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Recent studies demonstrated the role of executive functions in Prospective Memory (PM), even though it is still debated how these processes are overlapped. Our aim was to understand the role of executive functions in PM. Thus, we developed an experimental procedure in which we manipulated the level of executive load required by cognitive tasks. Experiment 1 required a simple arithmetic activity together with a PM task to be performed at a given time (time-based condition) or following cue presentation (event-based condition). In Experiment 2 we varied the complexity of the ongoing task (a PASAT test) maintaining the same procedure of Experiment 1. We examined the effect of executive load manipulation in a patient (man, 52 y.o.) with a severe disexecutive syndrome following post-anoxic brain damage and 9 healthy participants. Patient’s performance significantly differed in PM accuracy only in PASAT-time condition. The difference between simple arithmetic and PASAT task in time- based condition was statistically significant as compared to the difference observed in the control sample. No differences were found in event-based conditions. These results suggested a partial independence between executive functions and PM in tasks involving an automatic retrieval of PM intention (event based). Nevertheless, these mechanisms seem to share resources in complex tasks requiring PM self-retrieval (time based). Our findings support a multiprocess framework, which assumes the role of controlled processes in PM under certain task conditions and emphasized the strong influence of planning, monitoring and attention abilities even in complex daily-life PM tasks.

Prospective memory (PM) refers to the processes associated with the planning and execution of delayed intentions. PM involves a complex balance between the memory of an intention and the maintenance of concurrent activities, thus requiring different cognitive mechanisms. Recent studies have examined the involvement of WM in the PM in order to investigate whether these two processes share cognitive resources or they are independent mechanisms. It was shown that PM is supported by the central executive component of working memory (WM), which organizes the execution of joined actions through selection of relevant information and suppression of the irrelevant ones. According to the preparatory attention and memory model (PAM), PM task performance is always influenced by the availability of WM resources, since controlled attentional processes are needed. Differently, the multiprocess framework posits that a delayed intention can be automatically retrieve, at least under certain circumstances, suggesting that PM and WM are distinct mechanisms.This study aims to examine the role of WM in PM, by comparing the performance of MB, a patient with a disexecutive syndrome and proved PM difficulties acquired after brain damage, to that of nine healthy participants. Two experiments were developed, in which subjects had to perform an ongoing activity together with a PM switching task. We administered two distinct ongoing tasks for the Experiments, differing for the amount of cognitive resources required: a simple arithmetic (Experiment 1) and a high-load WM task (PASAT test, Experiment 2). As a further variable, the modality of PM retrieval was manipulated by introducing both time and event-based conditions for each experiments. In the time-based conditions, the PM task had to be performed at a given time, whereas in the event-based condition PM retrieval occurred following cue presentation. MB’s performances in PM tasks significantly differ from the controls only in the PASAT time

La Memoria Prospettica (MP) si riferisce alla funzione cognitiva deputata alla pianificazione e al recupero di piani di azione orientati al futuro. Nel suo funzionamento implica un equilibrio complesso tra memoria di un’intenzione e l’esecuzione di attività concomitanti, richiedendo quindi importanti risorse di working memory (WM). Recenti evidenze hanno esaminato il ruolo della WM nella MP allo scopo di valutare se le due funzioni condividono risorse cognitive o si caratterizzano come processi indipendenti. In particolare è ancora dibattuto se la MP sia sempre influenzata dalla disponibilità di risorse della WM oppure se il piano d’azione per il futuro possa essere recuperato in modo automatico in relazione alle condizioni del compito. Il nostro studio ha l’obiettivo di esaminare il rapporto tra WM e MP in un paziente con difficoltà di MP obiettivate da errori in ambito ecologico e severa sindrome disesecutiva a seguito di coma post anossico da arresto cardiocircolatorio. A tale scopo sono stati realizzati due esperimenti nei quali sono state manipolate le variabili di carico cognitivo (basso, alto) e modalità di recupero dell’informazione prospettica (event-based, time-based). Entrambi gli esperimenti richiedevano l’esecuzione di un compito prospettico: nell’esperimento 1 il soggetto eseguiva un compito concomitante a basso carico cognitivo (somma aritmetica semplice), nell’esperimento 2 il compito concomitante presentava un carico cognitivo maggiore (PASAT). In ciascun esperimento sono stati presentati blocchi di item in cui il compito di memoria prospettica veniva associato ad un cue sonoro (event-based condition) oppure recuperato autonomamente dal soggetto ad un tempo definito dallo sperimentatore (time-based condition). I risultati ottenuti dal paziente sono stati confrontati con un gruppo di 9 partecipanti neurologicamente sani di pari età e scolarità. I dati del paziente mostrano una prestazione significativamente deficitaria esclusivamente nella con