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1.
PeerJ ; 12: e17295, 2024.
Article in English | MEDLINE | ID: mdl-38827290

ABSTRACT

This study aimed to examine the influence of sport skill levels on behavioural and neuroelectric performance in visuospatial attention and memory visuospatial tasks were administered to 54 participants, including 18 elite and 18 amateur table tennis players and 18 nonathletes, while event-related potentials were recorded. In all the visuospatial attention and memory conditions, table tennis players displayed faster reaction times than nonathletes, regardless of skill level, although there was no difference in accuracy between groups. In addition, regardless of task conditions, both player groups had a greater P3 amplitude than nonathletes, and elite players exhibited a greater P3 amplitude than amateurs players. The results of this study indicate that table tennis players, irrespective of their skill level, exhibit enhanced visuospatial capabilities. Notably, athletes at the elite level appear to benefit from an augmented allocation of attentional resources when engaging in visuospatial tasks.


Subject(s)
Attention , Cognition , Evoked Potentials , Reaction Time , Humans , Male , Young Adult , Attention/physiology , Cognition/physiology , Evoked Potentials/physiology , Reaction Time/physiology , Female , Tennis/physiology , Tennis/psychology , Adult , Space Perception/physiology , Athletes/psychology , Athletic Performance/physiology , Visual Perception/physiology , Electroencephalography , Adolescent
2.
Sci Rep ; 14(1): 12657, 2024 06 03.
Article in English | MEDLINE | ID: mdl-38825633

ABSTRACT

When lying inside a MRI scanner and even in the absence of any motion, the static magnetic field of MRI scanners induces a magneto-hydrodynamic stimulation of subjects' vestibular organ (MVS). MVS thereby not only causes a horizontal vestibular nystagmus but also induces a horizontal bias in spatial attention. In this study, we aimed to determine the time course of MVS-induced biases in both VOR and spatial attention inside a 3 T MRI-scanner as well as their respective aftereffects after participants left the scanner. Eye movements and overt spatial attention in a visual search task were assessed in healthy volunteers before, during, and after a one-hour MVS period. All participants exhibited a VOR inside the scanner, which declined over time but never vanished completely. Importantly, there was also an MVS-induced horizontal bias in spatial attention and exploration, which persisted throughout the entire hour within the scanner. Upon exiting the scanner, we observed aftereffects in the opposite direction manifested in both the VOR and in spatial attention, which were statistically no longer detectable after 7 min. Sustained MVS effects on spatial attention have important implications for the design and interpretation of fMRI-studies and for the development of therapeutic interventions counteracting spatial neglect.


Subject(s)
Attention , Magnetic Resonance Imaging , Humans , Magnetic Resonance Imaging/methods , Male , Female , Adult , Attention/physiology , Eye Movements/physiology , Young Adult , Reflex, Vestibulo-Ocular/physiology , Space Perception/physiology , Vestibule, Labyrinth/physiology , Vestibule, Labyrinth/diagnostic imaging , Healthy Volunteers
3.
Cereb Cortex ; 34(6)2024 Jun 04.
Article in English | MEDLINE | ID: mdl-38850216

ABSTRACT

Whether attention is a prerequisite of perceptual awareness or an independent and dissociable process remains a matter of debate. Importantly, understanding the relation between attention and awareness is probably not possible without taking into account the fact that both are heterogeneous and multifaceted mechanisms. Therefore, the present study tested the impact on visual awareness of two attentional mechanisms proposed by the Posner model: temporal alerting and spatio-temporal orienting. Specifically, we evaluated the effects of attention on the perceptual level, by measuring objective and subjective awareness of a threshold-level stimulus; and on the neural level, by investigating how attention affects two postulated event-related potential correlates of awareness. We found that alerting and orienting mechanisms additively facilitate perceptual consciousness, with activation of the latter resulting in the most vivid awareness. Furthermore, we found that late positivity is unlikely to constitute a neural correlate of consciousness as its amplitude was modulated by both attentional mechanisms, but early visual awareness negativity was independent of the alerting and orienting mechanisms. In conclusion, our study reveals a nuanced relationship between attention and awareness; moreover, by investigating the effect of the alerting mechanism, this study provides insights into the role of temporal attention in perceptual consciousness.


