Slower but more accurate mental rotation performance in aphantasia linked to differences in cognitive strategies.

Mental rotation tasks are frequently used as standard measures of mental imagery. However, aphantasia research has brought such use into question. Here, we assessed a large group of individuals who lack visual imagery (aphantasia) on two mental rotation tasks: a three-dimensional block-shape, and a human manikin rotation task. In both tasks, those with aphantasia had slower, but more accurate responses than controls. Both groups demonstrated classic linear increases in response time and error-rate as functions of angular disparity. In the three-dimensional block-shape rotation task, a within-group speed-accuracy trade-off was found in controls, whereas faster individuals in the aphantasia group were also more accurate. Control participants generally favoured using object-based mental rotation strategies, whereas those with aphantasia favoured analytic strategies. These results suggest that visual imagery is not crucial for successful performance in classical mental rotation tasks, as alternative strategies can be effectively utilised in the absence of holistic mental representations.

Revisiting Snodgrass and Vanderwart in photograph form: The Keele Photo Stimulus Set (KPSS).

Over the last 40 years, object recognition studies have moved from using simple line drawings, to more detailed illustrations, to more ecologically valid photographic representations. Researchers now have access to various stimuli sets, however, existing sets lack the ability to independently manipulate item format, as the concepts depicted are unique to the set they derive from. To enable such comparisons, Rossion and Pourtois (2004) revisited Snodgrass and Vanderwart's (1980) line drawings and digitally re-drew the objects, adding texture and shading. In the current study, we took this further and created a set of stimuli that showcase the same objects in photographic form. We selected six photographs of each object (three color/three grayscale) and collected normative data and RTs. Naming accuracy and agreement was high for all photographs and appeared to steadily increase with format distinctiveness. In contrast to previous data patterns for drawings, naming agreement (H values) did not differ between grey and color photographs, nor did familiarity ratings. However, grey photographs received significantly lower mental imagery agreement and visual complexity scores than color photographs. This suggests that, in comparison to drawings, the ecological nature of photographs may facilitate deeper critical evaluation of whether they offer a good match to a mental representation. Color may therefore play a more vital role in photographs than in drawings, aiding participants in judging the match with their mental representation. This new photographic stimulus set and corresponding normative data provide valuable materials for a wide range of experimental studies of object recognition.

Holistic processing only? The role of the right fusiform face area in radiological expertise.

Radiologists can visually detect abnormalities on radiographs within 2s, a process that resembles holistic visual processing of faces. Interestingly, there is empirical evidence using functional magnetic resonance imaging (fMRI) for the involvement of the right fusiform face area (FFA) in visual-expertise tasks such as radiological image interpretation. The speed by which stimuli (e.g., faces, abnormalities) are recognized is an important characteristic of holistic processing. However, evidence for the involvement of the right FFA in holistic processing in radiology comes mostly from short or artificial tasks in which the quick, 'holistic' mode of diagnostic processing is not contrasted with the slower 'search-to-find' mode. In our fMRI study, we hypothesized that the right FFA responds selectively to the 'holistic' mode of diagnostic processing and less so to the 'search-to-find' mode. Eleven laypeople and 17 radiologists in training diagnosed 66 radiographs in 2s each (holistic mode) and subsequently checked their diagnosis in an extended (10-s) period (search-to-find mode). During data analysis, we first identified individual regions of interest (ROIs) for the right FFA using a localizer task. Then we employed ROI-based ANOVAs and obtained tentative support for the hypothesis that the right FFA shows more activation for radiologists in training versus laypeople, in particular in the holistic mode (i.e., during 2s trials), and less so in the search-to-find mode (i.e., during 10-s trials). No significant correlation was found between diagnostic performance (diagnostic accuracy) and brain-activation level within the right FFA for both, short-presentation and long-presentation diagnostic trials. Our results provide tentative evidence from a diagnostic-reasoning task that the FFA supports the holistic processing of visual stimuli in participants' expertise domain.

