How much do you trust eyewitness testimony?https://t.co/DbsrZEmrY1
— Jury Analyst (@JuryAnalyst) April 1, 2022
To answer this, we first need to know how memories are made and recalled. Prominent models of memory split it into two concepts: short-term memory and long-term memory. Short-term memory can be thought of as a gateway to long-term memory – it has a small capacity, and incoming information needs to be rehearsed for it to be successfully encoded into long-term memory. If information is not rehearsed (or there is too much information to rehearse) within a timeframe of a few seconds, then it is less likely to be encoded successfully into long-term memory. As an example, think about how easy it is to remember a shortlist of three random digits in comparison to trying to remember a long list of twelve random digits: with the long list, there isn’t enough space in short-term memory to successfully encode all the digits.
Long-term memory, conversely, has an almost limitless capacity. Older theories of long-term memory split into semantic memory and episodic memory. Semantic memory refers to an individual’s accumulated knowledge of facts, word meanings, and general knowledge. Episodic memory refers to specific autobiographical episodes of one’s life – this is the form of memory that was thought to be in play for Dean’s testimony, as he was recalling several separate events of which he was an active participant. Yet, it was found that the recorded conversations did not match the testimony. Dean had a tendency to remember his role as more important than it was in reality, and his memory of the gist of conversations was generally inaccurate, let alone recalling verbatim quotes (although admittedly Dean did frequently admit he couldn’t recall direct quotes during his testimony).
In the next post in this series, we will look at how memories decay and can be manipulated (particularly in the context of eyewitness testimony), before discussing different methods to increase the amount of information recalled by an eyewitness, as well as the accuracy of the information.
Reference: Neisser, U., 1981. John Dean’s memory: A case study. Cognition, 9(1), pp.1-22.