Dr. Grossi's Blog

Past Present and Future

Dr. Philip Grossi
Saturday, 02 July 2011

Arguably the central feature distinguishing humans from other animals is our ability to simulate future events and experience the feelings attendant to those events without having exactly experienced them. By simulating those events in our cortex and attaching feelings  and selective memories of similar events from subcortical levels, we produce a gestalt of the future.  This is at a different level than animals who do associate pleasure and pain with certain experienced events and avoid or embrace those events as they repeat through time though there is no evidence they simulate future events.  Yet, why do our simulations of the future so often lead us astray?  The following are some thoughts about that issue.

illustration to past present future blogSo, the brain melds stored information to build internal representations of our world.  If the event is past it is memory, if it is present it is perception, if in the future it is simulation.  Patients with damage to the prefrontal cortex or medial temporal lobes cannot simulate but are chained to the here and now.  The involvement of the frontal lobes, present in humans and absent in animals, is additional evidence for the assertion above that other animals do not simulate future events.  Indeed the work of C. M. Atance and colleagues has shown that this ability is not present in human children until about the fourth year of life, which is after language has developed. 

If a simulation is created, then how do feeling attach to those simulations?  We use our feeling reaction to that simulation as if it were in the present and simply  extrapolate those feelings to the future simulation.  So one imagines an event, feels unhappy about it, then takes this unhappiness as an indicator of the feeling that will be experienced when the event actually occurs.  This process allows a person to preview events.  Stimulation of future painful events and pleasurable events are stored in different brain areas, as is the magnitude of the pleasure of the future event. 

illustration to past present future blog

Yet all of us know from our experience that these simulations and the attendant feeling are often wrong.  What accounts for that?  All simulations are built of memories.  Therefore, if the memories are unrepresentative, then the simulations will be skewed.  People tend to recall their worst or best experience rather than their typical experience.  They recall their best day, worst day, or their last day but not the representative day.  Therefore, their simulations either exaggerate the pleasure or the pain of the simulated event.

Another reason for errors is that memories are stored in essences rather that in complete detail and simulations are essentialized and abbreviated. By omitting inessential details often critical modifying information is lost.  This tendency increases as time to simulation increases.  Also, the simulations are heavy on the early moments of the simulation and thus the capacity for adaptation over time is lost.  This usually results in the worst view in the simulation and the worst attendant feelings.

Finally, it is no understatement to say that all of the above factors are influenced by the current context in which the simulation takes place.  If one is angry, one might select a certain set of recollections to construct a simulation which could and likely would be different that those that would be used if one was satisfied or extraordinarily happy.  Furthermore, this context is always shifting. 

Our cerebral cortex has done an admirable job in trying to fool the subcortical centers to call upon what they have learned from our evolutionary past.  It is an imperfect system but it can be improved upon if we become more conscious of the factors that tend to make it imperfect and reflect upon them.