Common neural mechanism for maintaining representation in visual mental imagery and visual...

Increased difficulty in visual discrimination enhances attentionalcapture by both visual and auditory deviant stimuli

Fumie Sugimotoa, Jun'ichi KatayamabaKyushu University, JapanbKwansei Gakuin University, Japan

Background: The involuntary shift of attention toward task irrelevantdeviant information is enhanced when a large amount of attentionalresource is allocated to a task. This is shown by a phenomenon that theamplitude of the P3 component of the event-related brain potential(ERP) for distractor stimuli increases in a three-stimulus oddball taskwhen the discrimination between the target and standard stimuli isdifficult. However, it is not clear if the allocation of the attentionalresource to a task modulates the capture of attention by distractorstimuli when they appear in a task irrelevant modality. The presentstudy investigated whether the resource allocation to a visual task alsoaffects the processing of auditory deviant stimuli.Experiment 1: The ERP was recorded while 12 participants wereperforming a three-stimulus oddball task by discriminating visual targetstimuli (15%) from visual standard stimuli (70%). Visual distractors(15%) were presented in the visual distractor condition, and pure toneswere presented as distractors (15%) in the auditory distractor condition.In both distractor conditions, easy and difficult conditions were setdepending on the difficulty of the visual discrimination. Both the visualand auditory distractors elicited the distractor P3, and its amplitudeincreased in the difficult condition compared with the easy condition.This result showed that the attentional capture bynot only the visual butalso the auditory distractor was enhanced when the visual discrimina-tion was difficult.Experiment 2: We examined the possibility that the increase ofdistractor P3 for the auditory distractors in experiment 1 resultedfrom a shift of attention toward the absence of the visual stimulus.Twelve participants performed the same three-stimulus oddball taskas in the experiment 1 except for visual and auditory distractorstimuli. The auditory distractors were presented with the samevisual stimulus as the standard stimulus to prevent an absence of avisual stimulus. The visual distractors also consisted of the standardstimulus and other figures. The amplitudes of the distractor P3 forboth the visual and auditory distractors increased in the difficultcondition. This result confirmed that the increase of the amplitude ofthe auditory distractor P3 resulted from the capture of attention bythe auditory stimuli.Conclusion: This study indicates that allocating the attentionalresource to the visual modality enhances the processing of not onlyvisual but also the auditory task-irrelevant deviant information.

doi:10.1016/j.ijpsycho.2014.08.769

Common neural mechanism for maintaining representation invisual mental imagery and visual short-term memory

Keiko YamazakiGraduate School of Education, Hokkaido University, Japan

Visual mental imagery and visual short-term memory (VSTM)have been suggested to share a common mechanism for maintain-ing representation. The present study examined the extent ofthe commonality by comparing the contralateral delayed activity(CDA) in event-related potentials, which reflects the representationmaintained in VSTM, during mental imagery and VSTM tasks.Participants memorized four shapes: A, B, C, and D. Two wereSIMPLE composed of three segments, and the other twowere COMPLEXcomposed of five segments. In the imagery task, presentation of a

left or right arrow was followed by bilateral 5 × 5 grids and animagery cue, either A, B, C, or D, at the center of the grid.Participants visualized the designated shape on the grid indicatedby the arrow. 1500 ms after the cue offset, a probe mark appearedin one of the cells, and participants decided if it falls onto thevisualized shapes. In the VSTM task, the imagery cue was replacedby shapes drawn on the grid, and participants maintained it forlater decision. The CDA was elicited in both tasks during themaintenance period, with the effects of shape complexity on theCDA latency only in the imagery task. The results suggested thatthere are both shared and specific maintenance mechanisms forvisual mental imagery and VSTM.

doi:10.1016/j.ijpsycho.2014.08.770

The association between childhood obesity and neuroelectricmeasures of cognitive control

Keita Kamijoa, Charles H. Hillmanb

aFaculty of Sport Sciences, Waseda University, JapanbDepartment of Kinesiology and Community Health, University of Illinoisat Urbana-Champaign, United States

Recent studies have indicated that higher body mass index (BMI)during childhood is associated with lower academic achieve-ment scores, suggesting that maintaining a healthy weight may beessential for cognitive development. However, given that evidenceregarding the association between childhood obesity and cognitivefunction has remained scarce, the findings are still inconclusive.Accordingly, we examined whether childhood obesity is associatedwith cognitive control, which has been heavily implicated inacademic achievement, using neuroelectric and behavioral measuresof inhibition and action monitoring. In the first study, healthy weight(n= 37) and obese (n= 37) children performed a Go/NoGo taskwhile measures of task performance and the P3 component wereassessed. Analyses revealed that obese children had lower responseaccuracy relative to healthy weight children during the NoGo task,whereas no such difference was observed during the Go task.Further, healthy weight children exhibited a more frontal distribu-tion for the NoGo P3 relative to the Go P3 (i.e., NoGo anteriorization),whereas such NoGo anteriorization was less pronounced for obesechildren. These findings suggest that childhood obesity is negativelyassociated with inhibitory aspects of cognitive control. In the secondstudy, we compared healthy weight (n= 37) and obese (n = 37)children's task performance and the error-related negativity (ERN)during compatible and incompatible stimulus–response conditionsof a modified flanker task. Analyses revealed that obese children hadlower post-error response accuracy and smaller ERN amplitude,suggesting less effective action monitoring relative to healthy weightchildren. Further, healthy weight children exhibited comparablepost-error response accuracy between the compatibility conditionswith smaller ERN amplitude in the incompatible condition. Bycontrast, obese children had lower post-error response accuracy forthe incompatible relative to the compatible condition with compa-rable ERN amplitudes between the compatibility conditions. Thesefindings suggest that obese children demonstrate less ability tomodulate the cognitive control operations that support actionmonitoring. Together, these two studies support previous findingsindicating the negative association between BMI and academicachievement.

doi:10.1016/j.ijpsycho.2014.08.771

International Journal of Psychophysiology 94 (2014) 120–261182