Electrophysiological signatures of conscious perception: The influence of cognitive, cortical and pathological states on multisensory integration

At any given moment, information reaches us via our different sensory systems. In order to navigate this multitude of information, associated information needs to be integrated to a coherent percept. In recent years, the hypothesis that synchronous neural oscillations play a prominent role in unisensory and multisensory processing has received substantial support. Current findings further convey the idea that local oscillations and functional connectivity reflect bottom-up as well as top-down processes during multisensory integration and perception. In the current work, I review recent findings on the role of neural oscillations for conscious multisensory perception. Subsequently, I present an integrative network model for multisensory integration that describes the cortical correlates of conscious multisensory perception, the influence of fluctuations of oscillatory neural activity on subsequent perception, and the influence of cognitive processes on neural oscillations and perception. I propose that neural oscillations in distinct, coexisting frequencies reflect the various processing steps underlying multisensory perception.Jederzeit erreichen uns Informationen über unsere verschiedenen Sinnesorgane und Wahrnehmungssysteme. Um in dieser Menge an Informationen den Überblick zu behalten, müssen zusammengehörige Informationen zu einer kohärente Wahrnehmung zusammengefügt werden. In den letzten Jahren hat die Hypothese, dass synchrone neuronale Oszillationen eine wichtige Rolle bei der Verarbeitung von unisensorischen und multisensorischen Reizen spielen, viel Unterstützung erfahren. Neueste Befunde befördern weiterhin die Idee, dass lokale Oszillationen und funktionale Konnektivität aufsteigende und absteigende Prozesse bei multisensorischer Integration und Wahrnehmung widerspiegeln. In dieser Arbeit werde ich einen Überblick über die neuesten Befunde zur Rolle neuronaler Oszillationen bei bewusster, multisensorischer Wahrnehmung geben. Anschließend werde ich ein integratives Netzwerkmodell multisensorischer Wahrnehmung präsentieren, welches die kortikalen Korrelate bewusster, multisensorischer Wahrnehmung, den Einfluss von Schwankungen oszillatorischer neuronaler Aktivität auf darauffolgende Wahrnehmung, sowie den Einfluss kognitiver Prozesse auf neuronale Oszillationen und Wahrnehmung beschreibt. Ich schlage vor, dass neuronale Oszillationen in umschriebenen, gleichzeitig aktiven Frequenzbändern die verschiedenen Verarbeitungsschritte widerspiegeln, welche multisensorischer Wahrnehmung zugrunde liegen

Temporal expectancies driven by self- and externally generated rhythms

The dynamic attending theory proposes that rhythms entrain periodic fluctuations of attention which modulate the gain of sensory input. However, temporal expectancies can also be driven by the mere passage of time (foreperiod effect). It is currently unknown how these two types of temporal expectancy relate to each other, i.e. whether they work in parallel and have distinguishable neural signatures. The current research addresses this issue. Participants either tapped a 1Hz rhythm (active task) or were passively presented with the same rhythm using tactile stimulators (passive task). Based on this rhythm an auditory target was then presented early, in synchrony, or late. Behavioural results were in line with the dynamic attending theory as RTs were faster for in- compared to out-of-synchrony targets. Electrophysiological results suggested self-generated and externally induced rhythms to entrain neural oscillations in the delta frequency band. Auditory ERPs showed evidence of two distinct temporal expectancy processes. Both tasks demonstrated a pattern which followed a linear foreperiod effect. In the active task, however, we also observed an ERP effect consistent with the dynamic attending theory. This study shows that temporal expectancies generated by a rhythm and expectancy generated by the mere passage of time can work in parallel and sheds light on how these mechanisms are implemented in the brain

Temporal expectancies driven by self- and externally generated rhythms

The dynamic attending theory proposes that rhythms entrain periodic fluctuations of attention which modulate the gain of sensory input. However, temporal expectancies can also be driven by the mere passage of time (foreperiod effect). It is currently unknown how these two types of temporal expectancy relate to each other, i.e. whether they work in parallel and have distinguishable neural signatures. The current research addresses this issue. Participants either tapped a 1Hz rhythm (active task) or were passively presented with the same rhythm using tactile stimulators (passive task). Based on this rhythm an auditory target was then presented early, in synchrony, or late. Behavioural results were in line with the dynamic attending theory as RTs were faster for in- compared to out-of-synchrony targets. Electrophysiological results suggested self-generated and externally induced rhythms to entrain neural oscillations in the delta frequency band. Auditory ERPs showed evidence of two distinct temporal expectancy processes. Both tasks demonstrated a pattern which followed a linear foreperiod effect. In the active task, however, we also observed an ERP effect consistent with the dynamic attending theory. This study shows that temporal expectancies generated by a rhythm and expectancy generated by the mere passage of time can work in parallel and sheds light on how these mechanisms are implemented in the brain

