Memory is the nervous system’s ability to capture information, store it, and reconstruct it later. We are constantly confronted with a flow of new and old information, which must be processed by what neuroscientists call the memory systems of the brain. 1CONTINUUM 2018; 24-3, Behavioral Neurology and Psychiatry :727-44 The Nobel Prize winning neuroscientist, Eric Kandel, wrote that “Our brain creates, stores, and revises memories, constantly using them to make sense of the world… We depend on memory for thinking, learning, decision making, and interacting with other people. When memory is disrupted, these essential mental faculties suffer.” 2Eric R. Kandel, The Disordered Mind, Farrar Strauss Giroux, 2018.

As we consider the role of memory in Judaic thought, note that there is a big difference between “memory” and “history.” Many rabbinic authorities have observed that there is no word for “history” in Jewish writings. Rabbi Michael Safra points out that history is a litany of facts, a record of things that happened long ago. Memory, on the other hand, is an expression of what the past means to us now. Nothing can change what happened in the past, but the meaning of what happened can change. Memories change, and memories change the people who remember. 3Rabbi Michael Safra, “Memories Can Change Us For the Better,” Yom Kippur Sermon, 2017  “When we remember something, we re-connect with it in multiple ways and enable that information to shape our whole perspective…our sense of self is actually the meaning we weave out of memorable experiences in our past,” writes Rabbi Dr Raphael Zarum. 4Rabbi Dr Raphael Zarum, “The Memories That Keep Judaism Alive“, 2014

Yosef Haim Yerushalmi wrote in Zakhor: Jewish History and Jewish Memory that the concepts of remembrance and not forgetting are repeated nearly 200 times in the Hebrew Bible: Remember the Sabbath; Remember the Covenant; Remember the Exodus from Egypt; Do not forget how you provoked the Lord (the incident of the golden calf). Judaism indeed is a religion in which remembering and implicitly not forgetting are expressed in its sacred texts, rituals, and liturgy 5Avinoam Patt, PhD, “The Performance of Memory,” 2017.

In contrast to the ancient Jewish nature of memory, modern neuroscience began in 19th century Paris under the leadership of Jean Martin Charcot, who encouraged one of his pupils, Paul Sollier, to explore the topic of how memory worked in the brain. Sollier’s work on the anatomic and functional organization of memory was very influential, in turn, on his friend Marcel Proust, the author of one of the monumental works of Western literature and philosophy, The Remembrance of Things Past.

Proust (whose mother was Jewish) developed the idea of involuntary memory as containing the essence of the past. He reflected that an act as simple as eating a piece of pastry (one of his aunt’s now legendary madeleines) could unlock the memory systems of the brain. In a parallel way, many Jewish rituals, such as the eating of matzah during Pesach, also uncover the hidden worlds of memory: “For seven days you shall eat matzah, that you may remember your departure from Egypt”.

(At every Seder I ever attended since early childhood, the only wine ever served was Manischewitz Concord Grape wine. Several years ago, some friends decided to bring “real” wine to the Seder. Willamette Valley Pinot Noir, though delicious, was disappointing, as it evoked no “involuntary memories”).

One cannot even begin to talk about memory without delving into Freud’s ideas about memories. Freud (of Galician Jewish parentage) wrote about how adult behavior could arise the repression of the memory of childhood events. For all of the criticism of the validity of the psychoanalytic method, the Freudian idea that unconscious memories (whether accurate or fantasies) could drive behavior has been accepted throughout the world of psychiatry and culture 6Allen Esterson, “Freud’s Theories of Repression and Memory,” Book Review, 2003. The neuropsychiatric understanding of memory has evolved through the last 150 years since Charcot and Freud, spurred by the explosion of knowledge in the fields of neurobiology, neurochemistry, neuroimaging, neuropathology and neuroanatomy.

