MBI_5 Narrative Self

a continuum to our life story

Another theory of why we feel that we have a unique and separate self is that there is a

John Locke

Locke did not think that the most essential aspect of a person is their body

Instead, he said that what defines identity is the non-physical part – our consciousness or thoughts, and in particular, our memories

memory is critical to our narrative self because

we don’t maintain a single consciousness over the course of our lives

Rather, when we wake up in the morning, our conscious selves remember who we were the day before

Locke’s Memory Theory of Personal Identity

Personal identity persists over time because we retain memories of ourselves at different points, and each of those memories is connected to the one before it

Advantage of Memory Theory of Personal Identity over Body Theory of Personal Identity

The physical body changes, but consciousness/memory persists through those changes

Problem with Memory Theory

what if you don’t or can’t remember?

We generally don’t remember events from the first couple of years of life (infantile amnesia) – does that mean we didn’t become who we are until the age of two?

What happens when people lose their memory, e.g., due to dementia or amnesia – do they stop being that person?

Locke’s other theory of personal identity

Locke later posited another theory in which personal identity is made up of “sameness of consciousness,” not so much in the sense of continuity of memory as of continuity of character

Thought experiment: If a demon offered us a choice between remembering everything but feeling and valuing very differently, or feeling and valuing the same sorts of things but remembering nothing, most of us would choose the latter, Locke said

Neurological perspective of the narrative self

identity can be said to involve “the personalization of the brain through unique dynamic configurations of neuronal connections, driven by unique experiences” (Susan Greenfield)

That is, our unique experiences leave a unique brain signature or memory trace

(think: fingerprint)

Alzheimer’s Disease

Disease occurring in latter part of life that is characterized by deterioration of memory, reasoning, and language abilities

Associated with loss of neurons in cortical and sub-cortical regions: ventricles (fluid filled cavities) may be enlarged – patients might end up losing as much of 50% of their brain mass

Brains of patients contain many amyloid plaques, which contain a core of misfolded- amyloid protein surrounded by degenerating axons and dendrites, and neurofibrillary tangles, dying neurons that contain twisted filaments of tau protein

Apart from the deterioration in memory, Alzheimer’s seems to involve a selective inability to

update information regarding the self

For instance, someone with this disorder may not recognize that their driving ability is impaired but have no difficulty assessing other people’s driving ability

Anosognosia

condition in which a patient is unaware of their neurological deficit or psychiatric condition

fMRI study on Alzheimer’s patients with anosognosia

Found that these patients are far better at judging traits of a close friend, caregiver, or relative than they are at judging themselves

Moreover, fMRI revealed that the medial prefrontal cortex (mPFC) and left anterior temporal lobe – areas of the brain important in appraisal – are less active during self-appraisal than during a task that requires appraisal of others

The reminiscence bump

As memories start to fade, people with Alzheimer’s will often remember best and focus on early memories, particularly those in the late adolescent, early adulthood years

In general, this is the period for which people tend to have the strongest memories – psychologists call this the reminiscence bump

Why does the reminiscence bump occur

because this period tends to be a time of dramatic and emotionally powerful changes

As a result, these memories are powerfully incorporated into one’s sense of self

In addition, memories of experiences that are highly significant in meeting the goals of one’s life seem to remain more strongly associated with the self and its history

Late adolescence/early adulthood is a critical period when people are cementing their identity, defining their self-beliefs, self-concepts, and life goals

Causes of Alzheimer’s

• Genetic component

• Higher risk of disease in those who have previously suffered a stroke or head trauma

• Conditions associated with cardiovascular disease, e.g., obesity, diabetes, high blood pressure, high cholesterol, smoking, and lack of exercise, increase risk

• Associated with low levels of vitamin D and certain B vitamins

• Exposure to lead and toxic substances, such as air pollutants, may increase risk

• Article published in Lancet in 2017 noted that hearing loss is now known to be the largest modifiable risk factor for developing dementia, exceeding that of smoking, high blood pressure, lack of exercise, and social isolation

• anticholinergics: associated with reduced brain volume and lower levels of glucose metabolism, particularly in the hippocampus (Tylenol PM, Benadryl, Claritin)

• Tooth and gum disease

• Physically active and are non-obese

• people who keep their minds active tend to show less loss of intellectua functioning in general as they age (study of nuns)

Which regions of the brain are thicker in successful agers than in regular agers? Those regulating cognition or emotion?

Those regulating emotions, e.g., the midcingulate cortex and anterior insula.

What type of activities will increase your chances of remaining sharp into old age?

Those that require hard work and cause you to feel somewhat tired, stymied, frustrated, e.g., grappling with a math problem or pushing yourself to your physical limits.

Memory Disorder’s

alzheimer’s

amnesia

retrograde amnesia

anterograde amnesia

amnesia

partial or total loss of memory

retrograde amnesia

inability to remember events that occured before the onset of the condition

anterograde amnesia

inability to form lasting memories for new experiences

hippocampus

“save” button for explicit memories

The hippocampus acts as a loading dock where the brain temporarily holds to-be-remembered information

Items then migrate for storage in many different parts of the brain in process called memory consolidation

study on rats hippocampus

Removing a rat’s hippocampus 3 hours after it learns the location of some tasty new food prevents long-term memory formation

Removal 48 hours later does not

organize amnesia

memory loss due to physical cause

brain injury through accident or stroke

in most cases of trauma-induced organic amnesia, there is spontaneous recovery after matter of minutes or hours

korsakoff’s amnesia

(part of wernicke-korsakoff syndrome)
amnesia caused by brain damage resulting from thiamine deficiency, usually as a result of chronic alcoholism

patients tend to make things up (confabulate) rather than admit they can’t remember

alcohol-related blackouts

gaps in a person’s memory for events that occured while they were intoxicated

happens when a person drinks enough alcohol to temporarily block memory consolidation - the transfer of memories from short term to long term storage

psychogenic amnesia

psychologically caused memory loss

the default mode network and the narrative self

There is evidence that the default mode network (DMN) is strongly tied to the narrative self and our mental representation of the self

The DMN is most active when we are:

• Reflecting on the past

• Planning for the future

• Thinking about others’ intentions – or what they think of us!

• Ruminating (which usually involves the above)

The DMN is important in mental time travel, the ability to project forward and backward in time, and in formation of stories

some potential problems with the narrative self

Our “story” is a fiction: what we think we remember often never really occurred – we filter information and fill in missing pieces

1. reconsolidation: Whenever we retrieve a memory, the brain rewrites it a bit – it is slightly altered chemically by a new protein synthesis that links it to our present concerns and understanding (happens unconsciously)

2. Much of the material included in the stories we tell ourselves are actually mental elaborations – that is, stories we weave around events – and most of the negative emotions we typically feel do not come from actual aversive events, but from those mental elaboration