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Biology subjects

Frisson, S.

Publications and source records attributed to Frisson, S..

2 recordsLinked to original sources

A pipelining mechanism supporting previewing during visual exploration and reading

Humans have a remarkable ability to efficiently explore visual scenes and text by means of eye-movements. Humans typically make eye-movements (saccades) every ~250ms. Since the saccadic motor planning and execution takes 100ms this leaves only ~150ms to recognize the fixated object (or word), while simultaneously previewing candidates for the next saccade goal. We propose a pipelining mechanism that efficiently can coordinate visual exploration and reading. The mechanism is timed by alpha oscillations that coordinate the saccades, visual recognition and previewing in the cortical hierarchy. Consequently, the neuronal mechanism supporting visual processing and saccades must be studied in unison to uncover the brain mechanism supporting visual exploration and reading. HighlightsO_LIHumans have a remarkable ability to efficiently acquire information from visual scenes and pages of text by means of saccadic exploration. C_LIO_LIVisual exploration is surprisingly efficient given the temporal and spatial constraints imposed by the visual system. As such, both information from current fixations as well as upcoming locations must be processed within a 150 ms time window. C_LIO_LINew data recording in humans and non-human primates points to a link between the timing of saccades and alpha oscillations. C_LIO_LIWe present a framework in which visual exploration and reading are supported by similar neuronal mechanisms. C_LIO_LIWe propose a novel mechanism in which visual exploration and reading is supported by a pipelining mechanism organized by alpha oscillations. C_LIO_LIAccording to the pipelining mechanism, fixated and previewed objects/words are represented at different phases of an alpha cycle. C_LI

neuroscience

Lexical parafoveal previewing predicts reading speed

While reading is an essential human skill, many of the neuronal mechanisms supporting reading are not well understood. In spite of the reduced visual acuity, parafoveal information plays a critical role in natural reading1; however, it is strongly debated whether words are previewed parafoveally at the lexical level2-9. This is a key dispute for competing models on reading and of great significance since lexical retrieval is important for guiding eye movements. We found evidence for parafoveal previewing at the lexical level by combining a novel rapid invisible frequency tagging (RIFT)10, 11 approach with magnetoencephalography (MEG) and eye-tracking. In a silent reading task, target words of either low or high lexical frequency were tagged (flickered) subliminally at 60 Hz. The tagging response measured when fixating on the pre-target word reflected parafoveal previewing of the target word. We observed a stronger tagging response as early as 100 ms following fixations on pre-target words that were followed by target words of low compared with high lexical frequency. Moreover, the difference in tagging response with respect to target lexicality predicted individual reading speed. Our findings demonstrate that reading unfolds in the fovea and parafovea simultaneously to support fluent reading.

neuroscience