Subject(s)
Attention , Awareness , Electroencephalography , Evoked Potentials , Visual Perception , Humans , Attention/physiology , Awareness/physiology , Male , Female , Young Adult , Adult , Visual Perception/physiology , Evoked Potentials/physiology , Photic Stimulation/methods , Space Perception/physiology , Consciousness/physiology , Brain/physiology
4.
Sci Rep ; 14(1): 13147, 2024 06 07.
Article in English | MEDLINE | ID: mdl-38849392

ABSTRACT

Street performance or busking is common in public spaces. The literature highlights two psychological issues: the effect of street performance on public space perception and the complexity of the appreciation of street performance, regarded as street audience experience (SAE). The present study aims at verifying the effect of street performance on public space perception, while examining SAE as a mediator of this effect. We conducted a between-subjects field experiment (a quasi-experiment; N = 292) in Hong Kong. Participants assessed a public space without (control) or with (experimental) musical busking on essentialism, anti-essentialism, sonic restorativeness, and overall liking. In the experimental condition, unengaged passersby and engaged audience further evaluated SAE factors of emotion, intellect, novelty, place, interaction, and technique, and outcomes of overall satisfaction and donation worth. The public space with busking was perceived as significantly more sonically restorative. Engaged audience perceived the space as significantly more essentialist, anti-essentialist, sonically restorative, and likeable. Engaged audience also experienced more positive SAE and outcome variables. SAE fully mediated the effects of street performance on public space perception and outcome variables, respectively. These findings support the positive impact of street performance, which may enhance city inhabitants' well-being.


Subject(s)
Music , Space Perception , Humans , Female , Male , Music/psychology , Space Perception/physiology , Adult , Hong Kong , Young Adult , Emotions/physiology
5.
Sci Rep ; 14(1): 12852, 2024 06 04.
Article in English | MEDLINE | ID: mdl-38834578

ABSTRACT

The dorsal pulvinar has been implicated in visuospatial attentional and perceptual confidence processing. Pulvinar lesions in humans and monkeys lead to spatial neglect symptoms, including an overt spatial saccade bias during free choices. However, it remains unclear whether disrupting the dorsal pulvinar during target selection that relies on a perceptual decision leads to a perceptual impairment or a more general spatial orienting and choice deficit. To address this question, we reversibly inactivated the unilateral dorsal pulvinar by injecting GABA-A agonist THIP while two macaque monkeys performed a color discrimination saccade task with varying perceptual difficulty. We used Signal Detection Theory and simulations to dissociate perceptual sensitivity (d-prime) and spatial selection bias (response criterion) effects. We expected a decrease in d-prime if dorsal pulvinar affects perceptual discrimination and a shift in response criterion if dorsal pulvinar is mainly involved in spatial orienting. After the inactivation, we observed response criterion shifts away from contralesional stimuli, especially when two competing stimuli in opposite hemifields were present. Notably, the d-prime and overall accuracy remained largely unaffected. Our results underline the critical contribution of the dorsal pulvinar to spatial orienting and action selection while showing it to be less important for visual perceptual discrimination.


Subject(s)
Pulvinar , Saccades , Animals , Pulvinar/physiology , Saccades/physiology , Male , Space Perception/physiology , Visual Perception/physiology , Photic Stimulation , Macaca mulatta , Attention/physiology
6.
Brain Nerve ; 76(6): 749-754, 2024 Jun.
Article in Japanese | MEDLINE | ID: mdl-38853504

ABSTRACT

Unilateral spatial neglect is the failure of brain-damaged patients to report, respond, or orient to novel or meaningful stimuli presented to the contralateral side of the lesion. This usually involves the right cerebral hemisphere. Neglect presents with no restriction in gaze direction and results in difficulty across various aspects of daily activities, distinguishing it from simple homonymous hemianopia. The basic mechanisms underlying neglect is rightward bias of spatial attention, while non-direction-specific cognitive problems may contribute to clinical expressions of neglect.


