Revisiting Snodgrass and Vanderwart's object pictorial set: the role of surface detail in basic-level object recognition

Eye movements as a measure of word comprehension deficits in primary progressive aphasia

INTRODUCTION

Eye movement studies can uncover subtle aspects of language processing impairment in individuals with primary progressive aphasia (PPA), who may have difficulty understanding words. This study examined eye movement patterns on a word-object matching task in response to varying levels of word-knowledge in PPA.

METHODS

Participants with semantic and non-semantic PPA completed an object-matching task, where a word was presented and participants then selected the corresponding pictured object from an array. Afterwards, participants defined words for trials to which they incorrectly pointed. Linear mixed-effects analyses examined fixation differences on targets and related and unrelated foils.

RESULTS

On incorrectly-pointed trials, participants demonstrated greater fixation duration on related foils, demonstrating intra-category blurring. For words that could not be defined, there was similar fixation duration on related and unrelated foils, demonstrating inter-category semantic blurring.

DISCUSSION

This study demonstrated that fixation patterns reflect varying levels of word knowledge in PPA.

An individualized functional magnetic resonance imaging protocol to assess semantic congruency effects on episodic memory in an aging multilingual population

The cognitive stimulation induced by multilingualism may slow down age-related memory impairment. However, a suitable neuroscientific framework to assess the influence of multilingualism on age-related memory processes is missing. We propose an experimental paradigm that assesses the effects of semantic congruency on episodic memory using functional magnetic resonance imaging (fMRI). To this end, we modified the picture-word interference (PWI) task to be suitable for the assessment of older multilingual subjects undergoing fMRI. In particular, stimulus materials were prepared in multiple languages (French, German, Luxembourgish, English) and closely matched in semantic properties, thus enabling participants to perform the experiment in a language of their choice. This paradigm was validated in a group (n = 62) of healthy, older participants (over 64 years) who were multilingual, all practicing three or more languages. Consistent with the engagement of semantic congruency processes, we found that the encoding and recognition of semantically related vs. unrelated picture-word pairs evoked robust differences in behavior and the neural activity of parietal-temporal networks. These effects were negligibly modulated by the language used to perform the task. Based on this validation in a multilingual population, we conclude that the proposed paradigm will allow future studies to evaluate whether multilingualism aptitude engages neural systems in a manner that protects long-term memory from aging-related decline.

The Multilingual Picture Database

The growing interdisciplinary research field of psycholinguistics is in constant need of new and up-to-date tools which will allow researchers to answer complex questions, but also expand on languages other than English, which dominates the field. One type of such tools are picture datasets which provide naming norms for everyday objects. However, existing databases tend to be small in terms of the number of items they include, and have also been normed in a limited number of languages, despite the recent boom in multilingualism research. In this paper we present the Multilingual Picture (Multipic) database, containing naming norms and familiarity scores for 500 coloured pictures, in thirty-two languages or language varieties from around the world. The data was validated with standard methods that have been used for existing picture datasets. This is the first dataset to provide naming norms, and translation equivalents, for such a variety of languages; as such, it will be of particular value to psycholinguists and other interested researchers. The dataset has been made freely available.

Argentinean Psycholinguistic Picture Naming Test in color

Color has demonstrated to have an influence on picture naming tasks. Objects with high color diagnosticity are recalled faster than objects with low value. That is why the Argentinean Psycholinguistic Picture Naming Test in color (PAPDIC in Spanish) was designed. The items and semantic cues were built considering local psycholinguistic norms. A series of psychometric analyses were performed on a sample of patients with focal brain damage with (n = 11) and without (n = 14) aphasia, a sample of patients with degenerative disease (n = 46) and two samples of healthy participants (young n = 27, old n = 50). Evidence of convergent validity was obtained through the correlation with the brief Boston Naming Test (r = 0.871; p < .001); of criteria validity by means of contrasted groups analysis (t = 4.059, p < .001), and through the ROC curve analysis (AUC = 0.993). Scores' reliability was explored by means of an internal consistency analysis (KR20 = 0.905). These results indicate that the PAPDIC is a promising color naming test which can be applied in the field of clinical neuropsychology to identify anomia. This test has several advantages in comparison with the available naming tests in Argentina.

Pattern reinstatement and attentional control overlap during episodic long-term memory retrieval

Episodic long-term memory (eLTM) retrieval involves the reinstatement of neural patterns from the encoding phase. However, recent evidence suggests that comparable cortical activity patterns can also be linked to attentional control processes on the level of memory representations. The current investigation assesses these two processes independently based on alpha-beta-band activity in the electroencephalogram (EEG). During encoding, subjects were presented with an object on a certain position on the screen and had to imagine it on a new position. In each trial, either the task-irrelevant presentation position or the task-relevant imagination position was lateralized. In the retrieval phase, subjects first made an old/new judgement based on centrally presented objects and then reported the imagination position. Pattern reinstatement should be reflected in similar lateralized alpha-beta activity during encoding and retrieval. Conversely, the influence of attentional control processes during retrieval would be associated with the suppression of alpha-beta power contralateral to the to-be-reported imagination position and with the increase of activity contralateral to the irrelevant presentation position. Our results support this latter pattern. This shows that an experimental differentiation between selective attention and pattern reinstatement processes is necessary when studying the neural basis of eLTM retrieval.

