 26. Naturalizing the Self 573
Neuroanatomical  Studies
An understanding of the gross anatomy of 
the brain can help us to better understand 
cross-  species comparisons in self-  processes. 
For example, what distinguishes the brains 
of chimps (who show evidence of mirror 
self- recognition) from the brains of monkeys 
(who do not)? Which neuroanatomical areas 
are common to animals that show the ca -
pacity for self-  recognition or linguistic self- 
referencing, or self-  conscious emotions? One 
clue is that humans begin to show evidence 
of mirror self-  recognition around ages 18–24 
months, which is when the prefrontal cortex 
begins to mature in structure and function. 
Although there are likely many reasons why 
the neuroanatomy of two species might be 
similar or different, cross-  species compari -
sons can at least identify possible anatomical 
regions that merit further exploration.
Neurological Disorders and  Brain  Damage
Some of the most fascinating avenues for 
understanding the self have come from the 
study of neurological disorders. Although 
the complete loss of a sense of self is ex -
tremely rare, it has been known to occur in 
individuals suffering from dissociative fugue 
(a feature of DSM-5 dissociative amnesia 
disorder). These individuals wake up one 
day with no access to their autobiographical 
memory and no understanding of who they 
are—they become strangers to their own 
minds, forced to construct an entirely new 
identity or experience a complete absence of 
selfhood.
Many other neurological disorders also 
produce profound changes in the self (Fein -
berg & Paul, 2005; Moe & Docherty, 2014; 
Ramachandran, 2011). Individuals with 
autism exhibit widespread deficits in self- 
awareness, self-  understanding, and self- 
related processes such as empathy and theory 
of mind (Huang et al., 2017; but see Schrib -
er, Robins, & Solomon, 2014). Other disor -
ders are characterized by bizarre distortions 
in body image, including macropsia and mi -
cropsia (an Alice-in-  Wonderland-  like feeling 
of having grown incredibly large or incred -
ibly small in size), asomatognosia (e.g., a de -
nial that the left side of one’s body is part 
of oneself and assertions that any actions by 
one’s left side were caused by someone else), and exosomesthesia (a pathological exten -
sion of the body image in which touches to 
the body are experienced as touches to near -
by physical objects, and vice versa). Suffer -
ers of Lesch–Nyhan syndrome have a patho -
logical tendency toward self-harm, engaging 
in dramatic self-  injurious behaviors such as 
biting off their fingers and poking out their 
eyes; they often feel as if their hands and 
mouth do not belong to them and are under 
the control of someone or something else, 
suggesting that their sense of agency—  the 
feeling that “I” am the one controlling my 
body—is severely distorted. This same lack 
of “ownership” over self-  generated thoughts 
and actions is believe to account for the se -
vere delusions experienced by individuals 
with schizophrenia (Robinson, Wagner, & 
Northoff, 2016).
Studies of patients with brain damage 
due to strokes or accidents indicate that the 
frontal lobes are involved in self-  regulation. 
Phineas Gage is perhaps the most well 
known example. After an iron rod penetrat -
ed his frontal lobes, he showed a diminished 
capacity to self-  regulate, as well as dramatic 
personality changes, becoming more irrev -
erent, obstinate, and impatient. In general, 
patients suffering from frontal lobe damage 
show deficits in the capacity to monitor and 
reflect on their own mental states (Beer, Shi -
mamura, & Knight, 2004), suggesting that 
aspects of the self related to self-  awareness 
(the “I”) may be associated with activity in 
the frontal lobes. Pinker (1997) describes the 
case of a 15-year-old boy with frontal lobe 
damage who would stay in the shower for 
hours at a time, unable to decide whether to 
get out. Patients with damage to a specific 
region of the frontal lobes, known as the or -
bitofrontal cortex, often show highly inap -
propriate social behaviors that are believed 
to be caused by impairments in self-  insight, 
the capacity to experience self-  conscious 
emotions, and the ability to use emotional 
information in the service of self-  regulation 
(Beer, John, Scabini, & Knight, 2006; Beer, 
Lombargo, & Bhanji, 2010). Patients with 
damage to the right parietal or prefrontal 
cortex are unable to recognize themselves 
in the mirror, suggesting that they have lost 
the capacity for self-  recognition (Keenan, 
Wheeler, Gallup, & Pascual-  Leone, 2000).
Another provocative set of studies 
has examined self-  awareness and self- 