Holistic face recognition is an emergent phenomenon of spatial processing in face-selective regions.

Spatial processing by receptive fields is a core property of the visual system. However, it is unknown how spatial processing in high-level regions contributes to recognition behavior. As face inversion is thought to disrupt typical holistic processing of information in faces, we mapped population receptive fields (pRFs) with upright and inverted faces in the human visual system. Here we show that in face-selective regions, but not primary visual cortex, pRFs and overall visual field coverage are smaller and shifted downward in response to face inversion. From these measurements, we successfully predict the relative behavioral detriment of face inversion at different positions in the visual field. This correspondence between neural measurements and behavior demonstrates how spatial processing in face-selective regions may enable holistic perception. These results not only show that spatial processing in high-level visual regions is dynamically used towards recognition, but also suggest a powerful approach for bridging neural computations by receptive fields to behavior.

Decoding category and familiarity information during visual imagery.

Visual imagery relies on a widespread network of brain regions, partly engaged during the perception of external stimuli. Beyond the recruitment of category-selective areas (FFA, PPA), perception of familiar faces and places has been reported to engage brain areas associated with semantic information, comprising the precuneus, temporo-parietal junction (TPJ), medial prefrontal cortex (mPFC) and posterior cingulate cortex (PCC). Here we used multivariate pattern analyzes (MVPA) to examine to which degree areas of the visual imagery network, category-selective and semantic areas contain information regarding the category and familiarity of imagined stimuli. Participants were instructed via auditory cues to imagine personally familiar and unfamiliar stimuli (i.e. faces and places). Using region-of-interest (ROI)-based MVPA, we were able to distinguish between imagined faces and places within nodes of the visual imagery network (V1, SPL, aIPS), within category-selective inferotemporal regions (FFA, PPA) and across all brain regions of the extended semantic network (i.e. precuneus, mPFC, IFG and TPJ). Moreover, we were able to decode familiarity of imagined stimuli in the SPL and aIPS, and in some regions of the extended semantic network (in particular, right precuneus, right TPJ), but not in V1. Our results suggest that posterior visual areas - including V1 - host categorical representations about imagined stimuli, and that stimulus familiarity might be an additional aspect that is shared between perception and visual imagery.

Neural indicators of articulator-specific sensorimotor influences on infant speech perception.

While there is increasing acceptance that even young infants detect correspondences between heard and seen speech, the common view is that oral-motor movements related to speech production cannot influence speech perception until infants begin to babble or speak. We investigated the extent of multimodal speech influences on auditory speech perception in prebabbling infants who have limited speech-like oral-motor repertoires. We used event-related potentials (ERPs) to examine how sensorimotor influences to the infant's own articulatory movements impact auditory speech perception in 3-mo-old infants. In experiment 1, there were ERP discriminative responses to phonetic category changes across two phonetic contrasts (bilabial-dental /ba/-/ɗa/; dental-retroflex /ɗa/-/ɖa/) in a mismatch paradigm, indicating that infants auditorily discriminated both contrasts. In experiment 2, inhibiting infants' own tongue-tip movements had a disruptive influence on the early ERP discriminative response to the /ɗa/-/ɖa/ contrast only. The same articulatory inhibition had contrasting effects on the perception of the /ba/-/ɗa/ contrast, which requires different articulators (the lips vs. the tongue) during production, and the /ɗa/-/ɖa/ contrast, whereby both phones require tongue-tip movement as a place of articulation. This articulatory distinction between the two contrasts plausibly accounts for the distinct influence of tongue-tip suppression on the neural responses to phonetic category change perception in definitively prebabbling, 3-mo-old, infants. The results showing a specificity in the relation between oral-motor inhibition and phonetic speech discrimination suggest a surprisingly early mapping between auditory and motor speech representation already in prebabbling infants.

Mind your gaze: Examining the relation between trait mindfulness and visual attention to valenced images.

