Reading direction shifts visuospatial attention: An Interactive Account of attentional biases

A growing amount of evidence confirms the influence of reading and writing habits on visuospatial processing, although this phenomenon has been so far testified mainly as a lateralized shift of a single behavioral sign (e.g., line bisection), with lack of proof from pure right-to-left readers. The present study contributed to this issue by analyzing multiple attentional and motor indexes in monolingual Italian (i.e., reading from left-to-right), and monolingual (i.e., reading from right-to-left) and bilingual Israeli (i.e., reading from right-to-left in Hebrew but also from left-to-right in English) participants' visuospatial performance. Subjects were administered a computerized standard star cancellation task and a modified version in which English letters and words were replaced by Hebrew ones. Tasks were presented on a graphics tablet, allowing recording of both chronometric and spatial parameters (i.e., measured in (x, y) vector coordinates). Results showed that reading direction modulated the on-line visuomotor performance (i.e., left-to-right vs. right-to-left shifts) from the beginning (i.e., first mark) to the end of the task (i.e., spatial distribution of omissions and subjective epicenter). Additionally, the spatial bias observed in a computerized line bisection task was also related to the participants' habitual reading direction. Overall, the results favor the proposal of an Interactive Account of visuospatial asymmetries, according to which both cultural factors, such as the directional scanning associated with language processing, and biological factors, such as hemispheric specialization, modulate visuospatial processing. Results are discussed in light of recent behavioral and neuroanatomical findings.     

Reading/writing vs handedness influences on line length estimation

Left- and right-handed school children with differing reading/writing experiences (unidirectional left-to-right vs bidirectional) were asked to draw 3-cm lines from right-to-left or from left-to-right with each hand. With either hand, lines drawn from left to right were more accurate than those drawn from right to left, particularly for right-handed left-to-right users; bidirectional readers showed no directional bias. Moreover, bidirectional readers were more accurate than unidirectional readers. The findings support a greater influence of directional scanning effects than handedness on the task of line length estimation.     

Directional scanning effect and strength of reading habit in picture naming and recall

The present research examined directional scanning effects (DSE) as a function of reading habit strength among right handers. A picture array naming and recall task was administered to three groups of child readers--unidirectional right-to-left readers of Arabic, unidirectional left-to-right readers of Kannada, and bidirectional readers of Urdu and English--and one group of Urdu illiterate adults. The results showed a right-to-left DSE in the Arabic and Urdu readers. In the latter group the strength of the scanning effect decreased with greater schooling in English. No R-L effect was observed in the Kannada readers or in the Urdu illiterates. These results extend prior research in documenting an "invasion" of culturally acquired reading scan habits onto a nonlinguistic domain. It is suggested that directional scanning effects be controlled or else directly examined in future laterality research involving nonlinguistic stimuli.     

On the Eye Movement Control of Changing Reading Direction for a Single Word: The Case of Reading Numerals in Urdu

Typically orthographies are consistent in terms of reading direction, i.e. from left-to-right or right-to-left. However, some are bidirectional, i.e., certain parts of the text, (such as numerals in Urdu), are read against the default reading direction. Such sudden changes in reading direction may challenge the reader in many ways, at the level of planning of saccadic eye movements, changing the direction of attention, word recognition processes and cognitive reading strategies. The present study attempts to understand how readers achieve such sudden changes in reading direction at the level of eye movements and conscious cognitive reading strategies. Urdu readers reported employing a two-stage strategy for reading numerals by first counting the number of digits during right-to-left fixations, and only then forming numeric representation during left-to-right fixations. Eye movement findings were aligned with this strategy usage, as long numerals were often read with deliberate forward-and-backward fixation sequences. In these sequences fixations preceding saccades to default reading direction were shorter than against it, suggesting that different cognitive processes such as counting and formation of numeric representation were involved in fixations preceding left- and right-directed saccades. Finally, the change against the default reading direction was preceded by highly inflated fixation duration, pinpointing the oculomotor, attentional and cognitive demands in executing sudden changes in reading direction.     

