Every day, we face new situations with surprising ease: from understanding a rule that has just been explained to reacting appropriately to an unfamiliar sign. But how does the brain manage to turn a never-before-heard instruction into a precise and appropriate action? A team of researchers from the Mind, Brain and Behavior Research Center (CIMCYC) at the University of Granada (UGR) has shed new light on this fundamental question of human cognition.
The study, published in The Journal of Neuroscience, was conducted by Paula Pena, Ana F. Palenciano, Carlos González García, and María Ruz. Carried out entirely in Granada, the work combines methods from cognitive neuroscience with multivariate analyses to understand how the brain processes novel verbal instructions over time.
The puzzle of cognition
Following an apparently simple instruction such as “if you see a dog inside a green circle, press the right button” is, in reality, a cognitively demanding task. The brain must break down the sentence, identify what information is relevant, keep it active, and prepare to act even before the stimulus appears.
To understand this process, the researchers recorded the brain’s electrical activity using electroencephalography (EEG) in 40 healthy participants. During the experiment, participants were confronted with 512 unique instructions, created by combining different factors: task demands (selecting a single feature or integrating multiple features), the category of the target stimulus (animals or objects), and the relevant feature to attend to (color or shape). Thanks to the high temporal resolution of EEG, the team was able to observe with great precision when and how each type of information became active in the brain during instruction implementation.
A hierarchical and flexible organization
The results show that the brain does not treat all information equally. More general task demands (for example, whether information needs to be integrated or simply selected) are maintained in a sustained and abstract manner throughout most of the process. In contrast, more specific details, such as whether the stimulus is an animal, appear only transiently.
To make sense of this, imagine following a new cooking recipe. Your brain keeps the general goal, “prepare a vegetable stew”, constantly in mind. Specific actions like “chop the carrot,” however, are only activated at the appropriate moment. This hierarchy allows the brain to avoid being overloaded with unnecessary information at any given time.
In addition, the study reveals that the brain organizes information differently depending on the phase of the task. During preparation, representations are more abstract and generalizable, making it easier to apply similar rules to new situations. When it comes time to execute the response, these representations become more specific, reducing confusion between similar stimuli and minimizing errors (like avoiding cutting your finger when you meant to cut the carrot!).
Why is this relevant?
This work is innovative in showing the temporal dynamics with which the brain transforms instructions into actions, since previous studies using fMRI had not been able to capture them with such precision. The results suggest that the human brain continuously adjusts the “format” of information, compressing or expanding depending on the demands of the moment.
Understanding these mechanisms is not only key to explaining human cognitive flexibility, but may also have implications for the study of disorders in which instruction following is impaired, as well as for the design of artificial intelligence systems inspired by how the brain works.
Reference
Pena, P., Palenciano, A. F., González-García, C., & Ruz, M. (2025). Novel verbal instructions recruit abstract neural patterns of time-variable information dimensionality. Journal of Neuroscience, 45(17). https://doi.org/10.1523/JNEUROSCI.1964-24.2025
Contact
Paula Pena (@email)