Fast Periodic Visual Stimulation Research Articles

Learned trustworthiness and face trustworthiness do not have the same influence on implicit responses to faces measured via fast periodic visual stimulation (FPVS)

Learned trustworthiness and face trustworthiness do not have the same influence on implicit responses to faces measured via fast periodic visual stimulation (FPVS)

Between faces: childhood adversity is associated with reduced threat-safety discrimination during facial expression processing in adolescence

BackgroundChildhood adversity has been associated with alterations in threat-related information processing, including heightened perceptual sensitivity and attention bias towards threatening facial expressions, as well as hostile attributions of neutral faces, although there is a large degree of variability and inconsistency in reported findings.MethodsHere, we aimed to implicitly measure neural facial expression processing in 120 adolescents between 12 and 16 years old with and without exposure to childhood adversity. Participants were excluded if they had any major medical or neurological disorder or intellectual disability, were pregnant, used psychotropic medication or reported acute suicidality or an ongoing abusive situation. We combined fast periodic visual stimulation with electroencephalography in two separate paradigms to assess the neural sensitivity and responsivity towards neutral and expressive, i.e. happy and angry, faces. Linear mixed effects models were used to assess the impact of childhood adversity on facial expression processing.ResultsSixty-six girls, 53 boys and one adolescent who identified as ‘other’, between 12 and 16 years old (M = 13.93), participated in the current study. Of those, 64 participants were exposed to childhood adversity. In contrast to our hypotheses, adolescents exposed to adversity show lower expression-discrimination responses for angry faces presented in between neutral faces and higher expression-discrimination responses for happy faces presented in between neutral faces than unexposed controls. Moreover, adolescents exposed to adversity, but not unexposed controls, showed lower neural responsivity to both angry and neutral faces that were simultaneously presented.ConclusionsWe therefore conclude that childhood adversity is associated with a hostile attribution of neutral faces, thereby reducing the dissimilarity between neutral and angry faces. This reduced threat-safety discrimination may increase risk for psychopathology in individuals exposed to childhood adversity.

Increased sensitivity to social hierarchy during social competition versus cooperation.

Social hierarchy is a typical feature of social organization. The ability to quickly recognize social hierarchy information is crucial for adapting to social contexts. Here, we adopted fast periodic visual stimulation with electroencephalography to assess the neural responses to social hierarchy during social competition and cooperation, respectively. Participants first learned hierarchical faces from a competitive game versus a cooperative game. We then sequentially presented the learned hierarchical faces with a specific frequency in a set of faces. Results showed that participants rated the inferior player as lower in the social hierarchy in the cooperative context compared to the competitive context, indicating that social context affects the judgment of others' rank. Moreover, higher neural responses to high and low-hierarchy faces versus medium-hierarchy faces were observed, suggesting rapid discrimination of social hierarchy from faces. Interestingly, rank-specific neural responses were more pronounced in the competitive context than in the cooperative context, indicating increased sensitivity to social hierarchy during social competition versus social cooperation. This study provides behavioral and neural evidence for rapid, automatic processing of social hierarchy information and for an increased sensitivity to such information in competitive versus cooperative social contexts.

Selective Neural Entrainment Reveals Hierarchical Tuning to Linguistic Regularities in Reading.

Reading is both a visual and a linguistic task, and as such it relies on both general-purpose, visual mechanisms and more abstract, meaning-oriented processes. Disentangling the roles of these resources is of paramount importance in reading research. The present study capitalizes on the coupling of fast periodic visual stimulation and MEG recordings to address this issue and investigate the role of different kinds of visual and linguistic units in the visual word identification system. We compared strings of pseudo-characters; strings of consonants (e.g., sfcl); readable, but unattested strings (e.g., amsi); frequent, but non-meaningful chunks (e.g., idge); suffixes (e.g., ment); and words (e.g., vibe); and looked for discrimination responses with a particular focus on the ventral, occipito-temporal regions. The results revealed sensitivity to alphabetic, readable, familiar, and lexical stimuli. Interestingly, there was no discrimination between suffixes and equally frequent, but meaningless endings, thus highlighting a lack of sensitivity to semantics. Taken together, the data suggest that the visual word identification system, at least in its early processing stages, is particularly tuned to form-based regularities, most likely reflecting its reliance on general-purpose, statistical learning mechanisms that are a core feature of the visual system as implemented in the ventral stream.

Learned trustworthiness does not have the same influence on implicit responses measured via fast periodic visual stimulation as face trustworthiness.