Trait mindfulness pertains to one's ability to non-judgmentally attend to experiences. While attention regulation represents a core component of mindfulness, the relation between trait mindfulness and visual attention is unclear. Further, despite established associations between mindfulness and emotion regulation, few studies have examined whether trait mindfulness may be related to attention to emotionally valenced content. Thus, the present study used an eye-tracking paradigm to assess relations between trait mindfulness, emotion regulation and selective visual attention to valenced stimuli. Participants (N = 123; 75.6 % female; 87 % Caucasian; Mage = 19.14 years) completed measures of trait mindfulness, emotion regulation, and engaged in an eye-tracking paradigm in which they viewed sad, threatening, neutral, and happy images simultaneously. Dwell times on images (all categories combined), black space on screen, and each image category were calculated. Bivariate correlations were assessed to determine the relations among mindfulness, emotion regulation, and visual attention, controlling for mood. Trait mindfulness was associated with longer dwell time on images overall, but specifically longer dwell time on threatening and happy images. Although trait mindfulness and emotion regulation were positively associated, emotion regulation was not significantly associated with visual attention. These results suggest that trait mindfulness is associated with visual attention to valenced stimuli, particularly happy and threatening images, and emotion regulation does not account for these relations. These findings add to our understanding of the cognitive mechanisms underlying trait mindfulness.

The differential impact of viewing fitspiration and thinspiration images on men's body image concerns: An experimental ecological momentary assessment study.

To date, little is known about the impact of fitspiration and thinspiration exposure on men, as previous studies on these social media trends were primarily conducted on women. Male participants (n = 223) completed baseline measures of trait body image, then used a smartphone application to complete up to six state-based assessments daily for seven days. In each assessment, participants were randomly assigned to one of three image conditions (fitspiration, thinspiration, or neutral). Before and after viewing each image, they reported state body fat dissatisfaction, muscularity dissatisfaction, negative mood, and urge to engage in behaviours to reduce body fat and increase muscularity. Multi-level analyses revealed that compared to viewing neutral images, viewing fitspiration images increased men's body dissatisfaction, whereas viewing thinspiration images decreased body dissatisfaction. Viewing either fit- or thinspiration images also led to lower mood and greater urges to increase muscularity, whereas only fitspiration images increased urges to reduce body fat. Men with greater baseline muscularity dissatisfaction and higher appearance comparison were most vulnerable to muscularity dissatisfaction after viewing fitspiration images. Findings suggest the importance of limiting exposure to fitspiration imagery and implementing social media literacy programmes for men and well as women.

Generative modelling of the thalamo-cortical circuit mechanisms underlying the neurophysiological effects of ketamine.

Cortical recordings of task-induced oscillations following subanaesthetic ketamine administration demonstrate alterations in amplitude, including increases at high-frequencies (gamma) and reductions at low frequencies (theta, alpha). To investigate the population-level interactions underlying these changes, we implemented a thalamo-cortical model (TCM) capable of recapitulating broadband spectral responses. Compared with an existing cortex-only 4-population model, Bayesian Model Selection preferred the TCM. The model was able to accurately and significantly recapitulate ketamine-induced reductions in alpha amplitude and increases in gamma amplitude. Parameter analysis revealed no change in receptor time-constants but significant increases in select synaptic connectivity with ketamine. Significantly increased connections included both AMPA and NMDA mediated connections from layer 2/3 superficial pyramidal cells to inhibitory interneurons and both GABAA and NMDA mediated within-population gain control of layer 5 pyramidal cells. These results support the use of extended generative models for explaining oscillatory data and provide in silico support for ketamine's ability to alter local coupling mediated by NMDA, AMPA and GABA-A.

Nonspecific Visuospatial Imagery as a Novel Mental Task for Online EEG-Based BCI Control.

