Mean amplitudes (μV) and standard errors (<i>SE</i>) in four different trial types.

<p>Mean amplitudes (μV) and standard errors (<i>SE</i>) in four different trial types.</p

Mean reaction times (ms), accuracy (ACC), and standard errors (<i>SE</i>) for memory task in Experiment 2.

<p>Mean reaction times (ms), accuracy (ACC), and standard errors (<i>SE</i>) for memory task in Experiment 2.</p

Mean amplitude for four different trial types at nine electrode sites.

<p>Mean amplitude for four different trial types at nine electrode sites.</p

Reaction times for direction discrimination task in Experiment 2.

<p>Reaction times for direction discrimination task in Experiment 2.</p

The effects of different affective words on top cues (Cz site).

<p>The effects of different affective words on top cues (Cz site).</p

Reaction times for location detection task in Experiment 1.

<p>Reaction times for location detection task in Experiment 1.</p

Mean reaction times (ms), accuracy (ACC), and standard errors (<i>SE</i>) for direction discrimination task in Experiment 2.

<p>Mean reaction times (ms), accuracy (ACC), and standard errors (<i>SE</i>) for direction discrimination task in Experiment 2.</p

Voltage scalp maps of the P200 for four different trial types.

<p>Voltage scalp maps of the P200 for four different trial types.</p

Working memory operates over the same representations as attention

<div><p>A recent study observed a working memory (WM) Stroop effect with a magnitude equivalent to that of the classic Stroop effect, indicating that WM operates over the same representations as attention. However, more research is needed to examine this proposal. One unanswered question is whether the WM Stroop effect occurs when the WM item and the perceptual task do not have an overlapping response set. We addressed this question in Experiment 1 by conducting an attentional word-color task and a WM word-color task. The results showed that a WM Stroop effect also occurred in that condition, as a word that only indirectly evoked a color representation could interfere with the color judgement in both the attentional task and WM task. In Experiment 2, we used a classic Simon task and a WM Simon task to examine whether holding visuo-spatial information rather than verbal information in WM could interfere with perceptual judgment as well. We observed a WM Simon effect of equivalent magnitude to that of the classic Simon effect. The well-known stimulus-response compatibility effect also existed in the WM domain. The two experiments together demonstrated that WM operates over the same representations as attention, which sheds new light on the hypothesis that working memory is internally directed attention.</p></div

The procedures of the attentional Simon task (a) and the working memory (WM) Simon task (b).

<p> Fig 2(a) illustrates an incongruent trial of the attentional Simon task under the condition that participants were required to report the green square by “j” and report the red square by “f”. Fig 2(b) is a congruent trial of the WM Simon task. In this trial, participants were required to press “f” to report the red color of the patch as well as the WM probe that appeared at the same location as the peripheral square.</p