The effect of novel distractors on performance in focused attention tasks: a cognitive-psychophysiological approach

Memory-driven capture during focused visual attention

Attention can be captured by the presence of distractors that match the current content of working memory in the visual field. This memory-driven capture is well established when observers adopt diffused attentional settings prior to the onset of memory-matching distractors. However, it remains unclear whether memory-driven capture can occur when observers are in a state of focused attention. The present study attempted to address this question by examining whether memory-matching distractors can disrupt performance on a focused attention task. Participants were asked to hold a sample word in working memory and then had to name a central color while ignoring an irrelevant distractor word in the visual display. In Experiments 1 and 2, the distractor word was always presented centrally within the focus of attention. In Experiment 3, the distractor word could be presented either at the center or at the periphery (i.e., outside the focus of attention). The results showed that the irrelevant distractor word within the focus of attention interfered with color-naming performance when it matched the sample word held in working memory. However, no interference effect was observed when the distractor word was presented outside the attentional focus. The present findings indicate that working memory-driven capture during a state of focused visual attention depends crucially on whether or not memory-matching distractors are positioned within the focus of attention.

Personally-significant information affects performance only within the focus of attention: a direct manipulation of attention

It has been suggested that personally significant (PS) information interferes with performance only when presented within the focus of attention. However, this claim was never tested by a systematic manipulation of attention, but only by using correlative measures of its locus. We addressed this issue in two experiments, utilizing a cued visual search paradigm that allowed us to directly manipulate attention and to measure behavioral and physiological responses. One of the stimuli in the search display had a higher luminance value (i.e., was cued), and, orthogonally, one of the stimuli could be a PS or neutral name. When the cue did not predict target location, PS distractors mildly interfered with task performance, regardless of the cue's location. However, when the cue predicted target location, responses were facilitated for cued targets, indicating that attention was shifted to the cue. Importantly, PS distractors interfered with task performance and elicited enhanced orienting responses only when they were cued. This implies that PS information affects performance only when presented within but not outside the focus of attention.

Surprise-induced blindness: a stimulus-driven attentional limit to conscious perception

The cost of attending to a visual event can be the failure to consciously detect other events. This processing limitation is well illustrated by the attentional blink paradigm, in which searching for and attending to a target presented in a rapid serial visual presentation stream of distractors can impair one's ability to detect a second target presented soon thereafter. The attentional blink critically depends on 'top-down' attentional settings, for it does not occur if participants are asked to ignore the first target. Here we show that 'bottom-up' attention can also lead to a profound but ephemeral deficit in conscious perception: Presentation of a novel, unexpected, and task-irrelevant stimulus virtually abolishes conscious detection of a target presented within half a second after the 'Surprise' stimulus, but only for its earliest occurrences (generally 1 to 2 presentations). This powerful but short-lived deficit contrasts with a milder but more enduring form of attentional capture that accompanies singleton presentations in rapid serial visual presentations. We conclude that the capture of stimulus-driven attention alone can limit explicit perception.

Culture modulates eye-movements to visual novelty

BACKGROUND

When viewing complex scenes, East Asians attend more to contexts whereas Westerners attend more to objects, reflecting cultural differences in holistic and analytic visual processing styles respectively. This eye-tracking study investigated more specific mechanisms and the robustness of these cultural biases in visual processing when salient changes in the objects and backgrounds occur in complex pictures.

METHODOLOGY/PRINCIPAL FINDINGS

Chinese Singaporean (East Asian) and Caucasian US (Western) participants passively viewed pictures containing selectively changing objects and background scenes that strongly captured participants' attention in a data-driven manner. We found that although participants from both groups responded to object changes in the pictures, there was still evidence for cultural divergence in eye-movements. The number of object fixations in the US participants was more affected by object change than in the Singapore participants. Additionally, despite the picture manipulations, US participants consistently maintained longer durations for both object and background fixations, with eye-movements that generally remained within the focal objects. In contrast, Singapore participants had shorter fixation durations with eye-movements that alternated more between objects and backgrounds.

CONCLUSIONS/SIGNIFICANCE

The results demonstrate a robust cultural bias in visual processing even when external stimuli draw attention in an opposite manner to the cultural bias. These findings also extend previous studies by revealing more specific, but consistent, effects of culture on the different aspects of visual attention as measured by fixation duration, number of fixations, and saccades between objects and backgrounds.

Marital conflict and children's externalizing behavior: interactions between parasympathetic and sympathetic nervous system activity

Toward greater specificity in the prediction of externalizing problems in the context of interparental conflict, interactions between children's parasympathetic and sympathetic nervous system (PNS and SNS) activity were examined as moderators. PNS activity was indexed by respiratory sinus arrhythmia (RSA) and RSA reactivity (RSA-R) to lab challenges. SNS activity was indexed by skin conductance level (SCL) and SCL reactivity (SCL-R) to lab challenges. Moderation hypotheses were examined in 3 multi-informant studies with children ranging in age between 7 and 9 in Studies 1 and 2 and between 6 and 12 in Study 3. Findings are robust across studies and provide the first reported evidence of interactions between PNS and SNS activity as moderators of the association between children's exposure to marital conflict and externalizing behaviors. More specifically, opposing action of the PNS and SNS (i.e., coactivation and coinhibition) operated as a vulnerability factor for externalizing behavior in the context of marital conflict. Conversely, coordinated action of the PNS and SNS (i.e., reciprocal PNS or SNS activation) operated as a protective factor. Results are supportive of the authors' proposed biopsychosocial framework in which individual differences in the coordination of the activity of the PNS and SNS can function as vulnerability or protective factors in the context of family risk. Findings extend current theory indicating the importance of multisystem investigations for clarifying inconsistencies and discrepancies in the literature linking environmental stress, physiological responses, and child adjustment.

Distractor interference in focused attention tasks is not mediated by attention capture

Distractor stimuli possessing information that is relevant for a task (henceforth, task-relevant distractors) often interfere with task performance. The interference by task-relevant distractors is observed even when distractors are positioned outside the main attentional focus. We investigated whether such interference is due to an attention capture by the distractors. Participants responded to a target colour while ignoring word distractors positioned within (Experiment 1) or outside (Experiments 2 and 3) the attentional focus. The words carried task-relevant information in their colour and personally significant information in their content. Because personally significant information affects performance only when positioned in an attended region, it was used as a marker for the locus of the attentional focus. As expected, when distractors were attended, both task-relevant and personally significant information affected performance. However, when distractors were unattended, only task-relevant information caused interference, suggesting that attention did not shift to the distractors' location. We discuss possible accounts for interference effects in focused-attention tasks.