Target Letter Research Articles

Visual Performance With Small Concave and Convex Displays.

In this study, we aim to investigate how users' visual performance with a small flexible display changes based on the direction (i.e., convex, concave) and the magnitude (i.e., low, high) of the display curvature. Despite the wide interest in flexible display materials and deformable displays, the potential effects of nonplanar display surfaces on human perception and performance have received little attention. This study is the first to demonstrate how curving affects visual performance with an actual flexible display (4.5-in. active-matrix organic light-emitting diode). In a series of three experiments, we compared the performance with a planar display to the performance with concave and convex display surfaces with low and high curvature magnitudes. Two visual search tasks were employed that required the subject to detect target letters based on their contrast (Experiments 1 and 2) and identity (Experiment 3). Performance was measured as the sensitivity of target detection (d') and threshold time of the search, respectively. There were similar sensitivities for targets across the curvature variants, but the high-magnitude curvatures resulted in prolonged search times, especially for the convex form. In both of the tasks, performance was dependent on the display location, which was defined as the target's distance from the display center. High curvature magnitudes should be avoided, even in small displays, because large local changes in visual stimuli decrease processing speed outside the central display. The findings have implications for the development of technologies, applications, and user interfaces for flexible displays and the design of visual display devices.

Automaticity revisited: when print doesn't activate semantics.

It is widely accepted that the presentation of a printed word “automatically” triggers processing that ends with full semantic activation. This processing, among other characteristics, is held to occur without intention, and cannot be stopped. The results of the present experiment show that this account is problematic in the context of a variant of the Stroop paradigm. Subjects named the print color of words that were either neutral or semantically related to color. When the letters were all colored, all spatially cued, and the spaces between letters were filled with characters from the top of the keyboard (i.e., 4, #, 5, %, 6, and *), color naming yielded a semantically based Stroop effect and a semantically based negative priming effect. In contrast, the same items yielded neither a semantic Stroop effect nor a negative priming effect when a single target letter was uniquely colored and spatially cued. These findings (a) undermine the widespread view that lexical-semantic activation in word reading is automatic in the sense that it occurs without intention and cannot be derailed, and (b) strengthens the case that both implicit and explicit forms of visual word recognition require spatial attention as a necessary preliminary to lexical-semantic processing.

Functional fixedness: The functional significance of delayed disengagement based on attention set.

During search, the disengagement of attention is automatically delayed when a fixated but task-irrelevant object shares features of the search target. We examined whether delayed disengagement based on top-down attention set is potentially functional, resulting in additional processing of the fixated item. To accomplish this, we adapted the oculomotor disengagement paradigm. Participants saccaded to a peripheral object of a particular color and responded to the identity of the letter within it. To initiate search participants made a saccade away from an always irrelevant object at the center of the screen that matched or mismatched the target's color and contained a letter that was congruent or incongruent with the target letter. We found that delayed disengagement based on attention set was associated with deeper processing of the center item: a congruency effect between the center letter and peripheral target letter was only observed when the center object's color matched participants' attention set. Results are consistent with the proposal that delayed disengagement based on attention set is functionally significant, automatically encouraging deeper levels of processing of target-like objects that fall within the focus of attention.

Under the Influence: Alcohol Impairs Inhibition of Negative Distractors, but only in Men

