scholarly journals Memory for Stimulus Duration Is Not Bound to Spatial Information

2021 ◽  
pp. 1-19
Author(s):  
Wouter Kruijne ◽  
Christian N. L. Olivers ◽  
Hedderik van Rijn
Keyword(s):  
Working Memory ◽  
Human Brain ◽  
Stimulus Duration ◽  
Spatial Information ◽  
Temporal Information ◽  
Specific Class ◽  
Contralateral Delay Activity ◽  
Sense Of Time ◽  
Initial Perception ◽  
Subsequent Comparison

Abstract Different theories have been proposed to explain how the human brain derives an accurate sense of time. One specific class of theories, intrinsic clock theories, postulate that temporal information of a stimulus is represented much like other features such as color and location, bound together to form a coherent percept. Here, we explored to what extent this holds for temporal information after it has been perceived and is held in working memory for subsequent comparison. We recorded EEG of participants who were asked to time stimuli at lateral positions of the screen followed by comparison stimuli presented in the center. Using well-established markers of working memory maintenance, we investigated whether the usage of temporal information evoked neural signatures that were indicative of the location where the stimuli had been presented, both during maintenance and during comparison. Behavior and neural measures including the contralateral delay activity, lateralized alpha suppression, and decoding analyses through time all supported the same conclusion: The representation of location was strongly involved during perception of temporal information, but when temporal information was to be used for comparison, it no longer showed a relation to spatial information. These results support a model where the initial perception of a stimulus involves intrinsic computations, but that this information is subsequently translated to a stimulus-independent format to be used to further guide behavior.

scholarly journals Memory for stimulus durations is not bound to spatial information

2020 ◽  
Author(s):  
Wouter Kruijne ◽  
Christian N. L. Olivers ◽  
Hedderik van Rijn
Keyword(s):  
Working Memory ◽  
Human Brain ◽  
Spatial Information ◽  
Temporal Information ◽  
Specific Class ◽  
Behavioral Measures ◽  
Contralateral Delay Activity ◽  
Sense Of Time ◽  
Initial Perception ◽  
Subsequent Comparison

AbstractDifferent models have been proposed to explain how the human brain derives an accurate sense of time. One specific class of models, intrinsic models, state that temporal information of a stimulus is represented much like other features such as color and location, bound together to form a coherent percept. Here we explored to what extent this holds for temporal information after it has been perceived and is held in working memory for subsequent comparison. We recorded EEG of participants who were asked to time stimuli at lateral positions of the screen followed by comparison stimuli presented in the center. Using well-established markers of working memory maintenance, we investigated whether the usage of temporal information evoked neural signatures that were indicative of the location where the stimuli had been presented, both during maintenance and during comparison. Neural and behavioral measures, including the contralateral delay activity, lateralized alpha suppression and decoding analyses through time, all supported the same conclusion: while the representation of location was strongly involved during the perception of temporal information, once temporal information was committed to memory it no longer showed any relation to spatial information during maintenance or during comparisons. These results support a model where the initial perception of a stimulus involves intrinsic computations, but that this information is subsequently translated to a stimulus-independent format to be used to further guide behavior.

scholarly journals Understanding the computation of time using neural network models

2020 ◽  
Vol 117 (19) ◽  
pp. 10530-10540 ◽  
Author(s):  
Zedong Bi ◽  
Changsong Zhou
Keyword(s):  
Neural Network ◽  
Working Memory ◽  
Spatial Information ◽  
Temporal Structure ◽  
Network Models ◽  
Temporal Information ◽  
Neural Network Models ◽  
Time Intervals ◽  
State Evolution ◽  
The Right

To maximize future rewards in this ever-changing world, animals must be able to discover the temporal structure of stimuli and then anticipate or act correctly at the right time. How do animals perceive, maintain, and use time intervals ranging from hundreds of milliseconds to multiseconds in working memory? How is temporal information processed concurrently with spatial information and decision making? Why are there strong neuronal temporal signals in tasks in which temporal information is not required? A systematic understanding of the underlying neural mechanisms is still lacking. Here, we addressed these problems using supervised training of recurrent neural network models. We revealed that neural networks perceive elapsed time through state evolution along stereotypical trajectory, maintain time intervals in working memory in the monotonic increase or decrease of the firing rates of interval-tuned neurons, and compare or produce time intervals by scaling state evolution speed. Temporal and nontemporal information is coded in subspaces orthogonal with each other, and the state trajectories with time at different nontemporal information are quasiparallel and isomorphic. Such coding geometry facilitates the decoding generalizability of temporal and nontemporal information across each other. The network structure exhibits multiple feedforward sequences that mutually excite or inhibit depending on whether their preferences of nontemporal information are similar or not. We identified four factors that facilitate strong temporal signals in nontiming tasks, including the anticipation of coming events. Our work discloses fundamental computational principles of temporal processing, and it is supported by and gives predictions to a number of experimental phenomena.