Aesthetic Preference for Negatively-Valenced Artworks Remains Stable in Pathological Aging: A Comparison Between Cognitively Impaired Patients With Alzheimer's Disease and Healthy Controls

Background

Despite severe cognitive dysfunction in Alzheimer's disease (AD), aesthetic preferences in AD patients seem to retain some stability over time, similarly to healthy controls. However, the underlying mechanisms of aesthetic preference stability in AD remain unclear. We therefore aimed to study the role of emotional valence of stimuli for stability of aesthetic preferences in patients with AD compared to cognitively unimpaired elderly adults.

Methods

Fifteen AD patients (Mini-Mental State Examination (MMSE) score 12–26) without visual impairment and/or psychiatric disorder, as well as 15 healthy controls without cognitive impairment (MMSE ≥ 27) matched in age, sex, art interest and highest level of education were included in this study. All participants were asked to rank-order eight artworks per stimulus category (positive, negative, neutral in emotional valence) according to their preference twice with a 2-week span in-between. Based on these two rankings a preference change score was calculated. In order to assess explicit recognition memory of the artworks in the second testing session, four artworks of each stimulus category used in the preference ranking task were presented together with a content-matched distractor artwork painted by the same artist. Participants had to indicate which of the stimuli they had seen 2 weeks previously.

Results

AD patients [MMSE (M) = 18.9 ± 3.6; Age (M) = 85.4 ± 6.9; 33.3% male] had no explicit recognition memory of the artworks (recognition at chance level), whereas healthy controls [MMSE (M) = 27.7 ± 1.4; Age (M) = 84.3 ± 6.7; 33.3% male] correctly recognized 85% of stimuli after 2 weeks. AD patients had equally stable preferences compared to the control group for negative artworks, but less stable preferences for positive and neutral images (Bonferroni-corrected significance levels; p < 0.017).

Conclusion

Even in cognitively impaired AD patients, aesthetic preference for negatively-valenced artworks remains relatively stable. Our study provides novel evidence that AD patients may have a somewhat preserved implicit valence system for negative compared to neutral or positive visual information, especially in the domain of aesthetics. However, more studies need to further uncover the details of the underlying neurocognitive mechanisms of preference stability in pathological aging.

Developmental differences in processing the valence and magnitude of incentive cues: Mid-adolescents are more sensitive to potential gains than early- or late-adolescents

Recent research has focused on the interaction between motivation and cognitive control and shown that both are important for goal-directed behavior. There also is evidence for developmental differences in the sensitivity and behavioral effectiveness of incentives, showing that mid-adolescents might be especially susceptible to rewards. Further pursuing this line of research, the present study examined developmental differences in incentive processing and whether these potential differences also would correspond to changes in cognitive control. We compared the processing of high and low potential gains and losses in early-, mid-, and late adolescents by means of event-related potentials (ERPs) and examined whether these incentives also led to specific performance differences in task-switching. We expected that potential gains compared to potential losses and high compared to low incentives would lead to more preparatory updating as reflected in the P3b and consequently to better task performance and smaller global and local switch costs as indicators of cognitive control in all age groups. Furthermore, we expected that mid-adolescents should be especially sensitive to high gains and thus show the most pronounced enhancements in task performance and global and local switch costs in trials with high gains, respectively. Our results corroborate the idea of a special sensitivity to high rewards during mid-adolescence. The analysis of ERPs showed age-related differences in the processing of incentive cues that also varied with cognitive control demands. However, the different incentives did not impact age-related differences in indices of cognitive control, but had a general effect on response speed.

A Color-Picture Version of Boston Naming Test Outperformed the Black-and-White Version in Discriminating Amnestic Mild Cognitive Impairment and Mild Alzheimer's Disease

Despite the ubiquity of the Boston naming test (BNT) in clinical practice and research, concerns have been expressed about its poor quality pictures, insufficient psychometric properties, and cultural bias in non-English language backgrounds. We modified the black-and-white BNT with a set of color pictures since color effects have been suggested to improve naming accuracy in the visual naming test. This study aimed to examine and compare the reliability and validity of the color-picture version of BNT (CP-BNT) and the black-and-white version of BNT (BW-BNT) to differentiate amnestic mild cognitive impairment (aMCI) or mild Alzheimer's disease (AD) from the cognitive normals. This study included two subgroups, and each subgroup had 101 normal controls, 51 aMCI, and 52 mild AD. One subgroup undertook BW-BNT and the other conducted CP-BNT. The reliability, convergent and discriminant validity, and the diagnostic accuracy of two versions of BNT were evaluated. The CP-BNT showed a greater area under the curve (AUC) than the BW-BNT for aMCI (80.3 vs.s 69.4%) and mild AD (93.5 vs. 77.6%). The CP-BNT also demonstrated better convergent validity with CDR global scores and better reliability (Cronbach's coefficient 0.66 for the CP-BNT vs. 0.55 for the BW-BNT). At the optimal cutoff value of spontaneous naming, the CP-BNT demonstrated improved sensitivity and specificity for differentiating mild AD from NC with a higher positive predictive value, negative predictive value, and lower false-positive rate. Compared with BW-BNT, CP-BNT is a more reliable and valid test to assess cognitive and naming impairment.

