habituáció

Habituáció, or habituation, is a fundamental form of learning in which an organism's response to a stimulus decreases over time with repeated exposure. This process is a basic mechanism of neural plasticity, allowing living beings to adapt to their environment by filtering out irrelevant or non-threatening stimuli. Unlike classical conditioning, which involves pairing a neutral stimulus with an unconditioned response, habituation occurs simply through repeated exposure to a stimulus without additional reinforcement.

The phenomenon was first systematically studied in the late 19th and early 20th centuries by researchers such as Ivan Pavlov, though its existence had been observed long before. Habituation is widely observed across species, from simple organisms like sea slugs (*Aplysia californica*) to humans. In these organisms, repeated stimulation of a sensory neuron leads to a gradual reduction in the neuron’s firing rate, demonstrating how neural pathways can become less responsive to constant or predictable inputs.

Neuroscientifically, habituation is associated with changes in synaptic transmission, where repeated stimulation weakens the connection between neurons. This process helps conserve neural resources by reducing unnecessary responses. For example, humans may stop noticing the sound of a clock ticking after some time, or a person might ignore the smell of their own home after living there for years.

Habituation plays a role in various behaviors, including sensory adaptation, where prolonged exposure to a stimulus reduces its perceived intensity. It also contributes to cognitive processes like attention and memory by helping filter out background noise. However, habituation is not always beneficial; in some cases, it may lead to reduced sensitivity to important signals, such as danger cues, if they become too familiar. Conversely, dishabituation—the recovery of a habituated response after a novel stimulus—demonstrates the system’s ability to adapt when new information emerges.