Human memory is currently conceptualized as operating within a framework of four interconnected memory “systems,” each of which has an anatomical localization. 7Budson and Price, N Engl J Med 2005; 352:692-9

Explicit and Declarative Memory Systems
(associated with conscious awareness and conscious recollection)
Implicit and Non-declarative Memory Systems
(expressed by a change in behavior and are typically unconscious)
Episodic MemorySemantic MemoryProcedural MemoryWorking Memory
The ability to store and retrieve past episodes and experiencesThe general knowledge of people, objects, words, and conceptsThe ability to learn behavioral and cognitive skills and algorithms that are used at an automatic unconscious levelThe ability to keep information trace active in the brain for a short time after the initial stimulus is no longer available
Medial temporal lobes and pre-frontal cortexLateral temporal lobesPre-frontal, temporal and parietal cortex regionsBasal ganglia, supplemental motor area, and cerebellum

To illustrate, Alzheimer’s disease primarily affects episodic and semantic memory, which correlates with the anatomic localization of the pathology of Alzheimer’s disease. Procedural and working memory are located in parts of the brain not pathologically changed in Alzheimer’s disease, explaining why patients with early- Alzheimer’s dementia can recall how to tie shoes and ride a bicycle.

As a whimsical aside, think of what is involved in preparing for a seder. Reflecting on how my mother annually pulled off this incredible feat, I came up with a non-traditional version of the Four Questions (not exactly what we all learned in religious school as children) as a guide to understanding how the four memory systems are organized:

Which Haggadah did I say we were going to use for this year’s seder?Episodic MemoryThe ability to retrieve information into conscious awareness
Where do I hide the afikomen?Working MemoryThe ability to keep information traces active over a short time
Exactly what do I need for the seder plate?Semantic MemoryThe repository of knowledge of abjects, people, concepts, etc
How do I make those matzah balls?Procedural MemoryThe ability to learn behavioral and cognitive skills

As another exercise of looking at Jewish ideas from the neuroscientific perspective, consider one of the central prayers of our liturgy, the V’ahavta. Embodied within these hallowed verses from Deuteronomy are several mitzvot that can be understood as the ways in which memory, remembrance, and not forgetting work within us all:  

You shall love Adonai your God with all your mind,
With all your soul, and with all your strength.
Set these words, which I command you this day, upon your heart (Episodic Memory)
Teach them faithfully to your children.
Speak of them in your home and on your way, when you lie down and when you rise up.  (Working Memory)
Bind them as a sign upon your hand;
Let them be a symbol before your eyes;  (Semantic Memory)
Inscribe them on the doorposts of your house and on your gates. (Procedural Memory)

I hope I have been able to show that focusing on traditional Judaic religious writings with a modern scientific perspective deepens our understanding of these texts. Furthermore, in doing so we can achieve a renewed appreciation of the wisdom contained therein. By joining a neuroscientific analysis of memory with a religious exploration of remembrance, we can see how each process can help us understand the other — and ourselves.

(This post is part of Sinai and Synapses’ project Scientists in Synagogues, a grass-roots program to offer Jews opportunities to explore the most interesting and pressing questions surrounding Judaism and science. Dr. Mitchell Freedman is an Adjunct Professor of Neurology at the University of North Carolina at Raleigh, a practitioner at Raleigh Neurology Associates, and a community member at Temple Beth Or in Raleigh, NC).

References   [ + ]

1. CONTINUUM 2018; 24-3, Behavioral Neurology and Psychiatry :727-44
2. Eric R. Kandel, The Disordered Mind, Farrar Strauss Giroux, 2018.
3. Rabbi Michael Safra, “Memories Can Change Us For the Better,” Yom Kippur Sermon, 2017
4. Rabbi Dr Raphael Zarum, “The Memories That Keep Judaism Alive“, 2014
5. Avinoam Patt, PhD, “The Performance of Memory,” 2017
6. Allen Esterson, “Freud’s Theories of Repression and Memory,” Book Review, 2003
7. Budson and Price, N Engl J Med 2005; 352:692-9