Brain-computer interfaces (BCIs) can provide a means of communication to individuals with severe motor disorders, such as those presenting as locked-in. Many BCI paradigms rely on motor neural pathways, which are often impaired in these individuals. However, recent findings suggest that visuospatial function may remain intact. This study aimed to determine whether visuospatial imagery, a previously unexplored task, could be used to signify intent in an online electroencephalography (EEG)-based BCI. Eighteen typically developed participants imagined checkerboard arrow stimuli in four quadrants of the visual field in 5-s trials, while signals were collected using 16 dry electrodes over the visual cortex. In online blocks, participants received graded visual feedback based on their performance. An initial BCI pipeline (visuospatial imagery classifier I) attained a mean accuracy of [Formula: see text]% classifying rest against visuospatial imagery in online trials. This BCI pipeline was further improved using restriction to alpha band features (visuospatial imagery classifier II), resulting in a mean pseudo-online accuracy of [Formula: see text]%. Accuracies exceeded the threshold for practical BCIs in 12 participants. This study supports the use of visuospatial imagery as a real-time, binary EEG-BCI control paradigm.

Decoding dynamic affective responses to naturalistic videos with shared neural patterns.

This study explored the feasibility of using shared neural patterns from brief affective episodes (viewing affective pictures) to decode extended, dynamic affective sequences in a naturalistic experience (watching movie-trailers). Twenty-eight participants viewed pictures from the International Affective Picture System (IAPS) and, in a separate session, watched various movie-trailers. We first located voxels at bilateral occipital cortex (LOC) responsive to affective picture categories by GLM analysis, then performed between-subject hyperalignment on the LOC voxels based on their responses during movie-trailer watching. After hyperalignment, we trained between-subject machine learning classifiers on the affective pictures, and used the classifiers to decode affective states of an out-of-sample participant both during picture viewing and during movie-trailer watching. Within participants, neural classifiers identified valence and arousal categories of pictures, and tracked self-reported valence and arousal during video watching. In aggregate, neural classifiers produced valence and arousal time series that tracked the dynamic ratings of the movie-trailers obtained from a separate sample. Our findings provide further support for the possibility of using pre-trained neural representations to decode dynamic affective responses during a naturalistic experience.

Lip-Reading Enables the Brain to Synthesize Auditory Features of Unknown Silent Speech.

Lip-reading is crucial for understanding speech in challenging conditions. But how the brain extracts meaning from, silent, visual speech is still under debate. Lip-reading in silence activates the auditory cortices, but it is not known whether such activation reflects immediate synthesis of the corresponding auditory stimulus or imagery of unrelated sounds. To disentangle these possibilities, we used magnetoencephalography to evaluate how cortical activity in 28 healthy adult humans (17 females) entrained to the auditory speech envelope and lip movements (mouth opening) when listening to a spoken story without visual input (audio-only), and when seeing a silent video of a speaker articulating another story (video-only). In video-only, auditory cortical activity entrained to the absent auditory signal at frequencies <1 Hz more than to the seen lip movements. This entrainment process was characterized by an auditory-speech-to-brain delay of ∼70 ms in the left hemisphere, compared with ∼20 ms in audio-only. Entrainment to mouth opening was found in the right angular gyrus at <1 Hz, and in early visual cortices at 1-8 Hz. These findings demonstrate that the brain can use a silent lip-read signal to synthesize a coarse-grained auditory speech representation in early auditory cortices. Our data indicate the following underlying oscillatory mechanism: seeing lip movements first modulates neuronal activity in early visual cortices at frequencies that match articulatory lip movements; the right angular gyrus then extracts slower features of lip movements, mapping them onto the corresponding speech sound features; this information is fed to auditory cortices, most likely facilitating speech parsing.SIGNIFICANCE STATEMENT Lip-reading consists in decoding speech based on visual information derived from observation of a speaker's articulatory facial gestures. Lip-reading is known to improve auditory speech understanding, especially when speech is degraded. Interestingly, lip-reading in silence still activates the auditory cortices, even when participants do not know what the absent auditory signal should be. However, it was uncertain what such activation reflected. Here, using magnetoencephalographic recordings, we demonstrate that it reflects fast synthesis of the auditory stimulus rather than mental imagery of unrelated, speech or non-speech, sounds. Our results also shed light on the oscillatory dynamics underlying lip-reading.

