scholarly journals The effects of endogenous and exogenus orienting of attention on source memory

2018 ◽  
Vol 8 (2) ◽  
pp. 80-89
Author(s):  
Selene Cansino
Keyword(s):  
Eye Movements ◽  
Episodic Memory ◽  
Source Memory ◽  
Memory Task ◽  
Covert Attention ◽  
Control Mechanisms ◽  
Eye Tracker ◽  
Memory Representations ◽  
The Right ◽  
Symbolic Cues

The aim of this study was to determine the effects of endogenous and exogenous orienting of attention on episodic memory. Thirty healthy participants performed a cueing attention paradigm during encoding, in which images of common objects were presented either to the left or to the right of the center of the screen. Before the presentation of each image, three types of symbolic cues were displayed to indicate the location in which the stimuli would appear: valid cues to elicit endogenous orientation, invalid cues to prompt exogenous orientation and neutral or uncued trials. The participants’ task was to discriminate whether the images were symmetrical or not while fixating on the center of the screen to assure the manifestation of only covert attention mechanisms. Covert attention refers to the ability to orient attention by means of central control mechanisms alone, without head and eye movements. Trials with eye movements were excluded after inspection of eye-tracker recordings that were conducted throughout the task. During retrieval, participants conducted a source memory task in which they indicated the location where the images were presented during encoding. Memory for spatial context was superior during endogenous orientation than during exogenous orientation, whereas exogenous orientation was associated with a greater number of missed responses compared to the neutral trials. The formation of episodic memory representations with contextual details benefits from endogenous attention.

scholarly journals Are visual working memory and episodic memory distinct processes? Insight from stroke patients by lesion-symptom mapping

2021 ◽  
Author(s):  
Selma Lugtmeijer ◽  
◽  
Linda Geerligs ◽  
Frank Erik de Leeuw ◽  
Edward H. F. de Haan ◽  
...  
Keyword(s):  
Working Memory ◽  
Episodic Memory ◽  
Visual Working Memory ◽  
Visual Memory ◽  
Right Hemisphere ◽  
Memory Task ◽  
Stroke Patients ◽  
Lesion Symptom Mapping ◽  
Criterion Setting ◽  
The Right

AbstractWorking memory and episodic memory are two different processes, although the nature of their interrelationship is debated. As these processes are predominantly studied in isolation, it is unclear whether they crucially rely on different neural substrates. To obtain more insight in this, 81 adults with sub-acute ischemic stroke and 29 elderly controls were assessed on a visual working memory task, followed by a surprise subsequent memory test for the same stimuli. Multivariate, atlas- and track-based lesion-symptom mapping (LSM) analyses were performed to identify anatomical correlates of visual memory. Behavioral results gave moderate evidence for independence between discriminability in working memory and subsequent memory, and strong evidence for a correlation in response bias on the two tasks in stroke patients. LSM analyses suggested there might be independent regions associated with working memory and episodic memory. Lesions in the right arcuate fasciculus were more strongly associated with discriminability in working memory than in subsequent memory, while lesions in the frontal operculum in the right hemisphere were more strongly associated with criterion setting in subsequent memory. These findings support the view that some processes involved in working memory and episodic memory rely on separate mechanisms, while acknowledging that there might also be shared processes.

scholarly journals Effects of amnesia on processing in the hippocampus and default mode network during a naturalistic memory task: a case study

2018 ◽  
Author(s):  
Christiane Oedekoven ◽  
James L. Keidel ◽  
Stuart Anderson ◽  
Angus Nisbet ◽  
Chris Bird
Keyword(s):  
Functional Connectivity ◽  
Episodic Memory ◽  
Memory Performance ◽  
Memory Task ◽  
Structural Mri ◽  
Brain Regions ◽  
Left Hippocampus ◽  
Cortical Regions ◽  
The Right ◽  
Encoding And Retrieval

