Processing In Visual Word Recognition Research Articles

Body—object interaction ratings for 1,618 monosyllabic nouns

Body-object interaction (BOI) assesses the ease with which a human body can physically interact with a word's referent. Recent research has shown that BOI influences visual word recognition processes in such a way that responses to high-BOI words (e.g., couch) are faster and less error prone than responses to low-BOI words (e.g., cliff). Importantly, the high-BOI words and the low-BOI words that were used in those studies were matched on imageability. In the present study, we collected BOI ratings for a large set of words. BOI ratings, on a 1-7 scale, were obtained for 1,618 monosyllabic nouns. These ratings allowed us to test the generalizability of BOI effects to a large set of items, and they should be useful to researchers who are interested in manipulating or controlling for the effects of BOI. The body-object interaction ratings for this study may be downloaded from the Psychonomic Society's Archive of Norms, Stimuli, and Data, www.psychonomic.org/archive.

Pseudohomophone effects provide evidence of early lexico‐phonological processing in visual word recognition

Previous research using event-related brain potentials (ERPs) suggested that phonological processing in visual word recognition occurs rather late, typically after semantic or syntactic processing. Here, we show that phonological activation in visual word recognition can be observed much earlier. Using a lexical decision task, we show that ERPs to pseudohomophones (PsHs) (e.g., ROZE) differed from well-matched spelling controls (e.g., ROFE) as early as 150 ms (P150) after stimulus onset. The PsH effect occurred as early as the word frequency effect suggesting that phonological activation occurs early enough to influence lexical access. Low-resolution electromagnetic tomography analysis (LORETA) revealed that left temporoparietal and right frontotemporal areas are the likely brain regions associated with the processing of phonological information at the lexical level. Altogether, the results show that phonological processes are activated early in visual word recognition and play an important role in lexical access.

Neural Correlates of Morphological Processes in Hebrew

Is morphology a discrete and independent element of lexical structure or does it simply reflect a fine tuning of the system to the statistical correlation that exists among the orthographic and semantic properties of words? Imaging studies in English failed to show unequivocal morphological activation that is distinct from semantic or orthographic activation. Cognitive research in Hebrew has revealed that morphological decomposition is an important component of print processing. In Hebrew, morphological relatedness does not necessarily induce a clear semantic relatedness, thus, Hebrew provides a unique opportunity to investigate the neural substrates of morphological processing. In this functional magnetic resonance imaging study, participants were required to perform judgment tasks of morphological relatedness, semantic relatedness, rhyming, and orthographic similarity. Half of the morphologically related words were semantically related and half were semantically unrelated. This design was chosen to induce explicit morphological processing. We identified two locations involved in morphological processing: the left middle frontal gyrus and the left inferior parietal sulcus. Comparing locations of morphological related activation to the locations of semantic and orthographic related activation, we found that the areas neighbored but only partially overlapped. The similarity in activation between the two morphological conditions eliminates the possibility that morphological activation simply results from the semantic properties of the words. These results demonstrate the important role of morphological processing in reading and suggest that morphological analysis is a distinct process of visual word recognition.

Differential activation of frontal and parietal regions during visual word recognition: An optical topography study

The present study examined cortical oxygenation changes during lexical decision on words and pseudowords using functional Near-Infrared Spectroscopy (fNIRS). Focal hyperoxygenation as an indicator of functional activation was compared over three target areas over the left hemisphere. A 52-channel Hitachi ETG-4000 was used covering the superior frontal gyrus (SFG), the left inferior parietal gyrus (IPG) and the left inferior frontal gyrus (IFG). To allow for anatomical inference a recently developed probabilistic mapping method was used to determine the most likely anatomic locations of the changes in cortical activation [Tsuzuki, D., Jurcak, V., Singh, A.K., Okamoto, M., Watanabe, E., Dan, I., 2007. Virtual spatial registration of stand-alone fNIRS data to MNI space. NeuroImage 43 (4), 1506–1518.Subjects made lexical decisions on 50 low and 50 high frequency words and 100 pseudowords. With respect to the lexicality effect, words elicited a larger focal hyperoxygenation in comparison to pseudowords in two regions identified as the SFG and left IPG. The SFG activation difference was interpreted to reflect decision-related mechanisms according to the Multiple Read-Out Model [Grainger, J., Jacobs, A.M., 1996. Orthographic processing in visual word recognition: A multiple read-out model. Psychological Review 103, 518–565]. The greater oxygenation response to words in the left IPG suggests that this region connects orthographic, phonological and semantic representations. A decrease of deoxygenated hemoglobin was observed to low frequency in comparison to high frequency words in a region identified as IFG. This region’s sensitivity to word frequency suggests its involvement in grapheme–phoneme conversion, or its role during the selection of pre-activated semantic candidates.

