The memory-delay saccade task is often used to separate visual and motor responses in oculomotor structures such as the superior colliculus (SC), with the assumption that these same responses would sum with a short delay during immediate "reactive" saccades to visual stimuli. However, it is also possible that additional signals (suppression, delay) alter visual and/or motor response in the memory delay task. Here, we compared the spatiotemporal properties of visual and motor responses of the SC neurons recorded during both the reactive and memory-delay tasks in two head-unrestrained monkeys. Comparing tasks, visual (aligned with target onset) and motor (aligned on saccade onset) responses were highly correlated across neurons, but the peak response of visual neurons and peak motor responses (of both visuomotor (VM) and motor neurons) were significantly higher in the reactive task. Receptive field organization was generally similar in both tasks. Spatial coding (along a Target-Gaze (TG) continuum) was also similar, with the exception that pure motor cells showed a stronger tendency to code future gaze location in the memory delay task, suggesting a more complete transformation. These results suggest that the introduction of a trained memory delay alters both the vigor and spatial coding of SC visual and motor responses, likely due to a combination of saccade suppression signals and greater signal noise accumulation during the delay in the memory delay task.
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http://dx.doi.org/10.3389/fncir.2018.00074 | DOI Listing |
Alzheimers Dement
January 2025
Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Huddinge, Stockholm, Sweden.
Background: We sought to characterize the cognitive profile among individuals with mild cognitive impairment with Lewy bodies (MCI-LB) to help guide future clinical criteria.
Methods: Systematic review and meta-analysis included MCI-LB studies with cognitive data from PubMed, Embase, Web of Science, and PsycINFO (January 1990 to March 2023). MCI-LB scores were compared to controls, MCI due to Alzheimer's disease (MCI-AD), and dementia with Lewy bodies (DLB) groups with random-effects models.
Am J Lifestyle Med
January 2025
Department of Psychology, Central Michigan University, Mt. Pleasant, MI, USA (GTR, JAP, HO).
Acute exercise is linked to memory improvement. Several mediators may influence the effect of exercise such as the type of exercise (aerobic exercise, muscle stretching). The primary aim was to analyze memory outcomes after a 20-min bout of aerobic exercise or muscle stretching.
View Article and Find Full Text PDFMemory
January 2025
Department of Psychology, University of Portsmouth, Portsmouth, UK.
Many witnesses are intoxicated at crime scenes, yet little is known of their ability to accurately describe perpetrators to police. We therefore explored the impact of alcohol on delayed verbal face recall across two experiments. Participants were administered an alcoholic or non-alcoholic beverage prior to viewing either one or two unfamiliar female faces, which they described from memory the following day while in a sober state.
View Article and Find Full Text PDFProg Neurobiol
January 2025
Institute for Brain and Behavior Amsterdam, Department of Experimental and Applied Psychology, Vrije Universiteit Amsterdam, the Netherlands. Electronic address:
It is well established that when we hold more content in working memory, we are slower to act upon part of that content when it becomes relevant for behavior. Here, we asked whether this load-related slowing is due to slower access to the sensory representations held in working memory (as predicted by serial working-memory search), or by a reduced preparedness to act upon those sensory representations once accessed. To address this, we designed a visual-motor working-memory task in which participants memorized the orientation of two or four colored bars, of which one was cued for reproduction.
View Article and Find Full Text PDFNeural Comput
January 2025
Department of Psychological and Brain Sciences, Indiana University Bloomington, Bloomington, IN 47405, U.S.A.
How episodic memories are formed in the brain is a continuing puzzle for the neuroscience community. The brain areas that are critical for episodic learning (e.g.
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