Visuospatial Patterns Research Articles

Spatiotemporal brain hierarchies of auditory memory recognition and predictive coding

Our brain is constantly extracting, predicting, and recognising key spatiotemporal features of the physical world in order to survive. While neural processing of visuospatial patterns has been extensively studied, the hierarchical brain mechanisms underlying conscious recognition of auditory sequences and the associated prediction errors remain elusive. Using magnetoencephalography (MEG), we describe the brain functioning of 83 participants during recognition of previously memorised musical sequences and systematic variations. The results show feedforward connections originating from auditory cortices, and extending to the hippocampus, anterior cingulate gyrus, and medial cingulate gyrus. Simultaneously, we observe backward connections operating in the opposite direction. Throughout the sequences, the hippocampus and cingulate gyrus maintain the same hierarchical level, except for the final tone, where the cingulate gyrus assumes the top position within the hierarchy. The evoked responses of memorised sequences and variations engage the same hierarchical brain network but systematically differ in terms of temporal dynamics, strength, and polarity. Furthermore, induced-response analysis shows that alpha and beta power is stronger for the variations, while gamma power is enhanced for the memorised sequences. This study expands on the predictive coding theory by providing quantitative evidence of hierarchical brain mechanisms during conscious memory and predictive processing of auditory sequences.

Visual field inhomogeneous in brain–computer interfaces based on rapid serial visual presentation

Objective. Visual attention is not homogeneous across the visual field, while how to mine the effective electroencephalogram (EEG) characteristics that are sensitive to the inhomogeneous of visual attention and further explore applications such as the performance of brain–computer interface (BCI) are still distressing explorative scientists. Approach. Images were encoded into a rapid serial visual presentation (RSVP) paradigm, and were presented in three visuospatial patterns (central, left/right, upper/lower) at the stimulation frequencies of 10, 15 and 20 Hz. The comparisons among different visual fields were conducted in the dimensions of subjective behavioral and EEG characteristics. Furthermore, the effective features (e.g. steady-state visual evoked potential (SSVEP), N2-posterior-contralateral (N2pc) and P300) that sensitive to visual-field asymmetry were also explored. Main results. The visual fields had significant influences on the performance of RSVP target detection, in which the performance of central was better than that of peripheral visual field, the performance of horizontal meridian was better than that of vertical meridian, the performance of left visual field was better than that of right visual field, and the performance of upper visual field was better than that of lower visual field. Furthermore, stimuli of different visual fields had significant effects on the spatial distributions of EEG, in which N2pc and P300 showed left–right asymmetry in occipital and frontal regions, respectively. In addition, the evidences of SSVEP characteristics indicated that there was obvious overlap of visual fields on the horizontal meridian, but not on the vertical meridian. Significance. The conclusions of this study provide insights into the relationship between visual field inhomogeneous and EEG characteristics. In addition, this study has the potential to achieve precise positioning of the target’s spatial orientation in RSVP-BCIs.

The spatial logics of justification – the case of a dispute over a car-free street in Tampere, Finland

ABSTRACTThis article develops the spatial aspect of the justification theory of Luc Boltanski and Laurent Thévenot. The aim is to show that the worlds of justification, distinct constellations of moral values and material objects, also have distinct spatial logics. To illustrate my argument, I use a case study, namely a polarised dispute related to a car-free main street in Tampere, the third biggest city in Finland. I show that the spatial logics in this dispute are ordered by different types of image schemas, recurrent and shared visuospatial patterns depicted by George Lakoff and Mark Johnson. I analyse image schemas to make visible the differences and similarities between the worlds of justification concerned. Developing the spatial aspect of justification theory makes possible a novel way to study disputes related to city and space, as well as controversies that are not obviously spatial. Human thinking is multimodal and entails visuospatial metaphors, even though its subject-matter might on occasion appear non-spatial.

Pointing towards visuospatial patterns in short-term memory: differential effects on familiarity- and recollection-based judgments.