Subject(s)
Perceptual Disorders , Humans , Perceptual Disorders/physiopathology , Perceptual Disorders/etiology , Space Perception/physiology , Attention/physiology , Functional Laterality/physiology
7.
Sci Rep ; 14(1): 12329, 2024 05 29.
Article in English | MEDLINE | ID: mdl-38811593

ABSTRACT

Mental rotation is the ability to rotate mental representations of objects in space. Shepard and Metzler's shape-matching tasks, frequently used to test mental rotation, involve presenting pictorial representations of 3D objects. This stimulus material has raised questions regarding the ecological validity of the test for mental rotation with actual visual 3D objects. To systematically investigate differences in mental rotation with pictorial and visual stimuli, we compared data of N = 54 university students from a virtual reality experiment. Comparing both conditions within subjects, we found higher accuracy and faster reaction times for 3D visual figures. We expected eye tracking to reveal differences in participants' stimulus processing and mental rotation strategies induced by the visual differences. We statistically compared fixations (locations), saccades (directions), pupil changes, and head movements. Supplementary Shapley values of a Gradient Boosting Decision Tree algorithm were analyzed, which correctly classified the two conditions using eye and head movements. The results indicated that with visual 3D figures, the encoding of spatial information was less demanding, and participants may have used egocentric transformations and perspective changes. Moreover, participants showed eye movements associated with more holistic processing for visual 3D figures and more piecemeal processing for pictorial 2D figures.


Subject(s)
Eye Movements , Humans , Female , Male , Eye Movements/physiology , Young Adult , Adult , Rotation , Reaction Time/physiology , Photic Stimulation/methods , Space Perception/physiology , Virtual Reality , Visual Perception/physiology , Head Movements/physiology , Saccades/physiology
8.
Conscious Cogn ; 121: 103696, 2024 05.
Article in English | MEDLINE | ID: mdl-38703539

ABSTRACT

A serial reaction time task was used to test whether the representations of a probabilistic second-order sequence structure are (i) stored in an effector-dependent, effector-independent intrinsic or effector-independent visuospatial code and (ii) are inter-manually accessible. Participants were trained either with the dominant or non-dominant hand. Tests were performed with both hands in the practice sequence, a random sequence, and a mirror sequence. Learning did not differ significantly between left and right-hand practice, suggesting symmetric intermanual transfer from the dominant to the non-dominant hand and vice versa. In the posttest, RTs were shorter for the practice sequence than for the random sequence, and longest for the mirror sequence. Participants were unable to freely generate or recognize the practice sequence, indicating implicit knowledge of the probabilistic sequence structure. Because sequence-specific learning did not differ significantly between hands, we conclude that representations of the probabilistic sequence structure are stored in an effector-independent visuospatial code.


Subject(s)
Reaction Time , Space Perception , Transfer, Psychology , Humans , Male , Female , Adult , Reaction Time/physiology , Young Adult , Space Perception/physiology , Transfer, Psychology/physiology , Psychomotor Performance/physiology , Visual Perception/physiology , Functional Laterality/physiology , Serial Learning/physiology , Practice, Psychological , Hand/physiology
9.
Multisens Res ; 37(3): 185-216, 2024 Apr 25.
Article in English | MEDLINE | ID: mdl-38714316

