Beware of 'fish memory' and 'tunnel effect': experts warn of the risks of binge-watching TV series

It's the order of the day. After the release of any series on any platform, especially the most anticipated ones, the typical 'binge' of episodes follows. Some finish the season in a single weekend or even overnight if it's short. Watching series in a marathon or spending hours browsing an infinite catalog has become routine for millions of people, as pointed out by the Universitat Oberta de Catalunya (UOC). But what is really happening with our brain in this new era of compulsive viewing?

Experts from the Universitat Oberta de Catalunya (UOC) analyze how the design of platforms affects the consolidation of memories and the viewer's critical capacity. These experts warn about two side effects of intensive consumption of platforms like Netflix, Amazon Prime, or MAX: the so-called "fish memory" and "tunnel effect." Two phenomena that, as explained by professor Elena Neira, an expert in audiovisual communication, and clinical neuropsychologist Juan Luis García Fernández, have both cognitive and cultural implications.

Fish Memory and "Spaced Memory Effect"

The first of these phenomena, "fish memory," refers to the sensation of not remembering anything when a new season of a series starts. Elena Neira, a collaborating professor of Information and Communication Sciences at UOC and researcher at the GAME group, points out that "it is a phenomenon very linked to the block release of seasons, which usually encourages binge-watching."

Neira, an interdisciplinary researcher in content distribution on streaming platforms, explains that "watching many episodes at once influences two basic processes on which our memories are built." On one hand, "it affects the memory encoding processes carried out by our brain each time it receives new information of interest, in order to store it correctly and retrieve it later." On the other hand, the process of linking that information with what is already present in the memory is lost, since "discussing the series, reflecting on it while waiting for the next installment, reading articles... all these activities contribute to cementing long-term memory on a more solid foundation because the connections between those newly received stimuli and your brain's backup are stronger." When viewers binge-watch, Neira concludes that "the connections are weaker and, therefore, much easier to forget."

In addition, she adds, this prevents what psychologists call the "spaced memory effect." She illustrates this with a common example: "Those who have tried to cram for an exam the day before in a rush, have surely noticed how memory plays tricks when it comes to remembering a lot of information that has been stored in a short time."

From the field of clinical neuropsychology, Juan Luis García Fernández, a professor of Health Sciences at UOC and researcher at the NeuroADaS Lab group, confirms that this forgetfulness is not accidental. "It's not that we have bad memory, but that we are saturating the brain with too much information, without giving it time to process it properly."

He explains that "for something to stay in our long-term memory, we need to pay attention to it, understand it, relate it to other things in our life, and link it with emotional aspects." But if content is consumed in a marathon mode or while doing other tasks, "that content is not consolidated in the memory, and is quickly forgotten." Therefore, the necessary involvement in processing and storing is lost, and "even if we have some information stored, we also won't be able to retrieve it correctly."

When the Algorithm Thinks for You

The second phenomenon, the 'tunnel effect', has to do with how the platform's algorithm conditions what we watch. Despite having huge catalogs and theoretical freedom of choice, many users end up always consuming the same thing, according to UOC.

Neira maintains that "streaming has created a new model of viewer, active in consumption and passive in choice, despite having absolute freedom to choose." She points directly to the role of algorithms: "Algorithmic personalization is essentially a filter that makes predictions about what it believes you will like." This explains why "platforms highlight their premieres and original productions to the detriment of other alternatives." The result? "More adapted interfaces, but also more limited and concentrated around a few titles."

García Fernández explains it from a brain perspective: "The 'tunnel effect' occurs when, using platforms like Netflix or Amazon Prime, we end up watching always the same or very similar things, without exploring other options in the catalog." This responds to a natural tendency of the brain to repeat patterns that have already worked: "We seek to watch things that we like, and what better way than things similar to what we have liked."

This is reinforced by the reward system: "Having titles or images that catch our attention activates the brain's reward system, especially a substance called dopamine, which is associated with pleasure and motivation." Moreover, "our selective attentional system, mediated by frontoparietal attention networks, is interfered with by motivation and previous experiences," and tends to focus "on what it expects to like, and leaves out what it considers irrelevant." All this, concludes the expert, generates a kind of "tunnel vision, where we only see a part of the catalog, the one the algorithm suggests, but also the one that best fits our tastes."

García Fernández distinguishes between two types of attention: algorithm-driven (bottom-up) and voluntary (top-down). "This type of attention is bottom-up, that is, from the catalog of titles we like, when searching, something 'stands out' above the rest, a series that we have heard about, that we have seen promoted, or whose title or promotional poster we may like, and there we hit play." In contrast, voluntary attention requires effort and is activated "when we consciously decide to search for something new, compare options, or explore the catalog."

The expert warns that if we always let algorithms lead us by the hand, we increasingly subject what we can watch to that layer of facilitation provided by the platforms, and not to new titles. And he concludes: "It's as if the brain gets used to not having to decide, but to choose, and the fewer titles we choose, the more conditioned we can be."

Does all this have lasting consequences? According to the clinical neuropsychologist, "brain plasticity depends on the challenges we face and the new learnings we have in our life." Watching similar content does not completely block it, but it can limit it: "If everything we see is predictable, the adaptation to new challenges and learning is reduced." And he adds that watching content outside the comfort zone "also allows activating frontal regions related to critical thinking, learning new information, and even enhancing our cognitive reserve."

In her book Streaming wars, Elena Neira analyzes how the competition between platforms has exacerbated this saturation. Their virtual libraries have allowed multiplying the offer, although in reality, it has not translated into an improvement in consumption decisions. "Platforms know that a user's ability to choose is inversely proportional to the size of references they have in front of them," she explains. They also know that the best-retained user is the one who watches a lot of content, so "with the multiplication of the offer, this has made it more problematic to capture attention." Has the narrative quality worsened? Neira clarifies: "Perhaps we could talk about a greater proliferation of series with less complex plots, but not about a loss of narrative quality in a strict sense."

Both experts agree on a central idea: we must regain control. Spacing out viewing, choosing consciously, exploring beyond what is suggested, and discussing what has been seen improve both the experience and cognitive health. Because watching less, and better, is also a way to resist. And perhaps then, within a year, we might remember what happened in the previous season.