ERP Correlates of Prospective Memory and Cue Focality in Children

Prospective memory (PM) is essential in the everyday activities of children because it involves remembering intentions for the future, such as doing their homework or bringing written parental permissions to school. Developmental studies have shown increases in PM performance throughout childhood, but the specific processes underlying this development are still under debate. In the present study, event-related potentials were used to examine whether the focality of the PM task is related to the PM increments by testing two groups of children (first and last cycle of primary school) and assessing differences in N300 (cue detection), frontal positivity (switching), parietal positivity (retrieval of the intention) and frontal slow waves (monitoring of the retrieved intention). The results showed significant differences in focality in the group of older children but no differences in any of the components for their younger counterparts. In addition, the differences between prospective and ongoing trials were smaller for younger than older children. These findings suggest that the ability to adjust attentional strategies, monitor, switch and retrieve the intention develops across childhood and affects PM performance in attentionally demanding conditions.

Standardizing norms for 180 coloured Snodgrass and Vanderwart pictures in Kannada language

This study presents normative data in Kannada for 180 coloured Snodgrass & Vanderwart pictures. Data are presented for naming latency, image agreement, picture-name agreement, familiarity, visual complexity, and age of acquisition (AoA). Sixty-eight native Kannada speaking adults completed all tasks. The effects of the rated variables on naming latency were examined and compared with data on the same variables in other languages. A regression analysis revealed that image agreement, name agreement, familiarity, and age of acquisition all had a significant impact on naming latency, while visual complexity and frequency did not. Although, the correlations among rated variables in Kannada were equivalent to previous normative studies, the cross-linguistic comparison revealed that only AoA was strongly correlated with other studies. The findings point to the importance of understanding the interplay of psycholinguistic variables on naming latency in different languages.

LinguaPix database: A megastudy of picture-naming norms

The major aim of the present megastudy of picture-naming norms was to address the shortcomings of the available picture data sets used in psychological and linguistic research by creating a new database of normed colour images that researchers from around the world can rely upon in their investigations. In order to do this, we employed a new form of normative study, namely a megastudy, whereby 1620 colour photographs of items spanning across 42 semantic categories were named and rated by a group of German speakers. This was done to establish the following linguistic norms: speech onset times (SOT), name agreement, accuracy, familiarity, visual complexity, valence, and arousal. The data, including over 64,000 audio files, were used to create the LinguaPix database of pictures, audio recordings, and linguistic norms, which to our knowledge, is the largest available research tool of its kind ( http://linguapix.uni-mannheim.de ). In this paper, we present the tool and the analysis of the major variables.

Icon Design for Representing Safety-Critical Aircraft Functions to Support Supervisory Control of Remotely Piloted Aircraft Systems

(1) Background: The transition from conventional to remote aircraft control will necessitate the development of novel human machine interfaces. When we consider the pilot interface, icons are traditionally used to associate meanings with functions on the flight deck, allowing the pilot to assimilate information effectively. Using established icon design principles, 18 icons, representing key safety-critical functions related to the operation of an aircraft, were designed for integration into a ground station. Pilots were then asked to evaluate these icons based on established icon characteristics. (2) Method: In an online questionnaire study, 29 pilots rated the icons on the icon characteristics of concreteness, complexity, familiarity, meaningfulness, and semantic distance. Alongside these metrics, concept and name agreement were captured for the icon set. (3) Results: Analysis indicated good icon-function fit overall. The findings show that emphasizing concreteness and familiarity improves icon-function fit, as long as the familiarity is directed at aviation-related artifacts. Further, concept agreement appears to be a better measure of icon-function fit in comparison to name agreement. (4) Conclusion: Most of the designed icons were well suited to represent their intended meaning. However, this study emphasizes the need for dedicated standardized icon characteristic norms for aviation systems.

Grammatical Gender in Spoken Word Recognition in School-Age Spanish-English Bilingual Children

This study investigated grammatical gender processing in school-age Spanish-English bilingual children using a visual world paradigm with a 4-picture display where the target noun was heard with a gendered article that was either in a context where all distractor images were the same gender as the target noun (same gender; uninformative) or in a context where all distractor images were the opposite gender than the target noun (different gender; informative). We investigated 32 bilingual children (ages 5;6-8;6) who were exposed to Spanish since infancy and began learning English by school entry. Along with the eye-tracking experiment, all children participated in a standardized language assessment and told narratives in English and Spanish, and parents reported on their child's current Spanish language use. The differential proportion fixations to target (target - averaged distractor fixations) were analyzed in two time regions with linear mixed-effects models (LME). Results show that prior to the target word being spoken, these bilingual children did not use the gendered articles to actively anticipate upcoming nouns. In the subsequent time region (during the noun), it was shown that there are differences in the way they use feminine and masculine articles, with a lack of use of the masculine article and a potential facilitatory use of the feminine article for children who currently use more Spanish than English. This asymmetry in the use of gendered articles in processing is modulated by current Spanish language use and trends with results found for bilingual and second-language learning adults.