ABSTRACT

The influence of landmarks, that is, nearby non-target stimuli, on spatial perception has been shown in multiple ways. These include altered target localization variability near landmarks and systematic spatial distortions of target localizations. Previous studies have mostly been conducted in the visual modality using temporary, artificial landmarks or the tactile modality with persistent landmarks on the body. Thus, it is unclear whether both landmark types produce the same spatial distortions as they were never investigated in the same modality. Addressing this, we used a novel tactile setup to present temporary, artificial landmarks on the forearm and systematically manipulated their location to either be close to a persistent landmark (wrist or elbow) or in between both persistent landmarks at the middle of the forearm. Initial data (Exp. 1 and Exp. 2) suggested systematic differences of temporary landmarks based on their distance from the persistent landmark, possibly indicating different distortions of temporary and persistent landmarks. Subsequent control studies (Exp. 3 and Exp. 4) showed this effect was driven by the relative landmark location within the target distribution. Specifically, landmarks in the middle of the target distribution led to systematic distortions of target localizations toward the landmark, whereas landmarks at the side led to distortions away from the landmark for nearby targets, and toward the landmark with wider distances. Our results indicate that experimental results with temporary landmarks can be generalized to more natural settings with persistent landmarks, and further reveal that the relative landmark location leads to different effects of the pattern of spatial distortions.


Subject(s)
Space Perception , Touch Perception , Humans , Space Perception/physiology , Female , Touch Perception/physiology , Male , Young Adult , Adult , Touch/physiology , Physical Stimulation , Forearm/physiology
10.
Multisens Res ; 37(3): 217-241, 2024 May 17.
Article in English | MEDLINE | ID: mdl-38762220

ABSTRACT

Previous research has revealed congruency effects between different spatial dimensions such as right and up. In the audiovisual context, high-pitched sounds are associated with the spatial dimensions of up/above and front, while low-pitched sounds are associated with the spatial dimensions of down/below and back. This opens the question of whether there could also be a spatial association between above and front and/or below and back. Participants were presented with a high- or low-pitch stimulus at the time of the onset of the visual stimulus. In one block, participants responded according to the above/below location of the visual target stimulus if the target appeared in front of the reference object, and in the other block, they performed these above/below responses if the target appeared at the back of the reference. In general, reaction times revealed an advantage in processing the target location in the front-above and back-below locations. The front-above/back-below effect was more robust concerning the back-below component of the effect, and significantly larger in reaction times that were slower rather than faster than the median value of a participant. However, the pitch did not robustly influence responding to front/back or above/below locations. We propose that this effect might be based on the conceptual association between different spatial dimensions.


Subject(s)
Reaction Time , Space Perception , Humans , Male , Female , Space Perception/physiology , Young Adult , Adult , Reaction Time/physiology , Photic Stimulation , Acoustic Stimulation , Visual Perception/physiology , Pitch Perception/physiology
11.
Neuroimage ; 293: 120634, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38705431

ABSTRACT

Spatial image transformation of the self-body is a fundamental function of visual perspective-taking. Recent research underscores the significance of intero-exteroceptive information integration to construct representations of our embodied self. This raises the intriguing hypothesis that interoceptive processing might be involved in the spatial image transformation of the self-body. To test this hypothesis, the present study used functional magnetic resonance imaging to measure brain activity during an arm laterality judgment (ALJ) task. In this task, participants were tasked with discerning whether the outstretched arm of a human figure, viewed from the front or back, was the right or left hand. The reaction times for the ALJ task proved longer when the stimulus presented orientations of 0°, 90°, and 270° relative to the upright orientation, and when the front view was presented rather than the back view. Reflecting the increased reaction time, increased brain activity was manifested in a cluster centered on the dorsal anterior cingulate cortex (ACC), suggesting that the activation reflects the involvement of an embodied simulation in ALJ. Furthermore, this cluster of brain activity exhibited overlap with regions where the difference in activation between the front and back views positively correlated with the participants' interoceptive sensitivity, as assessed through the heartbeat discrimination task, within the pregenual ACC. These results suggest that the ACC plays an important role in integrating intero-exteroceptive cues to spatially transform the image of our self-body.