Parametric analysis of EEG and fMRI data reveals the neural basis of visual word processing

Parametric analysis of EEG and fMRI data reveals the neural basis of visual word processing

SERIOL Reading

In recent years, there has been a growing interest in the issue of orthographic processing in visual word recognition. We compare the SERIOL model to parallel models in their ability to explain experimental data at the lexical and sub-lexical levels. We find that the parallel models have difficulty accounting for position-independent letter priming, letter perceptibility patterns, and temporal effects.

An Optimal Viewing Position Effect in the Stroop Task When Only One Letter Is the Color Carrier

Coloring only a single letter in the Stroop task can result in a reduction or elimination of Stroop interference. The present experiments were designed to test whether this modulation of Stroop interference occurs at all letter positions. Specifically, we investigated whether Stroop interference was reduced when the colored letter occupied the optimal viewing position (OVP). The experiments show that Stroop interference is not reduced at the OVP (Experiment 1) and that Stroop interference at the OVP is significantly greater than at other letter positions (Experiments 1 and 2). This finding has important theoretical and methodological consequences for studies of automatic processing in visual word recognition.

The orthographic uniqueness point and eye movements during reading

Recent research found that naming and lexical decision times for words with an early orthographic uniqueness point (OUP) were faster than for words with a late OUP (Kwantes & Mewhort, 1999a; Lindell, Nicholls, & Castles, 2003). A word's OUP corresponds to the letter position in the word where that word is differentiated from other words. These results have been presented as evidence for sequential letter processing in visual word recognition (Kwantes & Mewhort, 1999a). In two experiments, we attempted to extend these results to a more natural reading situation by recording participants' eye movements. Readers read sentences with early or late OUP words embedded in them. In both experiments, we manipulated the amount of parafoveal information available during reading. Readers did not show any consistent benefit for reading words with an early OUP regardless of the amount of preview available. Our results are at odds with the naming and lexical decision data and prove problematic for models that predict OUP effects.

The time course of visual word recognition as revealed by linear regression analysis of ERP data

EEG correlates of a range of psycholinguistic word properties were used to investigate the time course of access to psycholinguistic information during visual word recognition. Neurophysiological responses recorded in a visual lexical decision task were submitted to linear regression analysis. First, 10 psycholinguistic features of each of 300 stimulus words were submitted to a principal component analysis, which yielded four orthogonal variables likely to reflect separable processes in visual word recognition: Word length, Letter n-gram frequency, Lexical frequency and Semantic coherence of a word's morphological family. Since the lexical decision task required subjects to distinguish between words and pseudowords, the binary variable Lexicality was also investigated using a factorial design. Word–pseudoword differences in the event-related potential first appeared at 160 ms after word onset. However, regression analysis of EEG data documented a much earlier effect of both Word length and Letter n-gram frequency around 90 ms. Lexical frequency showed its earliest effect slightly later, at 110 ms, and Semantic coherence significantly correlated with neurophysiological measures around 160 ms, simultaneously with the lexicality effect. Source estimates indicated parieto-temporo-occipital generators for the factors Length, Letter n-gram frequency and Word frequency, but widespread activation with foci in left anterior temporal lobe and inferior frontal cortex related to Semantic coherence. At later stages (>200 ms), all variables exhibited simultaneous EEG correlates. These results indicate that information about surface form and meaning of a lexical item is first accessed at different times in different brain systems and then processed simultaneously, thus supporting cascaded interactive processing models.