Event Abstract Back to Event Under the Influence: Alcohol Impairs Inhibition of Negative Distractors, but only in Men Laura Kranz1, Lauren Bell1, David Carmel2, Matt Crawford1, Natalija Andrejic1 and Gina Grimshaw1* 1 Victoria University of Wellington, School of Psychology, New Zealand 2 University of Edinburgh, Psychology Department, United Kingdom The world presents us with diverse stimuli, only some of which are relevant to our current goals. Executive control is the function that enables us to direct attention to relevant information and inhibit irrelevant distractions. Emotional distractors are particularly potent, and may therefore place greater demands on executive control and be harder to inhibit than neutral distractors. To test this hypothesis, we gave participants alcohol, which is known to compromise executive control processes. Participants were randomly assigned to drink either a high or low dose alcoholic mixture. They then performed a simple visual task in which a target letter (X or N) was discriminated within a circle of 'o's. On 80% of trials, a flanking irrelevant picture - a distractor - was also presented above or below the letter display. The high proportion of distractor-present trials allows for proactive executive control, which typically leads to low levels of distraction. Distractors were either high-arousal negative images (mutilations) or neutral scenes depicting people, and were presented in alternating blocks. Distraction was measured as slowing in RT for distractor-present relative to distractor-absent trials. To our surprise, alcohol affected distraction differently in men and women. Consistent with our hypothesis, men showed increased distraction from negative (but not neutral) distractors under a high dose of alcohol, but no distraction from either type of distractor in the low dose condition. Women showed a small distraction effect that was not moderated by either alcohol or emotion, indicating effective use of executive control across conditions. These findings support the idea that - in men, at least - emotional distraction taxes executive control to a greater extent than neutral distraction. The dissociation between men and women may reflect differential sensitivity to either alcohol or emotional images. Keywords: Attention, emotion, executive control, inhibition, alcohol, sex differences Conference: XII International Conference on Cognitive Neuroscience (ICON-XII), Brisbane, Queensland, Australia, 27 Jul - 31 Jul, 2014. Presentation Type: Poster Topic: Cognition and Executive Processes Citation: Kranz L, Bell L, Carmel D, Crawford M, Andrejic N and Grimshaw G (2015). Under the Influence: Alcohol Impairs Inhibition of Negative Distractors, but only in Men. Conference Abstract: XII International Conference on Cognitive Neuroscience (ICON-XII). doi: 10.3389/conf.fnhum.2015.217.00242 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 19 Feb 2015; Published Online: 24 Apr 2015. * Correspondence: Dr. Gina Grimshaw, Victoria University of Wellington, School of Psychology, Wellington, New Zealand, Gina.Grimshaw@vuw.ac.nz Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Laura Kranz Lauren Bell David Carmel Matt Crawford Natalija Andrejic Gina Grimshaw Google Laura Kranz Lauren Bell David Carmel Matt Crawford Natalija Andrejic Gina Grimshaw Google Scholar Laura Kranz Lauren Bell David Carmel Matt Crawford Natalija Andrejic Gina Grimshaw PubMed Laura Kranz Lauren Bell David Carmel Matt Crawford Natalija Andrejic Gina Grimshaw Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Effect of Structured and Unstructured Physical Activity Training on Cognitive Functions in Adolescents - A Randomized Control Trial.

Regular physical activity in children and adolescents promotes not only their physical health but also improves their cognition. Paper and pencil Neurocognitive tests (NCT) are commonly used to assess the various cognitive domains of a person and can be used as simple tests to assess improvements, if any, in the cognitive abilities of growing adolescents who practice regular physical activity. To study the effect of six months of structured and unstructured physical activity on cognitive functions in adolescents. We recruited 439 healthy adolescent volunteers in the age group of 12 to 17 years (boys 250, girls 189) from a residential school (Jawahar Navodaya Vidyalaya, Pondicherry). The following paper and pencil neuropsychological cognitive tests were administered: Two Target Letter Cancellation test, Trail Making test A and B, Ruff Figural Fluency test (RFFT). These participants were then divided into Structured Physical Activity (SPA: n=219; boys 117, girls 102) and Unstructured Physical Activity (USPA: n=220; boys 119, girls 101) groups based on age and gender block randomization method. Six-month intervention was successfully completed by 347 participants only (SPA group: n= 136; boys 77, girls 59; USPA group: n = 139; boys 75, girls 64) and the tests were repeated. The data were recorded and statistically analysed by per-protocol analysis method, using the Statistical Package for Social Sciences (SPSS), version 19. After six months of intervention, both SPA and USPA group participants showed significant improvements in all the tested neurocognitive parameters. On inter-group comparison, participants in SPA group showed significantly better improvements. Physical activity training in adolescents is more beneficial when structured as per WHO guidelines, probably due to higher cognitive loading.

Components of attention modulated by temporal expectation.

