Space-Time Congruency Effects Using Eye Movements During Processing of Past- and Future-Related Words.

In Western cultures where people read and write from left to right, time is represented along a spatial continuum that goes from left to right (past to future), known as the mental timeline (MTL). In language, this MTL was supported by space-time congruency effects: People are faster to make lexical decisions to words conveying past or future information when left/right manual responses are compatible with the MTL. Alternatively, in cultures where people read from right to left, space-time congruency effects go in the opposite direction. Such cross-cultural differences suggest that repeated writing and reading dynamic movements are critically involved in the spatial representation of time. In most experiments on the space-time congruency effect, participants use their hand for responding, an effector that is associated to the directionality of writing. To investigate the role of the directionality of reading in the space-time congruency effect, we asked participants to make lateralized eye movements (left or right saccades) to indicate whether stimuli were real words or not (lexical decision). Eye movement responses were slower and higher in amplitude for responses incompatible with the direction of the MTL. These results reinforce the claim that repeated directional reading and writing movements promote the embodiment of time-related words.

Embodied time: Effect of reading expertise on the spatial representation of past and future.

How do people grasp the abstract concept of time? It has been argued that abstract concepts, such as future and past, are grounded in sensorimotor experience. When responses to words that refer to the past or the future are either spatially compatible or incompatible with a left-to-right timeline, a space-time congruency effect is observed. In the present study, we investigated whether reading expertise determines the strength of the space-time congruency effect, which would suggest that learning to read and write drives the effect. Using a temporal categorization task, we compared two types of space-time congruency effects, one where spatial incongruency was generated by the location of the stimuli on the screen and one where it was generated by the location of the responses on the keyboard. While the first type of incongruency was visuo-spatial only, the second involved the motor system. Results showed stronger space-time congruency effects for the second type of incongruency (i.e., when the motor system was involved) than for the first type (visuo-spatial). Crucially, reading expertise, as measured by a standardized reading test, predicted the size of the space-time congruency effects. Altogether, these results reinforce the claim that the spatial representation of time is partially mediated by the motor system and partially grounded in spatially-directed movement, such as reading or writing.

As time goes by: Space-time compatibility effects in word recognition.

The processing of time activates a spatial left-to-right mental timeline, where past events are "located" to the left and future events to the right. If past and future words activate this mental timeline, then the processing of such words should interfere with hand movements that go in the opposite direction. To test this hypothesis, we conducted 3 visual lexical decision tasks with conjugated (past/future) verbs and pseudoverbs. In Experiment 1, participants moved a pen to the right or left of a trackpad to indicate whether a visual stimulus was a real word or not. Grammatical time and hand movements for yes responses went in the same direction in the congruent condition (e.g., past tense/leftward movement) but in opposite directions in the incongruent condition. Analyses showed that space-time incongruency significantly increased reaction times. In Experiment 2, we investigated the role of movement in this effect. Participants performed the same task by responding with a trackpad or a mouse, both of which required lateral movement through space, or a static keypress. We again obtained the space-time congruency effect, but only when the decision required movement through space. In Experiments 1 and 2, stimuli were preceded by a temporal prime. In Experiment 3, participants performed the same task without any prime. Results replicated the congruency effect, demonstrating that it does not depend upon temporal word priming. Altogether, results suggest automatic activation of a left-right mental timeline during word recognition, reinforcing the claim that the concept of Time is grounded in movement through space. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

The baboon: A model for the study of language evolution.

Comparative research on the origins of human language often focuses on a limited number of language-related cognitive functions or anatomical structures that are compared across species. The underlying assumption of this approach is that a single or a limited number of factors may crucially explain how language appeared in the human lineage. Another potentially fruitful approach is to consider human language as the result of a (unique) assemblage of multiple cognitive and anatomical components, some of which are present in other species. This paper is a first step in that direction. It focuses on the baboon, a non-human primate that has been studied extensively for years, including several brain, anatomical, cognitive and cultural dimensions that are involved in human language. This paper presents recent data collected on baboons regarding (1) a selection of domain-general cognitive functions that are core functions for language, (2) vocal production, (3) gestural production and cerebral lateralization, and (4) cumulative culture. In all these domains, it shows that the baboons share with humans many cognitive or brain mechanisms which are central for language. Because of the multidimensionality of the knowledge accumulated on the baboon, that species is an excellent nonhuman primate model for the study of the evolutionary origins of language.

Do Words Stink? Neural Reuse as a Principle for Understanding Emotions in Reading.

How do we understand the emotional content of written words? Here, we investigate the hypothesis that written words that carry emotions are processed through phylogenetically ancient neural circuits that are involved in the processing of the very same emotions in nonlanguage contexts. This hypothesis was tested with respect to disgust. In an fMRI experiment, it was found that the same region of the left anterior insula responded whether people observed facial expressions of disgust or whether they read words with disgusting content. In a follow-up experiment, it was found that repetitive TMS over the left insula in comparison with a control site interfered with the processing of disgust words to a greater extent than with the processing of neutral words. Together, the results support the hypothesis that the affective processes we experience when reading rely on the reuse of phylogenetically ancient brain structures that process basic emotions in other domains and species.

