scholarly journals Perception and memory have distinct spatial tuning properties in human visual cortex

2019 ◽  
Author(s):  
Serra E. Favila ◽  
Brice A. Kuhl ◽  
Jonathan Winawer
Keyword(s):  
Visual Cortex ◽  
Memory Retrieval ◽  
Poor Performance ◽  
Long Term Memory ◽  
Human Visual Cortex ◽  
Visual Areas ◽  
The Hierarchical Structure ◽  
Retinotopic Organization ◽  
Insight Into

AbstractReactivation of earlier perceptual activity is thought to underlie long-term memory recall. Despite evidence for this view, it is unknown whether mnemonic activity exhibits the same tuning properties as feedforward perceptual activity. Here, we leveraged population receptive field models to parameterize fMRI activity in human visual cortex during spatial memory retrieval. Though retinotopic organization was present during both perception and memory, large systematic differences in tuning were also evident. Notably, whereas there was a three-fold decline in spatial precision from early to late visual areas during perception, this property was entirely abolished during memory retrieval. This difference could not be explained by reduced signal-to-noise or poor performance on memory trials. Instead, by simulating top-down activity in a network model of cortex, we demonstrate that this property is well-explained by the hierarchical structure of the visual system. Our results provide insight into the computational constraints governing memory reactivation in sensory cortex.

Depressive symptomatology and learning: Does intermediate testing or restudying the information determine long-term memory retrieval of novel symbols?

2016 ◽  
Vol 33 (S1) ◽  
pp. S412-S412
Author(s):  
V. Giannouli
Keyword(s):  
Retention Interval ◽  
Music Education ◽  
Memory Retrieval ◽  
Testing Effect ◽  
Depressive Symptomatology ◽  
Long Term Memory ◽  
Music Notation ◽  
Testing Time ◽  
Term Memory

IntroductionThere is a hypothesis in cognitive psychology that long-term memory retrieval is improved by intermediate testing than by restudying the information. The effect of testing has been investigated with the use of a variety of stimuli. However, almost all testing effect studies to date have used purely verbal materials such as word pairs, facts and prose passages.ObjectiveHere byzantine music symbol–word pairs were used as to-be-learned materials to demonstrate the generalisability of the testing effect to symbol learning in participants with and without depressive symptoms.MethodFifty healthy (24 women, M age = 26.20, SD = 5.64) and forty volunteers with high depressive symptomatology (20 women, M age = 27.00, SD = 1.04) were examined. The participants did not have a music education. The examination material was completely new for them: 16 byzantine music notation stimuli, paired with a verbal label (the ancient Greek name of the symbol). Half of the participants underwent intermediate testing and the others restudied the information in a balanced design.ResultsResults indicated that there were no statistically significant differences in final memory test performance after a retention interval of 5 minutes for both groups of participants with low and high level depressive symptomatology (P > 0.005). After a retention interval of a week, tested pairs were retained better than repeatedly studied pairs for high and low depressive symptomatology groups (P < 0.005).ConclusionsThis research suggests that the effect of testing time on later memory retrieval can also be obtained in byzantine symbol learning.Disclosure of interestThe authors have not supplied their declaration of competing interest.

scholarly journals Hemispheric Asymmetries in Electroencephalogram Oscillations for Long-Term Memory Retrieval in Healthy Individuals

2020 ◽  
Vol 10 (12) ◽  
pp. 937
Author(s):  
Soyiba Jawed ◽  
Hafeez Ullah Amin ◽  
Aamir Saeed Malik ◽  
Ibrahima Faye
Keyword(s):  
Prefrontal Cortex ◽  
Episodic Memory ◽  
Memory Retrieval ◽  
Frontal Region ◽  
Long Term Memory ◽  
Healthy Individuals ◽  
Term Memory ◽  
Delta Band ◽  
The Right

The hemispherical encoding retrieval asymmetry (HERA) model, established in 1991, suggests that the involvement of the right prefrontal cortex (PFC) in the encoding process is less than that of the left PFC. The HERA model was previously validated for episodic memory in subjects with brain traumas or injuries. In this study, a revised HERA model is used to investigate long-term memory retrieval from newly learned video-based content for healthy individuals using electroencephalography. The model was tested for long-term memory retrieval in two retrieval sessions: (1) recent long-term memory (recorded 30 min after learning) and (2) remote long-term memory (recorded two months after learning). The results show that long-term memory retrieval in healthy individuals for the frontal region (theta and delta band) satisfies the revised HERA asymmetry model.

