scholarly journals Widespread shorter cortical adaptation in dyslexia

2017 ◽  
Author(s):  
Sagi Jaffe-Dax ◽  
Eva Kimel ◽  
Merav Ahissar
Keyword(s):  
General Characteristic ◽  
Frequency Discrimination ◽  
Previous Trial ◽  
Tone Frequency ◽  
Broad Distribution ◽  
Cortical Dynamics ◽  
Fast Acquisition ◽  
Sensory Cortices ◽  
Cortical Adaptation ◽  
Cortical Distribution

AbstractStudies of dyslexics’ performance on perceptual tasks suggest that their implicit inference of sound statistics is impaired. In a previous paper (Jaffe-Dax, Frenkel, & Ahissar, 2017), using 2-tone frequency discrimination, we found that the effect of previous trial frequencies on dyslexics’ judgments decayed faster than the effect on controls’ judgments, and that the adaptation of their ERP responses to tones recovered faster. Here, we show the cortical distribution of this abnormal dynamics of adaptation using fast acquisition fMRI. We find that dyslexics’ faster decay of adaptation is widespread, though the most significant effects are found in the left superior temporal lobe, including the auditory cortex. This broad distribution suggests that dyslexics’ faster decay of implicit memory is a general characteristic of their cortical dynamics, which also encompasses the sensory cortices.

scholarly journals Shorter cortical adaptation in dyslexia is broadly distributed in the superior temporal lobe and includes the primary auditory cortex

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Sagi Jaffe-Dax ◽  
Eva Kimel ◽  
Merav Ahissar
Keyword(s):  
Auditory Cortex ◽  
Temporal Lobe ◽  
Primary Auditory Cortex ◽  
General Characteristic ◽  
Frequency Discrimination ◽  
Tone Frequency ◽  
Cortical Dynamics ◽  
Sensory Cortices ◽  
Cortical Adaptation ◽  
Cortical Distribution

Studies of the performance of individuals with dyslexia in perceptual tasks suggest that their implicit inference of sound statistics is impaired. Previously, using two-tone frequency discrimination, we found that the effect of previous trials' frequencies on the judgments of individuals with dyslexia decays faster than the effect on controls' judgments, and that the adaptation (decrease of neural response to repeated stimuli) of their ERP responses to tones is shorter (<xref ref-type="bibr" rid="bib22">Jaffe-Dax et al., 2017</xref>). Here, we show the cortical distribution of these abnormal dynamics of adaptation using fast-acquisition fMRI. We find that faster decay of adaptation in dyslexia is widespread, although the most significant effects are found in the left superior temporal lobe, including the auditory cortex. This broad distribution suggests that the faster decay of implicit memory of individuals with dyslexia is a general characteristic of their cortical dynamics, which also affects sensory cortices.

Perceptual Learning Is Specific to the Trained Structure of Information

2013 ◽  
Vol 25 (12) ◽  
pp. 2047-2060 ◽  
Author(s):  
Yamit Cohen ◽  
Luba Daikhin ◽  
Merav Ahissar
Keyword(s):  
Temporal Structure ◽  
Frequency Discrimination ◽  
Perceptual Task ◽  
Hierarchy Theory ◽  
Tone Frequency ◽  
Potential Cost ◽  
Before And After ◽  
Group A ◽  
Fixed Reference ◽  
Key Questions

What do we learn when we practice a simple perceptual task? Many studies have suggested that we learn to refine or better select the sensory representations of the task-relevant dimension. Here we show that learning is specific to the trained structural regularities. Specifically, when this structure is modified after training with a fixed temporal structure, performance regresses to pretraining levels, even when the trained stimuli and task are retained. This specificity raises key questions as to the importance of low-level sensory modifications in the learning process. We trained two groups of participants on a two-tone frequency discrimination task for several days. In one group, a fixed reference tone was consistently presented in the first interval (the second tone was higher or lower), and in the other group the same reference tone was consistently presented in the second interval. When following training, these temporal protocols were switched between groups, performance of both groups regressed to pretraining levels, and further training was needed to attain postlearning performance. ERP measures, taken before and after training, indicated that participants implicitly learned the temporal regularity of the protocol and formed an attentional template that matched the trained structure of information. These results are consistent with Reverse Hierarchy Theory, which posits that even the learning of simple perceptual tasks progresses in a top–down manner, hence can benefit from temporal regularities at the trial level, albeit at the potential cost that learning may be specific to these regularities.