Previous studies have indicated that pointing toward to-be-remembered visuospatial patterns enhances short-term memory (STM) when the presentation of pointing and no-pointing trials is mixed (Chum et al., 2007; Dodd & Shumborski, 2009; Rossi-Arnaud et al., 2012). By contrast, when presentation is blocked, pointing has inhibitory effects on memory (Dodd & Shumborski, 2009; Rossi-Arnaud et al., 2012). In the present study, we demonstrated that pointing has different effects on short-term recollection- and familiarity-based judgments, depending on the length of the visuospatial patterns (5- vs. 7-item arrays) and the interval between the encoding and test phases (2 vs. 5 s). More specifically, pointing decreased the accuracy of recollection-based judgments for 5-item arrays, but not for 7-item arrays (this negative effect did not interact with interval length). In contrast, pointing facilitated familiarity-based judgments when the interval between the study and test phases was 5 s, but not when it was 2 s (this positive effect did not interact with pattern length). We proposed that the negative effects might be accounted for by the simultaneous recruitment of attention resources in the planning and execution of pointing movements. As a consequence, executive resources are diverted from the primary memory task, resulting in a less efficient use of attention-demanding retrieval strategies, like chunking. By contrast, the positive effects on familiarity judgments might reflect the unitization of the to-be-remembered items into a single shape.

From gestures to words: Spontaneous verbal labeling of complex sequential hand movements reduces fMRI activation of the imitation-related regions

The association of verbal labels with visuo-spatial patterns and sequences detectably alters neuronal activity in the brain in ways that have yet to be fully characterized. This study investigated the neural substrates involved in the effect of spontaneous verbal labeling on memorizing increasingly complex sequences of hand movements. We used functional magnetic resonance imaging (fMRI) to test our hypothesis that when verbal labels were employed, neuronal activity in imitation-related regions, such as the left inferior frontal gyrus (IFG), would be reduced, whereas without verbal labels, neuronal activation would increase. Sixteen healthy adults satisfactorily performed an immediate imitation task involving six levels of increasing complexity. After the fMRI experiment, participants reported at which complexity level they had formed verbal labels. Based on the self-report, we categorized the task blocks at each complexity level as either with verbal labeling (VL+) or without (VL−). Compared with VL+, the VL− condition activated the left IFG, bilateral middle frontal gyri, left precentral gyrus, and the right angular gyrus, whereas the opposite contrast revealed no significant brain activation. Verbal labeling seems to serve as an efficient heuristic that reduces the cost of cortical activation in the imitation-related regions.

Process-specific interference effects during recognition of spatial patterns and words.

The authors examined recognition memory for words or visuospatial patterns under full (FA) or divided attention (DA) conditions with a distracting task requiring either phonological (rhyme) or visuospatial (curved-line) processing of letters, in 72 young adults. The authors found an interaction such that the curved-line distracting task had a more detrimental effect on corrected recognition, and discriminability measured by d', for spatial patterns than did the rhyme distracting task, whereas the reverse was true for memory of words. There was also a general effect of DA on response bias such that C increased under DA relative to FA conditions, regardless of the distracting task, and type of information being remembered. Results suggest memory interference from DA at retrieval is process-specific, and that DA at retrieval leads to a more conservative response strategy.

Effects of early focal brain injury on memory for visuospatial patterns: Selective deficits of global-local processing.

Selective deficits in visuospatial processing are present early in development among children with perinatal focal brain lesions (PL). Children with right hemisphere PL (RPL) are impaired in configural processing, while children with left hemisphere PL (LPL) are impaired in featural processing. Deficits associated with LPL are less pervasive than those observed with RPL, but this difference may reflect the structure of the tasks used for assessment. Many of the tasks used to date may place greater demands on configural processing, thus highlighting this deficit in the RPL group. This study employed a task designed to place comparable demands on configural and featural processing, providing the opportunity to obtain within-task evidence of differential deficit. Sixty-two 5- to 14-year-old children (19 RPL, 19 LPL, and 24 matched controls) reproduced from memory a series of hierarchical forms (large forms composed of small forms). Global- and local-level reproduction accuracy was scored. Controls were equally accurate on global- and local-level reproduction. Children with RPL were selectively impaired on global accuracy, and children with LPL on local accuracy, thus documenting a double dissociation in global-local processing.