When Language Switching is Cost-Free: The Effect of Preparation Time

Previous research has shown that language switching is costly, and that these costs are likely to persist even when speakers are given ample time to prepare. The aim of this study was to determine whether there are cognitive limitations to speakers' ability to prepare for a switch, or whether a new language can be prepared in advance and any cost to switch language eliminated. To explore this, language switching costs were measured in a group of Dutch-English (L1-L2) bilinguals who named pictures in their two languages while the preparation time was manipulated. The participants were given either no time to prepare (cue to stimulus interval, CSI: 0 ms), or some time to prepare, for the target language (CSI: 250, 500, and 800 ms). The results revealed that when speakers had no time to prepare, language switching was costly. However, when preparation time was provided, switching costs disappeared. This suggests that there might be no cognitive limitations to the ability to prepare for a language switch, and that, provided enough preparation time, the effort to switch language could be eliminated. This finding might also explain why normal code-switched conversations seem effortless, as speakers typically have ample time to prepare for the language switch.

Prospective memory in bilinguals and monolinguals: ERP and behavioural correlates of prospective processing in bilinguals

Prospective memory (PM) allows us to form intentions and execute them in the future. Successful retrieval of prospective intentions depends on adequate context monitoring and disengagement from the ongoing task. These processes are also central in predicting incoming language information and guiding language production in bilinguals. We investigated if different bilingual experiences (early/late bilinguals, monolinguals) modulate performance in PM tasks that varied in attentional requirements (focal vs. non-focal). Behavioural and event-related potential (ERP) results indicated that early bilinguals differed from late bilinguals and monolinguals in how they performed the prospective task. Specifically, they showed larger differences between the ongoing activity and the prospective task in the N300 and P3b components when performing the more difficult non-focal PM task, indicating that they engaged in monitoring/updating to adapt to the task's demands. These differences were not observed in late bilinguals and monolinguals, suggesting that prospective processing is dependent on the bilingual experience.

Alterations in Neural Networks During Working Memory Encoding Related to Cognitive Impairment in Temporal Lobe Epilepsy

Objective: The aim of the current study was to investigate the alterations in the neural networks of patients with temporal lobe epilepsy (TLE) during working memory (WM) encoding.

Methods: Patients with TLE (n = 52) and healthy volunteers (n = 35) completed a WM task, during which 34-channel electroencephalogram signals were recorded. The neural networks during WM encoding were calculated in TLE patients with (TLE-WM) and without (TLE-N) WM deficits.

Results: Functional connectivity strength decreased, and the theta network was altered in the TLE-WM group, although no significant differences in clinical features were observed between the TLE-N and TLE-WM groups.

Conclusions: Not all patients with TLE present with cognitive impairments and alterations in the theta network were identified in TLE patients with functional cognitive deficits.

Significance: The theta network may represent a sensitive measure of cognitive impairment and could predict cognitive outcomes among patients with TLE.

Using temporo-spatial principal component analysis as tool to dissociate latent ERP components of episodic memory retrieval: Objectifying time-window selection for overlapping ERP components

This report details how principal component analysis (PCA) can be used as a valuable tool to dissociate latent ERP components, even when considerable temporal and spatial overlap makes it difficult to discern ERP effects in standard time windows. We illustrate our methodological approach in a data set from a recognition memory paradigm, in which event-related potential (ERP) correlates of familiarity, recollection and the late parietal negativity (LPN) were partially overlapping. By adapting standard time windows based on the results of a temporo-spatial PCA, small yet reliable ERP correlates reflecting familiarity and recollection for identical items and late recollection for changed items were identified, complementing the result pattern observed in behavioral performance. Due to similar temporo-spatial characteristics and opposing polarities in late parietal ERP correlates associated with memory retrieval, component overlap is often observed in this field of research. Hence, the complex interplay of several processes underlying higher cognitive functions such as memory retrieval may interfere with standard ERP assessment. In such instances, PCA can provide promising ways to objectively assess time window selection for subsequent ERP analyses.

Task-domain and hemisphere-asymmetry effects in cisgender and transmale individuals

The present research examined the extent to which transmale individuals’ functional brain organization resembles that of their assigned sex or gender identity. Cisgender-female, cisgender-male, and transmale participants, who were assigned female sex but did not have a female gender identity, were compared in terms of effects that have been observed in cisgender individuals: task-domain effects, in which males perform better than females on spatial tasks and females perform better than males on verbal tasks; and hemisphere-asymmetry effects, in which males show larger differences between the left and right hemispheres than females. In addition, the present research measured participants’ intelligence in order to control for potential moderating effects. Participants performed spatial (mental rotation) and verbal (lexical decision) tasks presented to each hemisphere using a divided-visual field paradigm, and then completed an intelligence assessment. In the mental-rotation task, cismale and transmale participants performed better than cisfemale participants, however this group difference was explained by intelligence scores, with higher scores predicting better performance. In the lexical-decision task, cismale and transmale participants exhibited a greater left-hemisphere advantage than cisfemales, and this difference was not affected by intelligence scores. Taken together, results do not support task-domain effects when intelligence is accounted for; however, they do demonstrate a hemisphere-asymmetry effect in the verbal domain that is moderated by gender identity and not assigned sex.

Veritable Untruths: Autistic Traits and the Processing of Deception

How do we decide whether a statement is literally true? Here, we contrast participants’ eventual evaluations of a speaker’s meaning with the real-time processes of comprehension. We record participants’ eye movements as they respond to potentially misleading instructions to click on one of two objects which might be concealing treasure (the treasure is behind thee, uh, hat). Participants are less likely to click on the named object when the instructions are disfluent. However, when hearing disfluent utterances, a tendency to fixate the named object early increases with participants’ autism quotient scores. This suggests that, even where utterances are equivalently understood, the processes by which interpretations are achieved vary across individuals.

