Latency of sequential eye movements: implications for reading

The best available estimates indicate that the average minimum latency of saccadic eye movements (175-200 msec) approaches the mean duration of fixations in reading (200-250 msec). This fact presents a problem for models of reading which assume that an eye movement is initiated only after substantial information is processed on a fixation. Three experiments are reported that support earlier estimates of saccadic latency; the experiments were conducted under conditions in which the length of measured latencies could not reflect a motoric refractory period, spatial uncertainty, or temporal uncertainty.     

The impact of television,print, and audio on children's recall of the news.

Recent research has shown that children remember more from television news than from print news, a finding that has been explained by the extra mnemonic support offered by redundant television pictures (the dual‐coding hypothesis). The present study was designed to examine three alternative explanations, which attribute children's superior recall of television news to (a) underutilization of the print medium, (b) a recall advantage of listening compared with reading, and imperfect reading ability. A sample of 192 fourth and sixth graders was presented with children's news stories, either in (a) their original television form, (b) a bare print version, a print version supplemented with photo material or in (d) an audio version. Results indicated that the television presentation was remembered better than any of the other three versions. The results of the study were consistent with the dual‐coding hypothesis, whereas no support was found for the alternative explanations tested in the study.     

Masking of foveal and parafoveal vision during eye fixations in reading

A window or visual mask as moved across text in synchrony with the reader's eye movements. The size of the window or mask was varied so that either information in foveal or parafoveal vision was masked on each fixation. In another experiment, the onset of the mask was delayed for a certain amount of time following the end of the saccade. The results of the experiments point out the relative importance of foveal and parafoveal vision for reading and further indicate that most of the visual information necessary for reading can be acquired during the first 50 msec that information is available during an eye fixation.     

Lateral stimulus-response compatibility effects in the oculomotor system.

Eye movement reaction time (RT) was measured in simple and choice RT situations in which monaural tones were presented to the left or right ear. In the choice RT conditions, tones of one frequency signaled a left looking response and tones of another frequency signaled a right looking response. In the simple RT condition, tones were presented in 2 blocks signaling right or left looking responses. RTs were measured by electro-oculogram (EOG), with electrodes placed over the outer canthus of each eye. In the choice RT condition, oculomotor RTs were faster when the tones signaling right or left looking were presented in the ears corresponding to the direction of looking than when they occured in the opposite ear. No such correspondence was present in the simple RT condition. Ss also performed a manual choice RT task. The lateral stimulus- response (S-R) compatibility effects obtained confirmed previous findings and were of the same magnitude as those obtained in the oculomotor response modality. Asymmetry in correlations between oculomotor and manual compatibility effects suggests differential hemispheric mediation.     

Development and Validation of a Short Health Behaviors Index for Use with Low Socioeconomic Status (SES) Older Adults

This study reports on the development and validation of a health behavior index in predominantly low socioeconomic status (SES) older adults. In order to develop and validate the index for use in low SES older adults, the 24-item Health and Human Services HealthStyle Self-Test was used for item generation. It was reduced to a relatively brief instrument, the Short HealthStyle (SHS) Index with 13 items that measures four major content areas of lifestyle behaviors among low SES older adults. The SHS Index was administered to a sample of 350 low SES older individuals. Principal component model factor analysis indicated a four-factor structure. Items loading on the first factor appeared to assess fitness and leisure activities, whereas those loading on the second and third factor assessed nutrition practices and stress control, respectively. A fourth factor assessed drinking/eating behaviors. Discriminant validity of the SHS was confirmed using the Instrumental Activities of Daily Living, and other health measures that indicated distinct constructs. Internal consistency for the SHS was .72 using Chronbach's alpha. Overall, the SHS Index displayed good psychometric properties in this sample, suggesting the appropriateness of using it to measure selected health behaviors with low SES older adults.     

The availability of useful information to the right of fixation in reading

A series of experiments that examined the characteristics of useful information to the right of fixation during reading is reported. In Experiments 1 and 2, reading performance when the information available to the right of fixation was determined by a fixed number of letters was compared with reading performance when the information to the right of fixation was determined by a fixed number of words. Beyond making more letters visible, both experiments showed that preserving all of the letters of a word was of no special benefit to reading. By explicitly presenting parts of the word to the right of fixation as well as the fixated word, Experiments 3 and 4 followed up on the implication that readers utilize partial letter information from words. Both experiments showed that reading was improved by this partial information and that preserving three letters of the word to the right of fixation improved reading almost as much as presenting the entire word. The implications the results have for models of reading are discussed.     

Eye movements and the span of the effective stimulus in visual search

The span of the effective stimulus during visual search through an unstructured alphanumeric array was investigated by using eye-contingent-display changes while the subjects searched for a target letter. In one condition, a window exposing the search array moved in synchrony with the subjects' eye movements, and the size of the window was varied. Performance reached asymptotic levels when the window was 5 degrees. In another condition, a foveal mask moved in synchrony with each eye movement, and the size of the mask was varied. The foveal mask conditions were much more detrimental to search behavior than the window conditions, indicating the importance of foveal vision during search. The size of the array also influenced performance, but performance reached asymptote for all array sizes tested at the same window size, and the effect of the foveal mask was the same for all array sizes. The results indicate that both acuity and difficulty of the search task influenced the span of the effective stimulus during visual search.