By varying the probabilities that a stimulus would appear at particular times after the presentation of a cue and modeling the data by the theory of visual attention (Bundesen, 1990), Vangkilde, Coull, and Bundesen (2012) provided evidence that the speed of encoding a singly presented stimulus letter into visual short-term memory (VSTM) is modulated by the observer's temporal expectations. We extended the investigation from single-stimulus recognition to whole report (Experiment 1) and partial report (Experiment 2). Cue-stimulus foreperiods were distributed geometrically using time steps of 500 ms. In high expectancy conditions, the probability that the stimulus would appear on the next time step, given that it had not yet appeared, was high, whereas in low expectancy conditions, the probability was low. The speed of encoding the stimuli into VSTM was higher in the high expectancy conditions. In line with the Easterbrook (1959) hypothesis, under high temporal expectancy, the processing was also more focused (selective). First, the storage capacity of VSTM was lower, so that fewer stimuli were encoded into VSTM. Second, the distribution of attentional weights across stimuli was less even: The efficiency of selecting targets rather than distractors for encoding into VSTM was higher, as was the spread of the attentional weights of the target letters.

Self-Reported ADHD Symptoms and Interhemispheric Interaction in Adults: A Dimensional Approach

The present study applied the dimensional approach to test whether self-reported symptoms of Attention Deficit/Hyperactivity Disorder (ADHD) in adults are associated with the speed of interhemispheric interaction. A sample of first grade students (N = 112) completed Conners' Adult ADHD Rating Scales and letter matching reaction time tasks. In the tasks, participants had to match a single target letter displayed below the fixation cross, either on left or right visual field, with one of two letters displayed above the fixation cross, one letter on each visual field. For each task, identical letters were presented either within the same visual field (within hemisphere condition) or across visual fields (across hemisphere condition). Interhemispheric interaction was indexed as the difference in mean reaction time between within and across hemisphere conditions. Comorbid problems such as depression, anxiety, and stress may affect task performance and are controlled for in this study. Findings indicated that self-reported ADHD symptomology, especially hyperactivity, in the presence of stress was weakly but significantly associated with fast interhemispheric interaction.

Interactions between space-based and feature-based attention.

Although early research suggested that attention to nonspatial features (i.e., red) was confined to stimuli appearing at an attended spatial location, more recent research has emphasized the global nature of feature-based attention. For example, a distractor sharing a target feature may capture attention even if it occurs at a task-irrelevant location. Such findings have been used to argue that feature-based attention operates independently of spatial attention. However, feature-based attention may nonetheless interact with spatial attention, yielding larger feature-based effects at attended locations than at unattended locations. The present study tested this possibility. In 2 experiments, participants viewed a rapid serial visual presentation (RSVP) stream and identified a target letter defined by its color. Target-colored distractors were presented at various task-irrelevant locations during the RSVP stream. We found that feature-driven attentional capture effects were largest when the target-colored distractor was closer to the attended location. These results demonstrate that spatial attention modulates the strength of feature-based attention capture, calling into question the prior evidence that feature-based attention operates in a global manner that is independent of spatial attention.

Enhanced visual detection in trait anxiety.

There is much evidence suggesting that trait anxiety is associated with impairments in the cognitive control of attention. Recent findings, though, have suggested that anxiety may also influence perception, conversely enhancing early information processing. The present study investigated this claim within a visual detection task. Participants searched for a target letter among a number of nontarget letters, varied to modulate the demands or load on perception, while also reporting whether an additional stimulus appeared on trials. Self-reported trait anxiety levels did not affect performance in the letter search task under any level of load. However, visual detection for the additional stimulus, as measured by d' sensitivity, was positively correlated with levels of anxiety regardless of the perceptual difficulty of the search task. These results suggest that trait vulnerability to anxiety is associated with improved visual detection, providing direct evidence that anxiety may modulate sensory processing.

Loss of attentional inhibition in older adults--Does it really exist? An experimental dissociation of inhibitory and memory retrieval processes.

It is commonly assumed that attentional inhibitory functioning decreases with age, even though empirical evidence is mixed. These inconsistencies possibly stem from methodological artifacts: distractor inhibition is typically assessed with the negative priming paradigm, which confounds inhibition and episodic retrieval. In the present study, we investigated age differences in a sequential distractor repetition paradigm (Giesen, Frings, & Rothermund, 2012) that provides independent estimates of distractor inhibition and episodic retrieval processes. Older (60+ yrs) and younger (below 30 years) adults identified target letters that were flanked by distractors (JKJ). Inhibitory processes were preserved in older adults, who showed reliable distractor repetition benefits resulting from persistent distractor inhibition; however, a significant loss of inhibition was apparent for the older subgroup of participants (65+ yrs) compared with a subgroup of young-old participants (60 to 64 years). No age differences were found for episodic retrieval processes of stimulus-response bindings that were indexed by an interaction of distractor repetition and response relation. Findings highlight the importance of dissociating between distractor inhibition and retrieval processes that are differently implicated in age-related cognitive change.

