Temporal dynamics of action affordance: An ERP study on everyday objects.

In the psychological literature action affordance is described as a ‘‘direct link between the perceived visual properties of an object and an action that may be performed with it” (Humphreys, 2001). This link may be based on a stored representation of a particular object, but may also be cued by the visual properties of the object, even if the object has never been encountered before. Evidence from neuropsychological and neuroimaging studies indicate the existence of a direct route to action that is not mediated by semantic knowledge, but it depends on the visual processing of objects structural properties (Phillips et al., 2002; Riddoch & Humphreys, 1987; Riddoch, Humphreys, & Price, 1989). By this token,the the way in which an object is designed may elicit a different perception of action affordance. (Righi et al., 2014). Adamo and Ferber (2009) employed an an attentional blink paradigm to study tools action affordance evidencing that the presentation of objects pictures stimuli that elicit motor action provoke a decreased attentional blink and enhanced attentive selection. This facilitated processing may be electrophysiologically indexed by more positive P3 (Adamo & Ferber, 2009) proposing again that action affordance perception is not linked to semantic elaboration but rather to selective attention processes. This could happen because observers implicitly recognize an object’s potential for action, thereby leading to an attentional bias toward that object. This hypothesis has been further supported by several behavioral and electrophysiological evidence. In a previous experiment Righi et al. (2014) evaluated the relationship between affordance perception and subjective preferences (attractiveness) for specific tools. These preferences are driven by the aesthetic and functional characteristics of the objects. The experiment (Righi, et al., 2014) using ERP’s technique, suggested that processing linked to sensorial gating and object characteristic extraction (indexed by N1) was sensible to action affordance as well as aesthetic. Moving forward in time course analysis N3, P3 and the Late Positive Potential (LPP) showed an augmented response for object with high affordance and aesthetic levels. Righi et al. (2014) concluded that the objects that are perceived as high functional engage a privileged neural activation. Righi et al. (2014) agreed with previous works, (i.e. Proverbio et al., 2011) indicating that functional features linked to perceived affordance are processed around 200 ms (P2) mostly in frontal areas. We can assume that there is evidence of a different motor area activation related to stimuli affordance. So the aim of the present study is to investigate a more specific processing pattern linked to motor activation through Go-NoGo like tasks. Moreover, considering that previous studies (Adamo & Ferber, 2009) showed a difference in attentional modulation (linked to P3) it would be really interesting to investigate how motor interaction is combined with attentional activation by the use of an oddball paradigm. Hence the aim of present work is to investigate the temporal dynamics of the interaction between perceived action affordance in modulating both motor-schemas-related neural activity and attentional processing. For our purpose we choose experimental tools which differ only in the dimension of perceived action affordance (elicited by the design) and used an oddball paradigm with go-nogo response during real time EEG recording. Looking at previous literature we can assume that activation difference in certain ERP components can index reliably the action affordance visual perception. For instance N2 amplitudes in visual discrimination task have been studied extensively in oddball and Go-NoGo paradigms, with greater standard-target variation linked to an increased N2 amplitude. Then we can assume that N2 amplitude is directly correlated with discrimination difficulty (Patel & Azzam. 2005). Moreover, several data indicate that the P3 may interact with the N2 in motor response control to external cues (Gajewski et al., 2008). Using Go-NoGo paradigm, requiring targets identification either with motor response or activity suppression, it is possible to examine the processes associated with voluntary movement. Typically, in visual Go-NoGo test the morphology of the N2-P3 pattern may reflect inhibition and attentional processes related to withhold and execution of motor responses (Gajewski & Falkenstein 2013). By this token, some authors (Gajewski & Falkenstein 2013) suggested that the frontal N2 enhancement is mainly associated with early motor inhibition in NoGo response (Gajewski & Falkenstein 2013). Taking into account that present work aimed to explore the temporal dynamics of the interaction between the perceived action affordance of everyday tools in modulating both motor-schemas activation and attentional processing two prediction can be made.