Reflexive orienting in response to short- and long-duration gaze cues in young,young-old,and old-old adults

Shifting visual focus on the basis of the perceived gaze direction of another person is one form of joint attention. In the present study, we investigated whether this socially relevant form of orienting is reflexive and whether it is influenced by age. Green and Woldorff (Cognition 122:96–101, 2012) argued that rapid cueing effects (i.e., faster responses to validly than to invalidly cued targets) were limited to conditions in which a cue overlapped in time with a target. They attributed slower responses following invalid cues to the time needed to resolve the incongruent spatial information provided by the concurrently presented cue and target. In the present study, we examined the orienting responses of young (18–31 years), young-old (60–74 years), and old-old (75–91 years) adults following uninformative central gaze cues that overlapped in time with the target (Exp. 1) or that were removed prior to target presentation (Exp. 2). When the cue and target overlapped, all three groups localized validly cued targets more quickly than invalidly cued targets, and validity effects emerged earlier for the two younger groups (at 100 ms post-cue-onset) than for the old-old group (at 300 ms post-cue-onset). With a short-duration cue (Exp. 2), validity effects developed rapidly (by 100 ms) for all three groups, suggesting that validity effects resulted from reflexive orienting based on the gaze cue information rather than from cue–target conflict. Thus, although old-old adults may be slow to disengage from persistent gaze cues, attention continues to be reflexively guided by gaze cues late in life.     

Transient suppression of processing during rapid serial visual presentation: Acquired distinctiveness of probes modulates the attentional blink

The attentional blink is revealed in studies of rapid serial visual processing, in which observers view a stream of letters presented sequentially at the same location in a visual display. Reporting the identity of a specially marked letter (the target) amidst distractors causes a transient loss of accuracy for detection of another prespecified symbol (the probe). In two experiments, observers viewed lists of letters, identified a randomly selected letter as a target, and detected the presence of a probe from a different category (a digit or a Greek letter). After several days of training, probe detection following a target had improved markedly. Posttarget probe detection was again impaired when the distractor set included members of the probe set. These results are compatible with an explanation of the attentional blink as an act of suppression aimed at the current set of distractors, but additional mechanisms are needed to account for the effects of training.     

Functional connectivity differences in autism during face and car recognition: underconnectivity and atypical age‐related changes

Face recognition abilities improve between adolescence and adulthood over typical development (TD), but plateau in autism, leading to increasing face recognition deficits in autism later in life. Developmental differences between autism and TD may reflect changes between neural systems involved in the development of face encoding and recognition. Here, we focused on whole‐brain connectivity with the fusiform face area (FFA), a well‐established face‐preferential brain region. Older children, adolescents, and adults with and without autism completed the Cambridge Face Memory Test, and a matched car memory test, during fMRI scanning. We then examined task‐based functional connectivity between the FFA and the rest of the brain, comparing autism and TD groups during encoding and recognition of face and car stimuli. The autism group exhibited underconnectivity, relative to the TD group, between the FFA and frontal and primary visual cortices, independent of age. Underconnectivity with the medial and rostral lateral prefrontal cortex was face‐specific during encoding and recognition, respectively. Conversely, underconnectivity with the L orbitofrontal cortex was evident for both face and car encoding. Atypical age‐related changes in connectivity emerged between the FFA and the R temporoparietal junction, and R dorsal striatum for face stimuli only. Similar differences in age‐related changes in autism emerged for FFA connectivity with the amygdala across both face and car recognition. Thus, underconnectivity and atypical development of functional connectivity may lead to a less optimal face‐processing network in the context of increasing general and social cognitive deficits in autism.