scholarly journals Effects of Exogenous and Endogenous Attention on Metacontrast Masking

Vision ◽  
2018 ◽  
Vol 2 (4) ◽  
pp. 39 ◽  
Author(s):  
Sevda Agaoglu ◽  
Bruno Breitmeyer ◽  
Haluk Ogmen
Keyword(s):  
Information Transfer ◽  
Visual Masking ◽  
Short Term Memory ◽  
Weak Interactions ◽  
Sensory Information ◽  
Absolute Magnitude ◽  
Exogenous Attention ◽  
Metacontrast Masking ◽  
Floor Effects ◽  
Response Errors

To efficiently use its finite resources, the visual system selects for further processing only a subset of the rich sensory information. Visual masking and spatial attention control the information transfer from visual sensory-memory to visual short-term memory. There is still a debate whether these two processes operate independently or interact, with empirical evidence supporting both arguments. However, recent studies pointed out that earlier studies showing significant interactions between common-onset masking and attention suffered from ceiling and/or floor effects. Our review of previous studies reporting metacontrast-attention interactions revealed similar artifacts. Therefore, we investigated metacontrast-attention interactions by using an experimental paradigm, in which ceiling/floor effects were avoided. We also examined whether metacontrast masking is differently influenced by endogenous and exogenous attention. We analyzed mean absolute-magnitude of response-errors and their statistical distribution. When targets are masked, our results support the hypothesis that manipulations of the levels of metacontrast and of endogenous/exogenous attention have largely independent effects. Moreover, statistical modeling of the distribution of response-errors suggests weak interactions modulating the probability of “guessing” behavior for some observers in both types of attention. Nevertheless, our data suggest that any joint effect of attention and metacontrast can be adequately explained by their independent and additive contributions.

scholarly journals Effects of Exogenous and Endogenous Attention on Metacontrast Masking

2018 ◽  
Author(s):  
Sevda Agaoglu ◽  
Bruno Breitmeyer ◽  
Haluk Ogmen
Keyword(s):  
Information Transfer ◽  
Visual Masking ◽  
Short Term Memory ◽  
Weak Interactions ◽  
Sensory Information ◽  
Absolute Magnitude ◽  
Exogenous Attention ◽  
Metacontrast Masking ◽  
Floor Effects ◽  
Response Errors

To efficiently use its finite resources, the visual system selects for further processing only a subset of the rich sensory information. Visual masking and spatial attention control the information transfer from visual sensory-memory to visual short-term memory. There is still a debate whether these two processes operate independently or interact, with empirical evidence supporting both arguments. However, recent studies pointed out that earlier studies showing significant interactions between common-onset masking and attention suffered from ceiling and/or floor effects. Our review of previous studies reporting metacontrast-attention interactions revealed similar artifacts. Therefore, we investigated metacontrast-attention interactions by using an experimental paradigm in which ceiling/floor effects were avoided. We also examined whether metacontrast masking is differently influenced by endogenous and exogenous attention. We analyzed mean absolute-magnitude of response-errors and their statistical distribution. Our results support the hypothesis that metacontrast and endogenous/exogenous attention are largely independent with negligible likelihood for interactions. Moreover, statistical modeling of the distribution of response-errors suggests weak interactions modulating the probability of “guessing” behavior for some observers in both types of attention. Nevertheless, our data suggest that any joint effect of attention and metacontrast can be adequately explained by their independent and additive contributions.

scholarly journals The Order of Information Transfer into Short- Term Memory from Visual Pathways with Different Spatial-Frequency Tunings

2020 ◽  
Vol 13 (2) ◽  
pp. 72-89
Author(s):  
D.S. Alekseeva ◽  
V.V. Babenko ◽  
D.V. Yavna
Keyword(s):  
Spatial Frequency ◽  
Information Transfer ◽  
Short Term Memory ◽  
Frequency Tuning ◽  
Visual Pathways ◽  
Input Image ◽  
Target Face ◽  
Short Term ◽  
Term Memory ◽  
Spatial Frequencies