Despite their severely impaired episodic memory, individuals with amnesia are able to comprehend ongoing events. Online representations of a current event are thought to be supported by a network of regions centred on the posterior midline cortex (PMC). By contrast, episodic memory is widely believed to be supported by interactions between the hippocampus and these cortical regions. In this MRI study, we investigated the encoding and retrieval of lifelike events (video clips) in a patient with severe amnesia likely resulting from a stroke to the right thalamus, and a group of 20 age-matched controls. Structural MRI revealed grey matter reductions in left hippocampus and left thalamus in comparison to controls. We first characterised the regions activated in the controls while they watched and retrieved the videos. There were no differences in activation between the patient and controls in any of the regions. We then identified a widespread network of brain regions, including the hippocampus, that were functionally connected with the PMC in controls. However, in the patient there was a specific reduction in functional connectivity between the PMC and a region of left hippocampus when both watching and attempting to retrieve the videos. A follow up analysis revealed that in controls the functional connectivity between these regions when watching the videos was correlated with memory performance. Taken together, these findings support the view that the interactions between the PMC and the hippocampus enable the encoding and retrieval of multimodal representations of the contents of an event.

Does Inverting Text Improve Reading Performance in Homonymous Hemianopes?

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 77-77
Author(s):  
M R Baker ◽  
J Henderson ◽  
A Hill
Keyword(s):  
Eye Movements ◽  
Low Vision ◽  
Reading Speed ◽  
Leading Edge ◽  
Visual Field Loss ◽  
Reading Performance ◽  
Sensory Level ◽  
Eye Tracker ◽  
Cognitive Component ◽  
The Right

Anecdotal information from rehabilitation practice of reading performance and low-vision practice suggests that where right homonymous parafoveal field loss impairs reading at the visual-sensory level, an improvement in reading speed can be achieved by inverting the text. This is because whilst left-field loss is considered to impair return eye movements to the beginning of a line, right-field loss is considered to reduce the spatial size of the perceptual window and increase its temporal extent by prolonging fixations times, reducing the amplitudes of saccades to the right, and introducing frequent regressive saccades. Inverting the text was thought to reverse these effects as the leading edge of the perceptual window is ‘returned’ to the sighted field so that in-line saccades can be visually guided. Here we report that this does not appear to be the case. In our study we measured the eye movements of patients with right homonymous hemianopia and others with peripheral loss due to retinitis pigmentosa as well as normal controls using an infrared video eye-tracker. All groups display a similar proportional prolongation of fixations times, reduction of saccadic amplitude, and proportion of regressive saccades when asked to read inverted text, which suggests a cognitive component of impairment independent of visual field loss in right homonymous hemianopes.

scholarly journals Modulation of Visual Working Memory Performance via Different Theta Frequency Stimulations

2021 ◽  
Vol 11 (10) ◽  
pp. 1358
Author(s):  
Xue Guo ◽  
Ziyuan Li ◽  
Liangyou Zhang ◽  
Qiang Liu
Keyword(s):  
Working Memory ◽  
Performance Enhancement ◽  
Memory Performance ◽  
Memory Task ◽  
Underlying Mechanism ◽  
Transcranial Alternating Current Stimulation ◽  
Memory Representations ◽  
The Right ◽  
Memory Resources

Previous studies have found that transcranial alternating current stimulation (tACS) can significantly enhance individuals’ working memory performance. However, it is still unclear whether the memory performance enhancement was attributed to the quantity or the quality of working memory. The current study applies tACS over the right parietal cortex at slower (4 Hz) and faster (7 Hz) frequencies to participants with high and low working memory capacities in a color recall memory task. This enabled us to explore the tACS effects on the quantity and quality of the working memory for individuals with different memory capacities. The results revealed that slower frequency (4 Hz) tACS enhanced the quality of memory representations, and faster frequency (7 Hz) tACS principally impaired the quantity of working memory. The underlying mechanism of this effect might be that tACS at different frequencies modulate the memory resources, which then selectively affect the quantity and quality of memory representations. Importantly, individual traits, as well as memory strategies, may be crucial factors to consider when testing the effect of tACS on working memory performance.

scholarly journals fMRI Evidence for Separable and Lateralized Prefrontal Memory Monitoring Processes

2004 ◽  
Vol 16 (6) ◽  
pp. 908-920 ◽  
Author(s):  
Ian G. Dobbins ◽  
Jon S. Simons ◽  
Daniel L. Schacter
Keyword(s):  
Prefrontal Cortex ◽  
Source Memory ◽  
Memory Task ◽  
Cognitive Models ◽  
Item Memory ◽  
Close Monitoring ◽  
Memory Research ◽  
Recognition Judgments ◽  
Memory Monitoring ◽  
The Right

