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Non-symbolic numerical stimuli play a crucial role in numerical cognition. Physical properties such as surface area, density, and item circumference are inherently correlated with quantity. The correlations between physical properties and quantity mask the mechanism underlying numerical perception. Non-symbolic stimuli are generated using different generation methods (GMs) aimed at controlling physical properties. The way a GM controls physical properties affects numerical judgments. Here, using a novel data-driven approach, we provide a methodological review of non-symbolic stimuli GMs developed since 2000. Annotators tagged the GMs’ control over physical properties. Next, GMs were qualitatively analyzed for different property controls, terminology, and definitions. The tagging and qualitative analysis provided data suitable for quantitative analysis of GMs. We found that the field thrives with a wide variety of GMs aimed at tackling new methodological and theoretical ideas. However, the field lacks a common language and a method to incorporate new ideas in the existing literature. Furthermore, these shortcomings impair the comparison, replication, and reanalysis of previous studies in light of new ideas. We present guidelines for GMs that will hopefully contribute to the field. First, researchers should define controlled properties explicitly and consistently. Second, researchers should provide the code package used to generate stimuli. Third, researchers should also provide the actual stimuli, coupled with the behavioral and neuronal responses. This last guideline would enable researchers to reanalyze previously obtained data, enabling incorporating new ideas in the context of prior research.

The colour-word Stroop task produces both information conflict (detection of the ink colour vs word meaning) and task conflict (respond to the ink colour vs read the word). In this study, we measured both reaction time and pupil dilation, and the neutral stimuli in our study were non-readable letter strings as well as meaningless non-readable stimuli (i.e., coloured patches and abstract character strings). Our results showed slowest responses in the incongruent trials and fastest responses in the congruent trials. However, no differences were found between the investigated neutrals. In contrast, pupil dilation was largest in the incongruent trials and smallest in the neutral trials. Moreover, the more the neutral stimuli were meaningless, the less the pupil dilation that was observed. Our results suggest that non-word meaningless stimuli reduced task conflict (compared with all the investigated conditions). Neutral equivalence should be taken into consideration in Stroop and Stroop-like tasks.

Studies of the Stroop color-word task have provided evidence for the existence of two conflicts: (1) an early task conflict between noting the relevant color and reading afforded by the irrelevant word (or word-like stimuli), and (2) a late information conflict between the information provided by the word and the information provided by the color. Measurements of pupil changes, in addition to reaction time (RT), have extended understanding regarding these two conflicts. The current work examines the generalizability of such understanding. We ask whether similar processes work in the comparative judgment of numbers (e.g., in the numerical Stroop task). We present two experiments that support and extend the knowledge gained in the word-color context to numerical processing. Similar to results with the Stroop color-word task, we found a dissociation between RT and pupillometry and an early task conflict followed by an information conflict.

Research advancements in the field of educational neuroscience (EN) have been remarkably compelling with proponents extolling its potential impact on educational practices. Through the development ...

Pupil dilation is an effective indicator of cognitive and affective processes. Although several eyetracker systems on the market can provide effective solutions for pupil dilation measurement, there is a lack of tools for processing and analyzing the data provided by these systems. For this reason, we developed CHAP: open-source software written in MATLAB. This software provides a user-friendly graphical user interface for processing and analyzing pupillometry data. Our software creates uniform conventions for the preprocessing and analysis of pupillometry data and provides a quick and easy-to-use tool for researchers interested in pupillometry. To download CHAP or join our mailing list, please visit CHAP's website: http://in.bgu.ac.il/en/Labs/CNL/chap .

Previously we found perspective taking (PT) influenced affect ratings of negative pictures more than neutral pictures. The current follow-up experiments extend that research to explore effects of perspective taking with positive valence pictures. We used stimuli consisting of neutral, happy and sad pictures. Stimuli were presented either mixed within blocks (Experiment 1) or separated by emotion (neutrals + happy/sad) into two separate blocks (Experiment 2). Participants rated (from 1‐ to 7 based on emotional strength) stimuli from different perspectives (sensitive/tough/their own, i.e., “me”). Emotional strength rating was a dependent variable. A significant interaction between valence and PT was found in both experiments. The difference between adopting sensitive and tough perspectives toward sadness was larger than toward the neutral condition, replicating our results from the previous study. The same difference (sensitive-tough) was larger toward the happiness condition than toward the neutral one (this was a trend in Experiment 1 and was significant in Experiment 2) and toward the sadness condition than toward the happy one. These results suggest that PT effects on emotional ratings are modulated by valence of stimuli.