scholarly journals The Effects of Visual Cues, Blindfolding, Synesthetic Experience, and Musical Training on Pure-Tone Frequency Discrimination

2018 ◽  
Vol 9 (1) ◽  
pp. 2
Author(s):  
Cho Tse ◽  
Calvin Yu
Keyword(s):  
Visual Cues ◽  
Musical Training ◽  
Frequency Discrimination ◽  
Difference Limen ◽  
Experimental Session ◽  
Tone Frequency ◽  
Music Practice ◽  
Forced Choice Task ◽  
Multiple Resource ◽  
Auditory Impairment

How perceptual limits can be reduced has long been examined by psychologists. This study investigated whether visual cues, blindfolding, visual-auditory synesthetic experience, and musical training could facilitate a smaller frequency difference limen (FDL) in a gliding frequency discrimination test. Ninety university students, with no visual or auditory impairment, were recruited for this one-between (blindfolded/visual cues) and one-within (control/experimental session) designed study. Their FDLs were tested by an alternative forced-choice task (gliding upwards/gliding downwards/no change) and two questionnaires (Vividness of Mental Imagery Questionnaire and Projector–Associator Test) were used to assess their tendency to synesthesia. The participants provided with visual cues and with musical training showed a significantly smaller FDL; on the other hand, being blindfolded or having a synesthetic experience before could not significantly reduce the FDL. However, no pattern was found between the perception of the gliding upwards and gliding downwards frequencies. Overall, the current study suggests that the inter-sensory perception can be enhanced through the training and facilitation of visual–auditory interaction under the multiple resource model. Future studies are recommended in order to verify the effects of music practice on auditory percepts, and the different mechanisms between perceiving gliding upwards and downwards frequencies.

Divided Attention Impairs Human Motor Adaptation But Not Feedback Control

2007 ◽  
Vol 98 (1) ◽  
pp. 317-326 ◽  
Author(s):  
Jordan A. Taylor ◽  
Kurt A. Thoroughman
Keyword(s):  
Feedback Control ◽  
Predictive Control ◽  
Divided Attention ◽  
Discrimination Task ◽  
Frequency Discrimination ◽  
Tone Frequency ◽  
Movement Trial ◽  
Control Versus ◽  
Dual Task Paradigm ◽  
Force Perturbation

When humans experience externally induced errors in a movement, the motor system's feedback control compensates for those errors within the movement. The motor system's predictive control then uses information about those errors to inform future movements. The role of attention in these two distinct motor processes is unclear. Previous experiments have revealed a role for attention in motor learning over the course of many movements; however, these experimental paradigms do not determine how attention influences within-movement feedback control versus across-movement adaptation. Here we develop a dual-task paradigm, consisting of movement and audio tasks, which can differentiate and expose attention's role in these two processes of motor control. Over the course of several days, subjects performed horizontal reaching movements, with and without the audio task; movements were occasionally subjected to transient force perturbations. On movements with a force perturbation, subjects compensated for the force-induced movement errors, and on movements immediately after the force perturbation subjects exhibited adaptation. On every movement trial, subjects performed a two-tone frequency-discrimination task. The temporal specificity of the frequency-discrimination task allowed us to divide attention within and across movements. We find that divided attention did not impair the within-movement feedback control of the arm, but did reduce subsequent movement adaptation. We suggest that the secondary task interfered with the encoding and transformation of errors into changes in predictive control.

scholarly journals Factors Affecting Sensitivity to Frequency Change in School-Age Children and Adults

2014 ◽  
Vol 57 (5) ◽  
pp. 1972-1982 ◽  
Author(s):  
Emily Buss ◽  
Crystal N. Taylor ◽  
Lori J. Leibold
Keyword(s):  
Pure Tone ◽  
Musical Training ◽  
Frequency Discrimination ◽  
School Age Children ◽  
Frequency Change ◽  
School Age ◽  
Older Children ◽  
Tone Frequency ◽  
Factors Affecting ◽  
Temporal Cues

Purpose The factors affecting frequency discrimination in school-age children are poorly understood. The goal of the present study was to evaluate developmental effects related to memory for pitch and the utilization of temporal fine structure. Method Listeners were 5.1- to 13.6-year-olds and adults, all with normal hearing. A subgroup of children had musical training. The task was a 3-alternative forced choice in which listeners identified the interval with the higher frequency tone or the tone characterized by frequency modulation (FM). The standard was 500 or 5000 Hz, and the FM rate was either 2 or 20 Hz. Results Thresholds tended to be higher for younger children than for older children and adults for all conditions, although this age effect was smaller for FM detection than for pure-tone frequency discrimination. Neither standard frequency nor modulation rate affected the child/adult difference FM thresholds. Children with musical training performed better than their peers on pure-tone frequency discrimination at 500 Hz. Conclusions Testing frequency discrimination using a low-rate FM detection task may minimize effects related to cognitive factors like memory for pitch or training effects. Maturation of frequency discrimination does not appear to differ across conditions in which listeners are hypothesized to rely on temporal cues and place cues.