Subject(s)
Brain Mapping , Gyrus Cinguli , Magnetic Resonance Imaging , Humans , Gyrus Cinguli/physiology , Gyrus Cinguli/diagnostic imaging , Female , Male , Young Adult , Adult , Brain Mapping/methods , Interoception/physiology , Body Image , Functional Laterality/physiology , Reaction Time/physiology , Space Perception/physiology , Arm/physiology
12.
PLoS One ; 19(5): e0298116, 2024.
Article in English | MEDLINE | ID: mdl-38722850

ABSTRACT

Spatial navigation is a multi-faceted behaviour drawing on many different aspects of cognition. Visuospatial abilities, such as mental rotation and visuospatial working memory, in particular, may be key factors. A range of tests have been developed to assess visuospatial processing and memory, but how such tests relate to navigation ability remains unclear. This understanding is important to advance tests of navigation for disease monitoring in various disorders (e.g., Alzheimer's disease) where spatial impairment is an early symptom. Here, we report the use of an established mobile gaming app, Sea Hero Quest (SHQ), as a measure of navigation ability in a sample of young, predominantly female university students (N = 78; 20; female = 74.3%; mean age = 20.33 years). We used three separate tests of navigation embedded in SHQ: wayfinding, path integration and spatial memory in a radial arm maze. In the same participants, we also collected measures of mental rotation (Mental Rotation Test), visuospatial processing (Design Organization Test) and visuospatial working memory (Digital Corsi). We found few strong correlations across our measures. Being good at wayfinding in a virtual navigation test does not mean an individual will also be good at path integration, have a superior memory in a radial arm maze, or rate themself as having a strong sense of direction. However, we observed that participants who were good in the wayfinding task of SHQ tended to perform well on the three visuospatial tasks examined here, and to also use a landmark strategy in the radial maze task. These findings help clarify the associations between different abilities involved in spatial navigation.


Subject(s)
Spatial Navigation , Humans , Female , Spatial Navigation/physiology , Male , Young Adult , Adult , Memory, Short-Term/physiology , Spatial Memory/physiology , Maze Learning/physiology , Space Perception/physiology , Adolescent , Mobile Applications
13.
Cereb Cortex ; 34(5)2024 May 02.
Article in English | MEDLINE | ID: mdl-38795357

ABSTRACT

Visuospatial processing impairments are prevalent in individuals with cerebral visual impairment (CVI) and are typically ascribed to "dorsal stream dysfunction" (DSD). However, the contribution of other cortical regions, including early visual cortex (EVC), frontal cortex, or the ventral visual stream, to such impairments remains unknown. Thus, here, we examined fMRI activity in these regions, while individuals with CVI (and neurotypicals) performed a visual search task within a dynamic naturalistic scene. First, behavioral performance was measured with eye tracking. Participants were instructed to search and follow a walking human target. CVI participants took significantly longer to find the target, and their eye gaze patterns were less accurate and less precise. Second, we used the same task in the MRI scanner. Along the dorsal stream, activation was reduced in CVI participants, consistent with the proposed DSD in CVI. Intriguingly, however, visual areas along the ventral stream showed the complete opposite pattern, with greater activation in CVI participants. In contrast, we found no differences in either EVC or frontal cortex between groups. These results suggest that the impaired visuospatial processing abilities in CVI are associated with differential recruitment of the dorsal and ventral visual streams, likely resulting from impaired selective attention.