scholarly journals Development of Spatial and Verbal Working Memory Capacity in the Human Brain

2009 ◽  
Vol 21 (2) ◽  
pp. 316-332 ◽  
Author(s):  
Moriah E. Thomason ◽  
Elizabeth Race ◽  
Brittany Burrows ◽  
Susan Whitfield-Gabrieli ◽  
Gary H. Glover ◽  
...  
Keyword(s):  
Working Memory ◽  
Human Brain ◽  
Hemispheric Asymmetry ◽  
Spatial Information ◽  
Hemispheric Specialization ◽  
Working Memory Capacity ◽  
Verbal Working Memory ◽  
Relevant Information ◽  
Cortical Regions ◽  
The Right

A core aspect of working memory (WM) is the capacity to maintain goal-relevant information in mind, but little is known about how this capacity develops in the human brain. We compared brain activation, via fMRI, between children (ages 7–12 years) and adults (ages 20–29 years) performing tests of verbal and spatial WM with varying amounts (loads) of information to be maintained in WM. Children made disproportionately more errors than adults as WM load increased. Children and adults exhibited similar hemispheric asymmetry in activation, greater on the right for spatial WM and on the left for verbal WM. Children, however, failed to exhibit the same degree of increasing activation across WM loads as was exhibited by adults in multiple frontal and parietal cortical regions. Thus, children exhibited adult-like hemispheric specialization, but appeared immature in their ability to marshal the neural resources necessary to maintain large amounts of verbal or spatial information in WM.

Human Event-Related Potentials to Higher-Order Acoustic Spatial Changes

2002 ◽  
Vol 16 (2) ◽  
pp. 114-118 ◽  
Author(s):  
Timo Ruusuvirta ◽  
Heikki Hämäläinen
Keyword(s):  
Working Memory ◽  
Mismatch Negativity ◽  
Spatial Information ◽  
Free Field ◽  
Event Related Potentials ◽  
Negative Polarity ◽  
Positive Polarity ◽  
Spatial Changes ◽  
Related Potentials ◽  
Human Event

Abstract Human event-related potentials (ERPs) to a tone continuously alternating between its two spatial loci of origin (middle-standards, left-standards), to repetitions of left-standards (oddball-deviants), and to the tones originally representing these repetitions presented alone (alone-deviants) were recorded in free-field conditions. During the recordings (Fz, Cz, Pz, M1, and M2 referenced to nose), the subjects watched a silent movie. Oddball-deviants elicited a spatially diffuse two-peaked deflection of positive polarity. It differed from a deflection elicited by left-standards and commenced earlier than a prominent deflection of negative polarity (N1) elicited by alone-deviants. The results are discussed in the context of the mismatch negativity (MMN) and previous findings of dissociation between spatial and non-spatial information in auditory working memory.

scholarly journals The Role of Spatio-Temporal Information to Govern the COVID-19 Pandemic: A European Perspective

2021 ◽  
Vol 10 (3) ◽  
pp. 166
Author(s):  
Hartmut Müller ◽  
Marije Louwsma
Keyword(s):  
European Union ◽  
Spatial Distribution ◽  
Spatial Information ◽  
National Level ◽  
Temporal Information ◽  
The European Union ◽  
Member States ◽  
Heavy Burden ◽  
Spatio Temporal

The Covid-19 pandemic put a heavy burden on member states in the European Union. To govern the pandemic, having access to reliable geo-information is key for monitoring the spatial distribution of the outbreak over time. This study aims to analyze the role of spatio-temporal information in governing the pandemic in the European Union and its member states. The European Nomenclature of Territorial Units for Statistics (NUTS) system and selected national dashboards from member states were assessed to analyze which spatio-temporal information was used, how the information was visualized and whether this changed over the course of the pandemic. Initially, member states focused on their own jurisdiction by creating national dashboards to monitor the pandemic. Information between member states was not aligned. Producing reliable data and timeliness reporting was problematic, just like selecting indictors to monitor the spatial distribution and intensity of the outbreak. Over the course of the pandemic, with more knowledge about the virus and its characteristics, interventions of member states to govern the outbreak were better aligned at the European level. However, further integration and alignment of public health data, statistical data and spatio-temporal data could provide even better information for governments and actors involved in managing the outbreak, both at national and supra-national level. The Infrastructure for Spatial Information in Europe (INSPIRE) initiative and the NUTS system provide a framework to guide future integration and extension of existing systems.

scholarly journals The Fear to Move in a Crowded Environment. Poor Spatial Memory Related to Agoraphobic Disorder

