PROCEDIMIENTO PENAL

1.5.2.1. Working memory definition

Working memory has been conceptualised as the updating component of EF (e.g. Miyake, Friedman, Emerson, Witzki, Howerter &Wager, 2000). It is a multi-component, limited-capacity system responsible for the temporary storage and processing (i.e. manipulation,

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integration and maintenance) of limited amounts of information (Baddeley, 1997). Working memory consists of two modality-specific slave systems, namely, the phonological loop which is involved in the storage and manipulation of phonologically-based information and the visuo-spatial sketchpad involved in the storage and manipulation of visual and visuo-spatial information (Baddeley, 1986; Baddeley & Hitch, 1974). There is also the central executive (CE) which is a controlling attentional system playing a supervisory role over the slave systems. The function of the CE is related to how, where and when to allocate resources, bind information, shift between tasks or retrieval strategies and inhibit responses. The CE has been thus claimed to be involved in the allocation of resources needed to manage and maintain information while temporal performance of other activities takes place (Baddeley, 1986; 2002). There is also one modality-free slave system constituting a part of WM, the episodic buffer which is a multi-dimensional storage, integrating information from different components of WM (Baddeley, 2000; 2007).

1.5.2.2. Working memory and prospective memory

Prospective memory has been suggested to be heavily dependent on WM (Einstein, McDaniel, Manzi, Cochran & Baker, 2000). This, as Einstein et al. (2000) explained, is because PM tasks require active or nonstrategic maintenance of the intended action in WM over the time interval between formation and execution of the intention, while also performing an ongoing task.

Furthermore, Smith, Persyn and Butler (2011) found a positive relationship between WM span and PM. This experiment with a large sample of participants (n = 413) used a symmetry span task as a measure of WM span. The PM task employed an ongoing lexical decision task and an event-based PM task, where participants were required to press the F1 key when syllables “per”

and “low” appeared. High and low WM span groups were created on the basis of span scores (top and bottom 25% of performers). The results showed that participants in the high WM span group were more likely to perform well on the PM task whereas, the low WM group performed more poorly.

It has been claimed by various researchers that the ongoing task can negatively affect PM performance as it draws on the same limited WM central executive resources (Einstein et al., 1997; Kliegel, McDaniel & Einstein, 2008; Marsh & Hicks, 1998). It is possible that the ongoing task draws away WM resources needed for PM task performance, causing interference effects. The interaction between ongoing tasks, which require WM, and PM tasks have been investigated by Basso, Ferrari and Palladino (2010). They investigated whether PM and WM share resources or whether they are distinct processes. To achieve this, the authors conducted

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three experiments employing a verbal task which allowed a manipulation of cognitive demand, related to event-based PM and WM tasks. This manipulation effectively varied the amounts of resources available for each of the memory processes (PM and WM). They also used

transcranial magnetic stimulation (TMS) in order to investigate the involvement of frontal areas of the brain in the performance of PM and WM tasks. The event-based PM task involved responding to cue words. The number of cue words was manipulated in order to vary the level of PM difficulty. There were two ongoing tasks employed in this study, one involved an updating WM task (Palladino & Jarrold, 2008), which created either high or medium WM demands and the other involved a lexical decision task which created low WM demands. The results of both experiments showed that higher PM demand impacted negatively on WM performance but only when the WM ongoing task involved higher loads. However, the PM load had an effect on PM performance regardless of WM load differences. The last experiment applied a single pulse TMS to right and left dorsal frontal cortices while participants were engaged in the PM/WM tasks. The results showed that regardless of whether the stimulation was applied to right or left dorsal frontal cortices, it resulted in more PM failures. However, the TMS simulation affected the WM task only marginally. On the basis of their results Basso et al.

(2010) argued that even though it seems that PM and WM are different processes, they are likely to share resources but only in tasks involving high demands. Namely, PM tasks have been argued to be dependent on WM resources at high demand. It was also shown that dorsolateral prefrontal cortex was activated bilaterally during PM tasks.

Van den Berg, Aarts, Midden and Verplanken (2004) have stated that tasks which are difficult are more likely to be affected by executive load compared to tasks that are easy and well supported by the environment. This is in line with the multiprocess theory of PM (McDaniel &

Einstein, 2000) which states that more difficult PM tasks (e.g. with non-focal PM targets) may require more monitoring processes compared to easier PM tasks (focal) and is likely to rely on spontaneous retrieval. More difficult PM tasks relying on monitoring processes are more taxing on WM in comparison to tasks that encourage spontaneous retrieval, and may result in worse PM performance compared to easier PM tasks.

Marsh, Hancock and Hicks (2002) conducted a series of experiments manipulating the WM load of the ongoing task and found that the PM performance was reduced when the ongoing task engaged more WM resources. They concluded that PM tasks are affected by WM load because PM tasks involve the coordination of both the ongoing task and the PM task and that this process involves executive control (at least to certain degree). There are a number of studies

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which have demonstrated the negative effect of high WM load on PM performance especially if the CE is affected (e.g. Einstein et al., 1997; Marsh & Hicks, 1998).

Khan, Narendra and Dixit (2008) investigated what effect low and high cognitive load has on time-based PM tasks. The results showed that PM performance was significantly lower in the high cognitive load condition compared to the low cognitive condition. The authors proposed that this occurred due to dividing attentional resources between the ongoing task, monitoring time and self-initiating the PM response at the required times. They suggested that monitoring of time is dependent on the limited resource of attentional capacity and thus, cognitively demanding tasks will have a negative effect on PM performance.