Dimensions:
- attention: attention is the main mechanism of the brain to differentiate between important and unimportant stimuli and has (maybe the most obvious) effect on memory encoding and later recall ability.
- general arousal: arousal refers to the general state of psychological and physiological activation and is majorly defined through the interplay of the sympathetic (fight or flight response) and parasympathetic (rest and digest) parts of the autonomic nervous system. For cognitively non-demanding tasks a higher level of arousal is associated with higher cognitive performance, for cognitively more demanding tasks there seems to be a sweet spot of moderate arousal. The psychologists Robert M. Yerkes and John Dillingham Dodson formalised this as the Yerkes–Dodson law already in the year 1908. Arousal together with strong emotions also seems to be the main driver for so-called flashbulb memories, i.e. memories that are vividly recallable decades without deliberate practice and are mostly formed during strongly moving moments like childbirths or events of trauma.
- emotion: different emotional states, especially states of strong emotion, seem to have a strong effect on later recall ability. Likely strongly connected to the impact of general arousal and is highly associated with flashbulb memories as well.
- metacognition: according to Wikipedia "an awareness of one's thought processes and an understanding of the patterns behind them.". The reflection of one's own thought and reasoning processes might be most prominent in various meditation paradigms like mindfulness. Different studies show quite a significant impact on different measures of cognitive performance through metacognition (or more predominantly meditation). This includes the general practice of meditation and the practice of meditating immediately before a learning task. Again, it seems to be difficult to separate the effects on general cognitive performance and memory. Even more importantly, it seems to be rather challenging to separate the effects of meditation or metacognition on cognitive performance from those on attention and thus only indirectly on cognitive performance.
- perceived novelty: different cognitive frameworks like predictive coding are based on principles of prediction error and model updating. To generalise well and to not overfit on specific stimuli, it would be useful to model the novelty of stimuli and associate encoding and consolidation strength with such novelty. Several neurotransmitters, most importantly Dopamine and Acetylcholine are associated with this perception of novelty and memory encoding strength at the same time. Studies show that novel environments improve memory performance. The role of acetylcholine in memory and novelty perception is established. Artificially increasing dopamine levels through administering a dopamine precursor (L-DOPA) increases memory performance.
- perceived (reward) relevance: different neurotransmitters, most importantly Dopamine, are connected to the reward-importance modelling of stimuli in the human brain. Research shows that this perceived reward relevance (also called incentive salience) is correlated with memory performance.
- context similarity train and test time: so far we have treated the impact of different dimensions like attention as being separate between train and test time. However, there is not only the notion of conditions being optimal for train and test time independently, but also the orthogonal effect of conditions just being similar between train and test time. Research shows that the similarity of specific aspects of the mental state (including the current perception of external stimuli aka the environment) between train and test time has a strong effect on successful recall probability. It very much feels like a form of compression in which a piece of information is stored not in its full size but conditioned on the current context. If my environment is represented through 1 bit and I want to store a piece of information of 10 bits, I only need 9 bits for storage if I condition the information on the environment and (obviously heavily constrained by only then being able to retrieve the information when the environment is fully reinstated). If the environment present during encoding has been memorized before anyway, it can also be mentally reinstated during a recall attempt, removing the condition of being in the same context physically. People have made use of this dynamic for thousands of years through the so-called method of loci in which pieces of information are associated with physical locations in an imagined memory palace. The abilities of mental reinstatement seem to be trainable and reach vast areas from visuals, and sounds but also physical movements and emotions.
Moving in that space?
Coming back to the question from the beginning, how can then recall probability be truly maximised? The different dimensions outlined above already indicate an optimal subspace of the space of mental states. The more interesting question is, how can we move in this space, that is how can we consciously influence all of the different aspects affecting recall probability? This task is a very hard one, firstly due to how many of these aspects are related to subconscious processes making them hard/impossible to control and secondly due to how difficult it is to measure a mental state on these dimensions, which if possible would make the self-training of moving in that space a lot easier. It also presents a difficult trade-off: is time better spent moving in this space (and learning how to move in this space) or doing the actual learning task? While this remains an open question, I will outline some thoughts on possible avenues of approaching mental-state optimality.
- attention: probably best trained and improved through attention exercises and focused meditation (i.e. meditation pratices that involve focusing on a single point or stimuli for prolonged periods of time)
- general arousal: specific types of meditation allow to increase and control levels of stimulation (the legendary Tummo meditation would be an example). Potentially more practical interventions might be the use of different breathing techniques and (light) physical activity.
- emotion: music?
- metacognition: probably best trained through performing deliberately performing metacognition, often central to meditation practices like mindfulness
- perceived novelty: could be achieved through performing a learning task in novel environments and settings and through deliberately trying to "defamiliarize" oneself with material and concepts learned
- perceived reward relevance: potentially achieved through the implementation of short-term rewards (gamification, treats). Some research suggests the visualisation of "mastery" to be helpful. Additionally, it might be helpful to frame material in ways that imply personal connection and evoke a perception of wonder. I.e. making oneself aware of how truly fascinating but also mysterios the nature of a specific problem is, might increase recall probabilities of associated information.
- context similarity: if possible true physical similarity between train time and test time environment. Otherwise: method of loci to an extreme. I.e. not only imagining a specific scene to be associated to a memory but also a specific emotion, proprioceptive state, sounds etc., again ideally associations present during test time anyway to limit the need of mental reinstatement.
attention: the concentration of awareness on some phenomenon to the exclusion of other stimuli
arousal: multidimensional state of physiological and psychological activation, characterized by varying degrees of autonomic nervous system engagement, hormonal changes, and alterations in cognitive and affective processes, which prepares an organism for action and modulates its responsiveness to internal and external stimuli
sympathetic nervous system: one of the three (physically distinct) divisions of the autonomic nervous system, stimulates a body's "fight or flight" response (or more general arousal)
parasympathetic nervous system: one of the three (physically distinct) divisions of the autonomic nervous system, stimulates "rest-and-digest"/"feed-and-breed" activities that occur when the body is at rest
Yerkes-Dodson law: empirical relationship between arousal and performance for both cognitively non-demanding and cognitively more demanding tasks
flashbulb memory: a vivid, long-lasting memory about a surprising or shocking event that has happened in the past
predictive coding: theory of brain function which postulates that the brain is constantly generating and updating a "mental model" of its environment
L-DOPA: precursor to dopamine (and medication as such)
- Aliases
- levodopa
- l-3,4-dihydroxyphenylalanine
incentive salience: a potentially attributed property of a stimulus when modelled to be motivationally relevant by the brain
method of loci: trategy for memory enhancement, which uses visualizations of familiar spatial environments in order to enhance the recall of information
mental imagery: the cognitive state of visualisation (in different modalities), heavily used by athletes (and e.g. dancers)
defamiliarization: the technique of presenting or understanding familiar concepts from a novel (potentially strange) perspective
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