Developmental emergence of holistic processing in word recognition

Holistic processing (HP) of faces refers to the obligatory, simultaneous processing of the parts and their relations, and it emerges over the course of development. HP is manifest in a decrement in the perception of inverted versus upright faces and a reduction in face processing ability when the relations between parts are perturbed. Here, adopting the HP framework for faces, we examined the developmental emergence of HP in another domain for which human adults have expertise, namely, visual word processing. Children, adolescents, and adults performed a lexical decision task and we used two established signatures of HP for faces: the advantage in perception of upright over inverted words and nonwords and the reduced sensitivity to increasing parts (word length). Relative to the other groups, children showed less of an advantage for upright versus inverted trials and lexical decision was more affected by increasing word length. Performance on these HP indices was strongly associated with age and with reading proficiency. Also, the emergence of HP for word perception was not simply a result of improved visual perception over the course of development as no group differences were observed on an object decision task. These results reveal the developmental emergence of HP for orthographic input, and reflect a further instance of experience-dependent tuning of visual perception. These results also add to existing findings on the commonalities of mechanisms of word and face recognition.

Research Highlights

• Children showed less of an advantage for upright versus inverted trials compared to adolescents and adults.
• Relative to the other groups, lexical decision in children was more affected by increasing word length.
• Performance on holistic processing (HP) indices was strongly associated with age and with reading proficiency.
• HP emergence for word perception was not due to improved visual perception over development as there were no group differences on an object decision task.

     

Cultural modulations of space–time compatibility effects

The representation of elapsing time may require spatial attention. In certain circumstances, this spatial representation develops from left to right. This is suggested by a performance advantage in responding short with the left hand and long with the right hand (spatial–temporal association between response codes [STEARC]). The present study tests whether one possible determinant of the directionality of the STEARC effect is cultural. In particular, we investigated whether reading/writing habits can affect STEARC direction by administering a visual time judgment task to Italian participants, who were exposed to a left-to-right reading/writing system, and Israeli participants, who mainly used a right-to-left system. The Italian participants showed a left-to-right STEARC effect, while this effect was not present in the Israeli group. The study demonstrates that cultural habits can influence the way in which spatial attention supports the representation of time, similar to the pattern found in other nonspatial domains such as numbers.     

Disorders of oculomotor scanning and graphic orientation in developmental Gerstmann syndrome

A patient with developmental Gerstmann syndrome who experiences great difficulty in performing tasks requiring visuoconstructive and reading abilities is described. Neuropsychological assessment revealed normal range verbal abilities but severe deficits in directional orientation, finger differentiation, calculational ability, copying, and reading ability. Achievement in reading was measured at the sixth-grade level despite the fact that this patient is a third-year college student. Using infrared photoelectric sensors, we monitored the horizontal saccades of this patient while reading from a standardized reading test. Fixation durations were not abnormal. However, instances of reverse-staircase movement were exhibited. While reading from an inverted test, she showed a normal eye-movement pattern (although in the reverse direction since the task now called for right-to-left saccades). The processing of spatial information in this patient is severely disturbed and this may account for the apparently abnormal oculomotor scanning, an “irrepressible tendency” to move her eyes in a right-to-left direction.     

面孔方位对返回抑制的影响

采用辨别任务探讨了正立与倒立的中性面孔线索对返回抑制的影响。实验一采用同时线索化范式考察了正立与倒立面孔线索对靶刺激反应的影响,结果发现,两种面孔线索对随后靶刺激的反应没有影响。实验二采用单线索范式考察正立与倒立面孔对返回抑制的影响,结果发现,两种线索条件下均产生了返回抑制,而且返回抑制量没有显著差异。实验三,正立与倒立面孔作为靶刺激呈现,得到与实验二相同的结果。这些结果表明当采用中性面孔为线索时,返回抑制的产生并不受线索与靶刺激显著性的影响,而且返回抑制这种盲目机制不受任务难度的影响。     

