When the WRENCH turns a few heads: Expectation and semantic relatedness in inattentional blindness.

Semantic relatedness and expectation were investigated in inattentional blindness-failure to perceive an unexpected object in plain sight when attention is engaged elsewhere. Participants named primary-task pictures and ignored distractor pictures. Four trials preceded a 'critical' trial where an unexpected six-letter-word appeared at fixation, simultaneously with the pictures. In Experiment 1, we found robust effects for both in-lab and on-line-Zoom methodology. More participants reported the unexpected word semantically-related to the primary-task pictures than a semantically-unrelated word. In Experiment 2, expectations were violated, by changing the semantic category of the primary-task pictures. More participants reported the unexpected word semantically-related to the unexpected picture category than a semantically-unrelated word. When attentional resources are consumed by a task, a violation to task expectations is not enough to reorient attention to an unexpected word. Attention reorients to what is meaningful to the task, and what is meaningful is updated in light of unexpected information.

Does animacy affect visual statistical learning? Revisiting the effects of selective attention and animacy on visual statistical learning.

Animates receive preferential attentional processing over inanimates because, from an evolutionary perspective, animates are important to human survival. We investigated whether animacy affects visual statistical learning-the detection and extraction of regularities in visual information from our rich, dynamic, and complex environment. Participants completed a selective-attention task, in which regularities were embedded in two visual streams, an attended and an unattended visual stream. The attended visual stream always consisted of line-drawings of non-objects, while the unattended visual stream consisted of line-drawings of either animates or inanimates. Participants then completed a triplet-discrimination task, which assessed their ability to extract regularities from the attended and unattended visual streams. We also assessed participants' awareness of regularities in the visual statistical learning task, and asked if any learning strategies were used. We were specifically interested in whether the animacy status of line-drawings in the unattended visual stream would affect visual statistical learning. There were four key findings. First, selective attention modulates visual statistical learning, with greater visual statistical learning for attended than for unattended information. Second, animacy does not affect visual statistical learning, with no differences found in visual statistical learning performance between the animate and inanimate condition. Third, awareness of regularities was associated with visual statistical learning of attended information. Fourth, participants used strategies (e.g., naming or labelling stimuli) during the visual statistical learning task. Further research is required to understand whether visual statistical learning is one of the adaptive functions that evolved from ancestral environments.

Inattentional blindness: Attentional set for efficient task success.

Inattentional blindness is the failure to notice an unexpected object in plain sight when attention is otherwise engaged. We investigated what determines observers' attentional set in a dynamic-counting inattentional blindness paradigm, when task instructions and visual distinctiveness of task-relevant objects were either congruent or in opposition. In seven experiments, observers counted bounces by task-relevant objects, with the instruction either to count-by-shape (squares, diamonds, crosses) or count-by-colour (blue, purple). To manipulate visual distinctiveness, we varied the extent to which task-relevant and task-irrelevant objects looked different on two dimensions: shape and colour. When colour better distinguished task-relevant from task-irrelevant objects, observers-even if instructed count-by-shape-reported an unexpected object that matched the colour of task-relevant objects. Crucially, when instructed count-by-colour, but shape better distinguished task-relevant from task-irrelevant objects, observers reported an unexpected object that matched the shape of task-relevant objects. We conclude that observers set their attention to promote efficient task performance.

Age differences in visual statistical learning: Investigating the effects of selective attention and stimulus category.

A cognitive function that is of interest when investigating age-related changes is statistical learning-the ability to detect and extract regularities in sensory information from our rich, dynamic, and complex environment. A previous study has suggested that there were age differences in visual statistical learning, with older adults demonstrating visual statistical learning of attended and unattended information (due to the "hyper-binding effect"). In the present study, we were interested in investigating whether there are age differences in visual statistical learning and whether stimulus category influenced visual statistical learning of unattended information in older adults. We tested two stimulus categories: highly familiar line drawings and abstract shapes. Participants completed a selective-attention task, in which regularities were embedded into both the attended and unattended visual streams. Then, participants completed a triplet-discrimination task, which assessed their ability to extract regularities from the attended and unattended visual streams. We also implemented a 4-point confidence-rating scale in the triplet-discrimination task as an assessment of participants' awareness of these regularities. There were four key findings. First, selective attention modulates visual statistical learning, with greater visual statistical learning for attended information than for unattended information. Second, there were age differences in visual statistical learning, but these differences were only observed for visual statistical learning of attended information. Third, stimulus category did not affect visual statistical learning of unattended information in older adults. Fourth, visual statistical learning occurs with awareness of statistical regularities. Further research is warranted to investigate the age-related mechanisms underlying visual statistical learning. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Are animates special? Exploring the effects of selective attention and animacy on visual statistical learning.

