An fMRI study of visual hemifield integration and cerebral lateralization

Strother, Lars; Zhang, Zhiheng; Coros, Alexandra; Vilis, Tutis

doi:10.1016/j.neuropsychologia.2017.04.003

Cited by 26 publications

(23 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…That is consistent with our conclusion that left VWFA-1 contains two spatial channels while VWFA-2 contains only a single channel. Strother et al (30,36) also found that the right posterior region was biased for the left hemifield, which is consistent with our finding that right VWFA-1 contained a single channel and was especially responsive when attention was focused to the left. Our results go further to show how this circuit responds to pairs of whole words, and to relate the multivoxel patterns to selective attention and task performance.…”

Section: Discussionsupporting

confidence: 92%

“…Several studies have concluded that the anterior portion of wordselective VOTC is more sensitive to higher-level, abstract, lexical properties (17,22,24). Another research group studied how VOTC integrates both halves of a single word that are split between hemifields (30,36). They found that a posterior left VOTC region (the "occipital word form area," roughly 12 mm posterior to our VWFA-1) represented both halves of a word but maintained them separately.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Parallel spatial channels converge at a bottleneck in anterior word-selective cortex

White

Palmer

Boynton

et al. 2019

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

In most environments, the visual system is confronted with many relevant objects simultaneously. That is especially true during reading. However, behavioral data demonstrate that a serial bottleneck prevents recognition of more than one word at a time. We used fMRI to investigate how parallel spatial channels of visual processing converge into a serial bottleneck for word recognition. Participants viewed pairs of words presented simultaneously. We found that retinotopic cortex processed the two words in parallel spatial channels, one in each contralateral hemisphere. Responses were higher for attended than for ignored words but were not reduced when attention was divided. We then analyzed two word-selective regions along the occipitotemporal sulcus (OTS) of both hemispheres (subregions of the visual word form area, VWFA). Unlike retinotopic regions, each word-selective region responded to words on both sides of fixation. Nonetheless, a single region in the left hemisphere (posterior OTS) contained spatial channels for both hemifields that were independently modulated by selective attention. Thus, the left posterior VWFA supports parallel processing of multiple words. In contrast, activity in a more anterior word-selective region in the left hemisphere (mid OTS) was consistent with a single channel, showing (i) limited spatial selectivity, (ii) no effect of spatial attention on mean response amplitudes, and (iii) sensitivity to lexical properties of only one attended word. Therefore, the visual system can process two words in parallel up to a late stage in the ventral stream. The transition to a single channel is consistent with the observed bottleneck in behavior.

show abstract

Section: Discussionsupporting

confidence: 92%

Section: Discussionmentioning

confidence: 99%

Parallel spatial channels converge at a bottleneck in anterior word-selective cortex

White

Palmer

Boynton

et al. 2019

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…Several studies have concluded that the anterior portion of word-selective VOTC is more sensitive to higher-level, abstract, lexical properties (Dehaene et al, 2004; Lerma-Usabiaga et al, 2018; Vinckier et al, 2007). Another research group studied how VOTC integrates both halves of a single word that are split between hemifields (Strother et al, 2016; Strother, Zhou, Coros, & Vilis, 2017). They found that left VWFA-1 (which they label the “occipital word form area”) represented both halves of a word but maintained them separately.…”

Section: Discussionmentioning

confidence: 99%

Parallel spatial channels converge at a bottleneck in anterior word-selective cortex

White

Palmer

Boynton

et al. 2018

Preprint

View full text Add to dashboard Cite

In most environments, the visual system is confronted with many relevant objects simultaneously. That is especially true during reading. However, behavioral data demonstrate that a serial bottleneck prevents recognition of more than one word at a time. We used functional magnetic resonance imaging (fMRI) to investigate how parallel spatial channels of visual processing converge into a serial bottleneck for word recognition. Observers viewed pairs of words presented simultaneously. We found that retinotopic cortex processed the two words in parallel spatial channels, one in each contralateral hemisphere. Responses were higher for attended words than ignored words, but were not reduced when attention was divided, even though behavioral performance suffered greatly. We then analyzed two word-selective regions along the occipito-temporal sulcus (OTS) of both hemispheres (i.e., sub-regions of visual word form area, VWFA). Unlike retinotopic cortex, each word-selective region responded to words on both sides of fixation. Nonetheless, a single region in the left hemisphere (VWFA-1 in posterior OTS) contained spatial channels for both hemifields that were independently modulated by selective attention. Thus, the left posterior VWFA supports parallel processing of multiple words. In contrast, a more anterior word-selective region in the left hemisphere (VWFA-2 in mid-OTS) showed limited spatial and attentional selectivity, consistent with activity of a single channel. Therefore, the visual system can process two words in parallel up to a late stage in the ventral stream. The transition from two parallel channels to a single channel in more anterior regions is consistent with the observed bottleneck in behavior.

show abstract

“…The first reason is that visual word processing involves interactions with phonological information, so that there is a strong push to process visually presented words in the hemisphere with the speech centre (usually the left hemisphere). Indeed, interhemispheric transfer from the non-language-dominant to the dominant hemisphere has been documented at the very first stages of visual word processing, in the occipital cortex and in the border region between the occipital and temporal cortex (Strother, Zhou, Coros, & Vilis, 2017;Van der Haegen, Cai, & Brysbaert, 2012). Although feedback from the frontal cortex is known to influence visual word processing up to the occipital cortex (Price & Devlin, 2011), it is unlikely that feedback from emotional brain centres could completely alter the information flow.…”

Section: Discussionmentioning

confidence: 99%

The influence of word valence on the right visual field advantage in the VHF paradigm: time to adjust the expectations

Clercq

Brysbaert

2020

Laterality

View full text Add to dashboard Cite

Previous studies found that valence (positive vs negative vs neutral) and visual half-field (left versus right) have an influence on word reading: Words are processed more efficiently when they evoke positive feelings and when they appear in the right visual field. In the present study we tried to address previous (contradictory) reports of an interaction between valence and visual half-field. A group of 39 right-handed undergraduates completed a lexical decision task in their native language (Dutch). They responded to 300 trials with real words (50 words per valence category -positive, negative, neutral -presented once in the left visual half-field and once in the right half-field) and 300 trials with non-words. Overall, participants responded more efficiently to positive words and there was a strong right visual field advantage. We did not find a significant interaction, however. Further analysis indicated that to find a replicable interaction between a stimulus characteristic and visual half-field, one requires much high numbers of participants and stimuli than done so far (and more than most researchers would be willing to invest). Experimental power is particularly low when the interaction is not fully crossed (a right visual field advantage for one type of stimulus and an equally large left visual field advantage for the other type of stimulus). If such investment cannot be made, the outcome is likely to be ambiguous at best and deceiving at worst if only significant findings are published.

show abstract

An fMRI study of visual hemifield integration and cerebral lateralization

Cited by 26 publications

References 61 publications

Parallel spatial channels converge at a bottleneck in anterior word-selective cortex

Parallel spatial channels converge at a bottleneck in anterior word-selective cortex

Parallel spatial channels converge at a bottleneck in anterior word-selective cortex

The influence of word valence on the right visual field advantage in the VHF paradigm: time to adjust the expectations

Contact Info

Product

Resources

About