Past research has demonstrated that it is possible to detect implicit responses to face trustworthiness using fast periodic visual stimulation (FPVS). Because people readily retrieve affective associations with faces, the current study investigated whether learned trustworthiness would yield similar responses to face trustworthiness as measured via FPVS. After learning to associate faces with untrustworthy or trustworthy behaviors, participants completed three separate tasks while electroencephalography (EEG) was recorded. In each of these tasks, participants viewed oddball sequences of faces where a single base face was presented repeatedly at a rate of 6 Hz and oddball faces with different identities were presented every fifth face (6 Hz/5 = 1.2 Hz). Providing evidence of learning, the oddball response at 1.2 Hz and its harmonics was stronger for the learned faces compared to novel faces over bilateral occipitotemporal cortex and beyond. In addition, reproducing previous findings with face trustworthiness, we observed a stronger response at 1.2 Hz and its harmonics for sequences with less trustworthy-looking versus trustworthy-looking oddball faces over bilateral occipitotemporal cortex and other sites. However, contrary to our predictions, we did not observe a significant influence of learned trustworthiness on the oddball response. These data indicate that impressions based on learning are treated differently than impressions based on appearance, and they raise questions about the types of design and stimuli that yield responses that are measurable via FPVS.

Linguistic and attentional factors – Not statistical regularities – Contribute to word-selective neural responses with FPVS-oddball paradigms

Studies using frequency-tagging in electroencephalography (EEG) have dramatically increased in the past 10 years, in a variety of domains and populations. Here we used Fast Periodic Visual Stimulation (FPVS) combined with an oddball design to explore visual word recognition. Given the paradigm's high sensitivity, it is crucial for future basic research and clinical application to prove its robustness across variations of designs, stimulus types and tasks. This paradigm uses periodicity of brain responses to measure discrimination between two experimentally defined categories of stimuli presented periodically. EEG was recorded in 22 adults who viewed words inserted every 5 stimuli (at 2 Hz) within base stimuli presented at 10 Hz. Using two discrimination levels (deviant words among nonwords or pseudowords), we assessed the impact of relative frequency of item repetition (set size or item repetition controlled for deviant versus base stimuli), and of the orthogonal task (focused or deployed spatial attention). Word-selective occipito-temporal responses were robust at the individual level (significant in 95% of participants), left-lateralized, larger for the prelexical (nonwords) than lexical (pseudowords) contrast, and stronger with a deployed spatial attention task as compared to the typically used focused task. Importantly, amplitudes were not affected by item repetition. These results help understanding the factors influencing word-selective EEG responses and support the validity of FPVS-EEG oddball paradigms, as they confirm that word-selective responses are linguistic. Second, they show its robustness against design-related factors that could induce statistical (ir)regularities in item rate. They also confirm its high individual sensitivity and demonstrate how it can be optimized, using a deployed rather than focused attention task, to measure implicit word recognition processes in typical and atypical populations.

The odd one out – Orthographic oddball processing in children with poor versus typical reading skills in a fast periodic visual stimulation EEG paradigm

The specialization of left ventral occipitotemporal brain regions to automatically process word forms develops with reading acquisition and is diminished in children with poor reading skills (PR). Using a fast periodic visual oddball stimulation (FPVS) design during electroencephalography (EEG), we examined the level of sensitivity and familiarity to word form processing in ninety-two children in 2nd and 3rd grade with varying reading skills (n = 35 for PR, n = 40 for typical reading skills; TR).To test children's level of “sensitivity”, false font (FF) and consonant string (CS) oddballs were embedded in base presentations of word (W) stimuli. “Familiarity” was examined by presenting letter string oddballs with increasing familiarity (CS, pseudoword – PW, W) in FF base stimuli.Overall, our results revealed stronger left-hemispheric coarse sensitivity effects (“FF in W” > “CS in W”) in TR than in PR in both topographic and oddball frequency analyses. Further, children distinguished between orthographically legal and illegal (“W/PW in FF” > “CS in FF”) but not yet between lexical and non-lexical (“W in FF” vs “PW in FF”) word forms. Although both TR and PR exhibit visual sensitivity and can distinguish between orthographically legal and illegal letter strings, they still struggle with nuanced lexical distinctions. Moreover, the strength of sensitivity is linked to reading proficiency. Our work adds to established knowledge in the field to characterize the relationship between print tuning and reading skills and suggests differences in the developmental progress to automatically process word forms.

