Specific phonological impairments in dyslexia revealed by eyetracking

Phonological deficits in dyslexia are typically assessed using metalinguistic tasks vulnerable to extraneous factors such as attention and memory. The present work takes the novel approach of measuring phonology using eyetracking. Eye movements of dyslexic children were monitored during an auditory word recognition task in which target items in a display (e.g., candle) were accompanied by distractors sharing a cohort (candy) or rhyme (sandal). Like controls, dyslexics showed slower recognition times when a cohort distractor was present than in a baseline condition with only phonologically unrelated distractors. However, unlike controls, dyslexic children did not show slowed recognition of targets with a rhyme distractor, suggesting they had not encoded rhyme relationships. This was further explored in an overt phonological awareness test of cohort and rhyme. Surprisingly, dyslexics showed normal rhyme performance but poorer judgment of initial sounds on these overt tests. The results implicate impaired knowledge of rhyme information in dyslexia; however they also indicate that testing methodology plays a critical role in how such problems are identified.     

Does driving experience in video games count? Hazard anticipation and visual exploration of male gamers as function of driving experience

Risk perception and distribution of visual attention while driving are crucial elements for accident prevention and new-driver improvement. This study investigates how racing videogames could shape the visual exploration of virtual and real road in male pre-drivers. The visual performance of players of racing video games with and without driver’s license was tested in virtual vs. real scenarios. Attention to specific elements of different types of road interactions was monitored using an eye-tracking system. Results showed that habitual use of racing video games was not found to foster a positive effect on users’ distribution of visual attention, supporting visual patterns typical of novice drivers. Gamers without driving experience replicated the same patterns in a real road scenario, ignoring road signs and potential areas of interactions with other drivers, while experienced drivers gamers explored video games roads like real roads. The fact that the gamers’ driving performance was not comparable to drivers in the virtual scenario suggests that there are other variables in the gameplay that create a less complex traffic scene, still the visual complexity of different real road interactions is kept in video game interactions, opening new perspectives towards gamers’ visual exploration of the road.     

Eyetracking and selective attention in category learning

An eyetracking version of the classic Shepard, Hovland, and Jenkins (1961) experiment was conducted. Forty years of research has assumed that category learning often involves learning to selectively attend to only those stimulus dimensions useful for classification. We confirmed that participants learned to allocate their attention optimally. We also found that learners tend to fixate all stimulus dimensions early in learning. This result obtained despite evidence that participants were also testing one-dimensional rules during this period. Finally, the restriction of eye movements to only relevant dimensions tended to occur only after errors were largely (or completely) eliminated. We interpret these findings as consistent with multiple-systems theories of learning which maximize information input in order to maximize the number of learning modules involved, and which focus solely on relevant information only after one module has solved the learning problem.     

Pragmatic expectations and linguistic evidence: Listeners anticipate but do not integrate common ground

When listeners search for the referent of a speaker’s expression, they experience interference from privileged knowledge, knowledge outside of their ‘common ground’ with the speaker. Evidence is presented that this interference reflects limitations in lexical processing. In three experiments, listeners’ eye movements were monitored as they searched for the target of a speaker’s referring expression in a display that also contained a phonological competitor (e.g., bucket/buckle). Listeners anticipated that the speaker would refer to something in common ground, but they did not experience less interference from a competitor in privileged ground than from a matched competitor in common ground. In contrast, interference from the competitor was eliminated when it was ruled out by a semantic constraint. These findings support a view of comprehension as relying on multiple systems with distinct access to information and present a challenge for constraint-based views of common ground.     

Selective scanpath repetition during memory-guided visual search

Visual search efficiency improves with repetition of a search display, yet the mechanisms behind these processing gains remain unclear. According to Scanpath Theory, memory retrieval is mediated by repetition of the pattern of eye movements or “scanpath” elicited during stimulus encoding. Using this framework, we tested the prediction that scanpath recapitulation reflects relational memory guidance during repeated search events. Younger and older subjects were instructed to find changing targets within flickering naturalistic scenes. Search efficiency (search time, number of fixations, fixation duration) and scanpath similarity (repetition) were compared across age groups for novel (V1) and repeated (V2) search events. Younger adults outperformed older adults on all efficiency measures at both V1 and V2, while the search time benefit for repeated viewing (V1–V2) did not differ by age. Fixation-binned scanpath similarity analyses revealed repetition of initial and final (but not middle) V1 fixations at V2, with older adults repeating more initial V1 fixations than young adults. In young adults only, early scanpath similarity correlated negatively with search time at test, indicating increased efficiency, whereas the similarity of V2 fixations to middle V1 fixations predicted poor search performance. We conclude that scanpath compression mediates increased search efficiency by selectively recapitulating encoding fixations that provide goal-relevant input. Extending Scanpath Theory, results suggest that scanpath repetition varies as a function of time and memory integrity.