Older Adults Automatically Detect Age of Older Adults' Photographs: A Visual Mismatch Negativity Study

The role of attention control in visual mismatch negativity (vMMN) studies

The detection of unattended visual changes is investigated by the visual mismatch negativity (vMMN) component of event-related potentials (ERPs). The vMMN is measured as the difference between the ERPs to infrequent (deviant) and frequent (standard) stimuli irrelevant to the ongoing task. In the present study, we used human faces expressing different emotions as deviants and standards. In such studies, participants perform various tasks, so their attention is diverted from the vMMN-related stimuli. If such tasks vary in their attentional demand, they might influence the outcome of vMMN studies. In this study, we compared four kinds of frequently used tasks: (1) a tracking task that demanded continuous performance, (2) a detection task where the target stimuli appeared at any time, (3) a detection task where target stimuli appeared only in the inter-stimulus intervals, and (4) a task where target stimuli were members of the stimulus sequence. This fourth task elicited robust vMMN, while in the other three tasks, deviant stimuli elicited moderate posterior negativity (vMMN). We concluded that the ongoing task had a marked influence on vMMN; thus, it is important to consider this effect in vMMN studies.

The effect of ambiguous and unambiguous stimuli on target processing in less creative and more creative groups

In the present study our aim was to examine how the processing of task-irrelevant stimuli changes with creativity and aging, and how this processing influences task-relevant responding. We hypothesized that the degree in which irrelevant stimuli attract attention and occupy cognitive capacity, thereby interfering with the motor task, depends not only on the stimuli's saliency, but also on the participants' creativity and age. We investigated event-related potentials (ERP) and behavioural data in four groups - more creative and less creative younger (18-30 years) and older (60-75 years) adults - by presenting unambiguous and ambiguous portrait paintings and photos of faces in equal proportions before and after the target stimuli. Our results showed that aging affected behavioural and ERP responses, but there were no interactions between age groups, creativity and the three types of stimuli. Older adults were not more exposed to the interference caused by distractor stimuli as they compensated with bilateral activity to reach a similar performance to the younger group. The reaction time was faster for targets when they followed the faces rather than the portrait paintings, so, faces may have been less salient to the participants than paintings. The three types of stimuli were differentiated in all the processing stages. Creativity had a measured effect in the earliest (P1) stage with more creative groups being able to distinguish between unambiguous and ambiguous stimuli; and also, in the last processing stage (CNV), in which task-irrelevant stimuli, particularly photos of faces, were less distracting for more creative participants in task preparation. The results show that creativity in general has an influence even at the earliest stage of visual perception.

Configural but Not Featural Face Information Is Associated With Automatic Processing

Configural face processing precedes featural face processing under the face-attended condition, but their temporal sequence in the absence of attention is unclear. The present study investigated this issue by recording visual mismatch negativity (vMMN), which indicates the automatic processing of visual information under unattended conditions. Participants performed a central cross size change detection task, in which random sequences of faces were presented peripherally, in an oddball paradigm. In Experiment 1, configural and featural faces (deviant stimuli) were presented infrequently among original faces (standard stimuli). In Experiment 2, configural faces were presented infrequently among featural faces, or vice versa. The occipital-temporal vMMN emerged in the 200–360 ms latency range for configural, but not featural, face information. More specifically, configural face information elicited a substantial vMMN component in the 200–360 ms range in Experiment 1. This result was replicated in the 320–360 ms range in Experiment 2, especially in the right hemisphere. These results suggest that configural, but not featural, face information is associated with automatic processing and provides new electrophysiological evidence for the different mechanisms underlying configural and featural face processing under unattended conditions.