The role of contextual materials in object recognition

While scene context is known to facilitate object recognition, little is known about which contextual "ingredients" are at the heart of this phenomenon. Here, we address the question of whether the materials that frequently occur in scenes (e.g., tiles in a bathroom) associated with specific objects (e.g., a perfume) are relevant for the processing of that object. To this end, we presented photographs of consistent and inconsistent objects (e.g., perfume vs. pinecone) superimposed on scenes (e.g., a bathroom) and close-ups of materials (e.g., tiles). In Experiment 1, consistent objects on scenes were named more accurately than inconsistent ones, while there was only a marginal consistency effect for objects on materials. Also, we did not find any consistency effect for scrambled materials that served as color control condition. In Experiment 2, we recorded event-related potentials and found N300/N400 responses-markers of semantic violations-for objects on inconsistent relative to consistent scenes. Critically, objects on materials triggered N300/N400 responses of similar magnitudes. Our findings show that contextual materials indeed affect object processing-even in the absence of spatial scene structure and object content-suggesting that material is one of the contextual "ingredients" driving scene context effects.

Volitional learning promotes theta phase coding in the human hippocampus

While behavioral evidence shows that volitionally controlled learning benefits human memory, little is known about the neural mechanisms underlying this effect. Insights from spatial navigation research in rodents point to the relevance of hippocampal theta oscillations. However, the mechanisms through which theta might support the beneficial effects of active learning in humans are currently unknown. Here, we demonstrate hippocampal theta oscillations increase during volitional learning, promoting a segregation of task-relevant representational signals according to their semantic content. Our results constitute a direct link to the animal literature on hippocampal theta oscillations and its relation to volition and memory processes.

Electrophysiological studies in rodents show that active navigation enhances hippocampal theta oscillations (4–12 Hz), providing a temporal framework for stimulus-related neural codes. Here we show that active learning promotes a similar phase coding regime in humans, although in a lower frequency range (3–8 Hz). We analyzed intracranial electroencephalography (iEEG) from epilepsy patients who studied images under either volitional or passive learning conditions. Active learning increased memory performance and hippocampal theta oscillations and promoted a more accurate reactivation of stimulus-specific information during memory retrieval. Representational signals were clustered to opposite phases of the theta cycle during encoding and retrieval. Critically, during active but not passive learning, the temporal structure of intracycle reactivations in theta reflected the semantic similarity of stimuli, segregating conceptually similar items into more distant theta phases. Taken together, these results demonstrate a multilayered mechanism by which active learning improves memory via a phylogenetically old phase coding scheme.

Attentional capture in multiple object tracking

Attentional processes are generally assumed to be involved in multiple object tracking (MOT). The attentional capture paradigm is regularly used to study conditions of attentional control. It has up to now not been used to assess influences of sudden onset distractor stimuli in MOT. We investigated whether attentional capture does occur in MOT: Are onset distractors processed at all in dynamic attentional tasks? We found that sudden onset distractors were effective in lowering probe detection, thus demonstrating attentional capture. Tracking performance as dependent measure was not affected. The attentional capture effect persisted in conditions of higher tracking load (Experiment 2) and was dramatically increased in lower presentation frequency of the onset distractor (Experiment 3). Tracking performance was shown to suffer only when onset distractors were presented serially with very short time gaps in between, thus effectively disturbing re-engaging attention on the tracking set (Experiment 4). We discuss that rapid dis- and re-engagement of the attention process on target objects and an additional more basic process that continuously provides location information allow managing strong disruptions of attention during tracking.

Distinct Neural Substrates Support Phonological and Orthographic Working Memory: Implications for Theories of Working Memory

Prior behavioral and neuroimaging evidence supports a separation between working memory capacities in the phonological and orthographic domains. Although these data indicate distinct buffers for orthographic and phonological information, prior neural evidence does indicate that nearby left inferior parietal regions support both of these working memory capacities. Given that no study has directly compared their neural substrates based on data from the same individuals, it is possible that there is a common left inferior parietal region shared by both working memory capacities. In fact, those endorsing an embedded processes account of working memory might suggest that parietal involvement reflects a domain-general attentional system that directs attention to long-term memory representations in the two domains, implying that the same neural region supports the two capacities. Thus, in this work, a multivariate lesion-symptom mapping approach was used to assess the neural basis of phonological and orthographic working memory using behavioral and lesion data from the same set of 37 individuals. The results showed a separation of the neural substrates, with regions in the angular gyrus supporting orthographic working memory and with regions primarily in the supramarginal gyrus supporting phonological working memory. The results thus argue against the parietal involvement as supporting a domain-general attentional mechanism and support a domain-specific buffer account of working memory.

