scholarly journals Neural Correlates of Task-related Refixation Behaviour

2019 ◽  
Author(s):  
Radha Nila Meghanathan ◽  
Cees van Leeuwen ◽  
Marcello Giannini ◽  
Andrey R. Nikolaev
Keyword(s):  
Working Memory ◽  
Memory Load ◽  
Top Down ◽  
Working Memory Load ◽  
Factors Affecting ◽  
Task Relevance ◽  
Two Factors ◽  
Related Potentials ◽  
Task Irrelevant ◽  
Saccade Preparation

AbstractInformation uptake during scene viewing under free viewing conditions is crucially determined by the scanning plan. This plan is determined both by top-down and bottom-up factors. To capture top-down factors affecting saccade planning, we compared EEG between first fixations and refixations on items varying in task-relevance. First fixations and refixations impose different working memory costs because first fixations involve encoding of new items whereas refixations involve rehearsal of existing items in working memory. These memory requirements also differ with the task-relevance of the item being encoded. Together, these two factors of task-relevance and memory processes related to refixation behavior would affect saccade planning. In a visual task involving search and memorization of multiple targets, we compared saccade-related potentials (SRPs) between first fixations and refixations for task-relevant (target) and task-irrelevant (distractor) items. We assessed the interval preceding a saccade away from the fixation of interest. Studying this presaccadic interval revealed how mechanisms related to saccade preparation are affected by task-relevance and refixation behavior. We found higher SRP amplitudes for first fixations than refixations over the occipital region for task-relevant items only. Our findings indicate that saccade planning is modulated by both task-relevance of an item and working memory load.

scholarly journals No evidence of the effect of cognitive load on self-paced cycling performance

2018 ◽  
Author(s):  
Darias Holgado ◽  
Mikel Zabala ◽  
Daniel Sanabria
Keyword(s):  
Heart Rate ◽  
Working Memory ◽  
Cognitive Load ◽  
Power Output ◽  
Memory Load ◽  
Load Condition ◽  
Anecdotal Evidence ◽  
Top Down ◽  
Working Memory Load ◽  
Back Task

Objectives: to test the hypothesis that cognitive load (low vs. high load) during a 20 min self-paced cycling exercise affects physical performance.Design: A pre-registered (https://osf.io/qept5/), randomized, within-subject design experiment.Methods: 28 trained and experienced male cyclists completed a 20 min self-paced cycling time-trial exercise in two separate sessions, corresponding to two working memory load conditions: 1-back or 2-back. We measured power output, heart rate, RPE and mental fatigue.Results: Bayes analyses revealed extreme evidence for the 2-back task being more demanding than the 1-back task, both in terms of accuracy (BF10 = 4490) and reaction time (BF =1316). The data only showed anecdotal evidence for the alternative hypothesis for the power output (BF10= 1.52), moderate evidence for the null hypothesis for the heart rate (BF10 = 0.172), anecdotal evidence for RPE (BF10 = 0.72) and anecdotal evidence for mental fatigue (BF10 = 0.588).Conclusions: Our data seem to challenge the idea that self-paced exercise is regulated by top-down processing, given that we did not show clear evidence of exercise impairment (at the physical, physiological and subjective levels) in the high cognitive load condition task with respect to the low working memory load condition. The involvement of top-down processing in self-pacing the physical effort, however, cannot be totally discarded. Factors like the duration of the physical and cognitive tasks, the potential influence of dual-tasking, and the participants’ level of expertise, should be taken into account in future attempts to investigate the role of top-down processing in self-pace exercise

Visual working memory load does not affect the overall stimulus processing time in visual search

2019 ◽  
Vol 73 (3) ◽  
pp. 330-343
Author(s):  
Keyun Xin ◽  
Zhi Li
Keyword(s):  
Working Memory ◽  
Visual Search ◽  
Visual Working Memory ◽  
Processing Time ◽  
Memory Load ◽  
Response Selection ◽  
Working Memory Load ◽  
Stimulus Processing ◽  
Load Effect ◽  
Factors Affecting

The dual-task paradigm is widely used in studying the interaction between visual search and working memory. A number of studies showed that holding items in working memory delays the overall response time (RT) in visual search, but it does not affect the efficiency of search (i.e., the slope of the RT × set size function). Why the memory load merely affects the overall RT? Some researchers proposed that this load-effect on overall RT may be caused by factors that only affect response selection processes, while others argued that it may reflect the effect of visual working memory load on visual search. This study investigated the two competing hypotheses by measuring the threshold stimulus exposure duration (TSED) for successfully fulfilling a search task. Experiment 1 replicated the large overall RT difference with the RT method but only found a small though reliable overall TSED difference with the TSED method. Experiment 2, with better controls, found no TSED difference by manipulating the visual working memory load. Experiment 3 showed that the TSED is not influenced by processes in the response selection stage. The present findings suggest that the overall stimulus processing time in visual search is not affected by visual working memory load and that the effect of memory load on overall RT is largely due to factors affecting response selection alone.

Visual Search Facilitation in Repeated Displays Depends on Visuospatial Working Memory

2012 ◽  
Vol 59 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Angela A. Manginelli ◽  
Franziska Geringswald ◽  
Stefan Pollmann
Keyword(s):  
Working Memory ◽  
Visual Search ◽  
Control Experiment ◽  
Memory Load ◽  
Contextual Cueing ◽  
Long Term Memory ◽  
Visuospatial Working Memory ◽  
Working Memory Load ◽  
Memory Resources

When distractor configurations are repeated over time, visual search becomes more efficient, even if participants are unaware of the repetition. This contextual cueing is a form of incidental, implicit learning. One might therefore expect that contextual cueing does not (or only minimally) rely on working memory resources. This, however, is debated in the literature. We investigated contextual cueing under either a visuospatial or a nonspatial (color) visual working memory load. We found that contextual cueing was disrupted by the concurrent visuospatial, but not by the color working memory load. A control experiment ruled out that unspecific attentional factors of the dual-task situation disrupted contextual cueing. Visuospatial working memory may be needed to match current display items with long-term memory traces of previously learned displays.

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