A passive, neural correlate of verbal fluency in Mild Cognitive Impairment using Fastball neurocognitive assessment

AbstractBackgroundFastball provides a passive and objective measure of an individual’s ability to discriminate between different visual categories using Fast Periodic Visual Stimulation and EEG. Our previous work adapted this approach to assess recognition memory in Alzheimer’s disease (Stothart et al., Brain, 2021). This research builds on previous findings by expanding the range of cognitive functions assessed to include visuo‐perceptual performance, and working with patients in an earlier stage of dementia, i.e., Mild Cognitive Impairment (MCI). The aim was to determine whether Fastball responses are sensitive to visuo‐perceptual performance in the early stages of dementia (MCI).MethodAll EEG data were collected in patients' homes using low‐cost, portable systems. Healthy older adult controls (n = 56, ACE‐III = 96 +‐ 6) and MCI patients (n = 50, ACE‐III = 82 +‐ 21) completed a battery of Fastball and neuropsychological tasks (ACE‐III, Freiburg visual acuity) designed to assess visuo‐perceptual performance. We created a letter recognition Fastball task using diffeomorphically scrambled letters as standards and whole letters as oddballs, see Figure 1.ResultA one‐way (Group; Old vs MCI) ANCOVA, controlling for basic steady state magnitude, was conducted to test for differences in oddball responses. Controls had significantly increased oddball responses compared with MCI patients (F (1,103) = 9.61, p = .003, d = 0.48). Oddball responses did not correlate with any neuropsychological measure of vision, but correlated strongly with verbal fluency performance as measured by the ACE‐III, (MCI patients (r(48) = .46, p = .001), controls (r(54) = .34, p = .01)), see Figure 2. There were no correlations between oddball responses and any other neuropsychological measure.ConclusionThese results were not anticipated as we originally hypothesised that oddball responses would correlate with visual performance. Instead, the specific relationship with verbal fluency performance indicates that the Fastball letter recognition task may provide a novel, passive correlate of verbal fluency performance in early dementia. We propose that whole letter oddball stimuli are more salient to participants with greater verbal fluency, resulting in larger oddball responses. A passive measure of verbal fluency could potentially bypass educational and linguistic confounds that can affect traditional measures of verbal fluency performance.

Differences in own-face but not own-name discrimination between autistic and neurotypical adults: A fast periodic visual stimulation-EEG study

Self-related processing is thought to be altered in autism, with several studies reporting that autistic individuals show a diminished neural response relative to neurotypicals for their own name and face. However, evidence remains scarce and is mostly based on event-related potential studies. Here, we used EEG to measure the neural activity of autistic adults (20 for faces, 27 for names) and neurotypical adults (24 for faces, 25 for names) while they were watching rapidly alternating faces and names, through a relatively new technique called Fast Periodic Visual Stimulation. We presented strangers' faces or names at a base frequency of 5.77 Hz, while one's own, a close other's, and a specific stranger's face/name was presented at an oddball frequency of 1.154 Hz. The neurotypical group showed a significantly greater response to their own face than both close other and stranger faces, and a greater response for close other than for stranger faces. In contrast, in the autism group, own and close other faces showed stronger responses than the stranger's face, but the difference between own and close other faces was not significant in a bilateral parieto-occipital cluster. No group differences in the enhanced response to familiar names were found. These results replicate and extend results obtained using traditional electroencephalographic techniques which suggest atypical responses to self-relevant stimuli in autism.

Neural discrimination of facial cues associated with trustworthiness in adults and 6-month-old infants as revealed by fast periodic visual stimulation.

Adults and children easily distinguish between fine-grained variations in trustworthiness intensity based on facial appearance, but the developmental origins of this fundamental social skill are still debated. Using a fast periodic visual stimulation (FPVS) oddball paradigm coupled with electroencephalographic (EEG) recording, we investigated neural discrimination of morphed faces that adults perceive as low- and high-trustworthy in a sample of 6-month-old infants (N = 29; 56% male; Mage = 196.8 days; all White) and young adults (N = 21; 40% male; Mage = 24.61 years; all White) recruited in Italy. Stimulus sequences were presented at 6 Hz with deviant faces interleaved every fifth stimulus (i.e., 1.2 Hz); oddball category (high/low trustworthiness) was varied within subjects. FPVS responses were analyzed at both frequencies of interest and their harmonics as a function of deviant type (high- vs. low-trustworthy) over occipital and occipitolateral electrode clusters. For both infants and adults, the baseline response did not differ between trustworthiness conditions. Significant responses were centered on the right parietal electrodes in infants, and on the occipital and left occipitotemporal clusters in adults. Oddball responses were significant for both infants and adults, with cross-age differences in the topographical localization of the response on the scalp. Overall, results suggest that, by the age of 6 months, infants discriminate between faces that adults rate as high and low in trustworthiness, extending prior evidence of early sensitivity to this face dimension in humans. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The development of visual categorization based on high-level cues.