Utilisation de l’électrophysiologie dans l’étude du développement des capacités d’intégration audiovisuelle du nourrisson à l’âge adulte

Une littérature abondante documente les bénéfices de l’intégration multisensorielle chez les adultes ainsi que les mécanismes cérébraux sous-jacents à ces habiletés. Toutefois, de nombreuses questions sur le développement de l’intégration multisensorielle chez l’enfant demeurent sans réponse et les travaux chez les animaux ainsi que les données comportementales, électrophysiologiques et en neuroimagerie chez l’homme ne forment pas de consensus quant à son caractère inné ou acquis. Le premier objectif de la présente thèse vise donc à recenser les écrits de la littérature sur le développement des capacités d’intégration multisensorielle. Cette revue de la littérature, qui constituera l’article 1 de la thèse, présente les études comportementales et neuronales en faveur du caractère inné ou acquis des processus d’intégration multisensorielle. L’article 1 suggère que certaines habiletés de traitement multisensoriel sont présentes chez le nourrisson et le jeune enfant, mais que la capacité à intégrer les informations multisensorielles de façon optimale demeure un long processus qui se développe tardivement au cours de l’enfance et de l’adolescence. Cette revue nous a également permis de mieux cibler les lacunes de la littérature relatives au développement neuronal des capacités d’intégration, avec une attention particulière sur l’intégration d’informations audiovisuelles non linguistiques. Ainsi, aucune étude en électrophysiologie ne s’est encore penchée sur la progression développementale des capacités d’intégration audiovisuelle chez les nourrissons et les enfants d’âge préscolaire. Ce constat a justifié la tenue de l’étude expérimentale présentée à l’article 2 dont l’objectif vise à caractériser la progression développementale neurotypique des mécanismes d’intégration d’informations audiovisuelles non linguistiques dès l’âge de 3 mois jusqu’à l’âge adulte. Cette recherche vise également à confirmer l'âge où les mécanismes d’intégration audiovisuelle, d’une part, commencent à fonctionner de façon similaire aux adultes et, d’autre part, atteignent leur pleine maturité. Pour ce faire, nous avons mené une étude expérimentale transversale sur un vaste échantillon composé de 121 participants neurotypiques en utilisant l’électrophysiologie à haute densité, plus sécifiquement par le biais d’analyses temps-fréquence. Notre étude démontre la présence de précurseurs de l’intégration audiovisuelle dès l’âge de 2 ans. De plus, nous observons que les jeunes de 11-14 ans commencent à intégrer ces informations de façon similaire aux adultes, mais que les mécanismes d’intégration audiovisuelle atteignent leur pleine maturité tardivement au cours de l’adolescence soit entre les âges de 15 et 17 ans. Cette étude appuie la littérature quant à l’émergence progressive des capacités à intégrer les informations audiovisuelles, permet de documenter la progression développementale de ces capacités et répond à l’absence de littérature sur les processus neuronaux de l’intégration audiovisuelle chez le nourrisson et l’enfant d’âge préscolaire. Dans l’ensemble, cette thèse offre une meilleure compréhension du développement neurotypique des mécanismes d’intégration audiovisuelle et fournit un point de comparaison pour étudier ces processus auprès d’enfants présentant des troubles neurodéveloppementaux souvent accompagnés de déficits sensoriels.An abundant litterature documents the benefits associated to multisensory integration in adults as well as brain mechanisms underlying these skills. However, numerous questions regarding the development of multisensory integration during childhood remain unanswered and there is no consensus among animal data in addition to behavioral, electrophysiological and neuroimaging studies conducted in humans wether these skills are innate or acquired. The first objective of this thesis is to review the literature on the development of multisensory integration capacities. This review, which will constitute the first article of this thesis, presents neuronal and behavioral studies in favour of the nature or nurture character of multisensory integration mechanisms. This review suggests that the capacity to detect and form multisensory associations begins very early in development, but that the ability to integrate multisensory information in an optimal manner is a progressive process that continues to develop over childhood and adolescence. This work has also allowed us to better target the gaps in the existing literature related to the neuronal development of integration capacities, with special emphasis on the integration of non linguistic audiovisual information. Thus, to date no electrophysiological study has yet address the developmental progression of audiovisual integration capacities in infants and preschool children. This ascertainment has justified the conduct of the experimental study presented in the second article with the aim of characterizing the neurotypical developmental progression of non linguistic audiovisual information integration mecanisms as early as 3 months of age to adulthood. This research is also aimed at confirming the age when audiovisual integration mechanisms, on the one hand, begin to operate in a similar fashion than adults and, on the other hand, reach their full maturity. For these purposes, we have conducted an experimental iv study. Here, we undertook a cross-sectional experimental investigation on a large cohort of 121 neurotypical individuals using high-density electrophysiology more specifically through time-frequency analysis. Our study revealed the presence of precursors of audiovisual integration in children as young as two years of age. Moreover, our results indicate that 11- to 14-year-old adolescents start to integrate this information in an adult-like manner, but that audiovisual integration mechanisms reach their full maturity late throughout adolescence between the age of 15 and 17 years. This study supports the literature regarding the progressive emergence of the capacities to integrate audiovisual information, documents the developmental progression of these capacities and answers the absence of literature on the neuronal processes of audiovisual integration in infants and preschool children. Overall, this thesis provides a better understanding of the development of audiovisual integration mechanisms and provides a benchmark to investigate these processes in children with neurodevelopmental disorders often accompanied with sensory impairments

