Influences on and consequences of parafoveal preview in reading

Parafoveal Word Frequency Does Not Modulate the Effect of Foveal Load on Preview in Chinese Reading: Evidence from Eye Movements

The foveal load effect is one of the most fundamental effects in reading psychology, and also one of the most controversial issues in recent years. The foveal load effect refers to the phenomenon that the difficulty of foveal processing affects parafoveal preview. In Chinese reading, whether the foveal load effect exists, as well as whether this effect is modulated by parafoveal word frequency, remains unclear. In this study, the eye-tracking technique was used to track the eye movements of 48 subjects. Utilized the boundary paradigm with single-character words as parafoveal words, the present study manipulated foveal word frequency (high and low), parafoveal word frequency (high and low), and two types of preview (identical preview and pseudocharacter preview) to investigate these questions. The results revealed that the foveal word frequency does not influence preview, suggesting the absence of the foveal load effect when using single-character words as parafoveal words. Furthermore, parafoveal word frequency does not modulate the effect of the foveal load on the preview. This empirical evidence contributes to refining the understanding of the Chinese reading model.

Large-scale evidence for logarithmic effects of word predictability on reading time

During real-time language comprehension, our minds rapidly decode complex meanings from sequences of words. The difficulty of doing so is known to be related to words' contextual predictability, but what cognitive processes do these predictability effects reflect? In one view, predictability effects reflect facilitation due to anticipatory processing of words that are predictable from context. This view predicts a linear effect of predictability on processing demand. In another view, predictability effects reflect the costs of probabilistic inference over sentence interpretations. This view predicts either a logarithmic or a superlogarithmic effect of predictability on processing demand, depending on whether it assumes pressures toward a uniform distribution of information over time. The empirical record is currently mixed. Here, we revisit this question at scale: We analyze six reading datasets, estimate next-word probabilities with diverse statistical language models, and model reading times using recent advances in nonlinear regression. Results support a logarithmic effect of word predictability on processing difficulty, which favors probabilistic inference as a key component of human language processing.

The influence of foveal lexical processing load on parafoveal preview and saccadic targeting during Chinese reading

Whether increased foveal load causes a reduction of parafoveal processing remains equivocal. The present study examined foveal load effects on parafoveal processing in natural Chinese reading. Parafoveal preview of a single-character parafoveal target word was manipulated by using the boundary paradigm (Rayner, 1975; pseudocharacter or identity previews) under high foveal load (low-frequency pretarget word) compared with low foveal load (high-frequency pretarget word) conditions. Despite an effective manipulation of foveal processing load, we obtained no evidence of any modulatory influence on parafoveal processing in first-pass reading times. However, our results clearly showed that saccadic targeting, in relation to forward saccade length from the pretarget word and in relation to target word skipping, was influenced by foveal load and this influence occurred independent of parafoveal preview. Given the optimal experimental conditions, these results provide very strong evidence that preview benefit is not modulated by foveal lexical load during Chinese reading.

The findings of the present study show that foveal processing load, as manipulated through lexical frequency, has no modulatory influence on preview benefit for the subsequent word in a sentence during natural Chinese reading. Foveal processing difficulty does, however, influence saccades that determine where the eyes fixate next, and this influence occurs regardless of preview benefit for the following word. These results pertain directly to the Foveal Load Hypothesis that has received significant scrutiny in recent years. They also directly inform current understanding of the complexities of the relationship between the oculomotor control system that is responsible for positioning the point of fixation during reading and the complex cognitive processes that occur during written Chinese language comprehension.

Spill the load: Mixed evidence for a foveal load effect, reliable evidence for a spillover effect in eye-movement control during reading

It has been hypothesized that the processing difficulty of the fixated word (i.e., "foveal load") modulates the amount of parafoveal preprocessing of the next word. Evidence for the hypothesis has been provided by the application of parafoveal masks within the boundary paradigm. Other studies that applied alternative means of manipulating the parafoveal preview (i.e., visual degradation) could not replicate the effect of foveal load. The present study examined the effect of foveal load by directly comparing the application of parafoveal masks (Exp. 1) with the alternative manipulation of visually degrading the parafoveal preview (Exp. 2) in adult readers. Contrary to expectation, we did not find the foveal-load interaction in the first experiment with traditional letter masks. We did, however, find the expected interaction in the second experiment with visually degraded previews. Both experiments revealed a spillover effect indicating that the processing of a word is not (always) fully completed when the reader already fixates the next word (i.e., processing "spills over" to the next word). The implications for models of eye-movement control in reading are discussed.

Time-Course of Motor Involvement in Literal and Metaphoric Action Sentence Processing: A TMS Study

There is evidence that the motor cortex is involved in reading sentences containing an action verb ("The spike was hammered into the ground") as well as metaphoric sentences ("The army was hammered in the battle"). Verbs such as 'hammered' may be homonyms, with separate meanings belonging to the literal action and metaphoric action, or they may be polysemous, with the metaphoric sense grounded in the literal sense. We investigated the time course of the effects of single-pulse transcranial magnetic stimulation to primary motor cortex on literal and metaphoric sentence comprehension. Stimulation 300 ms post-verb presentation impaired comprehension of both literal and metaphoric sentences, supporting a causal role of sensory-motor areas in comprehension. Results suggest that the literal meaning of an action verb remains activated during metaphor comprehension, even after the temporal window of homonym disambiguation. This suggests that such verbs are polysemous, and both senses are related and grounded in motor cortex.