Our visual system is built to extract regularities in how objects in our visual environment appear in relation to each other across time and space ("visual statistical learning"). Existing research indicates that visual statistical learning is modulated by selective attention. Our attentional system prioritises information that enables adaptive behaviour; for example, animates are prioritised over inanimates (the "animacy advantage"). The present study examined the effects of selective attention and animacy on visual statistical learning in young adults (N = 284). We tested visual statistical learning of attended and unattended information across four animacy conditions: (1) living things that can self-initiate movement (animals); (2) living things that cannot self-initiate movement (fruits and vegetables); (3) non-living things that can generate movement (vehicles); and (4) non-living things that cannot generate movement (tools and kitchen utensils). We implemented a 4-point confidence rating scale as an assessment of participants' awareness of the regularities in the visual statistical learning task. There were four key findings. First, selective attention plays a critical role by modulating visual statistical learning. Second, animacy does not play a special role in visual statistical learning. Third, visual statistical learning of attended information cannot be exclusively accounted for by unconscious knowledge. Fourth, performance on the visual statistical learning task is associated with the proportion of stimuli that were named or labelled. Our findings support the notion that visual statistical learning is a powerful mechanism by which our visual system resolves an abundance of sensory input over time.

What is a tilt table test and why is it performed during the investigation of syncope?

Falls are one of the most common reasons for patients to present to the emergency department. Syncope is a common cause of falls, which disproportionately affects older people. In most cases, syncope can be confirmed with a detailed history and simple bedside tests, but tilt table testing remains an invaluable diagnostic adjunct in more complex cases. Often misunderstood, the tilt table test is a useful way to reproduce a patient's symptoms in a safe and controlled environment. The tilt table test is considered positive if the patient experiences symptoms associated with a drop in blood pressure or postural tachycardia. The test can support a diagnosis and can direct therapeutic interventions.

Effects of Symmetry and Apparent Distance in a Parasagittal-Mirror Variant of the Rubber Hand Illusion Paradigm.

When I see my face in a mirror, its apparent position (behind the glass) is not one that my own face could be in. I accept the face I see as my own because I have an implicit understanding of how mirrors work. The situation is different if I look at the reflection of my right hand in a parasagittal mirror (parallel to body midline) when my left hand is hidden behind the mirror. It is as if I were looking through a window at my own left hand. The experience of body ownership has been investigated using rubber hand illusion (RHI) paradigms, and several studies have demonstrated ownership of a rubber hand viewed in a frontal mirror. Our "proof of concept" study was the first to combine use of a parasagittal mirror and synchronous stroking of both a prosthetic hand (viewed in the mirror) and the participant's hand, with a manipulation of distance between the hands. The strength of the RHI elicited by our parasagittal-mirror paradigm depended not on physical distance between the hands (30, 45, or 60 cm) but on apparent distance between the prosthetic hand (viewed in the mirror) and the participant's hand. This apparent distance was reduced to zero when the prosthetic hand and participant's hand were arranged symmetrically (e.g., 30 cm in front of and behind the mirror). Thus, the parasagittal-mirror paradigm may provide a distinctive way to assess whether competition for ownership depends on spatial separation between the prosthetic hand and the participant's hand.

Keeping an eye on visual search patterns in visuospatial neglect: A systematic review.

Patients with visuospatial neglect exhibit a failure to detect, respond, or orient towards information located in the side of space opposite to their brain lesion. To extend our understanding of the underlying cognitive processes involved in neglect, some studies have used eye movement measurements to complement behavioural data. We provide a qualitative synthesis of studies that have used eye-tracking in patients with neglect, with a focus on highlighting the utility of examining eye movements and reporting what eye-tracking has revealed about visual search patterns in these patients. This systematic review includes twenty studies that met the eligibility criteria. We extracted information pertaining to patient characteristics (e.g., age, type of stroke, time since stroke), neglect test(s) used, type of stimuli (e.g., static, dynamic), eye-tracker specifications (e.g., temporal and spatial resolution), and eye movement measurements (e.g., saccade amplitude, fixation duration). Five key themes were identified. First, eye-tracking is a useful tool to complement pen-and-paper neglect tests. Second, the lateral asymmetrical bias in eye movement patterns observed during active exploration also occurred while at rest. Third, the lateral asymmetrical bias was evident not only in the horizontal plane but also in the vertical plane. Fourth, eye movement patterns were modulated by stimulus- and task-related factors (e.g., visual salience, local perceptual features, image content, stimulus duration, presence of distractors). Fifth, measuring eye movements in patients with neglect is useful for determining and understanding other cognitive impairments, such as spatial working memory. To develop a fuller, and a more accurate, picture of neglect, future research would benefit from eye movement measurements.

