Dynaread Enforced Memory Consolidation

by C. Mark Wessinger PhD, Dynaread Cognitive Neuroscience

The need for time to allow for memory consolidation is well accepted within the memory research community. However, it is also clear that the time required varies by task and type of interference. To complicate matters, there are two types of consolidation that are often discussed as being interrelated. One type of consolidation refers to moving information into short-term memory following the initial study period, and usually involves seconds to minutes. The other type of consolidation involves moving information from short-term memory to long-term memory over several hours, and often involves sleep. The shorter term consolidation is believed to be related to memory strengthening at the neuronal or synaptic level, whereas, the longer term consolidation is related to memory strengthening at the system level (see reviews Dudai, 2004; Nadar & Hardt, 2009; Redondo & Morris, 2011).

Disrupting this consolidation has been shown to occur for both short-term, and long-term periods. Transcranial magnetic stimulation (TMS) has been used immediately following training to disrupt short-term consolidation (Censor & Cohen, 2011). Long-term consolidation has been shown to be less given a 10 hour delay without sleep compared to a 24-hour delay with sleep (Ortiz & Wright, 2010). There is also research showing that short periods of time, on the order of milliseconds, following the initial study phase can disrupt synaptic consolidation. More specifically, periods of 400-1200 msecs have been shown to reduce consolidation (Mercer & McKeown, 2010). Research in people with memory deficits has shown that a period of 9 minutes can enhance both short-term and long-term consolidation (Dewar, et al., 2009).

All of these papers and consolidation points aside, the most definitive answer available in the current body of research regarding the time required for short term consolidation is when it occurs "within the first minutes to hours after the encoding has occurred or practice ended" (from Dudai, 2009 page 54).

Given the need of consolidation and the range of current scientific uncertainty, Dynaread deploys a forced break of 4 minutes following a training period of 9 minutes (Reviews plus single round Words module), for short term consolidation to occur.

Limiting the number of sessions allowed per day would allow for long-term consolidation.

References

Censor N & Cohen LG. (2011). Using repetitive transcranial magnetic stimulation to study the underlying neural mechanisms of human motor learning and memory. Journal of Physiology, volume 589(1), pp21—28.

Dewar M, Garcia YF, Cowan N, & Sala, SD. (2009). Delaying Interference Enhances Memory Consolidation in Amnesic Patients,Neuropsychology, volume 23(5), pp627—634.

Dudai Y. (2004). The Neurobiology of Consolidations, or, how stable is the engram? Annual Review of Psychology, volume 55, pp 51-86.

Mercer T & McKeown D. (2010). Interference in short-term auditory memory. The Quarterly Journal of Experimental Psychology, volume 63(7), pp1256—1265.

Nader K and Hardt O. (2009). A single standard for memory: the case for reconsolidation, Nature Reviews: Neuroscience, volume 10, pp224-234.

Ortiz JA & Wright BA. (2010). Differential rates of consolidation of conceptual and stimulus learning following training on an auditory skill, Experimental Brain Research, volume 201, pp441—451.

Redondo RL & Morris RGM. (2011). Making memories last: the synaptic tagging and capture hypothesis, Nature Reviews: Neuroscience, volume 12, pp17-30.