Recognition in a visuospatial memory task: The effect of presentation

The influence of the mode of presentation (simultaneous vs. sequential) on accuracy and latency of visuospatial recognition was explored in three experiments. In Experiment 1, two groups were administered a visuospatial task in which a number of positions were shown either simultaneously or sequentially (in a random order); memory was tested using a recognition procedure of visuospatial patterns, either identical or different (a single cell displaced). The results showed that (1) performance was higher in the simultaneous than in the sequential presentation, and (2) decision time increased with complexity in the sequential presentation but not in the simultaneous presentation. In Experiment 2, the same task was used in three conditions of presentation, simultaneous, random sequential, and ordered sequential; at test, a single location, rather than a pattern, was presented for recognition. The results showed that (1) performance was higher in the simultaneous and in the ordered sequential presentations than in the random sequential one, and (2) decision time increased with complexity. In Experiment 3, the same task was used in the same three conditions of presentation, simultaneous, random sequential, and ordered sequential; at test either an identical or a “displaced” pattern was presented for recognition. The results showed that (1) performance was equivalent in the three types of presentation, and (2) decision time increased with complexity for “hit” items; different patterns of linear relations were observed for “correct rejections” items. The results are interpreted in terms of the organisation of visuospatial working memory, and three types of encoding—extrafigural spatial encoding, visual pattern encoding, and spatial path encoding—were proposed.

Exploring Developmental Change in the Neural Bases of Higher Cognitive Functions: The Promise of Functional Magnetic Resonance Imaging

The dramatic changes in cognitive ability observed throughout childhood mirror comparably significant changes in the developing brain. Studies of animals provide important data on associations between the development of behavior and the neural substrate. However, understanding the development of brain-behavior relations for higher cognitive functions in humans requires direct, concurrent measurement of behavior and brain functions in the children themselves. To date, such data have been very limited. Recent developments in functional magnetic resonance imaging (fMRI) provide the opportunity to systematically explore the development of brain-behavior relations in children. In this article we consider the potential of fMRI to contribute to researchers' understanding of the development of brain-behavior relations. We begin with an overview of the basic imaging method. We then review work from our own laboratory that demonstrates systematic patterns of association between performance on visuospatial tasks and patterns of brain activation, and we compare our findings with those from other laboratories focused on other cognitive domains. Finally, we discuss the potential impact of functional imaging on researchers' understanding of core issues in cognitive and brain development.

Face recognition in children with a pervasive developmental disorder not otherwise specified.

This study investigates the accuracy and speed of face recognition in children with a Pervasive Developmental Disorder Not Otherwise Specified (PDDNOS; DSM-IV, American Psychiatric Association [APA], 1994). The study includes a clinical group of 26 nonretarded 7- to 10-year-old children with PDDNOS and a control group of 65 normally developing children of the same age. Two computerized reaction time tasks were administered: a face recognition task and a control task designed to measure the recognition of abstract visuospatial patterns. The latter were either easy or difficult to distinguish from a set of alternative patterns. The normally developing children recognized the faces much faster than the hardly distinguishable abstract patterns. The children in the PDDNOS group needed an amount of time to recognize the faces that almost equalled the time they needed to recognize the abstract patterns that were difficult to distinguish. The results suggest that, when processing faces, children with PDDNOS use a strategy that is more attention-demanding and, hence, less automatic or "Gestalt-like" than the one used by the control children. The results are discussed in the light of a theory that explains the development of coherent mental representations.

Hemispheric asymmetries in global and local processing: evidence from fMRI.

Functional magnetic resonance imaging (fMRI) was used to explore the brain substrate associated with global and local processing of visuospatial patterns. Systematic differences in activation, consistent with differences observed in reaction time data collected under conditions of visual hemifield presentation, were found in occipitotemporal regions of the right and left hemispheres. Within the right hemisphere, area of activation and fractional signal changes were greater under conditions of global processing than under local processing conditions. In the left hemisphere, activation to global and local input was high and comparable.