The Impact of Supra- and Sub-liminal Facial Expressions on the Gaze-cueing Effect

Studies have shown that attention tends to shift to locations gazed by others. The gaze-cuing effect(GCE) means that targets presented at periphery are detected faster when the eyes in a central face are gazing at the same direction of the target than when the eyes are gazing at the opposite side. In the present study, we investigated the impact of consciously or unconsciously presented emotional faces on the gaze-cuing effect. A positive, neutral, or negative cue face with its eyes gazing at left or right side was presented supraliminally or subliminally in the center of the screen, followed by a target letter presented at the gazed(cued) location or the opposite(un-cued) location. Participants were asked to make localization responses to the target as accurately and quickly as possible. Results showed that, the GCE, in terms of RTs in the un-cued condition minus RTs in the cued condition, was significant and was not affected by facial expression when the face was presented supraliminally. However, when the cue was presented subliminally, the GCE effect was also significant and was modulated by the emotionality of the central face. Specifically, in the un-cued condition, RTs were significantly longer in the positive and negative conditions than that in the neutral condition. In other words, GCE was larger in the positive and negative conditions than in the neutral condition. These results indicated that GCE can be modulated by faces with biological importance. The emotional information conveyed through supraliminally presented face might be suppressed by the top-down control setting, whereas the subliminally presented gazing cue was processed automatically and was escaped from top-down suppression.

The location but not the attributes of visual cues are automatically encoded into working memory

Although it has been well known that visual cues affect the perception of subsequent visual stimuli, relatively little is known about how the cues themselves are processed. The present study attempted to characterize the processing of a visual cue by investigating what information about the cue is stored in terms of both location (“where” is the cue) and attributes (“what” are the attributes of the cue). In 11 experiments subjects performed several trials of reporting a target letter and then answered an unexpected question about the cue (e.g., the location, color, or identity of the cue). This surprise question revealed that participants could report the location of the cue even when the cue never indicated the target location and they were explicitly told to ignore it. Furthermore, the memory trace of this location information endured during encoding of the subsequent target. In contrast to location, attributes of the cue (e.g., color) were poorly reported, even for attributes that were used by subjects to perform the task. These results shed new light on the mechanisms underlying cueing effects and suggest also that the visual system may create empty object files in response to visual cues.

Does pronounceability modulate the letter string deficit of children with dyslexia? A study with the rate and amount model

The locus of the deficit of children with dyslexia in dealing with strings of letters may be a deficit at a pre-lexical graphemic level or an inability to bind orthographic and phonological information. We evaluate these alternative hypotheses in two experiments by examining the role of stimulus pronounceability in a lexical decision task (LDT) and in a forced-choice letter discrimination task (Reicher–Wheeler paradigm). Seventeen fourth grade children with dyslexia and 24 peer control readers participated to two experiments. In the LDT children were presented with high-, low-frequency words, pronounceable pseudowords (such as DASU) and unpronounceable non-words (such as RNGM) of 4-, 5-, or 6- letters. No sign of group by pronounceability interaction was found when over-additivity was taken into account. Children with dyslexia were impaired when they had to process strings, not only of pronounceable stimuli but also of unpronounceable stimuli, a deficit well accounted for by a single global factor. Complementary results were obtained with the Reicher–Wheeler paradigm: both groups of children gained in accuracy in letter discrimination in the context of pronounceable primes (words and pseudowords) compared to unpronounceable primes (non-words). No global factor was detected in this task which requires the discrimination between a target letter and a competitor but does not involve simultaneous letter string processing. Overall, children with dyslexia show a selective difficulty in simultaneously processing a letter string as a whole, independent of its pronounceability; however, when the task involves isolated letter processing, also these children can make use of the ortho-phono-tactic information derived from a previously seen letter string. This pattern of findings is in keeping with the idea that an impairment in pre-lexical graphemic analysis may be a core deficit in developmental dyslexia.

