Biomedical subjects

Carrick C Williams

Publications and source records attributed to Carrick C Williams.

7 recordsLinked to original sources

PubMed2006

Previewing the neighborhood: the role of orthographic neighbors as parafoveal previews in reading.

In 2 experiments, a boundary technique was used with parafoveal previews that were identical to a target (e.g., sleet), a word orthographic neighbor (sweet), or an orthographically matched nonword (speet). In Experiment 1, low-frequency words in orthographic pairs were targets, and high-frequency words were previews. In Experiment 2, the roles were reversed. In Experiment 1, neighbor words provided as much preview benefit as identical words and greater benefit than nonwords, whereas in Experiment 2, neighbor words provided no greater preview benefit than nonwords. These results indicate that the frequency of a preview influences the extraction of letter information without setting up appreciable competition between previews and targets. This is consistent with a model of word recognition in which early stages largely depend on excitation of letter information, and competition between lexical candidates becomes important only in later stages.

Attention↗

PubMed2006

The effect of word frequency, word predictability, and font difficulty on the eye movements of young and older readers.

Young adult and older readers' eye movements were recorded as they read sentences containing target words that varied in frequency or predictability. In addition, half of the sentences were printed in a font that was easy to read (Times New Roman) and the other half were printed in a font that was more difficult to read (Old English). Word frequency, word predictability, and font difficulty effects were apparent in the eye movement data of both groups of readers. In the fixation time data, the pattern of results was the same, but the older readers had larger frequency and predictability effects than the younger readers. The older readers skipped words more often than the younger readers (as indicated by their skipping rate on selected target words), but they made more regressions back to the target words and more regressions overall. The E-Z Reader model was used as a platform to evaluate the results, and simulations using the model suggest that lexical processing is slowed in older readers and that, possibly as a result of this, they adopt a more risky reading strategy.

Adolescent↗

PubMed2006

Younger and Older Adults' "Good-Enough" Interpretations of Garden-Path Sentences.

We report 3 experiments that examined younger and older adults' reliance on "good-enough" interpretations for garden-path sentences (e.g., "While Anna dressed the baby played in the crib") as indicated by their responding "Yes" to questions probing the initial, syntactically unlicensed interpretation (e.g., "Did Anna dress the baby?"). The manipulation of several factors expected to influence the probability of generating or maintaining the unlicensed interpretation resulted in 2 major age differences: Older adults were generally more likely to endorse the incorrect interpretation for sentences containing optionally transitive verbs (e.g., hunted, paid), and they showed decreased availability of the correct interpretation of subordinate clauses containing reflexive absolute transitive verbs (e.g., dress, bathe). These age differences may in part be linked to older adults' increased reliance on heuristic-like good-enough processing to compensate for age-related deficits in working memory capacity. The results support previous studies suggesting that syntactic reanalysis may not be an all-or-nothing process and might not be completed unless questions probing unresolved aspects of the sentence structure challenge the resultant interpretation.

Journal Article↗

PubMed2005

Incidental visual memory for targets and distractors in visual search.

We explored incidental retention of visual details of encountered objects during search. Participants searched for conjunction targets in 32 arrays of 12 pictures of real-world objects and then performed a token discrimination task that examined their memory for visual details of the targets and distractors from the search task. The results indicate that even though participants had not been instructed to memorize the objects, the visual details of search targets and distractor objects related to the targets were retained after the search. Distractor objects unrelated to the search target were remembered more poorly. Eye-movement measures indicated that the objects that were remembered were looked at more frequently during search than those that were not remembered. These results provide support that detailed visual information is included incidentally in the visual representation of an object after the object is no longer in view.

Attention↗

PubMed2005

Eye movements are functional during face learning.

In a free viewing learning condition, participants were allowed to move their eyes naturally as they learned a set of new faces. In a restricted viewing learning condition, participants remained fixated in a single central location as they learned the new faces. Recognition of the learned faces was then tested following the two learning conditions. Eye movements were recorded during the free viewing learning condition, as well as during recognition. The recognition results showed a clear deficit following the restricted viewing condition, compared with the free viewing condition, demonstrating that eye movements play a functional role during human face learning. Furthermore, the features selected for fixation during recognition were similar following free viewing and restricted viewing learning, suggesting that the eye movements generated during recognition are not simply a recapitulation of those produced during learning.

Eye Movements↗

PubMed2003

Stroop interference, practice, and aging.

We report two experiments that investigate practice effects on Stroop color-word interference in older and younger adults. Both experiments employed a computerized, single-item version of the Stroop task with a voice response, and both involved practice over hundreds of trials. Both experiments showed generally similar practice patterns, including a practice-related reduction in the size of the color-word interference effect. However, the older group continued to show a larger interference effect throughout practice. These findings indicate that older adults show the same trend in practice-related improvement on the Stroop task as younger adults.

Journal Article↗

PubMed2003

Eye movements and picture processing during recognition.

Eye movements were monitored during a recognition memory test of previously studied pictures of full-color scenes. The test scenes were identical to the originals, had an object deleted from them, or included a new object substituted for an original object. In contrast to a prior report (Parker, 1978), we found no evidence that object deletions or substitutions could be recognized on the basis of information acquired from the visual periphery. Deletions were difficult to recognize peripherally, and the eyes were not attracted to them. Overall, the amplitude of the average saccade to the critical object during the memory test was less than 4.5 degrees of visual angle in all conditions and averaged 4.1 degrees across conditions. We conclude that information about object presence and identity in a scene is limited to a relatively small region around the current fixation point.

Color Perception↗