Deficient inhibitory control and difficulty resolving uncertainty are central in psychopathology. How these factors interact remains unclear. Initial evidence suggests that inducing inhibitory control improves resolution of uncertainty. This may occur only when participants overcome action tendencies, which are dominant tendencies to perform certain behaviors. Our study explored the links between inhibitory control and behavioral responses to uncertainty while manipulating action-tendencies’ strength. In three experiments, 132 undergraduates completed a task that combined induction of momentary changes in inhibitory control level (Stroop task), with responses to uncertainty (visual-search task). We manipulated action-tendencies’ strength by varying uncertainty proportions across experiments. Results indicated that momentary induction of inhibitory control improved resolution of high-uncertainty during mostly low-uncertainty trials but hampered resolution of low-uncertainty during mostly high-uncertainty trials. Identical inhibitory control induction did not affect resolution of uncertainty when uncertainty conditions were equalized. Participants’ subjective uncertainty measures were similar across experiments. Our results suggest that momentary inhibitory control induction modifies behavioral responses to uncertainty and selectively affects trials that require overcoming dominant action tendencies. These findings indicate a potentially unique and multifaceted relationship between inhibitory control and behavioral responses to uncertainty. Clinical implications for models of Obsessive-Compulsive Disorder and experimental implications to post-conflict processes are discussed.

Various studies have shown that numerical processing is modulated by non-numerical physical properties. One such physical property is the convex hull – the smallest convex polygon surrounding all items in an array. The convex hull is usually discussed only in terms of its area. However, our group has shown that observers use the convex hull shape, as defined according to the number of vertices of the convex hull, to make numerical estimations (Katzin, Katzin, Rosen, Henik, & Salti, 2020). Yet, it is still unknown if and how the convex hull shape affects comparison tasks, and how it interacts with its counterpart, convex hull area. Here we re-examine the data collected by Katzin, Salti, and Henik (2019). Using image processing, we extracted the information on the convex hull shape and showed that the shape affects latency and accuracy of numerical comparisons. We found that both the convex hull shape and other physical properties (i.e., convex hull area, average diameter, density, total circumference, and total surface area) have distinct effects on performance. Finally, the convex hull shape effect was found in counting and estimation ranges, however its effect decreased with numerosities above the counting range. Our results indicate that the interplay between convex hull shape and other physical properties, including convex hull area and numerosity, plays an important role in numerical decisions. We suggest that the convex hull shape should be controlled for when designing non-symbolic numerical tasks.

In the numerical Stroop task, participants are asked to compare the physical sizes (physical task) or numerical values (numerical task) of two digits and ignore the irrelevant dimension. Participants are unable to ignore the irrelevant dimension as indicated by facilitation and interference effects. The literature suggests that there is asymmetry in the ability to adjust control in the physical and numerical tasks. The present study examined this suggestion in two experiments in which we manipulated the proportion of neutral/congruent trials in an experimental block. In addition, we examined the effects of control adjustment on the resolution of the task and informational conflicts. Our results suggest that adjustment of control can be bidirectional and is dependent on task requirements. Moreover, it might be easier to inhibit irrelevant information than to inhibit irrelevant task activation.

Emotional picture databases are commonly used in emotion research. The databases were first based on ratings of emotional dimensions, and the interest in studying discrete emotions led to the categorization of subsets from these databases to emotional categories. However, to-date, studies that categorized affective pictures used confidence intervals in their analysis, a method that provides important data but also results in a high percentage of blended or undifferentiated categorization of images. The current study used 526 affective pictures from four databases and categorized the pictures to discrete emotions in two steps (Pre-testing phase & Experiment 1). First, clinical psychologists were asked to generate emotional labels for each picture, according to the emotion the picture evoked in them. This resulted in the creation of 10 emotional categories. These labels were presented to students who were asked to choose the emotional category that matched the emotion a presented picture evoked in them. Agreement levels on the emotional categories were calculated for each picture, and pictures were categorized according to the most dominant emotion they evoked. The analysis of agreement levels rather than confidence intervals enabled us to provide both dominance of emotional category and agreement in the population regarding the dominance. In Experiment 2, we asked participants to provide ratings of emotional intensity and arousal, in order to provide more detailed information regarding the database. This is the first study to provide agreement levels on the categorization of affective pictures, and may be useful in various studies which aim at generating specific emotions.

