EMOTIONAL RELEARNING
(FEAR)
SUCH TRAUMATIC MEMORIES SEEM TO REMAIN AS FIXTURES IN BRAIN FUNCTION BECAUSE THEY INTERFERE WITH SUBSEQUENT LEARNING - SPECIALLY, WITH RELEARNING A MORE NORMAL RESPONSE TO THOSE TRAUMATIZING EVENTS. IN ACQUIRED FEAR SUCH AT PTSD, THE MECHANISMS OF LEARNING AND MEMORY HAVE GONE AWAY, AGAIN, IT IS THE AMYGDALA THAT IS KEY AMONG THE BRAIN REGIONS INVOLVED. BUT IN OVERCOMING THE LEARNED FEAR, THE NEOCORTEX IS CRITICAL.
FEAR CONDITIONING IS THE NAME PSYCHOLOGISTS USE FOR THE PROCESS WHEREBY SOMETHING THAT IS NOT IN THE LEAST THREATENING BECOMES DREADED AS IT IS ASSOCIATED IN SOMEONE'S MIND WITH SOMETHING FRIGHTENING. WHEN SUCH FRIGHTS ARE INDUCED IN LABORATORY ANIMALS, CHARNEY NOTES, THE FEARS CAN LAST FOR YEARS. THEY KEY REGION OF THE BRAIN THAT LEARNS, RETAINS, AND ACTS ON THIS FEARFUL RESPONSE IS THE CIRCUIT BETWEEN THE THALAMUS, AMYGDALA, AND PREFRONTAL LOBE- THE PATHWAY OF NEURAL HIJACKING.
ORDINARILY, WHEN SOMEONE LEARNS TO BE FRIGHTENED BY SOMETHING THROUGH FEAR CONDITONING, THE FEAR SUBSIDES WITH TIME. THIS SEEMS TO HAPPEN THROUGH A NATURAL RELEARNING, AS THE FEARED OBJECT IS ENCOUNTERED AGAIN IN THE ABSENSE OF ANYTHING TRULY SCARY. THUS A CHILD WHO ACQUIRES A FEAR OF DOGS BECAUSE OF BEING CHASED BY A SNARLING GERMAN SHEPHERED GRADUALLY AND NATURALLY LOSES THAT FEAR IF SAY, SHE MOVES NEXT DOOR TO SOMEONE WHO OWNS A FRIENDLY SHEPHERED, AND SPENDS TIME PLAYING WITH THE DOG.
IN PTSD, SPONTANEOUS RELEARNING FAILS TO OCCUR. CAHRNEY PROPOSES THAT THIS MAY BE DUE TO THE BRAIN CHANGES OF PTSD, WHICH ARE SO STRONG THAT, IN EFFECT, THE AMYGDALA HIJACKING OCCURS EVERY TIME SOMETHING EVEN VAGUELY REMINISCENT OF THE ORIGINAL TRAUMA COMES ALONG. STRENGTHENING THE FEAR PATHWAY. THIS MEANS THAT THERE IS NEVER A TIME WHEN WHAT IS FEARED IS PAIRED IS PAIRED WITH A FEELING A CALM- THE AMYGDALA NEVER RELEARNS A MORE MILD REACTION, "EXTINCTION" OF THE FEAR, HE OBSERVES, APPEARS TO INVOLVE AN ACTIVE PROCESS", WHICH IS ITSELF IMPAIRED IN PEOPLE WITH PTSD, LEADING TO THE ABNORMAL PERSISTENCE OF EMOTIONAL MEMORIES.
BUT GIVEN THE RIGHT EXPERIENCES, EVEN PTSD CAN LIFT, STRONG EMOTIONAL MEMORIES, AND THE PATTERNS OF THOUGHT AND REACTION THAT THEY TRIGGER, CAN CHANGE WITH TIME, THIS RELEARNING, CHARNEY PROPOSES, IS CORTIAL. THE ORGINAL FEAR INGRAINED IN THE AMYGDALA DOES NOT GO AWAY COMPLETELY, RATHER, THE PREFRONTAL CORTEX ACTIVELY SUPPRESSESS THE AMYGDALA'S COMMAND TO THE REST OF THE BRAIN TO RESPOND WITH FEAR.
THE QUESTION IS, HOW QUICKLY DO YOU LET GO LEARNED FEAR? ASKS RICHARD DAVIDSON, THE UNIVERSITY OF WISCONSIN PSYCHOLOGIST WHO DISCOVERED THE ROLE OF THE LEFT PREFRONTAL CORTEX AS A DAMPER ON DISTRESS. IN A LABORATORY EXPERIMENT IN WHICH PEOPLE FIRST LEARNED AS AVERSION TO A LOUD NOISE - A PARADIGM FOR LEANED FEAR, AND A LOWER-KEY PARALLELL OF PTSD - DAVIDSON FOUND THAT PEOPLE WHO HAD MORE ACTIVITY IN THE LEFT PREFRONTAL CORTEX GOT OVER THE ACQUIRED FEAR MORE QUICKLY, AGAIN SUGGESTING A CORTICAL ROLE IN LETTING GO OF LEARNED DISTRESS.