Subject(s)
Magnetic Resonance Imaging , Space Perception , Visual Cortex , Humans , Male , Female , Adult , Space Perception/physiology , Visual Cortex/diagnostic imaging , Visual Cortex/physiopathology , Visual Cortex/physiology , Visual Pathways/diagnostic imaging , Visual Pathways/physiology , Visual Pathways/physiopathology , Young Adult , Vision Disorders/physiopathology , Brain Mapping , Middle Aged , Visual Perception/physiology , Photic Stimulation/methods
14.
Cortex ; 175: 12-27, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38701643

ABSTRACT

Navigation through space is based on memory representations of landmarks ('place') or movement sequences ('response'). Over time, memory representations transform through consolidation. However, it is unclear how the transformation affects place and response navigation in humans. In the present study, healthy adults navigated to target locations in a virtual maze. The preference for using place and response strategies and the ability to recall place and response memories were tested after a delay of one hour (n = 31), one day (n = 30), or two weeks (n = 32). The different delays captured early-phase synaptic changes, changes after one night of sleep, and long-delay changes due to the reorganization of navigation networks. Our results show that the relative contributions of place and response navigation changed as a function of time. After a short delay of up to one day, participants preferentially used a place strategy and exhibited a high degree of visual landmark exploration. After a longer delay of two weeks, place strategy use decreased significantly. Participants now equally relied on place and response strategy use and increasingly repeated previously taken paths. Further analyses indicate that response strategy use predominantly occurred as a compensatory strategy in the absence of sufficient place memory. Over time, place memory faded before response memory. We suggest that the observed shift from place to response navigation is context-dependent since detailed landmark information, which strongly relied on hippocampal function, decayed faster than sequence information, which required less detail and depended on extra-hippocampal areas. We conclude that changes in place and response navigation likely reflect the reorganization of navigation networks during systems consolidation.


Subject(s)
Memory Consolidation , Spatial Navigation , Humans , Male , Memory Consolidation/physiology , Spatial Navigation/physiology , Female , Adult , Young Adult , Space Perception/physiology , Spatial Memory/physiology , Hippocampus/physiology , Mental Recall/physiology , Maze Learning/physiology
15.
J Affect Disord ; 358: 192-204, 2024 Aug 01.
Article in English | MEDLINE | ID: mdl-38703910

ABSTRACT

Anxiety is a pervasive emotional state where, phenomenologically, subjects often report changes in their experience of time and space. However, a systematic and quantified examination of time and space experience in terms of a self-report scale is still missing which eventually could also be used for clinical differential diagnosis. Based on historical phenomenological literature and patients' subjective reports, we here introduce, in a first step, the Scale for Time and Space Experience of Anxiety (STEA) in a smaller sample of 19 subjects with anxiety disorders and, in a second step, validate its shorter clinical version (cSTEA) in a larger sample of 48 anxiety subjects. The main findings are (i) high convergent and divergent validity of STEA with both Beck Anxiety Inventory (BAI) (r = 0.7325; p < 0.001) and Beck Depression Inventory (BDI) (r = 0.7749; p < 0.0001), as well as with spontaneous mind wandering (MWS) (r = 0.7343; p < 0.001) and deliberate mind wandering (MWD) (r = 0.1152; p > 0.05), (ii) statistical feature selection shows 8 key items for future clinical usage (cSTEA) focusing on the experience of temporal and spatial constriction, (iii) the effects of time and space experience (i.e., for both STEA and cSTEA scores) on the level of anxiety (BAI) are mediated by the degree of spontaneous mind wandering (MWS), (iv) cSTEA allows for differentiating high levels of anxiety from the severity of comorbid depressive symptoms, and (v) significant reduction in the cSTEA scores after a therapeutic intervention (breathing therapy). Together, our study introduces a novel fully quantified and highly valid self-report instrument, the STEA, for measuring time-space experiences in anxiety. Further we develop a shorter clinical version (cSTEA) which allows assessing time space experience in a valid, quick, and simple way for diagnosis, differential diagnosis, and therapeutic monitoring of anxiety.