Auditory cues and inhibition of return: the importance of oculomotor activation

We studied the effects of eccentric auditory cues to clarify the conditions that evoke inhibition of return (IOR). We found that auditory cues positioned 12° to the left or right of midline failed to produce IOR whereas visual cues produced IOR under the same experimental conditions. The eccentric auditory cues elicited automatic orienting as evidenced by more rapid detection of cued than uncued visual targets at short stimulus onset asynchrony. Yet these same cues did not produce IOR unless observers were required to saccade to the cue and back to center before generating a manual detection response. Thus, under the conditions examined herein automatic orienting was not sufficient to evoke IOR, but oculomotor activation appeared to be essential. The functional significance of IOR and the question of modality-specific orienting processes are considered.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46532/1/221_2004_Article_BF00227185.pd

Spatial representations of touch in infancy and early childhood

The primary aim of this thesis was to examine how infants, and young children, represent touches in space (i.e. with respect to their external environment). Studying infants in the first year of life allows us to map the emergence of the complex processes needed in order to correctly locate touches to the body (and, by extension, the location of the limbs and body parts on which those touches impinge). In a series of seven experiments, I examined the development of the spatial representation of touch. To do this, I explored the development of an external reference frame in which touches are coded, the modulatory effect of changes in posture on the neural representation of a touch and the relationship between vision and touch when locating a stimulus from these sensory modalities in space. To investigate the development of an external reference frame for touch, I used a ‘crossed-hands’ task. This task has been used as a marker of the influence of an external frame of reference for localizing touch and is considered to arise out of conflict (when the hands are crossed) between the anatomical and external frames of reference within which touches can be perceived. Previous research with children had found that this reference frame does not develop until after 5.5-years; I extended this finding by determining that children as young as 4-years are able to locate touches in external co-ordinates. Additionally, in a further study, I found that an external reference frame develops between 4 and 6 months of age. The modulatory role of vision on tactile localization was also investigated. These studies showed that when 4-year-old children are provided with current vision of the hand being touched, this interfered with the benefits of using an external reference frame. However, this interference was limited to when the limbs were in canonical postures. As such, it seems that young children are still refining the ways in which sensory cues to the body help them to locate touches in the world. Considering that early visual experience was implicated in the development of an external frame of reference I also examined the development of an ability to perceive visual and tactile stimuli in a common spatial location. Here, it was found that 6-month-olds demonstrated this ability, with tentative findings suggesting that it may develop even earlier in life (e.g., at 4 months of age). As such, the ability to co-locate tactile and visual stimuli at 6 months is consistent with a role for visual experience in the development of an external frame of reference for touch at this age. Further to this, I examined interactions between vision and touch using a crossmodal cueing event-related potential (ERP) paradigm. In this study, it was found that at 7 months of age visual cues to the hand modulate processing of a subsequent tactile stimulus on that same hand. This provides further evidence of early acquired crossmodal links, but this was the first demonstration of crossmodal attentional cuing effects in infancy. Finally, in a set of two experiments, I investigated how infants (in the first year of life) were able to update the location of a felt touch across changes in arm posture, using an ERP measure. Although these studies demonstrated a null relationship between sensorimotor experience and somatosensory remapping, it was found that only those 8-month-old infants that displayed contralateral reaching behaviours were able to update to the location of a touch across a change in posture. As such, the relationship between sensorimotor experience and somatosensory remapping may not be simple, with other factors (such as brain maturation) also influencing this relationship

