The influence of prosodic structure on the interpretation of temporary syntactic ambiguity by young and elderly listeners.

The contribution of prosody to the interpretation of temporary syntactic ambiguity was examined for young and elderly listeners using a sentence-completion task. Temporary syntactic ambiguity refers to cases where it may be temporarily unclear whether a syntactic clause boundary has or has not been reached based on what has been heard in the sentence to that point. Results suggest that both young and elderly adults use a computationally less demanding late-closure parsing strategy whenever possible, but that sentence prosody can override this tendency when an alternative closure position is clearly signaled. Although subtle differences appeared in regard to sentence completion strategies and latencies to completion, results suggest that efficient resolution of syntactic boundary uncertainty and effective use of sentence prosody are two features of language comprehension that remain well-preserved in normal aging.

The influence of prosodic structure on the resolution of temporary syntactic closure ambiguities.

This paper investigates the influence of prosodic structure on the process of sentence comprehension, with a specific focus on the relative contributions of syntactic and prosodic information to the resolution of temporary syntactic closure ambiguities. We argue that prosodic structure provides an initial memory representation for spoken sentences, and that information from this prosodic representation is available to inform syntactic parsing decisions. This view makes three predictions for the processing of temporary syntactic ambiguity: 1. When prosodic and syntactic boundaries coincide, syntactic processing should be facilitated. 2. When prosodic boundaries are placed at misleading points in syntactic structure, syntactic processing should show interference effects. 3. The processing difficulties that have been reliably demonstrated in reading experiments for syntactically complex sentences should disappear when those sentences are presented with a felicitous prosodic structure in listening experiments. These predictions were confirmed by series of experiments measuring end-of-sentence comprehension time and cross-modal naming time for sentences with temporary syntactic closure ambiguities. Sentences with coinciding or conflicting prosodic and syntactic boundaries were compared to a prosodic baseline condition.

Dissociations among structural-perceptual, lexical-semantic, and event-fact memory systems in Alzheimer, amnesic, and normal subjects.

Patients with Alzheimer's disease (AD), patients with global amnesia (AMN), and normal control (NC) subjects received tests of recall and recognition, word-completion priming, and incomplete-picture priming. The AD and AMN patients had impaired recall and recognition. The AD patients, but not the AMN patients, had impaired word-completion priming. In contrast, the AD patients had intact incomplete-picture priming, a form of priming shown to be perceptual in normal subjects. These results provide neuropsychological evidence for a dissociation between two components of repetition priming, perceptual priming as measured with identification tasks and nonperceptual priming as measured with generation tasks. Preserved perceptual priming in AD may be mediated by the occipital regions that are relatively spared in AD; compromised nonperceptual priming may be mediated by temporal regions that show dense neuropathological changes early in AD.