively synthesizes thoughts and perceptions via the mind and creates a “unity of consciousness” in each person. That is, each individual’s insight of the world differs from another based on the unique synthesis woven by the self (Chaffee, 2014: 130–135).
Kant’s theory provides explanation for the distinct sense of self acknowledged in the case of the amnesic persons, based on the “unity of consciousness,” thoughts and perceptions exclusive to the person. Through synthesis, K.C. and W.J. were able to unite the various representations and experiences to form their outlook of the world and eventually gain new knowledge about their selves. This concept is further supported by deep brain stimulation studies.
3.1 The case of deep brain stimulation
Deep brain stimulation (DBS) is a treatment type for neurological conditions and involves the implant of electrodes in deep brain structures. Abnormal neuron signals are replaced while existing brain circuits are enhanced. Patients with Parkinson’s disease or major depression are the primary users of DBS in a bid to improve motor skills, moods, behaviors. While effective, this relatively new approach have raised doubts in terms of structural changes that at times occur as a result of DBS implants.
To illustrate, a retired English professor suffering from Parkinson’s underwent DBS with good effects on his disease. Per contra, it was noticed that his behaviors and moods became increasingly unstable and impulsive. When asked however, the patient did not appear to notice any change: “Nope. . . but I do feel more energetic these days.” In other words, he was essentially his own self.
In another instance, an accountant with major depression benefited from the DBS treatment for the first three years before experiencing an uncontrollable recurrence of sadness, helplessness, even despair. Puzzled about his fluctuating emotions, he went for a check and discovered that they were produced by a technical fault in the DBS device. The relieved patient said, “I’m just happy it wasn’t me, that it was the battery” (Lipsman and Glannon, 2013).
Apparently, the DBS patients experienced a delineation of mental states and what they called “self.” Although the professor’s personality shifted due to the psychological effects of electrode stimulation, there was no discontinuity in his idea of self. Rather, in his perspective, he was unaffected, the same identity. For the accountant, persistent mood swings and emotions impaired his ability to exercise his intentions. Yet he merely referenced the affective states to a faulty component in the device: self was not recognized to be the source of those feelings. In Kant’s framework, when one is conscious of self, he conceives it as a distinct subject (Brooks, 2013). The “unity of consciousness” accounts for the distinct self that appears to be experienced by the DBS patients and the Hispanic lady with psychogenic amnesia mentioned earlier.
To summarize, current neuroscience research present a few incompatibilities with Hume's theory. In contrast, Kant’s framework of consciousness appears to provide a sufficient explanation for the exclusivity of self and accounts for the retained sense of self in amnesic and mentally-injured patients.
We conclude that while self is inextricably linked to the mind yet as one observed “may not exist in the brain in a way that permits us to find it” (Kihlstrom, 2012). Perhaps Self exists on a metaphysical plane, after all.
1The term “mind” in Hume’s account does not denote the metaphysical mind but refers to mental events or thinking processes.
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