Visual perceptual representations are formed from the results of processing the input image in parallel pathways with different spatial-frequency tunings. It is known that these representations are created gradually, starting from low spatial frequencies. However, the order of information transfer from the perceptual representation to short-term memory has not yet been determined. The purpose of our study is to determine the principle of entering information of different spatial frequencies in the short-term memory. We used the task of unfamiliar faces matching. Digitized photographs of faces were filtered by six filters with a frequency tuning step of 1 octave. These filters reproduced the spatial-frequency characteristics of the human visual pathways. In the experiment, the target face was shown first. Its duration was variable and limited by a mask. Then four test faces were presented. Their presentation was not limited in time. The observer had to determine the face that corresponds to the target one. The dependence of the accuracy of the solution of the task on the target face duration for different ranges of spatial frequencies was determined. When the target stimuli were unfiltered (broadband) faces, the filtered faces were the test ones, and vice versa. It was found that the short-term memory gets information about an unfamiliar face in a certain order, starting from the medium spatial frequencies, and this sequence does not depend on the processing method (holistic or featural).

scholarly journals Routing information flow by separate neural synchrony frequencies allows for “functionally labeled lines” in higher primate cortex

2019 ◽  
Vol 116 (25) ◽  
pp. 12506-12515 ◽  
Author(s):  
Mohammad Bagher Khamechian ◽  
Vladislav Kozyrev ◽  
Stefan Treue ◽  
Moein Esghaei ◽  
Mohammad Reza Daliri
Keyword(s):  
Information Flow ◽  
Information Transfer ◽  
Sensory Information ◽  
Spike Timing ◽  
Oscillatory Activity ◽  
Attention Task ◽  
Cortical Areas ◽  
High Gamma ◽  
Ventral Pathway ◽  
Visual Cortical

Efficient transfer of sensory information to higher (motor or associative) areas in primate visual cortical areas is crucial for transforming sensory input into behavioral actions. Dynamically increasing the level of coordination between single neurons has been suggested as an important contributor to this efficiency. We propose that differences between the functional coordination in different visual pathways might be used to unambiguously identify the source of input to the higher areas, ensuring a proper routing of the information flow. Here we determined the level of coordination between neurons in area MT in macaque visual cortex in a visual attention task via the strength of synchronization between the neurons’ spike timing relative to the phase of oscillatory activities in local field potentials. In contrast to reports on the ventral visual pathway, we observed the synchrony of spikes only in the range of high gamma (180 to 220 Hz), rather than gamma (40 to 70 Hz) (as reported previously) to predict the animal’s reaction speed. This supports a mechanistic role of the phase of high-gamma oscillatory activity in dynamically modulating the efficiency of neuronal information transfer. In addition, for inputs to higher cortical areas converging from the dorsal and ventral pathway, the distinct frequency bands of these inputs can be leveraged to preserve the identity of the input source. In this way source-specific oscillatory activity in primate cortex can serve to establish and maintain “functionally labeled lines” for dynamically adjusting cortical information transfer and multiplexing converging sensory signals.

Object and Place Memory in the Macaque Entorhinal Cortex

1997 ◽  
Vol 78 (2) ◽  
pp. 1062-1081 ◽  
Author(s):  
Wendy A. Suzuki ◽  
Earl K. Miller ◽  
Robert Desimone
Keyword(s):  
Entorhinal Cortex ◽  
Short Term Memory ◽  
Memory Task ◽  
Sensory Information ◽  
Short Term ◽  
Delayed Matching ◽  
Variable Sequence ◽  
Place Memory ◽  
Place Task ◽  
Spatial Locations

Suzuki, Wendy A., Earl K. Miller, and Robert Desimone. Object and place memory in the macaque entorhinal cortex. J. Neurophysiol. 78: 1062–1081, 1997. Lesions of the entorhinal cortex in humans, monkeys, and rats impair memory for a variety of kinds of information, including memory for objects and places. To begin to understand the contribution of entorhinal cells to different forms of memory, responses of entorhinal cells were recorded as monkeys performed either an object or place memory task. The object memory task was a variation of delayed matching to sample. A sample picture was presented at the start of the trial, followed by a variable sequence of zero to four test pictures, ending with a repetition of the sample (i.e., a match). The place memory task was a variation of delayed matching to place. In this task, a cue stimulus was presented at a variable sequence of one to four “places” on a computer screen, ending with a repetition of one of the previously shown places (i.e., a match). For both tasks, the animals were rewarded for releasing a bar to the match. To solve these tasks, the monkey must 1) discriminate the stimuli, 2) maintain a memory of the appropriate stimuli during the course of the trial, and 3) evaluate whether a test stimulus matches previously presented stimuli. The responses of entorhinal cortex neurons were consistent with a role in all three of these processes in both tasks. We found that 47% and 55% of the visually responsive entorhinal cells responded selectively to the different objects or places presented during the object or place task, respectively. Similar to previous findings in prefrontal but not perirhinal cortex on the object task, some entorhinal cells had sample-specific delay activity that was maintained throughout all of the delay intervals in the sequence. For the place task, some cells had location-specific maintained activity in the delay immediately following a specific cue location. In addition, 59% and 22% of the visually responsive cells recorded during the object and place task, respectively, responded differently to the test stimuli according to whether they were matching or nonmatching to the stimuli held in memory. Responses of some cells were enhanced to matching stimuli, whereas others were suppressed. This suppression or enhancement typically occurred well before the animals' behavioral response, suggesting that this information could be used to perform the task. These results indicate that entorhinal cells receive sensory information about both objects and spatial locations and that their activity carries information about objects and locations held in short-term memory.