Attentional shifting and the role of the dorsal pathway in visual word recognition

A substantial amount of evidence has been collected to propose an exclusive role for the dorsal visual pathway in the control of guided visual search mechanisms, specifically in the preattentive direction of spatial selection [Vidyasagar, T. R. (1999). A neuronal model of attentional spotlight: Parietal guiding the temporal. Brain Research and Reviews, 30, 66–76; Vidyasagar, T. R. (2001). From attentional gating in macaque primary visual cortex to dyslexia in humans. Progress in Brain Research, 134, 297–312]. Moreover, it has been suggested recently that the dorsal visual pathway is specifically involved in the spatial selection and sequencing required for orthographic processing in visual word recognition. In this experiment we manipulate the demands for spatial processing in a word recognition, lexical decision task by presenting target words in a normal spatial configuration, or where the constituent letters of each word are spatially shifted relative to each other. Accurate word recognition in the Shifted-words condition should demand higher spatial encoding requirements, thereby making greater demands on the dorsal visual stream. Magnetoencephalographic (MEG) neuroimaging revealed a high frequency (35–40 Hz) right posterior parietal activation consistent with dorsal stream involvement occurring between 100 and 300 ms post-stimulus onset, and then again at 200–400 ms. Moreover, this signal was stronger in the shifted word condition, compared to the normal word condition. This result provides neurophysiological evidence that the dorsal visual stream may play an important role in visual word recognition and reading. These results further provide a plausible link between early stage theories of reading, and the magnocellular-deficit theory of dyslexia, which characterises many types of reading difficulty.

Interpretation of Orthographic Uniqueness Point Effects in Visual Word Recognition.

The orthographic uniqueness point (OUP) of a word is the position of the first letter from the left that distinguishes a word from all other words. In 2 recent studies (P. J. Kwantes & D. J. K. Mewhort, 1999a; A. K. Lindell, M. E. R. Nicholls, & A. E. Castles, 2003), it has been observed that words with an early OUP were processed more quickly than words with a late OUP. This has been taken to suggest that observers process the letters of words sequentially in a left-to-right order. In this article, it is shown that the OUP results do not provide selective evidence for left-to-right sequential processing in visual word recognition because the data are also compatible with an account in which letter processing occurs in random order.

FMRI of two measures of phonological processing in visual word recognition: Ecological validity matters

Previous functional magnetic resonance imaging (fMRI) studies have investigated the role of phonological processing by utilizing nonword rhyming decision tasks (e.g., Pugh et al., 1996). Although such tasks clearly engage phonological components of visual word recognition, it is clear that decision tasks are more cognitively involved than the simple overt naming tasks, which more closely map onto normal reading behavior. Our research aim for this study was to examine the advantages of overt naming tasks for fMRI studies of word recognition processes. Process models are presented to highlight the similarities and differences between two cognitive tasks that are used in the word recognition literature, pseudohomophone naming (e.g., pronounce BRANE) and rhyming decision (e.g., do LEAT and JEAT rhyme?). An fMRI study identified several differences in cortical activation associated with the differences observed in the process models. Specifically, the results show that the overt naming task involved the insular cortex and inferior frontal gyrus, whereas the rhyming decision task engaged the temporal–parietal regions. It is argued that future fMRI research examining the neuroanatomical components of basic visual word recognition utilize overt naming tasks.

Interactive Activation in Visual Word Recognition: Constraints Imposed by the Joint Effects of Spatial Attention and Semantics.

Two lexical-decision experiments investigated the effects of semantic priming and stimulus intensity when target location varied and was cued by an abrupt onset. In Experiment 1, the spatial cue was a good predictor of target location, and in Experiment 2 it was not. The results indicate that word recognition processes were postponed until spatial attention was focused on the target and that whether attention further affected word recognition depended on cue validity. The joint effects of cue validity and priming interacted when cue validity was high but were additive when cue validity was low. The joint effects of stimulus intensity and semantic priming also varied according to cue validity (i.e., interactive when high and additive when low). The results are discussed in terms of their implications for visual word recognition, the distinction between exogenous and endogenous spatial attention, and how attention is affected by visual word recognition processes.

When parallel processing in visual word recognition is not enough: new evidence from naming.

Low-frequency irregular words are named more slowly and are more error prone than low-frequency regular words (the regularity effect). Rastle and Coltheart (1999) reported that this irregularity cost is modulated by the serial position of the irregular grapheme-phoneme correspondence, such that words with early irregularities exhibit a larger cost than words with late ones. They argued that these data implicate rule-based serial processing, and they also reported a successful simulation with a model that has a rule-based serial component--the DRC model of reading aloud (Coltheart, Rastle, Perry, Langdon, & Ziegler, 2001). However, Zorzi (2000) also simulated these data with a model that operates solely in parallel. Furthermore, Kwantes and Mewhort (1999) simulated these data with a serial processing model that has no rules for converting orthography to phonology. The human data reported by Rastle and Coltheart therefore neither require a serial processing account, nor successfully discriminate among a number of computational models of reading aloud. New data are presented wherein an interaction between the effects of regularity and serial position of irregularity is again reported for human readers. The DRC model simulated this interaction; no other implemented computational model does so. The present results are thus consistent with rule-based serial processing in reading aloud.

