Analysis of variance for the mean ERP amplitudes in the N1, N2, N3 and P3 window for all conditions.

<p><i>Note.</i> *<i>p</i><.05,</p>**<p><i>p</i><.01,</p>***<p><i>p</i><.001.</p

Analysis of variance for the mean ERP amplitudes in the N2 window for the non-match conditions compared to the match.

<p><i>Note.</i> *<i>p</i><.05,</p>**<p><i>p</i><.01,</p>***<p><i>p</i><.001.</p

Accuracy Data per Condition.

<p>Accuracy Data per Condition.</p

Scalp distributions of ERP effects (change minus match) for N2, N3, and P3 latency windows.

<p>Scalp distributions of ERP effects (change minus match) for N2, N3, and P3 latency windows.</p

Distribution of electrodes across the scalp with the five clusters selected for statistical analyses.

<p>Distribution of electrodes across the scalp with the five clusters selected for statistical analyses.</p

Analysis of variance for the mean ERP amplitudes in the P3 window for the non-match conditions compared to the match.

<p><i>Note.</i> *<i>p</i><.05,</p>**<p><i>p</i><.01,</p>***<p><i>p</i><.001.</p

Grand average ERP waveforms of A) location changes, and B) identity changes and switch, both including the match.

<p>Grand average ERP waveforms of A) location changes, and B) identity changes and switch, both including the match.</p

Experimental setup.

<p><b>A</b>) Illustrative examples of experimental conditions, <b>B</b>) Graphic display of time course of the trials.</p

Electrophysiological correlates of object location and object identity processing in spatial scenes

Contains fulltext : 102496.pdf (publisher's version ) (Open Access)The ability to quickly detect changes in our surroundings has been crucial to human adaption and survival. In everyday life we often need to identify whether an object is new and if an object has changed its location. In the current event-related potential (ERP) study we investigated the electrophysiological correlates and the time course in detecting different types of changes of an objecṫs location and identity. In a delayed match-to-sample task participants had to indicate whether two consecutive scenes containing a road, a house, and two objects, were either the same or different. In six randomly intermixed conditions the second scene was identical, one of the objects had changed its identity, one of the objects had changed its location, or the objects had switched locations. The results reveal different time courses for the processing of identity and location changes in spatial scenes. Whereas location changes elicited a posterior N2 effect, indicating early mismatch detection, followed by a P3 effect reflecting post-perceptual processing, identity changes elicited an anterior N3 effect, which was delayed and functionally distinct from the N2 effect found for the location changes. The condition in which two objects switched position elicited a late ERP effect, reflected by a P3 effect similar to that obtained for the location changes. In sum, this study is the first to cohesively show different time courses for the processing of location changes, identity changes, and object switches in spatial scenes, which manifest themselves in different electrophysiological correlates.9 p