The Stroop task gives rise to two major conflicts: the task conflict (respond to the color vs. read the word) and the information conflict that can result from the stimulus-response compatibility (SRC; difference between two responses) or from the stimulus-stimulus compatibility (SSC; difference between the two contradictive pieces of information). We conducted a two-to-one Stroop experiment (i.e., two colors are mapped to one response key) and measured reaction time and pupil dilation. The results showed clear evidence for informational conflict composed of both the SRC and SSC. In addition, pupil indications for task conflict appeared earlier than indications for both the SSC and the SRC, in line with the theory regarding task conflict.

The menstrual cycle is characterized partially by fluctuations of the ovarian hormones estradiol (E2) and progesterone (P4), which are implicated in the regulation of cognition. Research on attention in the different stages of the menstrual cycle is eclectic with discrepancies in attention definitions, and the three attentional networks (alerting, orienting and executive) and their interaction were not explored during the menstrual cycle. In the current study, we used the ANT-I (attentional network test - interactions) to examine naturally cycling women (NC) and women using oral contraceptives (OC). We tested their performance at two time points that fit, in natural cycles, the follicular phase and the luteal phase. We found no differences in performance between the two time points (day 4 / day 18) for the OC group: the response pattern replicated known ANT-I findings. However, the NC group showed differences between the two time points. In the follicular phase, responses replicated known ANT-I results, but in the luteal phase, alertness did not interact with executive and orienting networks, resulting in a larger congruency effect (executive network) when attention was not oriented to the target in alerting and no alerting conditions. Results-driven exploratory regression analysis of E2 and P4 suggested that change in P4 from the follicular phase/day 4 to the luteal phase/day 18 was a mediator for the alerting effect found between groups. In conclusion, the alerting state, found with or without alertness manipulation, suggests that there is a progesterone-mediated activation of the alerting system during the luteal phase.

Representations of the fingers are embodied in our cognition and influence performance in enumeration tasks. Among deaf signers, the fingers also serve as a tool for communication in sign language. Previous studies in normal hearing (NH) participants showed effects of embodiment (i.e., embodied numerosity) on tactile enumeration using the fingers of one hand. In this research, we examined the influence of extensive visuo-manual use on tactile enumeration among the deaf. We carried out four enumeration task experiments, using 1-5 stimuli, on a profoundly deaf group (n = 16) and a matching NH group (n = 15): (a) tactile enumeration using one hand, (b) tactile enumeration using two hands, (c) visual enumeration of finger signs, and (d) visual enumeration of dots. In the tactile tasks, we found salient embodied effects in the deaf group compared to the NH group. In the visual enumeration of finger signs task, we controlled the meanings of the stimuli presentation type (e.g., finger-counting habit, fingerspelled letters, both or neither). Interestingly, when comparing fingerspelled letters to neutrals (i.e., not letters or numerical finger-counting signs), an inhibition pattern was observed among the deaf. The findings uncover the influence of rich visuo-manual experiences and language on embodied representations. In addition, we propose that these influences can partially account for the lag in mathematical competencies in the deaf compared to NH peers. Lastly, we further discuss how our findings support a contemporary model for mental numerical representations and finger-counting habits.

Mental rotation and visual-spatial perspective taking (VSPT) are two visual-spatial abilities that are highly correlated. Judgment of relative direction (JRD) tasks are commonly used to examine VSPT in conjunction with mental rotation. Moreover, in many studies the task involves switching from an imagined perspective to a sensorimotor perspective at the response phase. The current study employed a JRD task that enabled examination of mental rotation, perspective taking, and perspective switching, separately. In two experiments we found that both perspective taking and perspective switching affected accuracy and response time (RT). Namely, trials with a perspective change larger than 90° (that required perspective taking) were harder than trials with a change smaller than 90° (that required mental rotation), and so were trials that required switching from an imagined perspective to a sensorimotor perspective. Importantly, we suggest that VSPT and mental rotation are dissociable.

Many attempts have been made to classify and evaluate the nature of intelligence in humans and other species (referred to as the 'g' factor in the former and the G factor in the latter). The search for this essential structure of mental life has generated various models and definitions, yet open questions remain. Specifically, referring to intelligence by overemphasizing the anthropocentric terminology and its ethnocentric overlay is insufficient to account for individual differences and limits its generalizability in biological and cultural contexts. The present work is an attempt to adopt a different perspective on the 'g/G' factor and its measurement. We suggest that intelligence, or g/G, is reflected in a biological capacity that evolved from object manipulation in animals, into mental manipulation in humans, in response to various environmental conditions.