Exploring visuospatial short-term memory defect in Alzheimer's disease

The present study aimed at controlling two variables that may affect the visuospatial short-term memory of Alzheimer patients: visuospatial coding efficiency and response modality. Thirty patients affected by Alzheimer-type dementia with relatively spared visuo-perceptual functions were tested under three conditions, all of which employed the same kind of stimuli (visuospatial patterns). At all memory tasks, patients achieved scores significantly lower than those of 30 age- and education-matched normal subjects. Patients did not benefit from longer presentation time, nor did their performance improve with pointing response modality, although they performed perceptual pattern recognition as well as did controls. These data confirm that visuospatial immediate memory capacity is reduced in dementia.

Memory for visuospatial patterns in Alzheimer's disease

Immediate memory for visuospatial information was assessed in patients affected by Alzheimer-type dementia but with unimpaired visuo-perceptual functions. Patients were given two tasks: one was a traditional visuospatial memory task (Corsi's block tapping test), the second explored specifically immediate memory for visuospatial patterns. The experiment was conducted in two parallel groups of patients in Italy and the United States, each with its own appropriate sample of normal control subjects. Results showed a specific deficit of visual working memory in demented patients, even in a task in which control subjects achieved error-free performance. These data are interpreted in the light of the Working Memory Model, and suggest that in dementia the functions of the Visuospatial Scratchpad, unlike the functions of the verbal subsystems, may be impaired.

Chiasmus in literature: Ornament or function?

In terms of recent research into the hemisphericity of the human brain, ‘word’ and ‘image’ are products of the left and the right brain respectively. A literary text, however, is the result of a sophisticated interaction between the left brain that controls verbal, propositional as well as sequential processes and the right brain which imposes non-temporal, visuo-spatial patterns on the verbal sequence. It is this hemispherical interaction which accounts for the presence of both a temporal and a spatial dimension in literature, as Northrop Frye has described it :

Hemispheric Asymmetry and Left and Right Manual versus Pedal Tapping during a Concurrent Cognitive Task

In the present experiment we investigated the effects of concurrent hemisphere-specific cognitive activity on manual and pedal tapping frequency in a dual-task interference paradigm. Typically, right-hand finger-tapping interference is observed during a verbal task, and left-hand interference is observed during a nonverbal task. This effect has theoretically been linked to the concept of competition for the same functional space within a hemisphere between two concurrently performed tasks. In the present study, the concept of functional space was examined by comparing finger-tapping with foot-tapping. The assumption was that finger-tapping should be more affected than foot-tapping to hemisphere-specific tasks, and especially a verbal task, considering the closer structural overlap between the cortical hand area and the speech area The experiment involved four tasks performed concurrently with either finger- or foot-tapping. The tasks were reading a text aloud, humming, watching slides with nonsense-syllables, and watching slides with visuospatial patterns. The subjects were 20 right-handed males. The results did not support the hypothesis of competition for functional space.

Relationships between speed, accuracy of performance and hemispheric superiorities for visuo-spatial pattern processing in the two sexes

The aim of this study was to investigate the relationship between visual field differences in tachistoscopic recognition of visuo-spatial patterns and overall proficiency in the two sexes. The results demonstrated a left visual field advantage in males but not in females. A female subgroup showed opposite rather than lacking visual field superiorities without affecting speed and accuracy of performance. These data warn against explaining differences in performance in the two sexes in terms of different hemispheric asymmetries.

Upright and Inverted Faces: The Right Hemisphere Knows the Difference

The existence of a right hemisphere capacity, specific to upright faces was investigated. Upright and inverted faces, equally complex as patterns, were presented under lateralized tachistoscopic conditions to two groups of normal adult subjects. A significant orientation by visual field advantage was found. While there was a highly significant left visual field advantage for upright faces, the visual field difference for inverted faces failed to reach significane. This pattern of results supports the hypothesis that the right hemisphere is specialized for the perception of faces in particular, in addition to its specialization for the perception of visuospatial patterns in general.

Electrical correlate of right hemisphere function.

IN right handed individuals, the two cerebral hemispheres seem to be specialized for different functions. The role of the left hemisphere in controlling language and the preferred hand is well known, but the specialization of the right hemisphere has proved harder to define1. The effects of unilateral cortical damage and, in particular, right temporal resections2 have led to the view that the right hemisphere is concerned with analysis of complex visuo-spatial patterns. This view is supported by work on brain bisected patients3 and by tachistoscopic studies such as those of Durnford and Kimura4.