Multiple Firing Patterns in Deep Dorsal Horn Neurons of the Spinal Cord: Computational Analysis of Mechanisms and Functional Implications

2010 ◽  
Vol 104 (4) ◽  
pp. 1978-1996 ◽  
Author(s):  
Yann Le Franc ◽  
Gwendal Le Masson
Keyword(s):  
Spinal Cord ◽  
Dorsal Horn ◽  
Information Transfer ◽  
Network Effects ◽  
Neuronal Response ◽  
Sensory Information ◽  
Firing Patterns ◽  
Dorsal Horn Neurons ◽  
The Impact

Deep dorsal horn relay neurons (dDHNs) of the spinal cord are known to exhibit multiple firing patterns under the control of local metabotropic neuromodulation: tonic firing, plateau potential, and spontaneous oscillations. This work investigates the role of interactions between voltage-gated channels and the occurrence of different firing patterns and then correlates these two phenomena with their functional role in sensory information processing. We designed a conductance-based model using the NEURON software package, which successfully reproduced the classical features of plateau in dDHNs, including a wind-up of the neuronal response after repetitive stimulation. This modeling approach allowed us to systematically test the impact of conductance interactions on the firing patterns. We found that the expression of multiple firing patterns can be reproduced by changes in the balance between two currents (L-type calcium and potassium inward rectifier conductances). By investigating a possible generalization of the firing state switch, we found that the switch can also occur by varying the balance of any hyperpolarizing and depolarizing conductances. This result extends the control of the firing switch to neuromodulators or to network effects such as synaptic inhibition. We observed that the switch between the different firing patterns occurs as a continuous function in the model, revealing a particular intermediate state called the accelerating mode. To characterize the functional effect of a firing switch on information transfer, we used correlation analysis between a model of peripheral nociceptive afference and the dDHN model. The simulation results indicate that the accelerating mode was the optimal firing state for information transfer.

scholarly journals Distinct roles of light-activated channels TRP and TRPL in photoreceptors of Periplaneta americana

2017 ◽  
Vol 149 (4) ◽  
pp. 455-464 ◽  
Author(s):  
Paulus Saari ◽  
Andrew S. French ◽  
Päivi H. Torkkeli ◽  
Hongxia Liu ◽  
Esa-Ville Immonen ◽  
...  
Keyword(s):  
Information Transfer ◽  
Periplaneta Americana ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Light Stimulus ◽  
Gaussian White Noise ◽  
Sensory Information ◽  
Receptor Potential ◽  
Light Sensitivity ◽  
Low Noise

Electrophysiological studies in Drosophila melanogaster and Periplaneta americana have found that the receptor current in their microvillar photoreceptors is generated by two light-activated cationic channels, TRP (transient receptor potential) and TRPL (TRP-like), each having distinct properties. However, the relative contribution of the two channel types to sensory information coding by photoreceptors remains unclear. We recently showed that, in contrast to the diurnal Drosophila in which TRP is the principal phototransduction channel, photoreceptors of the nocturnal P. americana strongly depend on TRPL. Here, we perform a functional analysis, using patch-clamp and intracellular recordings, of P. americana photoreceptors after RNA interference to knock down TRP (TRPkd) and TRPL (TRPLkd). Several functional properties were changed in both knockdown phenotypes: cell membrane capacitance was reduced 1.7-fold, light sensitivity was greatly reduced, and amplitudes of sustained light-induced currents and voltage responses decreased more than twofold over the entire range of light intensities. The information rate (IR) was tested using a Gaussian white-noise modulated light stimulus and was lower in TRPkd photoreceptors (28 ± 21 bits/s) than in controls (52 ± 13 bits/s) because of high levels of bump noise. In contrast, although signal amplitudes were smaller than in controls, the mean IR of TRPLkd photoreceptors was unchanged at 54 ± 29 bits/s1 because of proportionally lower noise. We conclude that TRPL channels provide high-gain/high-noise transduction, suitable for vision in dim light, whereas transduction by TRP channels is relatively low-gain/low-noise and allows better information transfer in bright light.