Attentional Processing of Letter Strings by Children

Reading a letter string requires attentional orienting toward the beginning of the string (left-dominant orientation), followed by orienting along the string. These attentional-orienting processes differ according to the lexicality of the letter string: Sequential processes apply when reading nonwords or pseudowords, while words can be processed more globally. The aim of this study was to evaluate the development of these attentional processes involved in reading. We conducted two experiments in 6- (first grade), 7- (second grade), and 9-year-old (fourth grade) children, using a procedure that required the detection of a letter (Experiment 1) or a nonletter (Experiment 2) target in a string of five characters. The target character could occur in the second (left) or fourth (right) position in the string. Results showed an advantage for left nonletter targets as early as age 6 and of left letter targets as early as age 7. In 6-year-olds, only good readers detected a left letter target faster than a right letter target; others detected a right letter target faster. Thus, dominant orienting toward the beginning of the letter string is not fully developed in children before the second year of reading. A possibility is that beginning readers have difficulties inhibiting an attention-orienting bias toward the right visual field in linguistic tasks. The results also showed that the lexicality effect on these attentional processes develops gradually until the fourth year of reading. We believe that the procedure used in this study will be very valuable for evaluating attentional difficulties during reading acquisition.

Effects of number, complexity, and familiarity of flankers on crowded letter identification.

We tested identification of target letters surrounded by a varying number (2, 4, 6) of horizontally aligned flanking elements. Strings were presented left or right of a central fixation dot, and targets were always at the center of the string. Flankers could be other letters, digits, symbols, simple shapes, or false fonts, and thus varied both in terms of visual complexity and familiarity. Two-alternative forced choice (2AFC) speed and accuracy was measured for choosing the target letter versus an alternative letter that was not present in the string. Letter identification became harder as the number of flankers increased. Greater flanker complexity led to more interference in target identification, whereas more complex targets were easier to identify. Effects of flanker complexity were found to depend on visual field and position of flankers, with the strongest effects seen for leftward flankers in the left visual field. Visual complexity predicted flanker interference better than familiarity, and better than target-flanker similarity. These results provide further support for an excessive feature-integration account of the interfering effects of both adjacent and nonadjacent flanking elements in horizontally aligned strings.

Prominent effects and neural correlates of visual crowding in a neurodegenerative disease population

Crowding is a breakdown in the ability to identify objects in clutter, and is a major constraint on object recognition. Crowding particularly impairs object perception in peripheral, amblyopic and possibly developing vision. Here we argue that crowding is also a critical factor limiting object perception in central vision of individuals with neurodegeneration of the occipital cortices. In the current study, individuals with posterior cortical atrophy (n=26), typical Alzheimer's disease (n=17) and healthy control subjects (n=14) completed centrally-presented tests of letter identification under six different flanking conditions (unflanked, and with letter, shape, number, same polarity and reverse polarity flankers) with two different target-flanker spacings (condensed, spaced). Patients with posterior cortical atrophy were significantly less accurate and slower to identify targets in the condensed than spaced condition even when the target letters were surrounded by flankers of a different category. Importantly, this spacing effect was observed for same, but not reverse, polarity flankers. The difference in accuracy between spaced and condensed stimuli was significantly associated with lower grey matter volume in the right collateral sulcus, in a region lying between the fusiform and lingual gyri. Detailed error analysis also revealed that similarity between the error response and the averaged target and flanker stimuli (but not individual target or flanker stimuli) was a significant predictor of error rate, more consistent with averaging than substitution accounts of crowding. Our findings suggest that crowding in posterior cortical atrophy can be regarded as a pre-attentive process that uses averaging to regularize the pathologically noisy representation of letter feature position in central vision. These results also help to clarify the cortical localization of feature integration components of crowding. More broadly, we suggest that posterior cortical atrophy provides a neurodegenerative disease model for exploring the basis of crowding. These data have significant implications for patients with, or who will go on to develop, dementia-related visual impairment, in whom acquired excessive crowding likely contributes to deficits in word, object, face and scene perception.

