The effect of shared distinctiveness on source memory: An event-related potential study

ORCA: A picture database of object-scene arrangements for cross-cultural and aging research

In recent years, cross-cultural research on the modulation of basic cognitive processes by culture has intensified - also from an aging perspective. Despite this increased research interest, only a few cross-culturally normed non-verbal stimulus sets are available to support cross-cultural cognitive research in younger and older adults. Here we present the ORCA (Official Rating of Complex Arrangements) picture database, which includes a total of 720 object-scene compositions sorted into 180 quadruples (e.g., two different helmets placed in two different deserts). Each quadruple contains visually and semantically matched pairs of objects and pairs of scenes with varying degrees of semantic fit between objects and scenes. A total of 95 younger and older German and Chinese adults rated every object-scene pair on object familiarity and semantic fit between object and scene. While the ratings were significantly correlated between cultures and age groups, small but significant culture and age differences emerged. Object familiarity was higher for older adults than younger adults and for German participants than for Chinese participants. Semantic fit was rated lower by German older adults and Chinese younger adults as compared to German younger adults and Chinese older adults. Due to the large number of stimuli, our database is particularly well suited for cognitive and neuroscientific research on cross-cultural and age-related differences in perception, attention, and memory.

Observing memory encoding while it unfolds: Functional interpretation and current debates regarding ERP subsequent memory effects

Our ability to remember the past depends on neural processes set in train in the moment an event is experienced. These processes can be studied by segregating brain activity according to whether an event is later remembered or forgotten. The present review integrates a large number of studies examining this differential brain activity, labeled subsequent memory effect (SME), with the ERP technique, into a functional organization and discusses routes for further research. Based on the reviewed literature, we suggest that memory encoding is implemented by multiple processes, typically reflected in three functionally different subcomponents of the ERP SME elicited by study stimuli, which presumably interact with preparatory SME activity preceding the to be encoded event. We argue that ERPs are a valuable method in the SME paradigm because they have a sufficiently high temporal resolution to disclose the subcomponents of encoding-related brain activity. Implications of the proposed functional organization for future studies using the SME procedure in basic and applied settings will be discussed.

Not so different after all? An event-related potential study on item and source memory for object-scene pairs in German and Chinese young adults

In recent years, several cross-cultural studies reported that Westerners focus more on central aspects of a scene (e.g., an object) relative to peripheral aspects (e.g., the background), whereas Easterners more evenly allocate attention to central and peripheral aspects. In memory tasks, Easterners exhibit worse recognition for the central object when peripheral aspects are changed, whereas Westerners are less affected by peripheral changes. However, most of these studies rely on hit rates without correcting for response bias, whereas studies accounting for response bias failed to replicate cultural differences in memory tasks. In this event-related potential (ERP) study, we investigated item and source memory for semantically unrelated object-scene pairs in German and Chinese young adults using memory measures corrected for response bias (i.e., the discrimination index Pr). Both groups completed study-test cycles with either item memory tests or source memory tests. In item memory blocks, participants completed an old/new recognition test for the central object. Source memory blocks entailed an associative recognition test for the association between object and background. Item and source memory were better for intact than for recombined pairs. However, as verified with frequentist and Bayesian analyzes, this context effect was not modulated by culture. The ERP results revealed an old/new effect for the item memory task in both groups which was again not modulated by culture. Our findings suggest that cultural differences in young adults do not manifest in intentional memory tasks probing memory for object-scene pairs without semantic relations when using bias-corrected memory measures.

Visual Selective Attention P300 Source in Frontal-Parietal Lobe: ERP and fMRI Study

Visual selective attention can be achieved into bottom-up and top-down attention. Different selective attention tasks involve different attention control ways. The pop-out task requires more bottom-up attention, whereas the search task involves more top-down attention. P300, which is the positive potential generated by the brain in the latency of 300 ~ 600 ms after stimulus, reflects the processing of attention. There is no consensus on the P300 source. The aim of present study is to study the source of P300 elicited by different visual selective attention. We collected thirteen participants' P300 elicited by pop-out and search tasks with event-related potentials (ERP). We collected twenty-six participants' activation brain regions in pop-out and search tasks with functional magnetic resonance imaging (fMRI). And we analyzed the sources of P300 using the ERP and fMRI integration with high temporal resolution and high spatial resolution. ERP results indicated that the pop-out task induced larger P300 than the search task. P300 induced by the two tasks distributed at frontal and parietal lobes, with P300 induced by the pop-out task mainly at the parietal lobe and that induced by the search task mainly at the frontal lobe. Further ERP and fMRI integration analysis showed that neural difference sources of P300 were the right precentral gyrus, left superior frontal gyrus (medial orbital), left middle temporal gyrus, left rolandic operculum, right postcentral gyrus, and left angular gyrus. Our study suggests that the frontal and parietal lobes contribute to the P300 component of visual selective attention.

May the source be with you! Electrophysiological correlates of retrieval orientation are associated with source memory performance

Successful source memory retrieval is assumed to rely on intact preretrieval processes, such as retrieval orientation (RO). RO is the specialized processing of retrieval cues, depending on the type of information, memory is searched for. In a previous study, a positive frontal slow wave RO ERP effect was interpreted as reflecting memory search for self-relevant information. However, such a functional interpretation is hampered by the use of retrieval strategies as a consequence of which target source information can be indirectly inferred from the correct classification of non-target source information. To overcome this limitation, the present study compared two types of source information (i.e. color or character information) by asking participants to remember details within each source type and thus enforcing the selective retrieval of target information. Consistent with previous research, a positive frontal ERP component (600-800 ms post-stimulus) differentiated between correct rejections in both tasks, probably reflecting memory search for self-relevant information. Moreover, the RO ERP effect was associated with better source memory performance, providing evidence for the beneficial effect of ROs for memory retrieval. This relationship might be covered in memory exclusion tasks due to non-target retrieval.