This study investigated the development of rapid visual object categorization. N = 20 adults (Experiment 1), N = 21 five to six-year-old children (Experiment 2), and N = 140 four-, seven-, and eleven-month-old infants (Experiment 3; all predominantly White, 81 females, data collected in 2013-2020) participated in a fast periodic visual stimulation electroencephalographic task. Similar categorization of animal and furniture stimuli emerged in children and adults, with responses much reduced by phase-scrambling (R2 = .34-.73). Categorization was observed from 4 months, but only at 11 months, high-level cues enhanced performance (R2 = .11). Thus, first signs of rapid categorization were evident from 4 months, but similar categorization patterns as in adults were recorded only from 11 months on.

Infants' fast neural categorization of artificial objects: The impact of stimulus and task characteristics.

This study explores how 7-month-old infants categorize graphical images varying in basic perceptual features by using a fast periodic visual stimulation (FPVS) task. Most participants were Caucasian and their parents had a higher education, but the family's socioeconomic background was mixed. Experiment 1 (N = 23) tested brain responses to configurational versus scrambled image sequences and found an oddball effect for both conditions, with configurational information leading to stronger neural responses. Experiment 2 explored the role of category learning for later FPVS performance: Group A (control; n = 22) participated in the FPVS categorization task only. Group B (fam; n = 21) was first familiarized with standard exemplars. Group C (fam + contrast; n = 29) was presented an additional exemplar of the contrasting category before the FPVS task. Electroencephalogram analyses revealed a decrease in Nc amplitude (measuring attention) throughout the familiarization phase. Long looking at the out-of-category exemplar in Group C indicated infants' visual interest. Brain responses in the subsequently presented FPVS were strong but did not differ between groups. This highlights the ability of the infant brain to organize perceptual input very rapidly without requiring familiarization but also points to the need for further studies exploring brain processes associated with infants' category learning and categorization at the brain level. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

N°117 – Identification of new electrophysiological biomarkers of Alzheimer’s disease with fast periodic visual stimulation and electroencephalography

N°117 – Identification of new electrophysiological biomarkers of Alzheimer’s disease with fast periodic visual stimulation and electroencephalography

Stronger neural response to canonical finger-number configurations in deaf compared to hearing adults revealed by FPVS-EEG.

The linguistic counting system of deaf signers consists of a manual counting format that uses specific structures for number words. Interestingly, the number signs from 1 to 4 in the Belgian sign languages correspond to the finger-montring habits of hearing individuals. These hand configurations could therefore be considered as signs (i.e., part of a language system) for deaf, while they would simply be number gestures (not linguistic) for hearing controls. A Fast Periodic Visual Stimulation design was used with electroencephalography recordings to examine whether these finger-number configurations are differently processed by the brain when they are signs (in deaf signers) as compared to when they are gestures (in hearing controls). Results showed that deaf signers show stronger discrimination responses to canonical finger-montring configurations compared to hearing controls. A second control experiment furthermore demonstrated that this finding was not merely due to the experience deaf signers have with the processing of hand configurations, as brain responses did not differ between groups for finger-counting configurations. Number configurations are therefore processed differently by deaf signers, but only when these configurations are part of their language system.

Intracerebral Electrophysiological Recordings to Understand the Neural Basis of Human Face Recognition.

Understanding how the human brain recognizes faces is a primary scientific goal in cognitive neuroscience. Given the limitations of the monkey model of human face recognition, a key approach in this endeavor is the recording of electrophysiological activity with electrodes implanted inside the brain of human epileptic patients. However, this approach faces a number of challenges that must be overcome for meaningful scientific knowledge to emerge. Here we synthesize a 10 year research program combining the recording of intracerebral activity (StereoElectroEncephaloGraphy, SEEG) in the ventral occipito-temporal cortex (VOTC) of large samples of participants and fast periodic visual stimulation (FPVS), to objectively define, quantify, and characterize the neural basis of human face recognition. These large-scale studies reconcile the wide distribution of neural face recognition activity with its (right) hemispheric and regional specialization and extend face-selectivity to anterior regions of the VOTC, including the ventral anterior temporal lobe (VATL) typically affected by magnetic susceptibility artifacts in functional magnetic resonance imaging (fMRI). Clear spatial dissociations in category-selectivity between faces and other meaningful stimuli such as landmarks (houses, medial VOTC regions) or written words (left lateralized VOTC) are found, confirming and extending neuroimaging observations while supporting the validity of the clinical population tested to inform about normal brain function. The recognition of face identity - arguably the ultimate form of recognition for the human brain - beyond mere differences in physical features is essentially supported by selective populations of neurons in the right inferior occipital gyrus and the lateral portion of the middle and anterior fusiform gyrus. In addition, low-frequency and high-frequency broadband iEEG signals of face recognition appear to be largely concordant in the human association cortex. We conclude by outlining the challenges of this research program to understand the neural basis of human face recognition in the next 10 years.