Unwanted Memory Intrusions Recruit Broad Motor Suppression

2021 ◽  
Vol 33 (1) ◽  
pp. 119-128
Author(s):  
Anna Castiglione ◽  
Adam R. Aron
Keyword(s):  
Memory Retrieval ◽  
Primary Motor Cortex ◽  
Motor Evoked Potentials ◽  
Motor Evoked Potential ◽  
Long Term Memory ◽  
Second Phase ◽  
Unexpected Result ◽  
Term Memory ◽  
Rapid Action

Quickly preventing the retrieval of (inappropriate) long-term memories might recruit a similar control mechanism as rapid action-stopping. A very specific characteristic of rapid action-stopping is “global motor suppression”: When a single response is rapidly stopped, there is a broad skeletomotor suppression. This is shown by the technique of TMS placed over a task-irrelevant part of the primary motor cortex (M1) to measure motor-evoked potentials. Here, we used this same TMS method to test if rapidly preventing long-term memory retrieval also shows this broad skeletomotor suppression effect. Twenty human participants underwent a Think/No-Think task. In the first phase, they learned word pairs. In the second phase, they received the left-hand word as a cue and had to either retrieve the associated right-hand word (“Think”) or stop retrieval (“No-Think”). At the end of each trial, they reported whether they had experienced an intrusion of the associated memory. Behaviorally, on No-Think trials, they reported fewer intrusions than Think trials, and the reporting of intrusions decreased with practice. Physiologically, we observed that the motor-evoked potential, measured from the hand (which was irrelevant to the task), was reduced on No-Think trials in the time frame of 300–500 msec, especially on trials where they did report an intrusion. This unexpected result contradicted our preregistered prediction that we would find such a decrease on No-Think trials where the intrusion was not reported. These data suggest that one form of executive control over (inappropriate) long-term memory retrieval is a rapid and broad stop, akin to action-stopping, that is triggered by the intrusion itself.

scholarly journals Seeing with Profoundly Deactivated Mid-level Visual Areas: Non-hierarchical Functioning in the Human Visual Cortex

2008 ◽  
Vol 19 (7) ◽  
pp. 1687-1703 ◽  
Author(s):  
Sharon Gilaie-Dotan ◽  
Anat Perry ◽  
Yoram Bonneh ◽  
Rafael Malach ◽  
Shlomo Bentin
Keyword(s):  
Visual Cortex ◽  
Human Visual Cortex ◽  
Visual Areas

scholarly journals Masking Disrupts Reentrant Processing in Human Visual Cortex

2007 ◽  
Vol 19 (9) ◽  
pp. 1488-1497 ◽  
Author(s):  
J. J. Fahrenfort ◽  
H. S. Scholte ◽  
V. A. F. Lamme
Keyword(s):  
Visual Cortex ◽  
Current Source ◽  
Visual Awareness ◽  
Human Visual Cortex ◽  
Density Maps ◽  
Visual Areas ◽  
Ground Segmentation ◽  
Feedback Connections ◽  
Subject Performance ◽  
Reentrant Processing

In masking, a stimulus is rendered invisible through the presentation of a second stimulus shortly after the first. Over the years, authors have typically explained masking by postulating some early disruption process. In these feedforward-type explanations, the mask somehow “catches up” with the target stimulus, disrupting its processing either through lateral or interchannel inhibition. However, studies from recent years indicate that visual perception—and most notably visual awareness itself—may depend strongly on cortico-cortical feedback connections from higher to lower visual areas. This has led some researchers to propose that masking derives its effectiveness from selectively interrupting these reentrant processes. In this experiment, we used electroencephalogram measurements to determine what happens in the human visual cortex during detection of a texture-defined square under nonmasked (seen) and masked (unseen) conditions. Electro-encephalogram derivatives that are typically associated with reentrant processing turn out to be absent in the masked condition. Moreover, extrastriate visual areas are still activated early on by both seen and unseen stimuli, as shown by scalp surface Laplacian current source-density maps. This conclusively shows that feedforward processing is preserved, even when subject performance is at chance as determined by objective measures. From these results, we conclude that masking derives its effectiveness, at least partly, from disrupting reentrant processing, thereby interfering with the neural mechanisms of figure-ground segmentation and visual awareness itself.

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