Fast Learning of Simple Perceptual Discriminations Reduces Brain Activation in Working Memory and in High-level Auditory Regions

2015 ◽  
Vol 27 (7) ◽  
pp. 1308-1321 ◽  
Author(s):  
Luba Daikhin ◽  
Merav Ahissar
Keyword(s):  
Working Memory ◽  
Brain Activity ◽  
Brain Activation ◽  
Frequency Discrimination ◽  
Reference Condition ◽  
Tone Frequency ◽  
Temporal Area ◽  
Fast Learning ◽  
High Level ◽  
Online Storage

Introducing simple stimulus regularities facilitates learning of both simple and complex tasks. This facilitation may reflect an implicit change in the strategies used to solve the task when successful predictions regarding incoming stimuli can be formed. We studied the modifications in brain activity associated with fast perceptual learning based on regularity detection. We administered a two-tone frequency discrimination task and measured brain activation (fMRI) under two conditions: with and without a repeated reference tone. Although participants could not explicitly tell the difference between these two conditions, the introduced regularity affected both performance and the pattern of brain activation. The “No-Reference” condition induced a larger activation in frontoparietal areas known to be part of the working memory network. However, only the condition with a reference showed fast learning, which was accompanied by a reduction of activity in two regions: the left intraparietal area, involved in stimulus retention, and the posterior superior-temporal area, involved in representing auditory regularities. We propose that this joint reduction reflects a reduction in the need for online storage of the compared tones. We further suggest that this change reflects an implicit strategic shift “backwards” from reliance mainly on working memory networks in the “No-Reference” condition to increased reliance on detected regularities stored in high-level auditory networks.

scholarly journals On the utility of perceptual anchors during pure-tone frequency discrimination

2020 ◽  
Vol 147 (1) ◽  
pp. 371-380 ◽  
Author(s):  
Samuel R. Mathias ◽  
Leonard Varghese ◽  
Christophe Micheyl ◽  
Barbara G. Shinn-Cunningham
Keyword(s):  
Pure Tone ◽  
Frequency Discrimination ◽  
Tone Frequency

scholarly journals Interneuron subtypes enable independent modulation of excitatory and inhibitory firing rates after sensory deprivation

2021 ◽  
Author(s):  
Leonidas M. A. Richter ◽  
Julijana Gjorgjieva
Keyword(s):  
Sensory Deprivation ◽  
Sensory Information ◽  
Mechanistic Explanation ◽  
Monocular Deprivation ◽  
Recurrent Networks ◽  
Cortical Circuits ◽  
Cortical Dynamics ◽  
Sensory Cortices ◽  
Synaptic Changes

Diverse interneuron subtypes determine how cortical circuits process sensory information depending on their connectivity. Sensory deprivation experiments are ideally suited to unravel the plasticity mechanisms which shape circuit connectivity, but have yet to consider the role of different inhibitory subtypes. We investigate how synaptic changes due to monocular deprivation affect the firing rate dynamics in a microcircuit network model of the visual cortex. We demonstrate that, in highly recurrent networks, deprivation-induced plasticity generates fundamentally different activity changes depending on interneuron composition. Considering parvalbumin-positive (PV+) and somatostatin-positive (SST+) interneuron subtypes can capture the experimentally observed independent modulation of excitatory and inhibitory activity during sensory deprivation when SST+ feedback is sufficiently strong. Our model also applies to whisker deprivation in the somatosensory cortex revealing that these mechanisms are general across sensory cortices. Therefore, we provide a mechanistic explanation for the differential role of interneuron subtypes in regulating cortical dynamics during deprivation-induced plasticity.

Effects of real and illusory glides on pure‐tone frequency discrimination

2003 ◽  
Vol 113 (4) ◽  
pp. 2291-2291
Author(s):  
Johannes Lyzenga ◽  
Robert P. Carlyon ◽  
Brian C. J. Moore
Keyword(s):  
Pure Tone ◽  
Frequency Discrimination ◽  
Tone Frequency
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