Constant curvature segments as building blocks of 2D shape representation

How the visual system represents shape, and how shape representations might be computed by neural mechanisms, are fundamental and unanswered questions. Here, we investigated the hypothesis that 2-dimensional (2D) contour shapes are encoded structurally, as sets of connected constant curvature segments. We report 3 experiments investigating constant curvature segments as fundamental units of contour shape representations in human perception. Our results showed better performance in a path detection paradigm for constant curvature targets, as compared with locally matched targets that lacked this global regularity (Experiment 1), and that participants can learn to segment contours into constant curvature parts with different curvature values, but not into similarly different parts with linearly increasing curvatures (Experiment 2). We propose a neurally plausible model of contour shape representation based on constant curvature, built from oriented units known to exist in early cortical areas, and we confirmed the model's prediction that changes to the angular extent of a segment will be easier to detect than changes to relative curvature (Experiment 3). Together, these findings suggest the human visual system is specially adapted to detect and encode regions of constant curvature and support the notion that constant curvature segments are the building blocks from which abstract contour shape representations are composed. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Alterations in neural oscillations related to working memory deficit in temporal lobe epilepsy

OBJECTIVE

Working memory (WM) is critical for higher level cognition, but the underlying neural mechanisms are not fully understood. Impaired WM affects routine daily activities and is observed in patients with temporal lobe epilepsy (TLE). This study investigated neural oscillations associated with different WM phases, to determine the specific neural activity linked with the phases of WM impairment.

METHODS

Patients with TLE (n = 52) and healthy volunteers (n = 35) completed a WM task, during which 34-channel electroencephalogram signals were recorded. Characteristic neural oscillation patterns during each WM phase were compared between the 2 groups.

RESULTS

Patients with TLE showed decreased theta power during the encoding phase of WM, which was associated with reduced accuracy in the WM task. Altered theta power in the frontal region of the brain during the encoding phase was associated with a longer reaction time.

CONCLUSIONS

Alterations in theta oscillation are related to WM impairment in patients with TLE and may serve as an early marker for evaluating WM deficits.

SIGNIFICANCE

This study provides an early marker for evaluating WM deficits in TLE.

Did you hear? Auditory prospective memory cues are more beneficial for autistic than for non-autistic children and adolescents

BACKGROUND

The transition from primary to secondary school is particularly difficult for autistic children, a transition underpinned by an increase in prospective memory (PM) demands.

AIMS

To better understand PM in autistic children of the relevant age range and its underlying processes, the current study investigated the impact of cue salience (distinctiveness) on PM in autistic and non-autistic children and adolescents. The study was unique in manipulating the visual and auditory salience of PM cues. Salient cues are assumed to put lower demands on executive control resources as compared to cues that blend in with the ongoing activity.

METHODS AND PROCEDURES

The children completed a computer-based categorisation task in which an event-based PM task was embedded. The salience of PM cues was manipulated (low, high visual and high auditory salience).

OUTCOMES AND RESULTS

Results revealed that both groups benefitted from an increase in visual and auditory salience, but only autistic participants were faster to respond to auditory cues.

CONCLUSIONS AND IMPLICATIONS

Increased cue salience improved PM performance for all children. Positive effects of auditory cues were especially evident in autistic children.

An implicit task reveals space-time associations along vertical and diagonal axes

In previous studies investigating the space-time compatibility effect, the experimental task always invites explicit spatial or temporal processing or both. In this study, we kept space and time irrelevant to the task. In a go/no-go task, participants (N = 50) were asked to either press a single button when they found the target or refrain from responding when there was no target in a search array. We manipulated the duration of the target-alone presentation that preceded a 7 × 7 search array consisting of either target plus distractors or distractors alone. The results revealed faster responses to shorter durations when the target appeared in the upper relative to the lower space. A similar effect also appeared along the diagonal axis with faster responses to shorter durations in upper-left relative to lower-right space. In contrast, no such difference was found along the horizontal axis. We hypothesize that vertical and diagonal space-time associations arise from the grounding of mental representation of time in physical experiences.

Unraveling brain interactions in vision: The example of crowding

Crowding, the impairment of target discrimination in clutter, is the standard situation in vision. Traditionally, crowding is explained with (feedforward) models, in which only neighboring elements interact, leading to a "bottleneck" at the earliest stages of vision. It is with this implicit prior that most functional magnetic resonance imaging (fMRI) studies approach the identification of the "neural locus" of crowding, searching for the earliest visual area in which the blood-oxygenation-level-dependent (BOLD) signal is suppressed under crowded conditions. Using this classic approach, we replicated previous findings of crowding-related BOLD suppression starting in V2 and increasing up the visual hierarchy. Surprisingly, under conditions of uncrowding, in which adding flankers improves performance, the BOLD signal was further suppressed. This suggests an important role for top-down connections, which is in line with global models of crowding. To discriminate between various possible models, we used dynamic causal modeling (DCM). We show that recurrent interactions between all visual areas, including higher-level areas like V4 and the lateral occipital complex (LOC), are crucial in crowding and uncrowding. Our results explain the discrepancies in previous findings: in a recurrent visual hierarchy, the crowding effect can theoretically be detected at any stage. Beyond crowding, we demonstrate the need for models like DCM to understand the complex recurrent processing which most likely underlies human perception in general.

