Aging and individual differences in binding during sentence understanding: evidence from temporary and global syntactic attachment ambiguities.

We report an investigation of aging and individual differences in binding information during sentence understanding. An age-continuous sample of adults (N=91), ranging from 18 to 81 years of age, read sentences in which a relative clause could be attached high to a head noun NP1, attached low to its modifying prepositional phrase NP2 (e.g., The son of the princess who scratched himself/herself in public was humiliated), or in which the attachment site of the relative clause was ultimately indeterminate (e.g., The maid of the princess who scratched herself in public was humiliated). Word-by-word reading times and comprehension (e.g., who scratched?) were measured. A series of mixed-effects models were fit to the data, revealing: (1) that, on average, NP1-attached sentences were harder to process and comprehend than NP2-attached sentences; (2) that these average effects were independently moderated by verbal working memory capacity and reading experience, with effects that were most pronounced in the oldest participants and; (3) that readers on average did not allocate extra time to resolve global ambiguities, though older adults with higher working memory span did. Findings are discussed in relation to current models of lifespan cognitive development, working memory, language experience, and the role of prosodic segmentation strategies in reading. Collectively, these data suggest that aging brings differences in sentence understanding, and these differences may depend on independent influences of verbal working memory capacity and reading experience.

Inhibition of object identity in inhibition of return: implications for encoding and retrieving inhibitory processes.

Inhibition of return (IOR) effects, in which participants detect a target in a cued box more slowly than one in an uncued box, suggest that behavior is aided by inhibition of recently attended irrelevant locations. To investigate the controversial question of whether inhibition can be applied to object identity in these tasks, in the present research we presented faces upright or inverted during cue and/or target sequences. IOR was greater when both cue and target faces were upright than when cue and/or target faces were inverted. Because the only difference between the conditions was the ease of facial recognition, this result indicates that inhibition was applied to object identity. Interestingly, inhibition of object identity affected IOR both when encoding a cue face and retrieving information about a target face. Accordingly, we propose that episodic retrieval of inhibition associated with object identity may mediate behavior in cuing tasks.

Long-term negative priming: support for retrieval of prior attentional processes.

Negative priming reveals that participants respond slowly to a probe target that was a task-irrelevant distractor in the preceding prime display (e.g., Tipper, 1985) and is thought to reflect processes mediating short-term behaviour. However, since the first surprising reports that negative priming is found with meaningless stimuli across delays of 30 days (e.g., DeSchepper & Treisman, 1996), researchers have questioned the existence of long-term negative priming effects. Because long-term negative priming could indicate that task-irrelevant information leaves a memory trace that impacts performance over time, such a finding is of immense theoretical importance. Indeed, the current research finds support for the existence of long-term negative priming as well as its generality across different stimuli and conditions. The authors propose that the initial processes that prevent response to irrelevant stimuli may be stored in memory, where retrieval of these processes can mediate behaviour over time.

Long-term inhibition of return of attention.

During search of the environment, the inhibition of the return (IOR) of attention to already-examined information ensures that the target will ultimately be detected. Until now, inhibition was assumed to support search of information during one processing episode. However, in some situations search may have to be completed long after it was begun. We therefore propose that inhibition can be associated with an episode encoded into memory such that later retrieval reinstates inhibitory processing and encourages examination of new information. In two experiments in which attention was drawn to face stimuli with an exogenous cue, we demonstrated for the first time the existence of long-term IOR. Interestingly. this was the case only for faces in the left visual field, perhaps because more efficient processing of faces in the right hemisphere than the left hemisphere results in richer, more retrievable memory representations.