Medial Prefrontal Theta Oscillations Track the Time Course of Interference during Selective Memory Retrieval

2014 ◽  
Vol 26 (4) ◽  
pp. 777-791 ◽  
Author(s):  
Catarina S. Ferreira ◽  
Alejandra Marful ◽  
Tobias Staudigl ◽  
Teresa Bajo ◽  
Simon Hanslmayr

Memory retrieval is often challenged by other irrelevant competing memories that cause interference. This phenomenon is typically studied with the retrieval practice paradigm in which a category cue (e.g., Fruits) is presented together with an item-specific cue (e.g., Or::). Presentation of the category cue usually induces interference by reactivating competing memories (e.g., Banana, Apple, etc.), which is thought to be solved by means of inhibition, leading to retrieval-induced forgetting of these competing memories. Previous studies associated interference with an increase in medial prefrontal theta band (4–8 Hz) oscillations, but these studies could not disentangle the interference from the inhibition processes. We here used a retrieval practice procedure in which the category cue was presented before the item-specific cue to disentangle the interference from the inhibition signal. Furthermore, a competitive retrieval condition was contrasted with a noncompetitive condition. At a behavioral level, retrieval-induced forgetting was found in the competitive but not in the noncompetitive condition. At a neural level, presentation of the category cue elicited higher levels of theta power in the competitive condition, when compared with the noncompetitive retrieval condition. Importantly, this difference was localized to the ACC, which has been associated with the detection and mediation of interference. Additionally, theta power decreased upon presentation of the item-specific cue, and this difference was related to later forgetting. Our results therefore disentangle, for the first time, interference and inhibition in episodic memory retrieval and suggest that theta oscillations track the fine-grained temporal dynamics of interference during competitive memory retrieval.

2009 ◽  
Vol 21 (5) ◽  
pp. 976-990 ◽  
Author(s):  
Bernhard Spitzer ◽  
Simon Hanslmayr ◽  
Bertram Opitz ◽  
Axel Mecklinger ◽  
Karl-Heinz Bäuml

Retrieval practice on a subset of previously studied material enhances later memory for practiced material but can inhibit memory for related unpracticed material. The present study examines the effects of prior retrieval practice on evoked (ERPs) and induced (oscillatory power) measures of electrophysiological activity underlying recognition of practiced and unpracticed words. Compared to control material, recognition of unpracticed words was characterized by reduced amplitudes of the P2 ERP component and by reduced early (200–400 msec) oscillatory theta power. The reduction in P2 amplitude was associated with decreased evoked theta power but not with decreased theta phase locking (phase-locking index). Recognition of unpracticed material was further accompanied by a reduction in occipital gamma power (>250 msec). In contrast, the beneficial effects of retrieval practice on practiced words were reflected by larger parietal ERP positivity (>500 msec) and by a stronger decrease in oscillatory alpha power in a relatively late time window (>700 msec). The results suggest that the beneficial and detrimental effects of retrieval practice are mediated by different processes. In particular, they suggest that reduced theta (4–7 Hz) and gamma (60–90 Hz) power reflect the specific effects of inhibitory processes on the unpracticed material's memory representation.


2021 ◽  
Author(s):  
Prasakti Tenri Fanyiwi ◽  
Beshoy Agayby ◽  
Ricardo Kienitz ◽  
Marcus Haag ◽  
Michael C. Schmid