Subject(s)
Anxiety Disorders , Psychiatric Status Rating Scales , Humans , Male , Female , Adult , Anxiety Disorders/diagnosis , Anxiety Disorders/psychology , Middle Aged , Psychiatric Status Rating Scales/standards , Reproducibility of Results , Psychometrics , Anxiety/diagnosis , Anxiety/psychology , Self Report , Space Perception , Time Perception , Young Adult , Clinical Relevance
16.
Curr Biol ; 34(10): 2256-2264.e3, 2024 05 20.
Article in English | MEDLINE | ID: mdl-38701787

ABSTRACT

The hippocampal formation contains neurons responsive to an animal's current location and orientation, which together provide the organism with a neural map of space.1,2,3 Spatially tuned neurons rely on external landmark cues and internally generated movement information to estimate position.4,5 An important class of landmark cue are the boundaries delimiting an environment, which can define place cell field position6,7 and stabilize grid cell firing.8 However, the precise nature of the sensory information used to detect boundaries remains unknown. We used 2-dimensional virtual reality (VR)9 to show that visual cues from elevated walls surrounding the environment are both sufficient and necessary to stabilize place and grid cell responses in VR, when only visual and self-motion cues are available. By contrast, flat boundaries formed by the edges of a textured floor did not stabilize place and grid cells, indicating only specific forms of visual boundary stabilize hippocampal spatial firing. Unstable grid cells retain internally coherent, hexagonally arranged firing fields, but these fields "drift" with respect to the virtual environment over periods >5 s. Optic flow from a virtual floor does not slow drift dynamics, emphasizing the importance of boundary-related visual information. Surprisingly, place fields are more stable close to boundaries even with floor and wall cues removed, suggesting invisible boundaries are inferred using the motion of a discrete, separate cue (a beacon signaling reward location). Subsets of place cells show allocentric directional tuning toward the beacon, with strength of tuning correlating with place field stability when boundaries are removed.


Subject(s)
Cues , Grid Cells , Virtual Reality , Animals , Grid Cells/physiology , Male , Hippocampus/physiology , Space Perception/physiology , Rats , Place Cells/physiology , Visual Perception/physiology , Rats, Long-Evans , Orientation/physiology
17.
Nat Rev Neurosci ; 25(6): 428-448, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38714834

ABSTRACT

The representation of distinct spaces by hippocampal place cells has been linked to changes in their place fields (the locations in the environment where the place cells discharge strongly), a phenomenon that has been termed 'remapping'. Remapping has been assumed to be accompanied by the reorganization of subsecond cofiring relationships among the place cells, potentially maximizing hippocampal information coding capacity. However, several observations challenge this standard view. For example, place cells exhibit mixed selectivity, encode non-positional variables, can have multiple place fields and exhibit unreliable discharge in fixed environments. Furthermore, recent evidence suggests that, when measured at subsecond timescales, the moment-to-moment cofiring of a pair of cells in one environment is remarkably similar in another environment, despite remapping. Here, I propose that remapping is a misnomer for the changes in place fields across environments and suggest instead that internally organized manifold representations of hippocampal activity are actively registered to different environments to enable navigation, promote memory and organize knowledge.


Subject(s)
Hippocampus , Space Perception , Hippocampus/physiology , Animals , Humans , Space Perception/physiology , Place Cells/physiology
18.
J Vis ; 24(5): 15, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38814934

ABSTRACT

Temporal asynchrony is a cue for the perceptual segregation of spatial regions. Past research found attribute invariance of this phenomenon such that asynchrony induces perceptual segmentation regardless of the changing attribute type, and it does so even when asynchrony occurs between different attributes. To test the generality of this finding and obtain insights into the underlying computational mechanism, we compared the segmentation performance for changes in luminance, color, motion direction, and their combinations. Our task was to detect the target quadrant in which a periodic alternation in attribute was phase-delayed compared to the remaining quadrants. When stimulus elements made a square-wave attribute change, target detection was not clearly attribute invariant, being more difficult for motion direction change than for luminance or color changes and nearly impossible for the combination of motion direction and luminance or color. We suspect that waveform mismatch might cause anomalous behavior of motion direction since a square-wave change in motion direction is a triangular-wave change in the spatial phase (i.e., a second-order change in the direction of the spatial phase change). In agreement with this idea, we found that the segregation performance was strongly affected by the waveform type (square wave, triangular wave, or their combination), and when this factor was controlled, the performance was nearly, though not perfectly, invariant against attribute type. The results were discussed with a model in which different visual attributes share a common asynchrony-based segmentation mechanism.