Human hippocampal CA3 damage disrupts both recent and remote episodic memories.

Neocortical-hippocampal interactions support new episodic (event) memories, but there is conflicting evidence about the dependence of remote episodic memories on the hippocampus. In line with systems consolidation and computational theories of episodic memory, evidence from model organisms suggests that the cornu ammonis 3 (CA3) hippocampal subfield supports recent, but not remote, episodic retrieval. In this study, we demonstrated that recent and remote memories were susceptible to a loss of episodic detail in human participants with focal bilateral damage to CA3. Graph theoretic analyses of 7.0-Tesla resting-state fMRI data revealed that CA3 damage disrupted functional integration across the medial temporal lobe (MTL) subsystem of the default network. The loss of functional integration in MTL subsystem regions was predictive of autobiographical episodic retrieval performance. We conclude that human CA3 is necessary for the retrieval of episodic memories long after their initial acquisition and functional integration of the default network is important for autobiographical episodic memory performance.

The vocabulary spurt predicts the emergence of backward semantic inhibition in 18-month-old toddlers.

The current study examines the relationship between 18-month-old toddlers' vocabulary size and their ability to inhibit attention to no-longer relevant information using the backward semantic inhibition paradigm. When adults switch attention from one semantic category to another, the former and no-longer-relevant semantic category becomes inhibited, and subsequent attention to an item that belongs to the inhibited semantic category is impaired. Here we demonstrate that 18-month-olds can inhibit attention to no-longer relevant semantic categories, but only if they have a relatively large vocabulary. These findings suggest that an increased number of items (word knowledge) in the toddler lexical-semantic system during the "vocabulary spurt" at 18-months may be an important driving force behind the emergence of a semantic inhibitory mechanism. Possessing more words in the mental lexicon likely results in the formation of inhibitory links between words, which allow toddlers to select and deselect words and concepts more efficiently. Our findings highlight the role of vocabulary growth in the development of inhibitory processes in the emerging lexical-semantic system.

Inattentional blindness on the full-attention trial: Are we throwing out the baby with the bathwater?

When attention is otherwise engaged, observers may experience inattentional blindness, failing to notice objects or events that are presented in plain sight. In an inattentional blindness experiment, an unexpectedstimulus ispresented alongside primary-task stimuli, and its detection is probed. We evaluate a criterion that is commonly used to exclude observers from the data analysis. On the final experimental trial, observers do not perform the primary task, but instead look for anything new. Observers who fail to report the unexpected stimulus on thisfull-attention trialare excluded. On the basis of 4 hypothetical experiments and a review of 128 actual experiments from the literature, we demonstrate some potentially problematic consequences of implementing the full-attention-trial exclusion criterion. Excluded observers may cluster in experimental conditions and the exclusion criterion may lead researchers to understate the pervasiveness of inattentional blindness. It may even render usblindto inattentional blindness on the full-attention trial.

Focal CA3 hippocampal subfield atrophy following LGI1 VGKC-complex antibody limbic encephalitis.

Magnetic resonance imaging has linked chronic voltage-gated potassium channel (VGKC) complex antibody-mediated limbic encephalitis with generalized hippocampal atrophy. However, autoantibodies bind to specific rodent hippocampal subfields. Here, human hippocampal subfield (subiculum, cornu ammonis 1-3, and dentate gyrus) targets of immunomodulation-treated LGI1 VGKC-complex antibody-mediated limbic encephalitis were investigated using in vivo ultra-high resolution (0.39 × 0.39 × 1.0 mm3) 7.0 T magnetic resonance imaging [n = 18 patients, 17 patients (94%) positive for LGI1 antibody and one patient negative for LGI1/CASPR2 but positive for VGKC-complex antibodies, mean age: 64.0 ± 2.55 years, median 4 years post-limbic encephalitis onset; n = 18 controls]. First, hippocampal subfield quantitative morphometry indicated significant volume loss confined to bilateral CA3 [F(1,34) = 16.87, P < 0.0001], despite hyperintense signal evident in 5 of 18 patients on presentation. Second, early and later intervention (<3 versus >3 months from symptom onset) were associated with CA3 atrophy. Third, whole-brain voxel-by-voxel morphometry revealed no significant grey matter loss. Fourth, CA3 subfield atrophy was associated with severe episodic but not semantic amnesia for postmorbid autobiographical events that was predicted by variability in CA3 volume. The results raise important questions about the links with histopathology, the impact of the observed focal atrophy on other CA3-mediated reconstructive and episodic mechanisms, and the role of potential antibody-mediated pathogenicity as part of the pathophysiology cascade in humans.

