Self and Memory 219“9x6” b2726 Self and the Phenomenon of Life: A Biologist Examines Life from Molecules to Humanitythe number (remember the expression “on the tip of my tongue”?); (3)
the sequential finger motion when dialing the number. I can recall on
numerous instances the difficulty of saying out loud the number in Chi-
nese if I initially stored it in English, although I am equally fluent in
both languages. I also have difficulty using a rotary dial if the number
is etched in my brain in the format of a rectangular keypad. These are
examples of declarative memory aided by procedural memory. Another
interesting fact concerns map memory. When going from one part of
town to another, I rely on the east-west/north-south coordination on my
mental map. My wife, by contrast, uses bodily movements as cues, like
turning right followed by turning left, and so on — another use of pro-
cedural memory. My point is that abstract memories are usually tied to
concrete references.
10.6 Emotion Enhances Memory
Emotion heightens alertness and facilitates memory fixation. Strong
memories are those engraved with intense feelings. Remember where
you were and what you were doing when President Kennedy was assas-
sinated? Or, for the younger generations, when the World Trade Center
was attacked on September 11, 2001? In our personal life, the indelible
experiences are also those highly emotionally charged — the first erotic
kiss, the first sexual intercourse, the first encounter with a dead person,
the first scene of a newborn baby...
In animal training, there is evidence that during negative rein-
forcement nerve impulses from the hippocampus activate the amygdala
(a fear center), whereas in positive reinforcement the hippocampus acti-
vates the nucleus accumbens (a motivation/reward center) instead.^10
10.7 Cellular and Molecular Basis of Memory: Lessons
From Invertebrates
The underlying mechanisms for all types of memories are quite similar.
In a nutshell, short-term memories involve transient, functional changes