scholarly journals Temporal integration of high-level summary statistical representation

2010 ◽  
Vol 8 (6) ◽  
pp. 343-343
Author(s):  
T. Harp ◽  
J. Haberman ◽  
D. Whitney
Keyword(s):  
Temporal Integration ◽  
Statistical Representation ◽  
Summary Statistical Representation ◽  
High Level

scholarly journals Summary statistical representation of temporal frequency

2017 ◽  
Vol 17 (10) ◽  
pp. 1375
Author(s):  
Shoko Kanaya ◽  
Masamichi Hayashi ◽  
David Whitney
Keyword(s):  
Temporal Frequency ◽  
Statistical Representation ◽  
Summary Statistical Representation

Signal coding in cockroach photoreceptors is tuned to dim environments

2012 ◽  
Vol 108 (10) ◽  
pp. 2641-2652 ◽  
Author(s):  
K. Heimonen ◽  
E.-V. Immonen ◽  
R. V. Frolov ◽  
I. Salmela ◽  
M. Juusola ◽  
...  
Keyword(s):  
Information Transfer ◽  
Periplaneta Americana ◽  
Single Photon ◽  
Signal To Noise Ratio ◽  
Temporal Integration ◽  
High Sensitivity ◽  
Single Photons ◽  
Low Frequencies ◽  
Whole Cell Patch Clamp ◽  
High Level

In dim light, scarcity of photons typically leads to poor vision. Nonetheless, many animals show visually guided behavior with dim environments. We investigated the signaling properties of photoreceptors of the dark active cockroach ( Periplaneta americana) using intracellular and whole-cell patch-clamp recordings to determine whether they show selective functional adaptations to dark. Expectedly, dark-adapted photoreceptors generated large and slow responses to single photons. However, when light adapted, responses of both phototransduction and the nontransductive membrane to white noise (WN)-modulated stimuli remained slow with corner frequencies ∼20 Hz. This promotes temporal integration of light inputs and maintains high sensitivity of vision. Adaptive changes in dynamics were limited to dim conditions. Characteristically, both step and frequency responses stayed effectively unchanged for intensities >1,000 photons/s/photoreceptor. A signal-to-noise ratio (SNR) of the light responses was transiently higher at frequencies <5 Hz for ∼5 s after light onset but deteriorated to a lower value upon longer stimulation. Naturalistic light stimuli, as opposed to WN, evoked markedly larger responses with higher SNRs at low frequencies. This allowed realistic estimates of information transfer rates, which saturated at ∼100 bits/s at low-light intensities. We found, therefore, selective adaptations beneficial for vision in dim environments in cockroach photoreceptors: large amplitude of single-photon responses, constant high level of temporal integration of light inputs, saturation of response properties at low intensities, and only transiently efficient encoding of light contrasts. The results also suggest that the sources of the large functional variability among different photoreceptors reside mostly in phototransduction processes and not in the properties of the nontransductive membrane.

scholarly journals Subliminal temporal integration of linguistic information

2020 ◽  
Author(s):  
Shao-Min Hung ◽  
Po-Jang Hsieh
Keyword(s):  
Information Integration ◽  
Word Association ◽  
Temporal Integration ◽  
Separate Experiment ◽  
Decision Task ◽  
Interocular Suppression ◽  
Linguistic Information ◽  
Complex Information ◽  
High Level ◽  
Over Time

Whether unconscious complex information integration occurs over time remains largely unknown and highly controversial. To directly examine the possibility, we introduced a novel interocular suppression where the suppressor and suppressed are presented intermittently. Such paradigm allowed us to insert a word in each suppression and over time deliver sentence level information unconsciously. We found that subsequent to a subliminal context, participants responded faster to a syntactically incongruent target word in a lexical decision task. This finding was later replicated in a separate experiment where participants exhibited chance rate localization of the prime word. Such effect disappeared when the context was disrupted by presenting only partial sentence or with reversed word order, showing that the effect was not merely driven by word-word association. These findings indicate that linguistic information could integrate over time under interocular suppression, serving as critical evidence supporting unconscious high-level, complex information integration.

scholarly journals Temporal integration of narrative information in a hippocampal amnesic patient

2019 ◽  
Author(s):  
Xiaoye Zuo ◽  
Christopher J. Honey ◽  
Morgan D. Barense ◽  
Davide Crombie ◽  
Kenneth A. Norman ◽  
...  
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Time Windows ◽  
Temporal Integration ◽  
Amnesic Patient ◽  
Network Activity ◽  
Default Network ◽  
Online Processing ◽  
Posterior Parietal ◽  
High Level