The current study explored the role of valence and self-relevance in size estimation of neutral and aversive animals. In Experiment 1, participants who were highly fearful of spiders and participants with low fear of spiders rated the size and unpleasantness of spiders and other neutral animals (birds and butterflies). We found that although individuals with both high and low fear of spiders rated spiders as highly unpleasant, only the highly fearful participants rated spiders as larger than butterflies. Experiment 2 included additional pictures of wasps (not self-relevant, but unpleasant) and beetles. The results of this experiment replicated those of Experiment 1 and showed a similar bias in size estimation for beetles, but not for wasps. Mediation analysis revealed that in the high-fear group both relevance and valence influenced perceived size, whereas in the low-fear group only valence affected perceived size. These findings suggest that the effect of highly relevant stimuli on size perception is both direct and mediated by valence.

Perceptual decisions such as that we have more strawberries than apples left in our fruit basket seem to be made effortlessly. However, it is not examined yet whether such decisions are also biased by the size of the objects, just like numerosity comparisons with meaningless dot-arrays. We presented two homogeneous sets of larger and smaller fruit (e.g. three apples and four strawberries) and participants had to indicate which set was more numerous. Although accuracy was nearly perfect, a strong congruency effect was found in reaction times, showing it is more difficult to compare the numerosities of sets of 2 apples and 3 strawberries than the opposite, i.e., 3 apples and 2 strawberries. Because the stimuli were selected to simulate everyday conditions as much as possible, the present results suggest that most likely also comparative numerosity judgement in daily life are biased by non-numerical cues such as size of the objects. ispartof: Experimental Psychology vol:65 issue:6 pages:353-359 ispartof: location:Germany status: published

Research in cognitive psychology has focused mainly on the visual modality as the input interface for mental processes. We suggest that integrating studies from different modalities can aid in resolving theoretical controversies. We demonstrate this in the case of subitizing. Subitizing, the quick and accurate enumeration of small quantities, has been studied since the 19th century. Nevertheless, to date, the underlying mechanism is still debated. Two mechanisms have been suggested: a domain-general mechanism—attention, and a domain-specific mechanism—pattern recognition. Here, we review pivotal studies in the visual, tactile, and auditory modalities. The accumulative findings shed light on the theoretical debate. Accordingly, we suggest that subitizing is a subprocess of counting that occurs in the presence of facilitating factors, such as attentional resources and familiar patterns.

Using a Stroop task, we investigated the effect of task-irrelevant emotional distractors on attentional proactive control and its interaction with trait anxiety. On the basis of recent findings showing opposed neural responses in the dorsal-executive versus the ventral-emotional systems in response to emotional distractors and of the attentional control theory (Eysenck, Derakshan, Santos, & Calvo, 2007), we hypothesized that negative distractors will result in a reduction of proactive task control in the executive system, especially for high-trait-anxious individuals. Using a computational model of the Stroop task, we derive 2 specific behavioral predictions of reduced proactive task control: increased Stroop interference and reversed Stroop facilitation. Twenty-five high- and 25 low-trait-anxious participants completed a Stroop task in which the target stimuli were preceded by brief (neutral vs. aversive) emotional distractors. While no effects of picture valence on proactive control was found in the low-anxious group, the predicted signatures of reduced proactive control were observed in the high-anxiety group. These results indicate that trait anxiety influences the interaction between irrelevant emotional stimuli and proactive control.

It is well established that, when comparing nonsymbolic magnitudes (e.g., dot arrays), adults can use both numerical (i.e., the number of items) and nonnumerical (density, total surface areas, etc.) magnitudes. It is less clear which of these magnitudes is more salient or processed more automatically. In this fMRI study, we used a nonsymbolic comparison task to ask if different brain areas are responsible for the automatic processing of numerical and nonnumerical magnitudes, when participants were instructed to attend to either the numerical or the nonnumerical magnitudes of the same stimuli. An interaction of task (numerical vs. nonnumerical) and congruity (congruent vs. incongruent) was found in the right TPJ. Specifically, this brain region was more strongly activated during numerical processing when the nonnumerical magnitudes were negatively correlated with numerosity (incongruent trials). In contrast, such an interference effect was not evident during nonnumerical processing when the task-irrelevant numerical magnitude was incongruent. In view of the role of the right TPJ in the control of stimulus-driven attention, we argue that these data demonstrate that the processing of nonnumerical magnitudes is more automatic than that of numerical magnitudes and that, therefore, the influence of numerical and nonnumerical variables on each other is asymmetrical.