Categorization does not promote symmetry in Guinea baboons (Papio papio).

Humans have the capacity to use stimuli interchangeably by forming equivalence classes, and this ability seems to be supported by our language system. According to Sidman and Tailby (Conditional discrimination vs. matching to sample: an expansion of the testing paradigm. J Exp Anal Behav 37:5-22, 1982), the formation of equivalence classes require that three relations are derived among the class members, and past experiments have shown that one of these relations, i.e., symmetry, corresponding to the ability to reverse a relation (if A â†’ B, then B â†’ A), is extremely difficult to obtain in non-human animals. Because language development and the ability to form equivalence classes both co-occur in children with an increased ability to form categories, the current study tested the idea that category learning might promote symmetry in a nonhuman primate species. In Experiment 1, twelve Guinea baboons (Papio papio) were trained to associate 60 pictures of bears and 60 pictures of cars to two category labels, before being tested in symmetry trials. In Experiment 2, symmetry was trained and tested by reversing the association order between labels and pictures, using a new set of stimuli. In both experiments, the baboons successfully demonstrated category discrimination, but had only a weak (though significant) tendency to respond in accordance with symmetry during test trials. Altogether, our results confirm that symmetry is inherently difficult in non-human animals. We discuss possible explanations for such a limitation and give reasons for thinking that the effects of categorization on symmetry should be further investigated.

Emotion processing in words: a test of the neural re-use hypothesis using surface and intracranial EEG.

This study investigates the spatiotemporal brain dynamics of emotional information processing during reading using a combination of surface and intracranial electroencephalography (EEG). Two different theoretical views were opposed. According to the standard psycholinguistic perspective, emotional responses to words are generated within the reading network itself subsequent to semantic activation. According to the neural re-use perspective, brain regions that are involved in processing emotional information contained in other stimuli (faces, pictures, smells) might be in charge of the processing of emotional information in words as well. We focused on a specific emotion-disgust-which has a clear locus in the brain, the anterior insula. Surface EEG showed differences between disgust and neutral words as early as 200 ms. Source localization suggested a cortical generator of the emotion effect in the left anterior insula. These findings were corroborated through the intracranial recordings of two epileptic patients with depth electrodes in insular and orbitofrontal areas. Both electrodes showed effects of disgust in reading as early as 200 ms. The early emotion effect in a brain region (insula) that responds to specific emotions in a variety of situations and stimuli clearly challenges classic sequential theories of reading in favor of the neural re-use perspective.

Emotions in reading: disgust, empathy and the contextual learning hypothesis.

Emotion effects in reading have typically been investigated by manipulating words' emotional valence and arousal in lexical decision. The standard finding is that valence and arousal can have both facilitatory and inhibitory effects, which is hard to reconcile with current theories of emotion processing in reading. Here, we contrasted these theories with the contextual-learning hypothesis, according to which, sensitivity to a specific emotion - disgust in the present study - rather than valence or arousal affects lexical decision performance. Participants were divided into two groups (high versus low disgust sensitivity). Results showed that participants with high disgust sensitivity showed an inhibitory effect, whereas participants with low-disgust sensitivity showed a facilitatory effect. Individual differences in lexical decision performance were predicted by disgust sensitivity but not valence, arousal, or general emotion sensitivity. These findings highlight the need to focus on individual differences both in studies and theories of emotion processing in reading.

Orthographic processing in baboons (Papio papio).

Skilled readers use information about which letters are where in a word (orthographic information) in order to access the sounds and meanings of printed words. We asked whether efficient processing of orthographic information could be achieved in the absence of prior language knowledge. To do so, we trained baboons to discriminate English words from nonsense combinations of letters that resembled real words. The results revealed that the baboons were using orthographic information in order to efficiently discriminate words from letter strings that were not words. Our results demonstrate that basic orthographic processing skills can be acquired in the absence of preexisting linguistic representations.

Orthographic Contamination of Broca's Area.

Strong evidence has accumulated over the past years suggesting that orthography plays a role in spoken language processing. It is still unclear, however, whether the influence of orthography on spoken language results from a co-activation of posterior brain areas dedicated to low-level orthographic processing or whether it results from orthographic restructuring of phonological representations located in the anterior perisylvian speech network itself. To test these hypotheses, we ran a fMRI study that tapped orthographic processing in the visual and auditory modalities. As a marker for orthographic processing, we used the orthographic decision task in the visual modality and the orthographic consistency effect in the auditory modality. Results showed no specific orthographic activation neither for the visual nor the auditory modality in left posterior occipito-temporal brain areas that are thought to host the visual word form system. In contrast, specific orthographic activation was found both for the visual and auditory modalities at anterior sites belonging to the perisylvian region: the left dorsal-anterior insula and the left inferior frontal gyrus. These results are in favor of the restructuring hypothesis according to which learning to read acts like a "virus" that permanently contaminates the spoken language system.