Parents Fine-Tune Their Speech to Children's Vocabulary Knowledge

Young children learn language at an incredible rate. Although children come prepared with powerful statistical-learning mechanisms, the statistics they encounter are also prepared for them: Children learn from caregivers motivated to communicate with them. How precisely do parents tune their speech to their children's individual language knowledge? To answer this question, we asked parent-child pairs (N = 41) to play a reference game in which the parents' goal was to guide their child to select a target animal from a set of three. Parents fine-tuned their referring expressions to their children's knowledge at the lexical level, producing more informative references for animals they thought their children did not know. Further, parents learned about their children's knowledge over the course of the game and tuned their referring expressions accordingly. Child-directed speech may thus support children's learning not because it is uniformly simplified but because it is tuned to individual children's language development.

How do phonological awareness, rapid automatized naming, and vocabulary contribute to early numeracy and print knowledge of Filipino children?

The current study investigated the contributions of phonological awareness, rapid automatized naming (RAN), and vocabulary to early numeracy and print knowledge developmental trajectories. A total of 128 young Filipino children were tracked three times at mean ages of 4.5, 5.0, and 5.5 years. The initial level (the intercept) and the growth rate (the slope) of early numeracy and print knowledge were estimated. Results showed that phonological awareness, vocabulary, and age significantly predicted the initial level of early numeracy. RAN and vocabulary explained significant variance in the growth rate of early numeracy. Phonological awareness, RAN, and vocabulary accounted for unique variance in the initial level of print knowledge. Results highlight the differential roles of phonological awareness, RAN, and vocabulary knowledge in the development of early numeracy and print knowledge among Filipino children.

Bidirectional propagation of low frequency oscillations over the human hippocampal surface

The hippocampus is diversely interconnected with other brain systems along its axis. Cycles of theta-frequency activity are believed to propagate from the septal to temporal pole, yet it is unclear how this one-way route supports the flexible cognitive capacities of this structure. We leveraged novel thin-film microgrid arrays conformed to the human hippocampal surface to track neural activity two-dimensionally in vivo. All oscillation frequencies identified between 1-15 Hz propagated across the tissue. Moreover, they dynamically shifted between two roughly opposite directions oblique to the long axis. This predominant propagation axis was mirrored across participants, hemispheres, and consciousness states. Directionality was modulated in a participant who performed a behavioral task, and it could be predicted by wave amplitude topography over the hippocampal surface. Our results show that propagation directions may thus represent distinct meso-scale network computations, operating along versatile spatiotemporal processing routes across the hippocampal body.

A new type of pictorial database: The Bicolor Affective Silhouettes and Shapes (BASS)

We introduce the Bicolor Affective Silhouettes and Shapes (BASS): a set of 583 normed black-and-white silhouette images that is freely available via https://osf.io/anej6/. Valence and arousal ratings were obtained for each image from US residents as a Western population (n = 777) and Chinese residents as an Asian population (n = 869). Importantly, the ratings demonstrate that, notwithstanding their visual simplicity, the images represent a wide range of affective content (from very negative to very positive, and from very calm to very intense). In addition, speaking to their cultural neutrality, the valence ratings correlated very highly between US and Chinese ratings. Arousal ratings were less consistent between the two samples, with larger discrepancies in the older age groups inviting further investigation. Due to their simplistic and abstract nature, our silhouette images may be useful for intercultural studies, color and shape perception research, and online stimulus presentation in particular. We demonstrate the versatility of the BASS by an example online experiment.

A Cross-Linguistic Study of Individual Differences in Speech Planning

Although previous research has shown that there exist individual and cross-linguistic differences in planning strategies during language production, little is known about how such individual differences might vary depending on which language a speaker is planning. The present series of studies examines individual differences in planning strategies exhibited by speakers of American English, French, and German. Participants were asked to describe images on a computer monitor while their eye movements were monitored. In addition, we measured participants' working memory capacity and speed of processing. The results indicate that in the present study, English and German were planned less incrementally (further in advance) prior to speech onset compared to French, which was planned more incrementally (not as far in advance). Crucially, speed of processing predicted the scope of planning for French speakers, but not for English or German speakers. These results suggest that the different planning strategies that are invoked by syntactic choices available in different languages are associated with the tendency for speakers to rely on different cognitive support systems as they plan sentences.

The Greek linguistic assessment for awake brain surgery: development process and normative data

Language mapping with direct electrical stimulation is considered the gold standard in surgical treatment of brain tumors. Assessing a variety of language functions intraoperatively can affect the extent of the tumor resection as well as the patient's postoperative quality of life. Although most tests include preoperative sessions where tasks are personalised to each patient, normative data are essential since they can ensure that the presented stimuli can be responded appropriately. In this study, we describe the development and standardisation procedures of the first linguistic test in Greek, designed specifically for brain mapping during awake craniotomies. The tasks are developed to comply with the special conditions and restrictions of language assessment inside the operating room. Each task is controlled for various psycholinguistic and lexical variables and it is associated with specific neuroanatomical areas and linguistic processes. Our population consists of 80 right-handed, healthy, Greek-speaking individuals aged 20-60 years. We found only a few main effects and interactions of demographic variables on our test scores. Most differences were found between age groups, since older participants tend to perform slightly worse than younger ones. Therefore, percentiles and cut-off scores were calculated separately for each demographic group. Regarding the clinical application of GLAABS, we describe the procedures we followed to administer it to brain tumor patients from our department and also discuss how sensitivity and specificity can affect patients' postoperative course.

