Eyewitness Testimony and Internal States |
State-dependent learning can explain why witnesses may forget details, not necessarily deceive.
Recognition tests, like multiple choice, reveal knowledge even when direct recall fails.
No objective test, including lie detectors, reliably identifies deception in courtrooms.
Is it possible for someone to know something but not know that they know it? If so, how would such a person be distinguished from someone who knows something but lies about it when asked? Interrogators and criminal investigators are faced with such conundrums all the time.
What is State-Dependent Learning?
In the 1960s researcher Donald Overton suggested that the likelihood of successful learning is greatest when there is a clear correlation between the circumstances which prevail while forming a memory, and during subsequent retrieval of that memory. Included here are both internal states, such as mood, alertness and attention, along with external conditions (temperature, nearby sounds or smells). Overton referred to this as “state-dependent learning”.
As an example, Overton tested rats learning to successfully wend their way through a maze while under the influence of pentobarbital. When later tested without the drug they failed to run the maze. Restoration of the pentobarbital led to a renewal of the rat’s successful performance.
Many of the findings on state dependent learning date from the 1960s, principally the work of Overton. His seminal 1964 paper “State-dependent or dissociated learning produced with pentobarbital” essentially defined the field. A person too may retain a memory, but the memory may be inaccessible, because conditions present when creating the memory were different during attempts at memory retrieval.
How State-Dependent Learning Affects Human Memory........