The Phantom Vanish Magic Trick: Investigating the Disappearance of a Non-existent Object in a Dynamic Scene.

Drawing inspiration from sleight-of-hand magic tricks, we developed an experimental paradigm to investigate whether magicians' misdirection techniques could be used to induce the misperception of "phantom" objects. While previous experiments investigating sleight-of-hand magic tricks have focused on creating false assumptions about the movement of an object in a scene, our experiment investigated creating false assumptions about the presence of an object in a scene. Participants watched a sequence of silent videos depicting a magician performing with a single object. Following each video, participants were asked to write a description of the events in the video. In the final video, participants watched the Phantom Vanish Magic Trick, a novel magic trick developed for this experiment, in which the magician pantomimed the actions of presenting an object and then making it magically disappear. No object was presented during the final video. The silent videos precluded the use of false verbal suggestions, and participants were not asked leading questions about the objects. Nevertheless, 32% of participants reported having visual impressions of non-existent objects. These findings support an inferential model of perception, wherein top-down expectations can be manipulated by the magician to generate vivid illusory experiences, even in the absence of corresponding bottom-up information.

Backward Semantic Inhibition in Toddlers.

Attention switching is a crucial ability required in everyday life, from toddlerhood to adulthood. In adults, shifting attention from one word (e.g., dog) to another (e.g., sea) results in backward semantic inhibition, that is, the inhibition of the initial word ( dog). In this study, we used the preferential-looking paradigm to examine whether attention switching is accompanied by backward semantic inhibition in toddlers. We found that 24-month-olds can indeed refocus their attention to a new item by selectively inhibiting attention to the old item. The consequence of backward inhibition is that subsequent attention to a word semantically related to the old item is impaired. These findings have important implications for understanding the underlying mechanism of backward semantic inhibition and the development of lexical-semantic inhibition in early childhood.

Backpack palsy: A rare complication of backpack use in children and young adults - A new case report.

Backpack palsy is a well-recognised, albeit rare, complication of carrying backpacks. Although it has been mostly described in cadets during strenuous training, sporadic cases of brachial nerve impairment have been reported in children and young adults. Here we reported the case of a 15-year-old girl who presented with a left-side brachial palsy with axonal denervation of C5C7 motor roots following a school challenge for the Duke of Edinburgh Award. Her symptoms began soon after starting the challenge and included weakness of shoulder abduction and elevation, as well as forearm, wrist and fingers extension. After 6 months of physiotherapy her motor function was completely restored. Backpack palsy can sometimes present in children and young adults. This disorder should be taken in consideration when planning for daily, as well as more challenging, physical activities in these age groups.

The nonvisual illusion of self-touch: Misaligned hands and anatomical implausibility.

The self-touch illusion is elicited when the participant (with eyes closed) administers brushstrokes to a prosthetic hand while the examiner administers synchronous brushstrokes to the participant's other (receptive) hand. In three experiments we investigated the effects of misalignment on the self-touch illusion. In experiment 1 we manipulated alignment (0 degrees, 45 degrees, 90 degrees, 135 degrees, 180 degrees) of the prosthetic hand relative to the participant's receptive hand. The illusion was equally strong at 0 degrees and 45 degrees: the two conditions in which the prosthetic hand was in an anatomically plausible orientation. To investigate whether the illusion was diminished at 90 degrees (and beyond) by anatomical implausibility rather than by misalignment, in experiment 2 hand positioning was changed. The illusion was equally strong at 0 degrees, 45 degrees, and 90 degrees, but diminished at 135 degrees despite the prosthetic hand now being in an anatomically plausible orientation. Thus the illusion is diminished with misalignment of 135 degrees, irrespective of anatomical plausibility. Having demonstrated that the illusion was equally strong with the hands aligned (0 degrees) or misaligned by 45 degrees, in experiment 3 we demonstrated that participants did not detect a 45 degrees misalignment. Large degrees of misalignment prevent a compelling experience of the self-touch illusion, and the self-touch illusion prevents detection of small degrees of misalignment.

The no-touch rubber hand paradigm and mirror-touch sensation: Support for the self-other theory of mirror-touch synesthesia.

We thoroughly enjoyed Ward and Banissy's Discussion Paper on mirror-touch synesthesia. The authors contrast two theories for explaining this phenomenon-the Threshold Theory and their Self-Other Theory. Ward and Banissy note that the Self-Other Theory garners support from studies that have tested individuals with mirror-touch synesthesia using the rubber hand paradigm. In this Commentary, we provide further support for the Self-Other Theory by drawing on findings from control participants without mirror-touch synesthesia tested with two different no-touch rubber hand paradigms-one paradigm makes it easier while the other makes it more difficult to make the self-other distinction.