Effect of direction of sequential presentation and redundancy on short-term recognition memory

Short-term recognition memory was tested by presenting six letters, one after the other, followed by a target letter and having S indicate whether or not the target matched one of the six letters. Recognition memory for a letter was better when it was embedded in a six-letter word, rather than a nonword, and when it was included in a sequence presented left-to-right, rather than right-to-left (Experiment 1). Reducing the presentation rate from 4/sec to 2.5/sec largely eliminated the left-to-right effect (Experiment 2). The effect of direction of presentation was greater for redundant (Experiment 1) than for nonredundant sequences (Experiment 3) and was greater for Ss who more frequently formed a word out of the sequence (Experiments 1 and 2), but was no greater for words than nonwords (Experiments 1 and 2) and no greater for letter than for line-figure sequences (Experiment 3). These findings suggest that the left-to-right effect depends as much, or more, on “peripheral” processes (e.g., eye movements) as on “central” processes (e.g., reading).     

Evidence for a Spatial–Numerical Association in Kindergartners Using a Number Line Task

In Western cultures, small numbers are often associated with the left and large with the right space. We investigated whether this association is already present in kindergartners and second graders. Children (N = 59) estimated the position of numbers on a number line that was labeled either with a small number on the left side and a large number on the right side (i.e., left-to-right orientation) or vice versa (i.e., right-to-left orientation). The estimations were less accurate if the number line was oriented from right to left and if the children started with this condition. The results suggest that already kindergartners possess a culture-typical spatial–numerical association that develops before the acquisition of reading and writing skills and significantly affects the accuracy of numerical estimations. The performance of second graders, too, was affected by the orientation of the number line, but to a smaller degree than that of kindergartners.     

Regional brain activity in dyslexic and control children during reading tasks: Visual probe event-related potentials

Event-related potentials (ERPs) elicited by task-irrelevant visual stimuli were recorded from 34 control and 32 dyslexic 10- to 12-year-old boys while they performed silent and oral reading at two levels of difficulty. All subjects were extensively screened for neurological problems, IQ, and sensory acuity. Specific features of the ERPs were affected in amplitude and latency by the experimental variables: group membership, oral vs. silent reading, difficulty level, and recording site (within and between hemispheres). A specific effect of difficulty on the central and parietal ERP was seen in the dyslexics but not the controls. Different patterns of asymmetry were found for the two groups in silent vs. oral reading at midtemporal placements. A marked asymmetry (R > L) was found at the midtemporal region for both groups.     

Shape recognition contributions to figure-ground reversal: which route counts?

Observers viewed upright and inverted versions of figure-ground stimuli, in which Gestalt variables specified that the center was figure. In upright versions, the surround was high in denotivity, in that most viewers agreed it depicted the same shape; in inverted versions, the surround was low in denotivity. The surround was maintained as figure longer and was more likely to be obtained as figure when the stimuli were upright rather than inverted. In four experiments, these effects reflected inputs to figure-ground computations from orientation-specific shape representations only. To account for these findings, a nonratiomorphic mechanism is proposed that enables shape recognition processes before figure-ground relationships are determined.     

The influence of divided attention on holistic face perception.

There is evidence that upright, but not inverted, faces are encoded holistically. The holistic coding of faces was examined in four experiments by manipulating the attention allocated to target faces. In Experiment 1, participants in a divided attention condition were asked to match two upright flanker faces while encoding a centrally presented upright target face. Although holistic coding was evident in the full attention conditions, dividing attention disrupted holistic coding of target faces. In Experiment 2, we found that while matching upright flanker faces disrupted holistic coding, matching inverted flanker faces did not. Experiment 3 demonstrated that the differential effects of flanker orientation were not due to participants taking longer to match upright, than inverted, flanker faces. In Experiment 4, we found that matching fractured faces had an intermediate effect to that of matching upright and inverted flankers, on the holistic coding of the target faces. The findings emphasize the differences in processing of upright, fractured and inverted faces and suggest that there are limitations in the number of faces that can be holistically coded in a brief time.     