Functional imaging studies of visual-auditory integration in man.

This thesis investigates the central nervous system's ability to integrate visual and auditory information from the sensory environment into unified conscious perception. It develops the possibility that the principle of functional specialisation may be applicable in the multisensory domain. The first aim was to establish the neuroanatomical location at which visual and auditory stimuli are integrated in sensory perception. The second was to investigate the neural correlates of visual-auditory synchronicity, which would be expected to play a vital role in establishing which visual and auditory stimuli should be perceptually integrated. Four functional Magnetic Resonance Imaging studies identified brain areas specialised for: the integration of dynamic visual and auditory cues derived from the same everyday environmental events (Experiment 1), discriminating relative synchronicity between dynamic, cyclic, abstract visual and auditory stimuli (Experiment 2 & 3) and the aesthetic evaluation of visually and acoustically perceived art (Experiment 4). Experiment 1 provided evidence to suggest that the posterior temporo-parietal junction may be an important site of crossmodal integration. Experiment 2 revealed for the first time significant activation of the right anterior frontal operculum (aFO) when visual and auditory stimuli cycled asynchronously. Experiment 3 confirmed and developed this observation as the right aFO was activated only during crossmodal (visual-auditory), but not intramodal (visual-visual, auditory-auditory) asynchrony. Experiment 3 also demonstrated activation of the amygdala bilaterally during crossmodal synchrony. Experiment 4 revealed the neural correlates of supramodal, contemplative, aesthetic evaluation within the medial fronto-polar cortex. Activity at this locus varied parametrically according to the degree of subjective aesthetic beauty, for both visual art and musical extracts. The most robust finding of this thesis is that activity in the right aFO increases when concurrently perceived visual and auditory sensory stimuli deviate from crossmodal synchrony, which may veto the crossmodal integration of unrelated stimuli into unified conscious perception

Early multisensory attention as a foundation for learning in multicultural Switzerland

Traditional laboratory research on visual attentional control has largely focused on adults, treated one sensory modality at a time, and neglected factors that are a constituent part of information processing in real-world contexts. Links between visual-only attentional control and children’s educational skills have emerged, but they still do not provide enough information about school learning. The present thesis addressed these gaps in knowledge through the following aims: 1) to shed light on the development of the neuro-cognitive mechanisms of attention engaged by multisensory objects in a bottom-up fashion, together with attentional control over visual objects in a top-down fashion, 2) to investigate the links between developing visual and multisensory attentional control and children’s basic literacy and numeracy attainment, and 3) to explore how contextual factors, such as the temporal predictability of a stimulus or the semantic relationships between stimulus features, further influence attentional control mechanisms. To investigate these aims, 115 primary school children and 39 adults from the French-speaking part of Switzerland were tested on their behavioural performance on a child-friendly, multisensory version of the Folk et al. (1992) spatial cueing paradigm, while 129-channel EEG was recorded. EEG data were analysed in a traditional framework (the N2pc ERP component) and a multivariate Electrical Neuroimaging (EN) framework. Taken together, our results demonstrated that children’s visual attentional control reaches adult-like levels at around 7 years of age, or 3rd grade, although children as young as 5 (at school entry) may already be sensitive to the goal- relevance of visual objects. Multisensory attentional control may develop only later. Namely, while 7-year-old children (3rd grade) can be sensitive to the multisensory nature of objects, such sensitivity may only reach an adult-like state at 9 years of age (5th grade). As revealed by EN, both bottom-up multisensory control of attention and top-down visual control of attention are supported by the recruitment of distinct networks of brain generators at each level of schooling experience. Further, at each level of schooling, the involvement of specific sets of brain generators was correlated with literacy and numeracy attainment. In adults, visual and multisensory attentional control were further jointly influenced by contextual factors. The semantic relationship between stimulus features directly influenced visual and multisensory attentional control. In the absence of such semantic links, however, it was the predictability of stimulus onset that influenced visual and multisensory attentional control. Throughout this work, the N2pc component was not sensitive to multisensory or contextual effects in adults, or even traditional visual attention effects in children, and it was owing to EN that the mechanisms of visual and multisensory attentional control were clarified. The present thesis demonstrates the strength of combining behavioural and EEG/ERP markers of attentional control with advanced EEG analytical techniques for investigating the development of attentional control in settings that closely approximate those that we encounter in everyday life