Visual Short-Term Memory, Age, and Imaging Ability

1978 ◽  
Vol 46 (2) ◽  
pp. 571-576 ◽  
Author(s):  
J. K. Adamowicz
Keyword(s):  
Older Adults ◽  
Visual Masking ◽  
Short Term Memory ◽  
Stimulus Complexity ◽  
Verbal Intelligence ◽  
Response Delay ◽  
Short Term ◽  
Term Memory ◽  
Visual Short Term Memory ◽  
Age Related

Visual short-term memory of young and older adults was studied in relation to imaging ability. Both recall and recognition memory tasks were used and additional variables included stimulus complexity and response delay (recognition tasks) and stimulus complexity and visual masking (recall tasks). Young and older participants were matched on visual discrimination, verbal intelligence, and imaging ability. Stimuli consisted of abstract visual patterns. Age-related decrements in recognition and recall were observed but performance was related to imaging ability only with recall tasks and only for older adults. The results were discussed with reference to mediational strategies and locus of occurrence of age-related decrements in short-term memory.

Information flow in the nervous system

1993 ◽  
Vol 1 (1) ◽  
pp. 31-39
Author(s):  
Arnold Burgen
Keyword(s):  
Information Flow ◽  
Information Transfer ◽  
Sensory Information ◽  
Nerve Fibres ◽  
Ionic Transfer ◽  
Electrical Pulses ◽  
Specific Receptors ◽  
Stored Information ◽  
High Level ◽  
Memory And Recall

Information is carried along nerve fibres by electrical pulses generated by ionic transfer; it is digitally coded. Information transfer between nerve cells depends on the release of a chemical transmitter which acts on specific receptors on the second neurone. This is a non-digital, analogue process which is highly non-linear. It involves the summation of inputs from highly divergent sources. In sensory systems such as vision, extensive compression, feature extraction and other high-level processing occur before presentation to the cerebral cortex, where a massive expansion in distribution of information occurs. Huge numbers of neurones are involved in the central presentation of even simple sensory information. This is because the neural events are relatively slow, so that a massive parallel information flow and processing occurs. Learning and memory involve changes in synaptic efficiency and the development of new stable connective patterns. Memory and recall must involve a comparison of contemporary events with stored information, but cannot involve a one-on-one comparison because it can deal with extensive transformation of sensory information.

LEARNING TASK-SPECIFIC SENSING, CONTROL AND MEMORY POLICIES

2005 ◽  
Vol 14 (01n02) ◽  
pp. 303-327
Author(s):  
SRIVIDHYA RAJENDRAN ◽  
MANFRED HUBER
Keyword(s):  
Real Time ◽  
Memory Management ◽  
Short Term Memory ◽  
Sensory Information ◽  
Learning Task ◽  
Focus Of Attention ◽  
Sensor Data ◽  
Management Policy ◽  
Task Completion ◽  
Control Approach

AI agents and robots that can adapt and handle multiple tasks in real time promise to be a powerful tool. To address the control challenges involved in such systems, the underlying control approach has to take into account the important sensory information. Modern sensors, however, can generate huge amounts of data, rendering the processing and representation of all sensor data in real time computationally intractable. This issue can be addressed by developing task-specific focus of attention strategies that limit the sensory data that is processed at any point in time to the data relevant for the given task. Alone, however, this mechanism is not adequate for solving complex tasks since the robot also has to maintain selected pieces of past information. This necessitates AI agents and robots to have the capability to remember significant past events that are required for task completion. This paper presents an approach that considers focus of attention as a problem of selecting controller and feature pairs to be processed at any given point in time to optimize system performance. This approach is further extended by incorporating short term memory and a learned memory management policy. The result is a system that learns control, sensing, and memory policies that are task-specific and adaptable to real world situations using feedback from the world in a reinforcement learning framework. The approach is illustrated using table cleaning, sorting, stacking, and copying tasks in the blocks world domain.

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