Orthographic effects in spoken language: on-line activation or phonological restructuring?

Previous research has shown that literacy (i.e., learning to read and spell) affects spoken language processing. However, there is an on-going debate about the nature of this influence. Some argued that orthography is co-activated on-line whenever we hear a spoken word. Others suggested that orthography is not activated on-line but has changed the nature of the phonological representations. Finally, both effects might occur simultaneously, that is, orthography might be activated on-line in addition to having changed the nature of the phonological representations. Previous studies have not been able to tease apart these hypotheses. The present study started by replicating the finding of an orthographic consistency effect in spoken word recognition using event-related brain potentials (ERPs): words with multiple spellings (i.e., inconsistent words) differed from words with unique spellings (i.e., consistent words) as early as 330 ms after the onset of the target. We then employed standardized low resolution electromagnetic tomography (sLORETA) to determine the possible underlying cortical generators of this effect. The results showed that the orthographic consistency effect was clearly localized in a classic phonological area (left BA40). No evidence was found for activation in the posterior cortical areas coding orthographic information, such as the visual word form area in the left fusiform gyrus (BA37). This finding is consistent with the restructuring hypothesis according to which phonological representations are "contaminated" by orthographic knowledge.

A new vibrator to stimulate muscle proprioceptors in fMRI.

Studying cognitive brain functions by functional magnetic resonance imaging (fMRI) requires appropriate stimulation devices that do not interfere with the magnetic fields. Since the emergence of fMRI in the 90s, a number of stimulation devices have been developed for the visual and auditory modalities. Only few devices, however, have been developed for the somesthesic modality. Here, we present a vibration device for studying somesthesia that is compatible with high magnetic field environments and that can be used in fMRI machines. This device consists of a poly vinyl chloride (PVC) vibrator containing a wind turbine and of a pneumatic apparatus that controls 1-6 vibrators simultaneously. Just like classical electromagnetic vibrators, our device stimulates muscle mechanoreceptors (muscle spindles) and generates reliable illusions of movement. We provide the fMRI compatibility data (phantom test), the calibration curve (vibration frequency as a function of air flow), as well as the results of a kinesthetic test (perceived speed of the illusory movement as a function of vibration frequency). This device was used successfully in several brain imaging studies using both fMRI and magnetoencephalography.

Visual phonology: the effects of orthographic consistency on different auditory word recognition tasks.

In this study, we investigated orthographic influences on spoken word recognition. The degree of spelling inconsistency was manipulated while rime phonology was held constant. Inconsistent words with subdominant spellings were processed more slowly than inconsistent words with dominant spellings. This graded consistency effect was obtained in three experiments. However, the effect was strongest in lexical decision, intermediate in rime detection, and weakest in auditory naming. We conclude that (1) orthographic consistency effects are not artifacts of phonological, phonetic, or phonotactic properties of the stimulus material; (2) orthographic effects can be found even when the error rate is extremely low, which rules out the possibility that they result from strategies used to reduce task difficulty; and (3) orthographic effects are not restricted to lexical decision. However, they are stronger in lexical decision than in other tasks. Overall, the study shows that learning about orthography alters the way we process spoken language.

PURE ALEXIA AND THE VIEWING POSITION EFFECT IN PRINTED WORDS.

In the present article, we investigated the reading ability of CP, a pure alexic patient, using an experimental paradigm that is known to elicit the viewing position effect in norm al readers. The viewing position effect consists of a systematic variation of word recognition performance as a function of fixation location w ithin a word: Word recognition is best when the eyes fixate slightly left from the word centre and decreases when the eyes deviate from this optimal viewing position. A mathematical model (Nazir, O'Regan, & Jacobs, 1991), which provides a good description and quantification of the prototypical shape of the viewing position effect, served to interpret CP's reading performance. The results show ed that, like normal readers, CP was able to process all letters of a w ord in one fixation. However, in contrast to normal readers, reading performance was optimal when CP w as fixating the right half of the word. This somewhat abnormal pattern of performance was due to (1) poor perceptual processing in the right visual field, and (2) poor processing of letters situated towards the end of the word, independent of visual field presentation. A similar pattern of perform ance w as obtained with normal readers under experimental conditions in which lexical know ledge was of restricted use. We suggest that CP's reading impairment stems from a dysfunction in the coupling between incoming visual information and stored lexical information. This dysfunction is thought to uncover a prelexical level of word processing, where letter information is weighted differently as a function of letter position in a word-centred space.