Highlights • Space is a central dimension in different types of synesthesia. • We examined the spatial coordinate system that defines color-space synesthesia. • Task required responding to the location of a target relative to a colored object. • Only the synesthete’s responses were sensitive to the relative location of objects. • An automatic object-based coding was observed in color-space synesthesia., Synesthesia is characterized by the association between different stimuli modalities. For example, in sequence-space synesthesia, numbers, weekdays, months, and musical tones are visualized in specific spatial locations. Although sequence-space synesthesia tends to co-occur with other types of synesthesia (e.g., grapheme-color), our knowledge about how these individuals represent space is still limited. A central issue for understanding spatial processing refers to the coordinate system used to represent spatial locations. We report on a space-color synesthete (N.W.) who vividly experiences colors in specific spatial locations. We used a task where N.W. and control subjects were required to report the location of a gray square relative to a colored square. The color of the square was task-irrelevant. Participants responded to the following trial types: (1) central trials, where one stimulus appeared on the left and the other on the right side of fixation, and (2) relative location trials, where both stimuli appeared either on the left or on the right side of fixation. Results showed that the color of the target had a strong impact on N.W.’s responses on both trial types, but not on the controls’ responses. These results show that the spatial representation underlying N.W.’s synesthetic experience is automatic and sensitive to the relative location of objects.

Enumeration of elements differs as a function of their range. Subitizing (quantities 1–4) is considered to be an accurate and quick process with reaction times minimally affected by the number of presented elements within its range. In contrast, small estimation (range of 5–9 elements exposed briefly) is a less precise linear process. Subitizing was consider to be a pre-attentive process for many years. However, recent studies found that when attentional resources were occupied elsewhere, the subitizing process was impaired. In the current study, we examined whether subitizing can be facilitated by improving engagement of attention. Specifically, brief alerting cues that increase attentional engagement were presented in half of the trials during enumeration tasks. In Experiment 1, participants were required to enumerate dots presented in random arrays within the subitizing or small estimation range. Alerting facilitated enumeration of quantities in the subitizing range, but not in the small estimation range. We suggested that the benefit of alerting on the subitizing process was achieved via enhancement of global processing, a process that was previously associated with both alerting and subitizing. In Experiment 2, we provided direct evidence for this hypothesis by demonstrating that when global processing was used for items in the small estimation range (i.e., presenting quantities in a canonical array), a subitizing-like pattern was revealed in quantities beyond the subitizing range., Highlights • We examined the influence of an alerting cue on enumerating 1–9 quantities. • The alerting cue appeared in 50% of trials before random/canonical arrays of dots. • Alerting facilitated enumeration in the subitizing range in both types of arrays. • Alerting facilitated enumerating more than 4 dots only when presented canonically. • We conclude that alerting facilitates subitizing by enhancing global processing.

The ability to regulate emotions is essential for adaptive behavior. This ability is suggested to be mediated by the connectivity between prefrontal brain regions and the amygdala. Yet, it is still unknown whether the ability to regulate emotions can be trained by using a non-emotional procedure, such as the recruitment of executive control (EC). Participants who were trained using a high-frequent executive control (EC) task (80% incongruent trials) showed reduced amygdala reactivity and behavioral interference of aversive pictures. These effects were observed only following multiple-session training and not following one training session. In addition, they were not observed for participants exposed to low-frequent EC training (20% incongruent trials). Resting-state functional connectivity analysis revealed a marginally significant interaction between training group and change in the connectivity between the amygdala and the right inferior frontal gyrus (IFG). Amygdala-IFG connectivity was significantly increased following the training only in the high-frequent EC training group. These findings are the first to show that non-emotional training can induce changes in amygdala reactivity to aversive information and alter amygdala-prefrontal connectivity.

Observers exhibit larger leftward bias when bisecting words compared with lines. According to the Attentional Scaling Hypothesis, attempting to access lexical entries involves focusing attention on the initial letters of words to establish a cohort of potential matches with entries in the mental lexicon. We test this account by examining two predictions: (1) greater leftward bias for words should be evident in English readers in which the word beginning is on the left but not in Hebrew readers. (2) Dyslexics who have lexical impairments should show greater bias. Results reveal that word length modulated bisection bias differently for Hebrew and English readers, although the bias stays always leftward. Furthermore, dyslexics exhibited an exaggerated leftward bias than controls. We propose this effect arises from an interaction between reading and spatial attention rather than from the scaling of attention relative to the beginning of the word in the service of lexical access.

