Marking the Mind is a history of scientific ideas about memory – such as the introduction of recall tasks in the 1880s, the discovery of synaptic plasticity, and debates about false memories in the 1980s and 90s. It’s the sort of book I wish existed when I first got interested in biology of memory over a decade ago. Kurt Danziger, an influential psychologist, recounts how basic concepts like remembering and forgetting became technical terms, and the ways researchers have struggled with using these notions in rigorous experimental contexts. The main theme is the manner in which the concepts of memory have changed historically and influenced sciences like psychology and neuroscience, and how very old concepts inform contemporary memory research far more than in other fields.
Many fields of psychology and biology coined their basic terms in the 19th or 20th centuries. Not so with memory research. Basic concepts such as cerebral localization and blocking were known from the ancient Greeks and revised for centuries, which makes it a lot harder for contemporary scientists to use these concepts without a risk of confusion. For instance, the idea that memory has “seat” or “base” shows up in Greek natural philosophy and became a major source of conflict during the early days of neurological localization two centuries past. Metaphors of storage, or memory “locations” persist in contemporary neuroscience, with many different meanings attached to the term across the discipline. Metaphorical language gets reinterpreted as science advances but seldom disappears. Despite the rise of network and distributed processing models in cognitive science, psychologists and neuroscientists were reluctant to abandon the ancient idea of a place or “seat” of memory within the brain, falling back on vague concepts like memory storage that depicted memories were discrete items or held in books or tablets with inscriptions on them.
Danziger surveys the literature on how literacy changed memory, in terms of culture and ideas of plasticity. The reading and writing of texts has altered how people remember, yet literacy is not usually part of memory studies. Danziger argues that it should be because, “for the history of human memory the crucial development involves the use of materials outside an individual’s body for purposes of representation.” Books and photographs don’t just help people recall things – they change the way people remember in the first place. The expansion of literacy and invention of mnemonic tools from stone monuments to computer hard drives is ongoing, and shapes the distinctive ways people remember things. These haven’t been given enough weight, Danziger suggests, in experimental models of remembering.
There’s also the question of whether some memory concepts carry over from one culture to another. Some ideas in contemporary neuroscience were taken over from much older psychological studies done in mono-cultural settings – usually, the U.S. or Europe. There’s not clear evidence that all recollection processes are experienced the same way by humans everywhere, nor even for that they’ve been consistent for Western people over time. Yet controversial concepts like emotional memory or working memory have been quickly adopted by researchers.
For instance, when biologists described “emotional memory,” the assumption is that was a discrete subset of memory. But we don’t know if a discrete type of “emotional memory” exists in the same way that procedural memory surely does. Test subjects report emotional connections to many types of memories, and some studies show emotional arousal during recollection of abstract data. Only certain cultures would differentiate between purely semantic and emotional memory, Danziger notes, observing that medieval Europeans and many people in non-Western cultures today think most of their memories are laden with emotion.
Memory tasks in humans and learning models in laboratory animals represent a small subset of neural processes compared to functions we label as “memory” in psychology and in everyday life. This raises questions about whether we can say there is a “generic human memory” that’s being modeled in laboratory animals or merely several brain processes that are necessary for – but not sufficient to explain – how human memory is generated within the brain. We don’t know, Danziger writes, “whether the findings of modern memory research represent anything more than a documentation of how human memory functions when confronted with memory tasks that are as historically culture-bound as the tasks faced by an illiterate storyteller, a Roman lawyer, or a medieval preacher.”
Marking the Mind encourages readers to think carefully about the ways that culture and language can affect the ways they parse behavior and the types of experiments they design to better understand it. Kurt Danziger reminds us that language, culture, social structures, and literacy all contribute to memory, and ultimately biology must engage with the effects of these on the brain and not just the structures that enable memory to exist.