scholarly journals Gamma oscillations dynamically couple hippocampal CA3 and CA1 regions during memory task performance

2007 ◽  
Vol 104 (36) ◽  
pp. 14495-14500 ◽  
Author(s):  
S. M. Montgomery ◽  
G. Buzsaki
Author(s):  
Maryam Daniali ◽  
Dario D. Salvucci ◽  
Maria T. Schultheis

Concussions are common cognitive impairments, but their effects on task performance in general, and on driving in particular, are not well understood. To better understand the effects of concussion on driving, we investigated previously gathered data on twenty-two people with a concussion, driving in a virtual-reality driving simulator (VRDS), and twenty-two non-concussed matched drivers. Participants were asked to per-form a behavioral task (either coin sorting or a verbal memory task) while driving. In this study, we chose a few common metrics from the VRDS and tracked their changes through time for each participant. Our pro-posed method—namely, the use of convolutional neural networks for classification and analysis—can accu-rately classify concussed driving and extract local features on driving sequences that translate to behavioral driving signatures. Overall, our method improves identification and understanding of clinically relevant driv-ing behaviors for concussed individuals and should generalize well to other types of impairments.


2021 ◽  
Vol 11 (7) ◽  
pp. 935
Author(s):  
Ying Xing Feng ◽  
Masashi Kiguchi ◽  
Wei Chun Ung ◽  
Sarat Chandra Dass ◽  
Ahmad Fadzil Mohd Hani ◽  
...  

The effect of stress on task performance is complex, too much or too little stress negatively affects performance and there exists an optimal level of stress to drive optimal performance. Task difficulty and external affective factors are distinct stressors that impact cognitive performance. Neuroimaging studies showed that mood affects working memory performance and the correlates are changes in haemodynamic activity in the prefrontal cortex (PFC). We investigate the interactive effects of affective states and working memory load (WML) on working memory task performance and haemodynamic activity using functional near-infrared spectroscopy (fNIRS) neuroimaging on the PFC of healthy participants. We seek to understand if haemodynamic responses could tell apart workload-related stress from situational stress arising from external affective distraction. We found that the haemodynamic changes towards affective stressor- and workload-related stress were more dominant in the medial and lateral PFC, respectively. Our study reveals distinct affective state-dependent modulations of haemodynamic activity with increasing WML in n-back tasks, which correlate with decreasing performance. The influence of a negative effect on performance is greater at higher WML, and haemodynamic activity showed evident changes in temporal, and both spatial and strength of activation differently with WML.


1992 ◽  
Vol 36 (18) ◽  
pp. 1398-1402
Author(s):  
Pamela S. Tsang ◽  
Tonya L. Shaner

The secondary task technique was used to test two alternative explanations of dual task decrement: outcome conflict and resource allocation. Subjects time-shared a continuous tracking task and a discrete Sternberg memory task. The memory probes were presented under three temporal predictability conditions. Dual task performance decrements in both the tracking and memory tasks suggested that the two tasks competed for some common resources, processes, or mechanisms. Although performance decrements were consistent with both the outcome conflict and resource allocation explanations, the two explanations propose different mechanisms by which the primary task could be protected from interference from the concurrent secondary task. The primary task performance could be protected by resource allocation or by strategic sequencing of the processing of the two tasks in order to avoid outcome conflict. In addition to examining the global trial means, moment-by-moment tracking error time-locked to the memory probe was also analyzed. There was little indication that the primary task was protected by resequencing of the processing of the two tasks. This together with the suggestion that predictable memory probes led to better protected primary task performance than less predictable memory probes lend support for the resource explanation.


2014 ◽  
Vol 28 (1) ◽  
pp. 127-134 ◽  
Author(s):  
Urs Maurer ◽  
Silvia Brem ◽  
Martina Liechti ◽  
Stefano Maurizio ◽  
Lars Michels ◽  
...  

Author(s):  
Samantha L. Epling ◽  
Graham K. Edgar ◽  
Paul N. Russell ◽  
William S. Helton

Dual-tasking situations are common in military, firefighting, search and rescue, and other high risk operations. Cognitive and physical demands can occur at the same time, but little is known about the specific demands of real world tasks or how they might interfere with one another. It is well known that attempting simultaneous tasks will divide and divert attention, but to what extent? In this experiment, a narrative memory task was paired with an outdoor running task, and as expected, memory task performance declined when participants were asked to run at the same time. It is suggested that more cognitively demanding physical tasks be used within this dual-task paradigm for a better understanding of the human cognitive resource structure, i.e., how and why certain tasks interfere.


