Experience-dependent neural specialization during infancy

The ability to recognize the difference among faces of another race or species declines from 6 to 9 months of age. During this time, perceptual biases are formed, leading to lasting deficits in recognizing individuals of other races and species. However, little is known about how early infant experience shapes the neural structures underlying face processing. Here we found neural specialization, in infants who received 3 months of training with six individually labeled monkey faces. However, neural specialization was not found after an equal amount of training with the same six faces labeled at the category-level (i.e., all faces labeled “monkey”) or when infants were exposed to faces without labels. These results suggest that neural specialization for faces requires learning at the individual level during infancy.     

Conflict monitoring and stimulus categorization processes involved in the prosocial attitude implicit association test: Evidence from event-related potentials

The implicit association test (IAT) is a promising method used to assess individual implicit attitudes by indirectly measuring the strengths of associations between target and attribute categories. To date, the cognitive processes involved in the prosocial attitude IAT task have received little attention. The present study examined the temporal dynamics of the IAT that measures prosocial attitude using event-related potentials (ERPs). ERP results revealed enhanced N2 amplitudes for incongruent trials when compared with congruent trials and enhanced P300 amplitudes for congruent trials when compared with incongruent trials. In addition, the N2 amplitude differences were significantly correlated with individual prosocial behavior (the amount of donation). Our findings suggest that conflict monitoring and stimulus categorization processes are involved in the prosocial attitude IAT task and that the ERP indices of IATs that measure prosocial attitude may predict individual prosocial behavior.     

Social exclusion in middle childhood: Rejection events,slow-wave neural activity,and ostracism distress

This study examined neural activity with event-related potentials (ERPs) in middle childhood during a computer-simulated ball-toss game, Cyberball. After experiencing fair play initially, children were ultimately excluded by the other players. We focused specifically on “not my turn” events within fair play and rejection events within social exclusion. Dense-array ERPs revealed that rejection events are perceived rapidly. Condition differences (“not my turn” vs. rejection) were evident in a posterior ERP peaking at 420 ms consistent, with a larger P3 effect for rejection events indicating that in middle childhood rejection events are differentiated in <500 ms. Condition differences were evident for slow-wave activity (500–900 ms) in the medial frontal cortical region and the posterior occipital–parietal region, with rejection events more negative frontally and more positive posteriorly. Distress from the rejection experience was associated with a more negative frontal slow wave and a larger late positive slow wave, but only for rejection events. Source modeling with Geosouce software suggested that slow-wave neural activity in cortical regions previously identified in functional imaging studies of ostracism, including subgenual cortex, ventral anterior cingulate cortex, and insula, was greater for rejection events vs. “not my turn” events.     

The Potential for New Understandings of Normal and Abnormal Cognition by Integration of Neuroimaging and Behavioral Data: Not an Exercise in Carrying Coals to Newcastle

Discovering the means to prevent and cure schizophrenia is a vision that motivates many scientists. But in order to achieve this goal, we need to understand its neurobiological basis. The emergent metadiscipline of cognitive neuroscience fields an impressive array of tools that can be marshaled towards achieving this goal, including powerful new methods of imaging the brain (both structural and functional) as well as assessments of perceptual and cognitive capacities based on psychophysical procedures, experimental tasks and models developed by cognitive science. We believe that the integration of data from this array of tools offers the greatest possibilities and potential for advancing understanding of the neural basis of not only normal cognition but also the cognitive impairments that are fundamental to schizophrenia. Since sufficient expertise in the application of these tools and methods rarely reside in a single individual, or even a single laboratory, collaboration is a key element in this endeavor. Here, we review some of the products of our integrative efforts in collaboration with our colleagues on the East Coast of Australia and Pacific Rim. This research focuses on the neural basis of executive function deficits and impairments in early auditory processing in patients using various combinations of performance indices (from perceptual and cognitive paradigms), ERPs, fMRI and sMRI. In each case, integration of two or more sources of information provides more information than any one source alone by revealing new insights into structure-function relationships. Furthermore, the addition of other imaging methodologies (such as DTI) and approaches (such as computational models of cognition) offers new horizons in human brain imaging research and in understanding human behavior.

The time-course of auditory and visual distraction effects in a new crossmodal paradigm

Vision often dominates audition when attentive processes are involved (e.g., the ventriloquist effect), yet little is known about the relative potential of the two modalities to initiate a “break through of the unattended”. The present study was designed to systematically compare the capacity of task-irrelevant auditory and visual events to withdraw attention from the other modality. Sequences of auditory and visual stimuli were presented with different amounts of temporal offset to determine the presence, strength, and time-course of attentional orienting and reorienting as well as their impact on task-related processing. One of the streams was task-relevant, while crossmodal distraction caused by unexpected events in the other stream was measured by impairments of behavioral task performance and by the N2, P3a, and reorienting negativity (RON) components of the event-related potential (ERP). Unexpected events in the visual modality proved to be somewhat more salient than those in the auditory modality, yet crossmodal interference caused by auditory stimuli was more pronounced. The visual modality was relatively constrained in terms of a critical time-range within which distraction effects could be elicited, while the impact of auditory stimuli on task-related processing extended over a longer time-range. These results are discussed in terms of functional differences between the auditory and visual modalities. Further applications of the new crossmodal protocol are deemed promising in view of the considerable size of the obtained distraction effects.