Recognition by top-down and bottom-up processing in cortex: the control of selective attention.

Visual recognition is achieved by a hierarchy of bidirectionally connected cortical areas. The entry of signals into higher areas involves the serial sampling of information within a movable window of attention. Here we explore how the cortex can move this window and integrate the sampled information. To make this concrete, we modeled the process of visual word recognition by hierarchical cortical areas representing features, letters, and words. At the start of the recognition process, nodes representing all contextually possible words are active. Simple connectivity rules allow a parallel top-down (T-D) computation of the relative probability of each feature at each location given the set of active words. This information is then used to guide the window of attention to information-rich features (e.g., a feature that is present in the visual image but has lowest probability). Bottom-up processing of this feature excludes words that do not contain it and leads to T-D recomputation of feature probabilities. Recognition occurs after several such cycles when all but one word has been excluded. We show that when 950 words are stored in long-term memory, recognition occurs after an average of 4.9 cycles. Because covert attention can be moved every 20-30 ms, word recognition could be as fast as determined experimentally (<200 ms of cortical processing). This model accounts for the findings that recognition time depends logarithmically on set size, recognition time is reduced when context reduces the number of possible targets, the time to classify a nonword decreases when its approximation to English decreases, and in high level cortex, the firing of neurons tuned to an object increases progressively as its recognition occurs. More generally the model provides a physiologically plausible view of how bi-directional signal flow in cortex guides attention to produce efficient recognition.

The impact of reader skill on phonological processing in visual word recognition.

There has been much debate about the role of phonology in reading. This debate has been fuelled, in part, by mixed findings for phonological effects in lexical decision tasks. In the present research we investigated the impact of reader skill on three phonological effects (homophone, homograph, and regularity effects) in a lexical decision task and in a phonological lexical decision task. In both tasks, the more skilled readers showed different patterns of phonological effects from those of the less skilled readers; in particular, less skilled readers showed regularity effects in both tasks whereas more skilled readers did not. We concluded that more skilled readers activate phonology in these tasks but do so more efficiently, with less spurious phonological activation.

Semantic processing in visual word recognition: activation blocking and domain specificity.

Lexical decision to a target is typically facilitated when a related prime is simply read, but is typically eliminated if subjects carry out a letter search on the prime when probe and prime appear simultaneously. Three experiments involving the addition of a task-irrelevant word to this prime search paradigm address (1) Stolz and Besner's (1996, 1998) account in which semantic priming is eliminated because letter search on the prime instantiates an activation block between lexical and semantic levels of representation, (2) Chiappe, Smith, and Besner's (1996) account that activation blocking is domain specific, and (3) Neely and Kahan's (2001) claim that semantic activation is context independent and capacity free. The results are (1) consistent with the account that activation blocking is general to a level, rather than item specific, (2) consistent with the account that activation blocking is domain specific, and (3) inconsistent with the claim that semantic activation is context independent and capacity free.

Visual word recognition: reattending to the role of spatial attention.

Three experiments examine whether spatial attention and visual word recognition processes operate independently or interactively in a spatially cued lexical-decision task. Participants responded to target strings that had been preceded first by a prime word at fixation and then by an abrupt onset cue either above or below fixation. Targets appeared either in the cued (i.e., valid) or uncued (i.e., invalid) location. The proportion of validly cued trials and the proportion of semantically related prime-target pairs were manipulated independently. It is concluded that spatial attention and visual word recognition processes are best seen as interactive. Spatial attention affects word recognition in 2 distinct ways: (a) it affects the uptake of orthographic information, possibly acting as "glue" to hold letters in their proper places in words, and (b) it (partly) determines whether or not activation from the semantic level feeds down to the lexical level during word recognition.

Bihemispheric representation, foveal splitting, and visual word recognition

Pulverm&amp;uuml;ller's account of lexical representation has implications for visual word recognition, given the claim we make that a foveally presented word is precisely split and contralaterally projected to the two hemispheres, and that this splitting conditions the whole process of visual word recognition. This elaboration of Pulverm&amp;uuml;ller's account raises issues of hemispheric differences and collaboration.

Evidence for sequential processing in visual word recognition.

Evidence for sequential processing in visual word recognition.