2021 ◽  
Vol 11 (6) ◽  
pp. 796
Author(s):  
Micaela Maria Zucchelli ◽  
Laura Piccardi ◽  
Raffaella Nori
Keyword(s):  
Working Memory ◽  
Spatial Information ◽  
Theoretical Background ◽  
Exploratory Activity ◽  
Visuospatial Working Memory ◽  
Spatial Tasks ◽  
And Performance ◽  
The Relationship ◽  
Crowded Environment ◽  
Active Processing

Individuals with agoraphobia exhibit impaired exploratory activity when navigating unfamiliar environments. However, no studies have investigated the contribution of visuospatial working memory (VSWM) in these individuals’ ability to acquire and process spatial information while considering the use of egocentric and allocentric coordinates or environments with or without people. A total of 106 individuals (53 with agoraphobia and 53 controls) navigated in a virtual square to acquire spatial information that included the recognition of landmarks and the relationship between landmarks and themselves (egocentric coordinates) and independent of themselves (allocentric coordinates). Half of the participants in both groups navigated in a square without people, and half navigated in a crowded square. They completed a VSWM test in addition to tasks measuring landmark recognition and egocentric and allocentric judgements concerning the explored square. The results showed that individuals with agoraphobia had reduced working memory only when active processing of spatial elements was required, suggesting that they exhibit spatial difficulties particularly in complex spatial tasks requiring them to process information simultaneously. Specifically, VSWM deficits mediated the relationship between agoraphobia and performance in the allocentric judgements. The results are discussed considering the theoretical background of agoraphobia in order to provide useful elements for the early diagnosis of this disorder.

A direct neural measure of variable precision representations in visual working memory

2021 ◽  
Author(s):  
Christian Merkel ◽  
Mandy Viktoria Bartsch ◽  
Mircea A Schoenfeld ◽  
Anne-Katrin Vellage ◽  
Notger G Müller ◽  
...  
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Recall Performance ◽  
Human Subjects ◽  
Item Information ◽  
Estimation Task ◽  
Active Representation ◽  
Contralateral Delay Activity ◽  
Memory Representations ◽  
Precision Estimation

Visual working memory (VWM) is an active representation enabling the manipulation of item information even in the absence of visual input. A common way to investigate VWM is to analyze the performance at later recall. This approach, however, leaves uncertainties about whether the variation of recall performance is attributable to item encoding and maintenance or to the testing of memorized information. Here, we record the contralateral delay activity (CDA) - an established electrophysiological measure of item storage and maintenance - in human subjects performing a delayed orientation precision estimation task. This allows us to link the fluctuation of recall precision directly to the process of item encoding and maintenance. We show that for two sequentially encoded orientation items, the CDA amplitude reflects the precision of orientation recall of both items, with higher precision being associated with a larger amplitude. Furthermore, we show that the CDA amplitude for each item varies independently from each other, suggesting that the precision of memory representations fluctuates independently.

Different trait markers for schizophrenia and bipolar disorder: a neurocognitive approach

2001 ◽  
Vol 31 (5) ◽  
pp. 915-922 ◽  
Author(s):  
S. KÉRI ◽  
O. KELEMEN ◽  
G. BENEDEK ◽  
Z. JANKA
Keyword(s):  
Bipolar Disorder ◽  
Working Memory ◽  
Information Processing ◽  
Cognitive Functions ◽  
Visual Information ◽  
Spatial Information ◽  
Target Location ◽  
Memory Task ◽  
Visual Information Processing ◽  
Verbal Recall

Background. The aim of this study was to assess visual information processing and cognitive functions in unaffected siblings of patients with schizophrenia, bipolar disorder and control subjects with a negative family history.Methods. The siblings of patients with schizophrenia (N = 25), bipolar disorder (N = 20) and the controls subjects (N = 20) were matched for age, education, IQ, and psychosocial functioning, as indexed by the Global Assessment of Functioning scale. Visual information processing was measured using two visual backward masking (VBM) tests (target location and target identification). The evaluation of higher cognitive functions included spatial and verbal working memory, Wisconsin Card Sorting Test, letter fluency, short/long delay verbal recall and recognition.Results. The relatives of schizophrenia patients were impaired in the VBM procedure, more pronouncedly at short interstimulus intervals (14, 28, 42 ms) and in the target location task. Marked dysfunctions were also found in the spatial working memory task and in the long delay verbal recall test. In contrast, the siblings of patients with bipolar disorder exhibited spared performances with the exception of a deficit in the long delay recall task.Conclusions. Dysfunctions of sensory-perceptual analysis (VBM) and working memory for spatial information distinguished the siblings of schizophrenia patients from the siblings of individuals with bipolar disorder. Verbal recall deficit was present in both groups, suggesting a common impairment of the fronto-hippocampal system.

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