AbstractA growing body of psychophysical research reports theta (3-8 Hz) rhythmic fluctuations in visual perception that are often attributed to an attentional sampling mechanism arising from theta rhythmic neural activity in mid- to high-level cortical association areas. However, it remains unclear to what extent such neuronal theta oscillations might already emerge at early sensory cortex like the primary visual cortex (V1), e.g. from the stimulus filter properties of neurons. To address this question, we recorded multi-unit neural activity from V1 of two macaque monkeys viewing a static visual stimulus with variable sizes, orientations and contrasts. We found that among the visually responsive electrode sites, more than 50 % showed a spectral peak at theta frequencies. Theta power varied with varying basic stimulus properties. Within each of these stimulus property domains (e.g. size), there was usually a single stimulus value that induced the strongest theta activity. In addition to these variations in theta power, the peak frequency of theta oscillations increased with increasing stimulus size and also changed depending on the stimulus position in the visual field. Further analysis confirmed that this neural theta rhythm was indeed stimulus-induced and did not arise from small fixational eye movements (microsaccades). When the monkeys performed a detection task of a target embedded in a theta-generating visual stimulus, reaction times also tended to fluctuate at the same theta frequency as the one observed in the neural activity. The present study shows that a highly stimulus-dependent neuronal theta oscillation can be elicited in V1 that appears to influence the temporal dynamics of visual perception.


2018 ◽  
Author(s):  
Catarina S. Ferreira ◽  
Maria Jesús Maraver ◽  
Simon Hanslmayr ◽  
Bajo Teresa

ABSTRACTSeemingly effortless tasks, such as recognizing faces and retrieving names, become significantly harder as people get older. These age-related difficulties may be partially due to the concurrent activation of related competitors. However, it remains unclear whether older adults struggle with detecting an early interference signal or with suppressing irrelevant competitors once competition is detected. To investigate this question, we used the retrieval practice paradigm, shown to elicit interference, while recording electrophysiological activity in young and older adults. In two experiments, young participants showed the typical Retrieval Induced Forgetting (RIF) effect whereas the elderly did not. Neurally, young adults were more capable to detect interference than the older, as evidenced by an increase in mid-frontal theta power (~4-8Hz). This efficient interference detection allowed young adults to recruit inhibitory mechanisms that overcome competition, as traced by a theta power reduction across retrieval cycles. No such reduction was found for the elderly, indicating that the lack of an early interference detection signal renders older adults unable to recruit memory selection mechanisms, eliminating RIF.AUTHORS NOTEThis research was supported by the doctoral research grants AP2009-2215 to C.S.F and BES-2013-066842 to M.J.M.; by grants PSI2012-33625; PSI2015-65502-C2-1-P from the Spanish Ministry of Economy and Competiveness, and by the Economic Council of the Andalusian Government P08-HUM-03600-Feder and P12-CTS-2369-Feder to T.B.Declaration of interestThe authors have no conflicts of interest to disclose


2013 ◽  
Vol 25 (10) ◽  
pp. 1624-1633 ◽  
Author(s):  
Brendan Eliot Depue ◽  
Nick Ketz ◽  
Matthew V. Mollison ◽  
Erika Nyhus ◽  
Marie T. Banich ◽  
...  

Although investigations of memory and the dynamics of ERP components and neural oscillations as assessed through EEG have been well utilized, little research into the volitional nature of suppression over memory retrieval have used these methods. Oscillation analyses conducted on the Think/No-Think (TNT) task and volitional suppression of retrieval are of interest to broaden our knowledge of neural oscillations associated not only during successful memory retrieval but also when retrieval is unwanted or suppressed. In the current study, we measured EEG during a TNT task and performed ERP and EEG spectral power band analyses. ERP results replicated other researchers' observations of increases in 500–800 msec parietal effects for items where retrieval was instructed to be elaborated compared with being suppressed. Furthermore, EEG analyses indicated increased alpha (8–12 Hz) and theta (3–8 Hz) oscillations across parietal electrodes for items that were instructed to be suppressed versus those to be elaborated. Additionally, during the second half of the experiment (after repeated attempts at control), increases in theta oscillations were found across both frontal and parietal electrodes for items that were instructed to be suppressed and that were ultimately forgotten versus those ultimately remembered. Increased alpha power for items that were instructed to be suppressed versus elaborated may indicate reductions of retrieval attempts or lack of retrieval success. Increased theta power for items that were instructed to be suppressed versus elaborated may indicate increased or prolonged cognitive control to monitor retrieval events.


2020 ◽  
Vol 9 (2) ◽  
pp. 339-346
Author(s):  
Barbara Penolazzi ◽  
Fabio Del Missier ◽  
Davide Francesco Stramaccia ◽  
Anna Laura Monego ◽  
Luigi Castelli ◽  
...  

