A fundamental aspect of incarceration, one which enhances the punitivity of imprisonment, is the dichotomized separation of the prison space from the outside world. The distinction of the environment within the prison space from that which surrounds it creates the sense that the prisoner has been entirely removed from the world of their past, forcing them to learn to navigate unfamiliar territory. In addition to being confined to an enclosed space and having freedoms severely limited, the insecurity and vulnerability a prisoner feels in this entirely new situation, separated from the outside world, augments the torture of incarceration. This is especially pertinent throughout the dictatorships in Spain and Argentina where those who were deemed subversive or threatening to the dictatorial system were detained suddenly and frequently denied due process or any hope of release. In these situations, even the smallest glimpse into the outside world served as an aspirational symbol of eventual release.

While the prisoners in La voz dormida are confined to cells within a prison complex, they maintain a level of contact with the spaces and people outside of this space. The film opens with a scene in the prison where women are being called individually to be taken to the firing squad after saying tearful goodbyes to their compañeras. Although these women are then taken away to be killed in the courtyard of the prison complex, the women within the collective cell have a window through which they are auditory and visual spectators to this event. Some even go as far as to scream to the soldiers in protest, which provokes them to shoot into the cell through the open window, establishing a more concrete physical connection between the cell and the surrounding space. Not only can they experience what is happening outside of the confines of their imprisonment within the cell through this view into the rest of the prison compound, but they also maintain contact with the more distant space outside of the prison in general. There is a visitation room arranged that, although it keeps prisoners and visitors separated by two sets of bars, allows verbal and visual contact with people who are not imprisoned.  Additionally, these visitors are allowed to bring packages for the prisoners with fresh clothing and mementos from their previous lives. Even though these packages are not supposed to contain contraband, including letters, they are not thoroughly screened by the prison guards, as Tensi is shown receiving letters from her husband, who is fleeing imprisonment for Republican activity.

Unlike the characters in La voz dormida, those in La noche de los lápices have neither a  window into the outside world nor a physical sense of where they are located. As the students are abducted they are blindfolded in order to prevent them from detecting where the torture centers are located and once they arrive their heads are continuously covered with hoods. Additionally, they are placed in individual cells at the detention center and in both situations their hands are bound behind their backs to restrict any physical contact. This limiting of their senses to only hearing contributes to the sense of uncertainty the students experience; not only are they unsure of what their futures may hold in these detention centers, but they also have no knowledge about their physical environment in order to orient themselves. The only sense they have of the space of confinement is what they hear, which is generally the sounds and screams of other detenidos being tortured. In one instance, the rest of the students even hear one female student being assaulted and raped by one of the prison guards in her cell. In the beginning of the imprisonment in La noche de los lápices, in the one scene where the detainees are confined in collective spaces, Pablo and another student are seen blindfolded and bound back to back while discussing their previous lives outside of the cell and how they knew each other.

This type of verbal communication does not come from outside the prison space, but does concretely connect them to this space by conjuring memories of the outside. In addition to only having an auditory awareness of the prison space, their perception of the space outside only derives from sound. The only sound they can hear from the other side of the prison walls are gunshots, presumably the soundtrack to other prisoners being executed.

The space of incarceration in La noche de los lápices differs from that in La voz dormida in that the prison in the latter is an official space, while the former is an unofficial torture center that is not disclosed to the general Argentinian population. Toward the beginning of their imprisonment, Pablo and Claudia, from their individual cells, discuss what they will do once they are released, including planning a dinner date, therefore inferring that their detention is only temporary.   This expression of hope shifts by the end of the film, with the students losing hope that they will ever reach the outside again. Instead, they hope for a transfer to an official prison where their families will know where they are and there will be a record of their internment. In La voz dormida there exists a dichotomized space between the prison space and that which is outside of the prison. Even though the two are generally separated, the contingency of these spaces shows the points of contact between imprisoned and ‘free.’ Those who are not confined to a prison continuously run the risk of being detained and losing their freedom. La noche de los lápices maintains the same fluid binary between the unofficial detention center and the outside world; while those who are within the prison space have no connection to the outside and little prospects of eventual release, those outside toe the line between freedom and incarceration. Additionally, this film references another space - the official prison - that creates a ternary, rather than a binary.