Children show neural sensitivity to facial trustworthiness as measured by fast periodic visual stimulation

Adults exhibit neural responses over the visual occipito-temporal area in response to faces that vary in how trustworthy they appear. However, it is not yet known when a mature pattern of neural sensitivity can be seen in children. Using a fast periodic visual stimulation (FPVS) paradigm, face images were presented to 8-to-9-year-old children (an age group which shows development of trust impressions; N = 31) and adult (N = 33) participants at a rate of 6 Hz (6 face images per second). Within this sequence, an ‘oddball’ face differing in the level of facial trustworthiness compared to the other faces, was presented at a rate of 1 Hz (once per second). Children were sensitive to variations in facial trustworthiness, showing reliable and significant neural responses at 1 Hz in the absence of instructions to respond to facial trustworthiness. Additionally, the magnitude of children's and adults' neural responses was similar, with strong Bayesian evidence that implicit neural responses to facial trustworthiness did not differ across the groups, and therefore, that visual sensitivity to differences in facial trustworthiness can show mature patterns by this age. Thus, nine or less years of social experience, perceptual and/or cognitive development may be sufficient for adult-like neural sensitivity to facial trustworthiness to emerge. We also validate the use of the FPVS methodology to examine children's implicit face-based trust processing for the first time, which is especially valuable in developmental research because this paradigm requires no explicit instructions or responses from participants.

Supplemental Material for Neural Discrimination of Facial Cues Associated With Trustworthiness in Adults and 6-Month-Old Infants as Revealed by Fast Periodic Visual Stimulation

Supplemental Material for Neural Discrimination of Facial Cues Associated With Trustworthiness in Adults and 6-Month-Old Infants as Revealed by Fast Periodic Visual Stimulation

Attention to faces and races in the infant brain: Evidence from fast periodic visual stimulation

Attention to faces and races in the infant brain: Evidence from fast periodic visual stimulation

Frequency tagging with infants: The visual oddball paradigm.

Combining frequency tagging with electroencephalography (EEG) provides excellent opportunities for developmental research and is increasingly employed as a powerful tool in cognitive neuroscience within the last decade. In particular, the visual oddball paradigm has been employed to elucidate face and object categorization and intermodal influences on visual perception. Still, EEG research with infants poses special challenges that require consideration and adaptations of analyses. These challenges include limits to attentional capacity, variation in looking times, and presence of artefacts in the EEG signal. Moreover, potential differences between age-groups must be carefully evaluated. This manuscript evaluates challenges theoretically and empirically by (1) a systematic review of frequency tagging studies employing the oddball paradigm and (2) combining and re-analyzing data from seven-month-old infants (N = 124, 59 females) collected in a categorization task with artifical, unfamiliar stimuli. Specifically, different criteria for sequence retention and selection of harmonics, the influence of bins considered for baseline correction and the relation between fast periodic visual stimulation (FPVS) responses and looking time are analyzed. Overall, evidence indicates that analysis decisions should be tailored based on age-group to optimally capture the observed signal. Recommendations for infant frequency tagging studies are developed to aid researchers in selecting appropriate stimulation and analysis strategies in future work.

Trustworthiness perception is mandatory: Task instructions do not modulate fast periodic visual stimulation trustworthiness responses

Although it is often assumed that humans spontaneously respond to the trustworthiness of others' faces, it is still unclear whether responses to facial trust are mandatory or can be modulated by instructions. Considerable scientific interest lies in understanding whether trust processing is mandatory, given the societal consequences of biased trusting behavior. We tested whether neural responses indexing trustworthiness discrimination depended on whether the task involved focusing on facial trustworthiness or not, using a fast periodic visual stimulation electroencephalography oddball paradigm with a neural marker of trustworthiness discrimination at 1 Hz. Participants judged faces on size without any reference to trust, explicitly formed impressions of facial trust, or were given a financial lending context that primed trust, without explicit trust judgement instructions. Significant trustworthiness discrimination responses at 1 Hz were found in all three conditions, demonstrating the robust nature of trustworthiness discrimination at the neural level. Moreover, no effect of task instruction was observed, with Bayesian analyses providing moderate to decisive evidence that task instruction did not affect trustworthiness discrimination. Our finding that visual trustworthiness discrimination is mandatory points to the remarkable spontaneity of trustworthiness processing, providing clues regarding why these often unreliable impressions are ubiquitous.