The benefit (and cost) of drawing as an encoding strategy.

Drawing, as an encoding strategy for to-be-remembered words, has previously been shown to provide robust memory benefits. In the current study, we investigated the effect of drawing on false memory endorsements during a recognition test. We found that while drawing led to higher hit rates relative to writing (Experiment 1) and creating visual mental imagery (Experiment 2), it also led to higher false alarm (FA) rates to critical lures in a variant of the Deese-Roediger-McDermott (DRM) paradigm. When compared with an encoding strategy requiring listing of object features (Experiment 3), drawing led to a lower FA rate. We suggest that drawing enhances memory by promoting recollection of rich visual contextual information during retrieval, and this leads to the unintended side effect of increasing FA rates to related information.

Auditory and Semantic Cues Facilitate Decoding of Visual Object Category in MEG.

Sounds (e.g., barking) help us to visually identify objects (e.g., a dog) that are distant or ambiguous. While neuroimaging studies have revealed neuroanatomical sites of audiovisual interactions, little is known about the time course by which sounds facilitate visual object processing. Here we used magnetoencephalography to reveal the time course of the facilitatory influence of natural sounds (e.g., barking) on visual object processing and compared this to the facilitatory influence of spoken words (e.g., "dog"). Participants viewed images of blurred objects preceded by a task-irrelevant natural sound, a spoken word, or uninformative noise. A classifier was trained to discriminate multivariate sensor patterns evoked by animate and inanimate intact objects with no sounds, presented in a separate experiment, and tested on sensor patterns evoked by the blurred objects in the 3 auditory conditions. Results revealed that both sounds and words, relative to uninformative noise, significantly facilitated visual object category decoding between 300-500 ms after visual onset. We found no evidence for earlier facilitation by sounds than by words. These findings provide evidence for a semantic route of facilitation by both natural sounds and spoken words, whereby the auditory input first activates semantic object representations, which then modulate the visual processing of objects.

The effects of visual distractors on cognitive load in a motor imagery brain-computer interface.

A brain-computer interface (BCI) is a system that translates neural activity into a practical output. Its functionality, therefore, depends not only on the computer itself, but also on the cognitive system of the user. Distractors have the potential to capture attention, increase cognitive load, and may therefore impact BCI use. The purpose of the current study is to determine the effects of small visual distractors on the cognitive load of users of a motor imagery-BCI, and to examine whether these distractor-mediated effects can be improved by modifying the task interface. Sixteen typically-developed participants completed two sessions of online motor imagery to control an EEG-BCI, under conditions of no distractors, visual distractors, and cognitive strategies (intended to mitigate cognitive load) amid distractors. Cognitive load for each session was assessed through both a ratio of theta to alpha power and the NASA-Task Load Index (NASA-TLX). Task-irrelevant visual stimuli were found to significantly increase the objective measure of cognitive load, particularly for parietal channels. Subjective cognitive load as indexed by the NASA-TLX was predictive of a decrease in BCI performance for participants with below 0.75 classification accuracy (R2 = 0.32, p < 0.001), which may indicate a differential susceptibility to changes in workload for "low"-performing participants. Quantifying and addressing the increased cognitive load imparted by distractors on BCI users can aid in the future applicability of the technology in real-world settings.

Children Learn to Read: How Visual Analysis and Mental Imagery Contribute to the Reading Performances at Different Stages of Reading Acquisition.

Reading in alphabetic orthography requires analysis and recognition of specific attributes of visual stimuli, and generation, reactivation, and use of mental images of letters and words. This study evaluated the role of visual analysis and mental imagery in reading performances of students at different stages of reading acquisition. Reading "comprehension," "accuracy," and "speed," were analyzed. Participants were 90 children who attended primary school. Children were assessed in the first and third grade. The results highlighted that mental imagery and visual analysis influenced reading acquisition. These abilities are differently involved in the three dimensions of reading skill. The issues of this study have practical and educational applications. The early assessment of visual analysis and mental imagery skills and specific training on these abilities could contribute to facilitate reading acquisition. Strategies of intervention centered on visual imagery could increase reading performances in typically developing children and children at risk of learning difficulties.