ERP evidence of attentional somatosensory processing and stimulus-response coupling under different hand and arm postures

We investigated (1) the effects of divided and focused attention on event-related brain potentials (ERPs) elicited by somatosensory stimulation under different response modes, (2) the effects of hand position (closely-placed vs. separated hands) and arm posture (crossed vs. uncrossed forearms) on the attentional modulation of somatosensory ERPs, and (3) changes in the coupling of stimulus- and response-related processes by somatosensory attention using a single-trial analysis of P300 latency and reaction times. Electrocutaneous stimulation was presented randomly to the thumb or middle finger of the left or right hand at random interstimulus intervals (700–900 ms). Subjects attended unilaterally or bilaterally to stimuli in order to detect target stimuli by a motor response or counting. The effects of unilaterally-focused attention were also tested under different hand and arm positions. The amplitude of N140 in the divided attention condition was intermediate between unilaterally attended and unattended stimuli in the unilaterally-focused attention condition in both the mental counting and motor response tasks. Attended infrequent (target) stimuli elicited greater P300 in the unilaterally attention condition than in the divided attention condition. P300 latency was longer in the divided attention condition than in the unilaterally-focused attention condition in the motor response task, but remained unchanged in the counting task. Closely locating the hands had no impact, whereas crossing the forearms decreased the attentional enhancement in N140 amplitude. In contrast, these two manipulations uniformly decreased P300 amplitude and increased P300 latency. The correlation between single-trial P300 latency and RT was decreased by crossed forearms, but not by divided attention or closely-placed hands. Therefore, the present results indicate that focused and divided attention differently affected middle latency and late processing, and that hand position and arm posture also differently affected attentional processes and stimulus–response coupling

Horizontal asymmetries derived from script direction : consequences for attention and action