AbstractDefault network regions appear to integrate information over time windows of 30 seconds or more during narrative listening. Does this long-timescale capability require the hippocampus? Amnesic behavior suggests that the hippocampus may not be needed for online processing when input is continuous and semantically rich: amnesics can participate in conversations and tell stories spanning minutes, and when tested immediately on recently heard prose their performance is relatively preserved. We hypothesized that default network regions can integrate the semantically coherent information of a narrative across long time windows, even in the absence of the hippocampus. To test this prediction, we measured BOLD activity in the brain of a hippocampal amnesic patient (D. A.) and healthy control participants while they listened to a seven-minute narrative. The narrative was played either in its intact form, or as a paragraph-scrambled version, which has been previously shown to interfere with the long-range temporal dependencies in default network activity. In the intact story condition, D. A.’s moment-by-moment BOLD activity spatial patterns were similar to those of controls in low-level auditory cortex as well as in some high-level default network regions (including lateral and medial posterior parietal cortex). Moreover, as in controls, D. A.’s response patterns in medial and lateral posterior parietal cortex were disrupted when paragraphs of the story were presented in a shuffled order, suggesting that activity in these areas did depend on information from 30 seconds or more in the past. Together, these results suggest that some default network cortical areas can integrate information across long timescales, even in the absence of the hippocampus.

scholarly journals Individual representations in visual working memory inherit ensemble properties

2019 ◽  
Author(s):  
Igor Utochkin ◽  
Timothy F. Brady
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Uncertain Information ◽  
Individual Item ◽  
Statistical Representation ◽  
The Mean ◽  
Summary Statistical Representation ◽  
Source Of Information

Prevailing theories of visual working memory assume that each encoded item is stored or forgotten as a separate unit independent from other items. Here, we show that items are not independent and that the recalled orientation of an individual item is strongly influenced by the summary statistical representation of all items (ensemble representation). We find that not only is memory for an individual orientation substantially biased toward the mean orientation, but the precision of memory for an individual item also closely tracks the precision with which people store the mean orientation (which is, in turn, correlated with the physical range of orientations). Thus, individual items are reported more precisely when items on a trial are more similar. Moreover, the narrower the range of orientations present on a trial, the more participants appear to rely on the mean orientation as representative of all individuals. This can be observed not only when the range is carefully controlled, but also shown even in randomly generated, unstructured displays, and after accounting for the possibility of location-based ‘swap’ errors. Our results suggest that the information about a set of items is represented hierarchically, and that ensemble information can be an important source of information to constrain uncertain information about individuals.

scholarly journals Heterogeneous Integration of Bilateral Whisker Signals by Neurons in Primary Somatosensory Cortex of Awake Rats

2005 ◽  
Vol 93 (5) ◽  
pp. 2966-2973 ◽  
Author(s):  
Michael C. Wiest ◽  
Nick Bentley ◽  
Miguel A. L. Nicolelis
Keyword(s):  
Somatosensory Cortex ◽  
Single Unit ◽  
Temporal Integration ◽  
Primary Somatosensory Cortex ◽  
Neural Responses ◽  
Hemispheric Processing ◽  
Tactile Stimuli ◽  
The Face ◽  
Left And Right ◽  
High Level

Bilateral single-unit recordings in primary somatosensory cortex (S1) of anesthetized rats have revealed substantial cross talk between cortical hemispheres, suggesting the possibility that behaviorally relevant bilateral integration could occur in S1. To determine the extent of bilateral neural responses in awake animals, we recorded S1 multi- and single-unit activity in head-immobilized rats while stimulating groups of 4 whiskers from the same column on both sides of the head. Results from these experiments confirm the widespread presence of single units responding to tactile stimuli on either side of the face in S1 of awake animals. Quantification of bilateral integration by multiunits revealed both facilitative and suppressive integration of bilateral inputs. Varying the interval between left and right whisker stimuli between 0 and 120 ms showed the temporal integration of bilateral stimuli to be dominated on average by suppression at intervals around 30 ms, in agreement with comparable recordings in anesthetized animals. Contrary to the anesthetized data, in the awake animals we observed a high level of heterogeneity of bilateral responses and a strong interaction between synchronous bilateral stimuli. The results challenge the traditional conception of highly segregated hemispheric processing channels in the rat S1 cortex, and support the hypothesis that callosal cross-projections between the two hemispheres mediate rats' known ability to integrate bilateral whisker signals.

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