Effects of normal and abnormal visual experience on the development of opposing aftereffects for upright and inverted faces

We used opposing figural aftereffects to investigate whether there are at least partially separable representations of upright and inverted faces in patients who missed early visual experience because of bilateral congenital cataracts (mean age at test 19.5 years). Visually normal adults and 10-year-olds were tested for comparison. Adults showed the expected opposing aftereffects for upright and inverted faces. Ten-year-olds showed an adultlike aftereffect for upright faces but, unlike the adult group, no aftereffect for inverted faces. Patients failed to show an aftereffect for either upright or inverted faces. Overall, the results suggest that early visual input is necessary for the later development of (at least partially) separable representations of upright and inverted faces, a developmental process that takes many years to reach an adult-like refinement.     

Physical and perceptual accuracy of upright and inverted face drawings

This study considers the conception that drawing or copying a face that is vertically inverted will improve the accuracy of the drawing by preventing holistic interference. We used a novel parameterized face space both for generating face stimuli and for measuring the physical accuracy of drawings. One group of participants (the artists) were asked to draw 16 parameterized faces (eight upright and eight inverted). We computed two physical measures of accuracy by comparing the face-space representation of each drawing to the original face. A second and third group of participants (the raters) compared the similarity between each original face and each pair of drawings of that face (one upright and one inverted per artist). For the second group, all faces were presented upright; for the third group, all faces were presented inverted. Our results showed that upright drawings were more accurate than inverted drawings, both in terms of the physical face-space measure and in terms of the perceptual judgments for both orientations. Our data suggest that holistic processing may aid rather than hinder face drawing accuracy.     

SNARC for numerosities is modulated by comparative instruction (and resembles some non-numerical effects)

The spatial–numerical association of response codes (SNARC) effect is observed for both numerical (Arabic digits) and non-numerical stimuli (size, duration, height). However, in a context of comparative judgment, Arabic numbers are mapped onto space differently from sizes and heights: SNARC for Arabic digits is formed consistently in a certain cultural reading direction, whereas SNARC for sizes and heights is additionally modulated by comparative instruction (it reverses when participants choose larger magnitudes). In the present study, we test whether the spatial characteristic of magnitude processing revealed in a context of comparison is determined by a presence or lack of numerical content of the processed information, or it depends on specific directional experience (e.g., left-to-right ordering) associated with the processed magnitude format. We examine the SNARC effect with the pairwise comparison design, by using non-symbolic numerical stimuli (objects’ collections), for which the left-to-right spatial structure is not as exceedingly overlearned as for Arabic numbers. We asked participants from two reading cultures (left-to-right vs. mixed reading culture) to compare numerosities of two sets, choosing either a larger or smaller one. SNARC emerged in both groups. Additionally, it was modulated by comparative instruction: It appeared in a left-to-right direction when participants selected a smaller set, but it tended to reverse when participants selected a larger set. We conclude that spatial processing of numerosities is dissociated from spatial processing of Arabic numbers, at least in a context of comparative judgment. This dissociation could reflect differences in spatial ordering experience specific to a certain numerical input.     

Memory and metamemory for inverted words: illusions of competency and desirable difficulties

Research regarding how people monitor their learning has shown that ease of processing strongly guides people’s judgments of learning (JOLs). However, the desirable difficulties concept (Bjork, 1994) suggests that studying information that is less fluent can result in greater learning. Currently, it is unclear whether people are aware of the potential benefits of desirable difficulties during learning. To address this, in Experiment 1, participants studied inverted and upright words and also made JOLs. While participants’ JOLs did not differ for inverted and upright words, recall was greater for inverted words. Experiment 2 used several study–test cycles in which participants could potentially learn about the beneficial effects of processing inverted words with task experience, and similar results were obtained. Thus, reading inverted words requires processing that enhances recall, but memory predictions do not differentiate between upright and inverted words. We interpret these results in terms of processing fluency, desirable difficulties, and theories of metacognitive monitoring.