Tese apresentada para cumprimento dos requisitos necessários à obtenção do grau de Doutor em Psicologia na área de especialização de Psicologia Social apresentada no ISPA - Instituto Universitário, no ano de 2021.A direção de leitura e escrita estabelecem uma trajetória preferencial de exploração do espaço que é reforçada por diversas regularidades culturais consistentes com essa direccionalidade. A correlação espaço-movimento cria um esquema para a ação que enviesa a representação da agência humana, estendendo-se à representação de outros conceitos abstratos que não possuem bases sensoriomotoras. A dimensão horizontal é recrutada para melhor compreender estes conceitos, sendo ancorados de acordo com a direção de escrita e leitura da nossa língua. A assimetria espacial que esta direccionalidade induz constitui um contributo crucial para a área do embodiment, tendo sido demonstrado que afeta processos sociais e cognitivos. Contudo, os processos específicos que estas assimetrias ativam permanecem pouco explorados. Em sete estudos, esta dissertação investiga de que forma as assimetrias espaciais afetam inferências sociais e a performance visuo-motora para com estímulos ancorados na dimensão horizontal. O primeiro estudo indica que inferências sociais relacionadas com agência são preferencialmente atribuídas a faces de perfil orientadas para a direita (versus esquerda). Em duas experiências, o segundo estudo mostra que faces orientadas para a direita servem como pistas para a orientação de atenção. Faces orientadas para a direita, que traduzem a direção utilizada para representar a agência humana, facilitam a atenção para e deteção de alvos no campo visual direito, comparativamente a faces orientadas para a esquerda no campo visual esquerdo. No terceiro estudo, as faces foram substituídas por palavras temporais auditivas e visuais, que se sabe serem ancoradas horizontalmente. A assimetria espacial foi testada em duas experiências em comunidades com direções de leitura e escrita opostas (Português e Árabe). Observou-se uma ancoragem contrária do conceito abstrato ‘tempo’ entre as duas amostras (Português: passado-esquerda/futuro-direita; Árabe: passado-direita/futuro-esquerda). Adicionalmente, uma performance assimétrica reversa entre as duas comunidades linguísticas confirma que o mapeamento do tempo é enviesado pelos hábitos ortográficos e pela representação cultural da agência humana. Isto é, palavras temporais que coincidem com a direção induzida por ambos os sistemas de escrita (i.e., palavras relacionadas com futuro), dão origem a vantagem à direita na amostra Portuguesa, e vantagem à esquerda na amostra Árabe. O quarto estudo estendeu estes resultados à categoria da política, tipicamente representada através de coordenadas de esquerda e de direita. Respostas manuais e atencionais foram mais rápidas para alvos localizados à direita após terem sido apresentadas termos políticos de direita (versus alvos à esquerda após termos políticos de esquerda), que correspondiam à direção em que habitualmente se representa movimento. O quinto e último estudo demonstrou que a apresentação de palavras temporais simultaneamente com um tom auditivo não-espacial impede os efeitos de emergirem. Estas pistas bimodais revelaram as condições limitativas dos efeitos da assimetria espacial. Em conclusão, esta dissertação demonstra que existe uma propriedade genérica de movimento que deriva da direção ortográfica e que é transversal à representação de estímulos distintos, em várias tarefas e modalidades sensoriais. Estes resultados oferecem uma perspetiva mais abrangente sobre o impacto prevalente que uma característica da língua aparentemente irrelevante tem em processos cognitivos fundamentais de perceção, atenção, e julgamento.The directional activities of reading and writing have been shown to ground a preferential trajectory when scanning space. This horizontal directional formation is further reinforced by other cultural regularities that overlap with it. This space-movement correlation creates a left-right (or vice-versa) schema for action that biases the representation of human agency and extends to the representation of other abstract concepts lacking experiential sensorimotor bases. Consequently, the horizontal dimension is recruited to reason about abstract concepts that are mapped congruently with one’s dominant reading and writing or script direction. The spatial asymmetry that this combined directionality induces is a core finding in the embodiment area and has been shown to affect important social and cognitive processes. However, the specific processes activated by these asymmetries remain unclear. A series of seven experiments are outlined to investigate how spatial asymmetries affect social inferences and visuomotor performance to stimuli anchored in the horizontal dimension. The first study indicated that a range of agency-related social inferences are preferentially assigned to face profiles oriented rightward (versus leftward). Across two experiments, the second study showed that right oriented faces serve as attention-orienting primes. Rightward faces, which are in line with the direction used to represent human agency, facilitate attention to and detection of targets on the right hemifield, relative to leftward faces and targets on the left hemifield. In the third study, face primes were replaced by visual and auditory time words known to ground horizontally in space. Spatial asymmetries were tested in two experiments with communities holding opposite writing scripts (Portuguese and Arabic). We observed the mapping of time to be reversed between the two samples (Portuguese: past-left/future-right; Arabic: past-right/future-left). Further, a mirrored asymmetric performance between the two linguistic communities confirmed that the mapping of time is biased by orthographic habits and the cultural representation of human agency. That is, time words that coincide with the direction induced by both writing systems (i.e., future-related) gave rise to right-side advantage in the Portuguese sample and left-side advantage in the Arabic sample. The fourth study extended these results to the category of politics, commonly represented through coordinates of left and right. Manual and gaze responses were faster to targets embedded on the right following conservatism-related words (versus the left following socialism-related words) that embody the habitualized rightward movement direction. The fifth and final study demonstrated that presenting time words synchronously with an auditory nonspatial tone impaired cueing effects. These bimodal cues revealed the boundary conditions of the spatial agency bias. Overall, this dissertation underscores that a generic property of movement that is derived from orthographic direction underlies the representation of very distinct stimuli across tasks and sensory modalities. These findings offer a broader perspective on the pervasive impact a seemingly irrelevant feature of language has on fundamental cognitive processes of perception, attention, and judgment