Dissociating the LPC to affective words from the P3b with residue iteration decomposition (RIDE)

frequent (80%) and one rare (20%) target letter. Responses had to wait for “go” signals (appearing in 90% of trials). Between blocks, stimulusonset asynchronies (SOAs) from targets to go-signals varied from 0 ms to 800 ms. Rare targets were expected to evoke large P3bs (“oddball effect”). If related to S processing only, this effect will be equally large across all SOAs and will be modeled by RIDE's S-cluster. If related to R initiation only, the oddball effect will be evoked by go-signals rather than by targets and will be modeled by RIDE's R-cluster. If indicating integration of rare stimuli with their rare responses, the oddball effect will be evoked by targets but will be reduced and stretched in time across SOAs and will be modeled by RIDE's intermediate cluster. RIDE analysis confirmed this latter view, for the most part. SOA effects in part conformed to predictions made by each of the three views (S only, R only, S–R link) calling for a refined account of the oddball effect on P3b in terms of S–R integration. In a clinically oriented application, we reanalyzed data from patients with Parkinson's disease whose P3 components had been found to be much smaller in R-locked than in S-locked averages, unlike in healthy participants. We had assumed that this was due to overlap of a fronto-central R-related negativity. Results will be presented from testing this assumption by applying RIDE. This analysis is still in progress. Taken together, being a method of multivariate data decomposition that is specifically tailored for ERPs, RIDE indeed appears to be extremely useful for ERP analysis.

Multisensory Integration in Complete Unawareness: Evidence From Audiovisual Congruency Priming

Multisensory integration is thought to require conscious perception. Although previous studies have shown that an invisible stimulus could be integrated with an audible one, none have demonstrated integration of two subliminal stimuli of different modalities. Here, pairs of identical or different audiovisual target letters (the sound /b/ with the written letter “b” or “m,” respectively) were preceded by pairs of masked identical or different audiovisual prime digits (the sound /6/ with the written digit “6” or “8,” respectively). In three experiments, awareness of the audiovisual digit primes was manipulated, such that participants were either unaware of the visual digit, the auditory digit, or both. Priming of the semantic relations between the auditory and visual digits was found in all experiments. Moreover, a further experiment showed that unconscious multisensory integration was not obtained when participants did not undergo prior conscious training of the task. This suggests that following conscious learning, unconscious processing suffices for multisensory integration.

A moving overlay shrinks the attentional blink.

This report describes a study examining the effects of overlaying a veil of spots on the letters in a central rapid serial visual presentation stream. Observers identified two target letters (T1 and T2, respectively) embedded in a stream of distractor letters printed in a different color. In Experiment 1, the attentional blink (AB) diminished when a different overlay veiled each letter, such that the spots appeared to move as the letters changed. Experiment 2 concerned whether the performance enhancement occurred because the overlay hampered processing of the lag1 distractor, thus weakening the distractor's interference with T1. Experiment 3 focused on how changing the overlay at or around T1 affected the AB. The attention disengagement hypothesis was proposed to explain the common theme in the results-that performance was only enhanced when different overlays were applied to the T1 and lag1 frames. The claim is that the AB reflects a failure of prompt attentional disengagement from T1, which, in turn, delays reengagement when T2 appears shortly thereafter. When T1's disappearance is accompanied by an overlay change, the perceptual system gets an additional cue signaling that the visual scene has changed, thereby inducing attentional disengagement. Apart from facilitating prompt reengagement at the next target, earlier disengagement also improves target recovery by excluding features of the trailing item, likely to be a distractor, from working memory.

How hand placement modulates interference from extraneous stimuli.

Placing the hands around the position in which the relevant target letter for an Eriksen flanker task appears has been shown to reduce the interference produced by incompatible, irrelevant flanker letters presented outside of the hands. This result has been attributed to the hands providing an attentional window in the space between them, which results in enhanced processing of the stimulus within it. Alternatively, the hands may act as a reference frame relative to which attention can also be directed more effectively to the space outside of the hands. We conducted four experiments to test implications of the attention window and reference-frame accounts, using left and right foot-press responses. Although placing the hands around the inner letter reduced interference on flanker-incompatible trials, as previously found, it did so just as much when the letter outside of the hands was specified as the target and the letter between the hands was the distractor. Also, placement of wooden blocks around the inner letter reduced interference to a similar extent, again regardless of whether the inner or outer letter was designated as the target. These findings support the view that the reduction in flanker interference produced by placing the hands around the inner letter is due to their providing a reference frame relative to which visual attention can be directed either inside or outside.