No fruits without color: Cross-modal priming and EEG reveal different roles for different features across semantic categories

Category-specific impairments witnessed in patients with semantic deficits have broadly dissociated into natural and artificial kinds. However, how the category of food (more specifically, fruits and vegetables) fits into this distinction has been difficult to interpret, given a pattern of deficit that has inconsistently mapped onto either kind, despite its intuitive membership to the natural domain. The present study explores the effects of a manipulation of a visual sensory (i.e., color) or functional (i.e., orientation) feature on the consequential semantic processing of fruits and vegetables (and tools, by comparison), first at the behavioral and then at the neural level. The categorization of natural (i.e., fruits/vegetables) and artificial (i.e., utensils) entities was investigated via cross-modal priming. Reaction time analysis indicated a reduction in priming for color-modified natural entities and orientation-modified artificial entities. Standard event-related potentials (ERP) analysis was performed, in addition to linear classification. For natural entities, a N400 effect at central channel sites was observed for the color-modified condition compared relative to normal and orientation conditions, with this difference confirmed by classification analysis. Conversely, there was no significant difference between conditions for the artificial category in either analysis. These findings provide strong evidence that color is an integral property to the categorization of fruits/vegetables, thus substantiating the claim that feature-based processing guides as a function of semantic category.

Evaluating the evidence for expectation suppression in the visual system

Reports of expectation suppression have shaped the development of influential predictive coding-based theories of visual perception. However recent work has highlighted confounding factors that may mimic or inflate expectation suppression effects. In this review, we describe four confounds that are prevalent across experiments that tested for expectation suppression: effects of surprise, attention, stimulus repetition and adaptation, and stimulus novelty. With these confounds in mind we then critically review the evidence for expectation suppression across probabilistic cueing, statistical learning, oddball, action-outcome learning and apparent motion designs. We found evidence for expectation suppression within a specific subset of statistical learning designs that involved weeks of sequence learning prior to neural activity measurement. Across other experimental contexts, whereby stimulus appearance probabilities were learned within one or two testing sessions, there was inconsistent evidence for genuine expectation suppression. We discuss how an absence of expectation suppression could inform models of predictive processing, repetition suppression and perceptual decision-making. We also provide suggestions for designing experiments that may better test for expectation suppression in future work.

Reversal of neurovascular coupling in the default mode network: Evidence from hypoxia

Local changes in cerebral blood flow are thought to match changes in neuronal activity, a phenomenon termed neurovascular coupling. Hypoxia increases global resting cerebral blood flow, but regional cerebral blood flow (rCBF) changes are non-uniform. Hypoxia decreases baseline rCBF to the default mode network (DMN), which could reflect either decreased neuronal activity or altered neurovascular coupling. To distinguish between these hypotheses, we characterized the effects of hypoxia on baseline rCBF, task performance, and the hemodynamic (BOLD) response to task activity. During hypoxia, baseline CBF increased across most of the brain, but decreased in DMN regions. Performance on memory recall and motion detection tasks was not diminished, suggesting task-relevant neuronal activity was unaffected. Hypoxia reversed both positive and negative task-evoked BOLD responses in the DMN, suggesting hypoxia reverses neurovascular coupling in the DMN of healthy adults. The reversal of the BOLD response was specific to the DMN. Hypoxia produced modest increases in activations in the visual attention network (VAN) during the motion detection task, and had no effect on activations in the visual cortex during visual stimulation. This regional specificity may be particularly pertinent to clinical populations characterized by hypoxemia and may enhance understanding of regional specificity in neurodegenerative disease pathology.

Object-Location Memory Training in Older Adults Leads to Greater Deactivation of the Dorsal Default Mode Network

Substantial evidence indicates that cognitive training can be efficacious for older adults, but findings regarding training-related brain plasticity have been mixed and vary depending on the imaging modality. Recent years have seen a growth in recognition of the importance of large-scale brain networks on cognition. In particular, task-induced deactivation within the default mode network (DMN) is thought to facilitate externally directed cognition, while aging-related decrements in this neural process are related to reduced cognitive performance. It is not yet clear whether task-induced deactivation within the DMN can be enhanced by cognitive training in the elderly. We previously reported durable cognitive improvements in a sample of healthy older adults (age range = 60-75) who completed 6 weeks of process-based object-location memory training (N = 36) compared to an active control training group (N = 31). The primary aim of the current study is to evaluate whether these cognitive gains are accompanied by training-related changes in task-related DMN deactivation. Given the evidence for heterogeneity of the DMN, we examine task-related activation/deactivation within two separate DMN branches, a ventral branch related to episodic memory and a dorsal branch more closely resembling the canonical DMN. Participants underwent functional magnetic resonance imaging (fMRI) while performing an untrained object-location memory task at four time points before, during, and after the training period. Task-induced (de)activation values were extracted for the ventral and dorsal DMN branches at each time point. Relative to visual fixation baseline: (i) the dorsal DMN was deactivated during the scanner task, while the ventral DMN was activated; (ii) the object-location memory training group exhibited an increase in dorsal DMN deactivation relative to the active control group over the course of training and follow-up; (iii) changes in dorsal DMN deactivation did not correlate with task improvement. These results indicate a training-related enhancement of task-induced deactivation of the dorsal DMN, although the specificity of this improvement to the cognitive task performed in the scanner is not clear.