Pupillometry (or the measurement of pupil size) is commonly used as an index of cognitive load and arousal. Pupil size data are recorded using eyetracking devices that provide an output containing pupil size at various points in time. During blinks the eyetracking device loses track of the pupil, resulting in missing values in the output file. The missing-sample time window is preceded and followed by a sharp change in the recorded pupil size, due to the opening and closing of the eyelids. This eyelid signal can create artificial effects if it is not removed from the data. Thus, accurate detection of the onset and the offset of blinks is necessary for pupil size analysis. Although there are several approaches to detecting and removing blinks from the data, most of these approaches do not remove the eyelid signal or can result in a relatively large amount of data loss. The present work suggests a novel blink detection algorithm based on the fluctuations that characterize pupil data. These fluctuations (“noise”) result from measurement error produced by the eyetracker device. Our algorithm finds the onset and offset of the blinks on the basis of this fluctuation pattern and its distinctiveness from the eyelid signal. By comparing our algorithm to three other common blink detection methods and to results from two independent human raters, we demonstrate the effectiveness of our algorithm in detecting blink onset and offset. The algorithm’s code and example files for processing multiple eye blinks are freely available for download ( https://osf.io/jyz43 ).

Participants are slower to report a feature, such as color, when the target appears on the side opposite the instructed response, than when the target appears on the same side. This finding suggests that target location, even when task-irrelevant, interferes with response selection. This effect is magnified in older adults. Lengthening the inter-trial interval, however, suffices to normalize the congruency effect in older adults, by re-establishing young-like sequential effects ( Aisenberg et al., 2014 ). We examined the neurological correlates of age related changes by comparing BOLD signals in young and old participants performing a visual version of the Simon task. Participants reported the color of a peripheral target, by a left or right-hand keypress. Generally, BOLD responses were greater following incongruent than congruent targets. Also, they were delayed and of smaller amplitude in old than young participants. BOLD responses in visual and motor regions were also affected by the congruency of the previous target, suggesting that sequential effects may reflect remapping of stimulus location onto the hand used to make a response. Crucially, young participants showed larger BOLD responses in right anterior cerebellum to incongruent targets, when the previous target was congruent, but smaller BOLD responses to incongruent targets when the previous target was incongruent. Old participants, however, showed larger BOLD responses to congruent than incongruent targets, irrespective of the previous target congruency. We conclude that aging may interfere with the trial by trial updating of the mapping between the task-irrelevant target location and response, which takes place during the inter-trial interval in the cerebellum and underlays sequential effects in a Simon task.

We examined the effect of a task-irrelevant dimension on response times in young adults and seniors. We used the Simon task with congruent trials where the target and manual response were on the same side, incongruent trials where the target and response were on opposite sides, and neutral trials where the target appeared along the vertical meridian. We observed two age-related effects. First, there was a larger congruency effect in senior participants that was driven by greater interference; namely, their responses were slower on incongruent relative to neutral trials. Second, there was a Gratton effect; namely, a diminished Simon effect was found in young adults but not in seniors when the preceding trial was incongruent. However, these effects of aging were normalised when the inter-trial interval was increased; the Simon effect and interference were reduced and a Gratton effect appeared for seniors. We conclude that aging may impair the ability to quickly adapt to changing environmental circumstances when they require reformulating current behavioral strategies.

Previous research has shown that individuals with DD (developmental dyslexia) demonstrated a left mini neglect on visual line (VL) bisection tasks, which has been commonly referred to as right parietal dysfunction. However, insufficient reading experience characterizes dyslexia and may call into question the validity of this interpretation, since the VL bisection task has been found to be influenced by reading habits. The current study investigated whether altered performance of individuals with DD on bisection tasks may be attributed to impaired attentional mechanisms or to insufficient reading exposure. DD and control groups performed visual and mental number line bisection tasks, which have been shown to be modulated differently by reading habits. In both tasks, the magnitude of left bisection errors was significantly larger in the DD group compared with controls. This finding suggests attentional mechanisms act differently in dyslexia and supports evidence linking dyslexia to decreased function of the left hemisphere.