ambIEntES ProPICIoS Para EL aPrEndIzajE

Rationale

The general aim of this series of three experiments was to systematically investigate response-related ERP components in terms of task salience, task difficulty, task specificity, response awareness, and conscientiousness. When considered as whole, investigations and subsequent explanations of ERN/Ne, CRN, early and late Pe, and corresponding early and late Pc provide a somewhat incomplete picture. As Inzlicht and Bartholow (2009) point out, since the first reports of the ERN/Ne in the early 1990s, this and associated ERP components “have become one of the most vigorously explored topics in psychophysiology” (p. S15). A number of theories have been suggested to explain both the ERN/Ne and Pe; however, to date none have been able to fully account for all research evidence (Inzlicht & Bartholow, 2009). The disparate and, at times, inconsistent findings across experimental paradigms and conditions provide an opportunity and need to investigate all response-related components in terms of the prevailing experimental conditions in an effort to clarify some of the processes involved in the generation of response-related ERP

components.

An abundance of evidence is available within the current research literature focusing on the developmental and psychopathological factors that impact response- related components. Most researchers have explained early differences in terms of maturational changes or dysfunction within the ACC and related dopaminergic activity. However, a number of researchers have reported task-specific changes in one or more response-related components that are somewhat difficult to reconcile with overall explanations of this activity. On the one hand ERN/Ne has been found to

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be modulated by age related differences while Pe was not (Davies et al., 2004; Mathalon et al., 2003); on the other ERN/Ne amplitude differences according to age were only evident in difficult compared to easy tasks (Hogan et al., 2005). CRN amplitudes have been evidenced to display age related differences (Davies et al., 2004), although other researchers reported that this change was dependent on the method of component quantification (Santesso et al., 2006). Pe has been reported to differ in amplitude according to task type (Mathewson et al., 2005); however since this component has been quantified within various time windows across a number of studies, systematic comparisons are not possible (Overbeek et al., 2005).

Similar discrepancies are evident when response-related ERP components are considered in terms of task or response importance and individual differences related to personality traits and motivation. Motivation, measured as a function of incentive or evaluation, has been found to modulate ERN/Ne amplitudes (Hajcak et al., 2005; Morris et al., 2006). Other researchers have found the subjective importance of responses to be reflected in ERN/Ne amplitudes when individual personality differences were taken into account (Dikman & Allen, 2000; Pailing & Segalowitz, 2004a). Again, while Pe is investigated in some studies, diverse quantification methods and time-windows do not allow conclusions to be drawn regarding the influence of task or response salience on this component.

Pe has been variously researched in terms of a number of posited explanations for this component, with a considerable body of research evidence indicating that this component alone may be reflective of error recognition or awareness (Endrass et al., 2005; Nieuwenhuis et al., 2001). Furthermore, some researchers report the

modulation of Pe amplitude according to response awareness or certainty at early and not late latencies (Endrass et al., 2005) and vice versa (Endrass et al., 2007). This is

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also the case in terms of the topography, with differences reported at frontal areas (Hajcak et al., 2004; Mathalon et al., 2003) and conversely, at parietal areas (Falkenstein et al., 2005). ERN/Ne and CRN amplitude changes have also been linked to perceived response accuracy (Mathalon et al., 2003; Scheffers & Coles, 2000). Whereas ERN/Ne, CRN and Pe have been vigorously investigated, late correct response positivities (Pc) have been somewhat neglected, with only a small number of researchers including this component in reports of investigations (e.g., Burgio-Murphy et al., 2007; Kim et al., 2006). Few researchers have offered

explanations of this activity, indeed some suggest that the Pc reflects the absence of a Pe rather than a component per se, while still others argue that this component is representative of comparative response monitoring process (Falkenstein et al., 1990).

Contradictory and inconsistent findings across a large body of research indicate a need for a systematic comparison of all response-related ERP components that are posited to represent a response-monitoring executive process. Since most theories of early negativities indicate, either directly or indirectly, a comparative process

occurring between correct and error responses, and many instances are reported where experimental variables modulate both early negativities and later positivities differentially, investigation of the impact of antecedent conditions on all components is necessary.

In order to address these issues, three experiments were conducted to examine early and late, error and correct related components in terms of task difficulty, conscientiousness, task and response salience, and response awareness. Task

difficulty and task specificity were investigated using an Eriksen (1974) flanker task and a phonological decision task. All tasks included a response awareness question designed to determine participant‟s certainty of response type (error, correct). The

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inclusion of a conscientious variable (high, low) allowed examination of the impact of conscientiousness on response-related components.

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