Resting state network plasticity related to picture naming in low-grade glioma patients before and after resection.

The dynamic connectome perspective states that brain functions arise from the functional integration of distributed and/or partly overlapping networks. Diffuse low-grade gliomas (DLGG) have a slow infiltrating character. Here we addressed whether and how anatomical disconnection following DLGG growth and resection might interfere with functional resting-state connectivity, specifically in relation to picture naming. Thirty-nine native French persons with a left DLGG were included. All underwent awake surgical resection of the tumor using direct brain electrostimulation to preserve critical eloquent regions. The anatomical disconnectivity risk following the DLGG volume and the resection, and the functional connectivity of resting-state fMRI images in relation to picture naming were evaluated prior to and three months after surgery. Resting-state connectivity patterns were compared with nineteen healthy controls. It was demonstrated that picture naming was strongly dependent on the semantic network that emerged from the integration and interaction of regions within multiple resting-state brain networks, in which their specific role could be explained in the light of the broader resting-state network they take part in. It emphasized the importance of a whole brain approach with specific clinical data input, during resting-state analysis in case of lesion. Adaptive plasticity was found in secondary regions, functionally connected to regions close to the tumor and/or cavity, marked by an increased connectivity of the right and left inferior parietal lobule with the left inferior temporal gyrus. In addition, an important role was identified for the superior parietal lobe, connected with the frontal operculum, suggesting functional compensation by means of attentional resources in order to name a picture via recruitment of the frontoparietal attention network.

The hippocampus as a visual area organized by space and time: A spatiotemporal similarity hypothesis.

The hippocampus is the canonical memory system in the brain and is not typically considered part of the visual system. Yet, it sits atop the ventral visual stream and has been implicated in certain aspects of vision. Here I review the place of the hippocampal memory system in vision science. After a brief primer on the local circuity, external connectivity, and computational functions of the hippocampus, I explore what can be learned from each field about the other. I first present four areas of vision science (scene perception, imagery, eye movements, attention) that challenge our current understanding of the hippocampus in terms of its role in episodic memory. In the reverse direction, I leverage this understanding to inform vision science in other ways, presenting a working hypothesis about a unique form of visual representation. This spatiotemporal similarity hypothesis states that the hippocampus represents objects according to whether they co-occur in space and/or time, and not whether they look alike, as elsewhere in the visual system. This tuning may reflect hippocampal mechanisms of pattern separation, relational binding, and statistical learning, allowing the hippocampus to generate visual expectations to facilitate search and recognition.

Task-uninformative visual stimuli improve auditory spatial discrimination in humans but not the ideal observer.

In order to survive and function in the world, we must understand the content of our environment. This requires us to gather and parse complex, sometimes conflicting, information. Yet, the brain is capable of translating sensory stimuli from disparate modalities into a cohesive and accurate percept with little conscious effort. Previous studies of multisensory integration have suggested that the brain's integration of cues is well-approximated by an ideal observer implementing Bayesian causal inference. However, behavioral data from tasks that include only one stimulus in each modality fail to capture what is in nature a complex process. Here we employed an auditory spatial discrimination task in which listeners were asked to determine on which side they heard one of two concurrently presented sounds. We compared two visual conditions in which task-uninformative shapes were presented in the center of the screen, or spatially aligned with the auditory stimuli. We found that performance on the auditory task improved when the visual stimuli were spatially aligned with the auditory stimuli-even though the shapes provided no information about which side the auditory target was on. We also demonstrate that a model of a Bayesian ideal observer performing causal inference cannot explain this improvement, demonstrating that humans deviate systematically from the ideal observer model.