Source memory research suggests that attempting to remember specific contextual aspects surrounding prior stimulus encounters results in greater left prefrontal cortex (PFC) activity than simple item-based old/new recognition judgments. Here, we tested a complementary hypothesis that predicts increases in the right PFC with tasks requiring close monitoring of item familiarity. More specifically, we compared a judgment of frequency (JOF) task to an item memory task, in which the former required estimating the number of previous picture encounters and the latter required discriminating old from new exemplars of previously seen items. In comparison to standard old/new recognition, both source memory and the JOF task examined here require more precise mnemonic judgments. However, in contrast to source memory, cognitive models suggest the JOF task relies heavily upon item familiarity, not specific contextual recollections. Event-related fMRI demonstrated greater recruitment of right, not left, dorso-lateral and frontopolar PFC regions during the JOF compared to item memory task. These data suggest a role for right PFC in the close monitoring of the familiarity of objects, which becomes critical when contextual recollection is ineffective in satisfying a memory demand.

scholarly journals CONTROLLED EPISODIC RETRIEVAL IN BEHAVIORAL VARIANT FRONTOTEMPORAL DEMENTIA AND ALZHEIMER DISEASE.

2021 ◽  
Author(s):  
Antônio Jaeger ◽  
Eduarda Carreira ◽  
Natália Gama ◽  
Paulo Caramelli ◽  
Leonardo Souza
Keyword(s):  
Alzheimer Disease ◽  
Episodic Memory ◽  
Frontotemporal Dementia ◽  
Executive Control ◽  
Source Memory ◽  
Current Source ◽  
Memory Task ◽  
Spatial Location ◽  
Control Objective ◽  
Executive Dysfunctions

Background: Recent studies showed that episodic memory is impaired in behavioral variant of Frontotemporal dementia (bvFTD), but in contrast to Alzheimer disease (AD) it is assumed to be caused primarily by deficits in executive control. Objective: Our goal was to probe this possibility by testing bvFTD and AD patients in a source memory task which manipulated executive control. Methods: We assessed 14 healthy controls (HC), 20 bvFTD patients, and 18 AD patients in a source memory task for spatial location in which objects were first seen at the left or right side of the screen, and at test in the center of the screen, when participants were asked to indicate in which side of the screen each object was studied. Importantly, at test, predictive arrow cues (66.7% valid/33.3% invalid) indicated the likely prior location of each object. Results: BvFTD and AD patients showed indistinguishable overall memory performances, although both showed significantly poorer performances than HC. Furthermore, although both HC and bvFTD participants had their memory judgments affected by cueing, showing poorer memory accuracy after invalid than after valid cues, AD patients showed equivalent performance for both cue types. Conclusion: The current findings support the notion that episodic memory is impaired in bvFTD, and suggests that such impairment can be as severe as in AD. The cause of this impairment, however, was not related to the executive dysfunctions manipulated in the current source memory task, but rather to further mechanisms in the bvFTD memory deficits.

Acute tryptophan depletion reduces activation in the right hippocampus during encoding in an episodic memory task

NeuroImage ◽  
2006 ◽  
Vol 31 (3) ◽  
pp. 1188-1196 ◽  
Author(s):  
Frederik M. van der Veen ◽  
Elisabeth A.T. Evers ◽  
Jeroen A. van Deursen ◽  
Nicolaas E.P. Deutz ◽  
Walter H. Backes ◽  
...  
Keyword(s):  
Episodic Memory ◽  
Memory Task ◽  
Acute Tryptophan Depletion ◽  
Tryptophan Depletion ◽  
The Right

scholarly journals Neural Correlates of Confidence during Item Recognition and Source Memory Retrieval: Evidence for Both Dual-process and Strength Memory Theories

2011 ◽  
Vol 23 (12) ◽  
pp. 3959-3971 ◽  
Author(s):  
Scott M. Hayes ◽  
Norbou Buchler ◽  
Jared Stokes ◽  
James Kragel ◽  
Roberto Cabeza
Keyword(s):  
Episodic Memory ◽  
Source Memory ◽  
Memory Retrieval ◽  
Memory Task ◽  
Dual Process ◽  
Item Memory ◽  
Strength Theory ◽  
High Confidence ◽  
Medial Temporal Lobes ◽  
Memory Network