AbstractBackground and aimsMany psychopathologies, including addictions, are characterized by inhibitory control deficits. In this regard, recent studies on substance-related disorders (SRD) have shown an impairment in the ability to inhibit potentially interfering memories, despite preserved motor inhibition. To investigate whether the same dissociation could also characterize gambling disorder (GD) in a transdiagnostic perspective, we tested both cognitive and motor inhibitory processes through dedicated tasks, for the first time in this behavioral addiction.Methods30 outpatients with GD and 30 healthy controls performed a go/no-go task addressing the integrity of motor inhibition, and the Retrieval Practice Paradigm, a task addressing the integrity of memory inhibition as indexed by the Retrieval-Induced Forgetting (RIF) effect. Self-report questionnaires assessing impulsivity were also administered.ResultsWhereas RIF was similar across the two groups, patients showed more commission errors in the go/no-go task, and higher self-rated scores of impulsivity than controls.DiscussionThe present findings suggest preserved memory inhibition and impaired motor response inhibition in GD, a pattern of inhibitory deficits opposite to that previously reported for SRD. Therefore, although both GD and SRD are characterized by altered inhibitory processing, a more fine-grained analysis revealed a specific inhibitory profile indicating vulnerability in different inhibitory components.ConclusionThe present study highlights the need to investigate the multifaceted construct of inhibition more thoroughly, using performance measures able to assess its various components. This approach would enable to both better characterize different psychopathologies and orient their treatment.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sandro L. Wiesmann ◽  
Laurent Caplette ◽  
Verena Willenbockel ◽  
Frédéric Gosselin ◽  
Melissa L.-H. Võ

AbstractHuman observers can quickly and accurately categorize scenes. This remarkable ability is related to the usage of information at different spatial frequencies (SFs) following a coarse-to-fine pattern: Low SFs, conveying coarse layout information, are thought to be used earlier than high SFs, representing more fine-grained information. Alternatives to this pattern have rarely been considered. Here, we probed all possible SF usage strategies randomly with high resolution in both the SF and time dimensions at two categorization levels. We show that correct basic-level categorizations of indoor scenes are linked to the sampling of relatively high SFs, whereas correct outdoor scene categorizations are predicted by an early use of high SFs and a later use of low SFs (fine-to-coarse pattern of SF usage). Superordinate-level categorizations (indoor vs. outdoor scenes) rely on lower SFs early on, followed by a shift to higher SFs and a subsequent shift back to lower SFs in late stages. In summary, our results show no consistent pattern of SF usage across tasks and only partially replicate the diagnostic SFs found in previous studies. We therefore propose that SF sampling strategies of observers differ with varying stimulus and task characteristics, thus favouring the notion of flexible SF usage.


2004 ◽  
Vol 92 (5) ◽  
pp. 3030-3042 ◽  
Author(s):  
Jay Hegdé ◽  
David C. Van Essen

The firing rate of visual cortical neurons typically changes substantially during a sustained visual stimulus. To assess whether, and to what extent, the information about shape conveyed by neurons in visual area V2 changes over the course of the response, we recorded the responses of V2 neurons in awake, fixating monkeys while presenting a diverse set of static shape stimuli within the classical receptive field. We analyzed the time course of various measures of responsiveness and stimulus-related response modulation at the level of individual cells and of the population. For a majority of V2 cells, the response modulation was maximal during the initial transient response (40–80 ms after stimulus onset). During the same period, the population response was relatively correlated, in that V2 cells tended to respond similarly to specific subsets of stimuli. Over the ensuing 80–100 ms, the signal-to-noise ratio of individual cells generally declined, but to a lesser degree than the evoked-response rate during the corresponding time bins, and the response profiles became decorrelated for many individual cells. Concomitantly, the population response became substantially decorrelated. Our results indicate that the information about stimulus shape evolves dynamically and relatively rapidly in V2 during static visual stimulation in ways that may contribute to form discrimination.


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