2021 ◽  
Author(s):  
Aleš Oblak ◽  
Anka Slana Ozimič ◽  
Grega Repovš ◽  
Urban Kordeš

In experimental cognitive psychology, objects of inquiry have typically been operationalized with psychological tasks. If we are interested in measuring the target phenomena, we must inquire into the validity of the task; that is, to what extent does the task elicit the phenomenon in question. If we subscribe to the second view, evaluating the validity and the interpretation of the gathered data can be supplemented by understanding the experience of solving psychological tasks. The aim of the present article is to investigate how individuals experience performing a psychological task, specifically, a visuo-spatial working memory task. We present ethnographic descriptions of different ways individuals can experience the same task. We focus on aspects of experience that comprise the overall sense of experience (e.g., bodily feelings, emotional atmosphere, mood). We discuss the methodological implications of our findings and the possibility of conducting a neurophenomenology of visuo-spatial working memory.


2021 ◽  
Author(s):  
Jefferson Ortega ◽  
Chelsea Reichert Plaska ◽  
Bernard A Gomes ◽  
Timothy M Ellmore

Spontaneous eye blink rate (sEBR) has been found to be a non-invasive indirect measure of striatal dopamine activity. Dopamine (DA) neurons project to the prefrontal cortex (PFC) through the mesocortical dopamine pathway and their activity is implicated in a range of cognitive functions, including attention and working memory (WM). The goal of the present study was to understand how fluctuations in sEBR during different phases of a working memory task relate to task performance. Across two experiments, with recordings of sEBR inside and outside of a magnetic resonance imaging bore, we observed sEBR to be positively correlated with WM performance during the WM delay period. Additionally we investigated the non-linear relationship between sEBR and WM performance, and modeled a proposed Inverted-U-shape relationship between DA and WM performance. We also investigated blink duration, which is proposed to be related to sustained attention, and found blink duration to be significantly shorter during the encoding and probe periods of the task. Taken together, these results provide support towards sEBR as an important correlate of working memory task performance. The relationship of sEBR to DA activity and the influence of DA on the PFC during WM maintenance is discussed.


2021 ◽  
Author(s):  
Anton E Malkov ◽  
Ludmila Shevkova ◽  
Alexandra Latyshkova ◽  
Valentina Kitchigina

Cortical oscillations in different frequency bands have been shown to be intimately involved in exploration of environment and cognition. Here, the local field potentials in the hippocampus, the medial prefrontal cortex (mPFC), and the medial entorhinal cortex (mEC) were recorded simultaneously in rats during the execution of the episodic-like memory task. The power of hippocampal theta (~4-10 Hz), slow gamma (~25-50 Hz), and fast gamma oscillations (~55-100 Hz) was analyzed in all structures examined. Particular attention was paid to the theta coherence between three mentioned structures. The modulation of the power of gamma rhythms by the phase of theta cycle during the execution of the episodic-like memory test by rats was also closely studied. Healthy rats and rats one month after kainate-induced status epilepticus (SE) were examined. Paroxysmal activity in the hippocampus (high amplitude interictal spikes), excessive excitability of animals, and the death of hippocampal and dentate granular cells in rats with kainate-evoked SE were observed, which indicated the development of seizure focus in the hippocampus (epileptogenesis). One month after SE, the rats exhibited a specific impairment of episodic memory for the what-where-when triad: unlike healthy rats, epileptogenic SE animals did not identify the objects during the test. This impairment was associated with the changes in the characteristics of theta and gamma rhythms and specific violation of theta coherence and theta/gamma coupling in these structures in comparison with the healthy animals. We believe that these disturbances in the cortical areas play a role in episodic memory dysfunction in kainate-treated animals. These findings can shed light on the mechanisms of cognitive deficit during epileptogenesis.


2018 ◽  
Vol 51 (7) ◽  
pp. 1128-1138
Author(s):  
R Lasauskaite ◽  
EM Hazelhoff ◽  
C Cajochen

Light exerts a number of non-image-forming effects that are mostly apparent during night-time but can also been seen during daytime. Recently, we have shown that exposure to light of higher colour temperature prior to performing a cognitive task leads to a weaker effort-related cardiovascular response compared to exposure to light of lower colour temperature. This present study tested if presenting light of different colour temperatures during rather than before the task performance would lead to equivalent changes in effort mobilization. Participants performed a modified Sternberg short-memory task for eight minutes as lighting conditions were adjusted to one of four experimental lighting conditions (2800 K, 4000 K, 5000 K, or 6500 K) after the first four minutes, for the remaining four minutes. We predicted that effort-related cardiovascular response would strengthen with decreasing colour temperature. The results, however, did not follow this predicted pattern. No significant effects of lighting conditions on subjective measures were observed. Therefore, we conclude that four minutes might not be enough for light colour temperature to induce changes in effort-related cardiovascular response or affect subjective ratings of sleepiness and lighting.


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