Although the medial-temporal lobes (MTL), PFC, and parietal cortex are considered primary nodes in the episodic memory network, there is much debate regarding the contributions of MTL, PFC, and parietal subregions to recollection versus familiarity (dual-process theory) and the feasibility of accounts on the basis of a single memory strength process (strength theory). To investigate these issues, the current fMRI study measured activity during retrieval of memories that differed quantitatively in terms of strength (high vs. low-confidence trials) and qualitatively in terms of recollection versus familiarity (source vs. item memory tasks). Support for each theory varied depending on which node of the episodic memory network was considered. Results from MTL best fit a dual-process account, as a dissociation was found between a right hippocampal region showing high-confidence activity during the source memory task and bilateral rhinal regions showing high-confidence activity during the item memory task. Within PFC, several left-lateralized regions showed greater activity for source than item memory, consistent with recollective orienting, whereas a right-lateralized ventrolateral area showed low-confidence activity in both tasks, consistent with monitoring processes. Parietal findings were generally consistent with strength theory, with dorsal areas showing low-confidence activity and ventral areas showing high-confidence activity in both tasks. This dissociation fits with an attentional account of parietal functions during episodic retrieval. The results suggest that both dual-process and strength theories are partly correct, highlighting the need for an integrated model that links to more general cognitive theories to account for observed neural activity during episodic memory retrieval.

scholarly journals Are visual working memory and episodic memory distinct processes? Insight from stroke patients by lesion-symptom mapping.

2021 ◽  
Author(s):  
Selma Lugtmeijer ◽  
Linda Geerligs ◽  
Frank Erik De Leeuw ◽  
Edward H. F. De Haan ◽  
Roy P. C. Kessels
Keyword(s):  
Working Memory ◽  
Episodic Memory ◽  
Visual Working Memory ◽  
Visual Memory ◽  
Right Hemisphere ◽  
Memory Task ◽  
Stroke Patients ◽  
Lesion Symptom Mapping ◽  
Criterion Setting ◽  
The Right

Abstract Working memory and episodic memory are two different processes, although the nature of their interrelationship is debated. As these processes are predominantly studied in isolation, it is unclear whether they crucially rely on different neural substrates. To obtain more insight in this, eighty-one adults with sub-acute ischemic stroke and twenty-nine elderly controls were assessed on a visual working memory task, followed by a surprise subsequent memory test for the same stimuli. Multivariate, atlas- and track-based lesion-symptom mapping (LSM) analyses were performed to identify anatomical correlates of visual memory. Behavioral results gave moderate evidence for independence between discriminability in working memory and subsequent memory, and strong evidence for a correlation in response bias on the two tasks in stroke patients. LSM analyses suggested there might be independent regions associated with working memory and episodic memory. Lesions in the right arcuate fasciculus were more strongly associated with discriminability in working memory than in subsequent memory, while lesions in the frontal operculum in the right hemisphere were more strongly associated with criterion setting in subsequent memory. These findings support the view that some processes involved in working memory and episodic memory rely on separate mechanisms, while acknowledging that there might also be shared processes.

Positive Arousal Enhances the Consolidation of Item Memory

2015 ◽  
Vol 74 (2) ◽  
pp. 91-104 ◽  
Author(s):  
Bo Wang
Keyword(s):  
Episodic Memory ◽  
Memory Consolidation ◽  
Source Memory ◽  
Emotional Arousal ◽  
Theoretical Models ◽  
Memory Test ◽  
Learning Phase ◽  
Item Memory ◽  
Memory Tests ◽  
Immediate Memory

Emotional arousal induced after learning has been shown to modulate memory consolidation. However, it is unclear whether the effect of postlearning arousal can extend to different aspects of memory. This study examined the effect of postlearning positive arousal on both item memory and source memory. Participants learned a list of neutral words and took an immediate memory test. Then they watched a positive or a neutral videoclip and took delayed memory tests after either 25 minutes or 1 week had elapsed after the learning phase. In both delay conditions, positive arousal enhanced consolidation of item memory as measured by overall recognition. Furthermore, positive arousal enhanced consolidation of familiarity but not recollection. However, positive arousal appeared to have no effect on consolidation of source memory. These findings have implications for building theoretical models of the effect of emotional arousal on consolidation of episodic memory and for applying postlearning emotional arousal as a technique of memory intervention.

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