Subject(s)
Motion Perception , Photic Stimulation , Space Perception , Humans , Motion Perception/physiology , Photic Stimulation/methods , Space Perception/physiology , Color Perception/physiology , Cues , Adult
19.
Sci Rep ; 14(1): 10304, 2024 05 05.
Article in English | MEDLINE | ID: mdl-38705917

ABSTRACT

Understanding neurogenetic mechanisms underlying neuropsychiatric disorders such as schizophrenia and autism is complicated by their inherent clinical and genetic heterogeneity. Williams syndrome (WS), a rare neurodevelopmental condition in which both the genetic alteration (hemideletion of ~ twenty-six 7q11.23 genes) and the cognitive/behavioral profile are well-defined, offers an invaluable opportunity to delineate gene-brain-behavior relationships. People with WS are characterized by increased social drive, including particular interest in faces, together with hallmark difficulty in visuospatial processing. Prior work, primarily in adults with WS, has searched for neural correlates of these characteristics, with reports of altered fusiform gyrus function while viewing socioemotional stimuli such as faces, along with hypoactivation of the intraparietal sulcus during visuospatial processing. Here, we investigated neural function in children and adolescents with WS by using four separate fMRI paradigms, two that probe each of these two cognitive/behavioral domains. During the two visuospatial tasks, but not during the two face processing tasks, we found bilateral intraparietal sulcus hypoactivation in WS. In contrast, during both face processing tasks, but not during the visuospatial tasks, we found fusiform hyperactivation. These data not only demonstrate that previous findings in adults with WS are also present in childhood and adolescence, but also provide a clear example that genetic mechanisms can bias neural circuit function, thereby affecting behavioral traits.


Subject(s)
Magnetic Resonance Imaging , Williams Syndrome , Humans , Williams Syndrome/physiopathology , Williams Syndrome/genetics , Williams Syndrome/diagnostic imaging , Magnetic Resonance Imaging/methods , Adolescent , Child , Female , Male , Brain Mapping/methods , Brain/diagnostic imaging , Brain/physiopathology , Face , Facial Recognition/physiology , Parietal Lobe/physiopathology , Parietal Lobe/diagnostic imaging , Space Perception/physiology
20.
Sci Rep ; 14(1): 10377, 2024 05 06.
Article in English | MEDLINE | ID: mdl-38710784

ABSTRACT

This study investigated the development of spatiotemporal perceptual interactions in 5-to-7 years old children. Participants reproduced the temporal and spatial interval between sequentially presented visual stimuli. The time and spacing between stimuli were experimentally manipulated. In addition, cognitive capacities were assessed using neuropsychological tests. Results revealed that starting at 5 years old, children exhibited spatial biases in their time estimations and temporal biases in their spatial estimations, pointing at space-time interference. In line with developmental improvement of temporal and spatial abilities, these spatiotemporal biases decreased with age. Importantly, short-term memory capacity was a predictor of space-time interference pointing to shared cognitive mechanisms between time and space processing. Our results support the symmetrical hypothesis that proposes a common neurocognitive mechanism for processing time and space.


Subject(s)
Memory, Short-Term , Space Perception , Humans , Child, Preschool , Female , Child , Male , Space Perception/physiology , Memory, Short-Term/physiology , Time Perception/physiology , Child Development/physiology , Cognition/physiology , Neuropsychological Tests , Photic Stimulation/methods
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