Discriminative functions and over-training as class-enhancing determinants of meaningful stimuli

2014 ◽  
Vol 102 (1) ◽  
pp. 47-65 ◽  
Author(s):  
Robert W. Travis ◽  
Lanny Fields ◽  
Erik Arntzen
Keyword(s):  
Meaningful Stimuli ◽  
Discriminative Functions

Greater Visual Working Memory Capacity for Visually Matched Stimuli When They Are Perceived as Meaningful

2021 ◽  
Vol 33 (5) ◽  
pp. 902-918 ◽  
Author(s):  
Isabel E. Asp ◽  
Viola S. Störmer ◽  
Timothy F. Brady
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Visual Information ◽  
Memory Performance ◽  
Working Memory Capacity ◽  
Visual Complexity ◽  
Memory Capacity ◽  
Subjective Perception ◽  
Neural Delay ◽  
Meaningful Stimuli

Abstract Almost all models of visual working memory—the cognitive system that holds visual information in an active state—assume it has a fixed capacity: Some models propose a limit of three to four objects, where others propose there is a fixed pool of resources for each basic visual feature. Recent findings, however, suggest that memory performance is improved for real-world objects. What supports these increases in capacity? Here, we test whether the meaningfulness of a stimulus alone influences working memory capacity while controlling for visual complexity and directly assessing the active component of working memory using EEG. Participants remembered ambiguous stimuli that could either be perceived as a face or as meaningless shapes. Participants had higher performance and increased neural delay activity when the memory display consisted of more meaningful stimuli. Critically, by asking participants whether they perceived the stimuli as a face or not, we also show that these increases in visual working memory capacity and recruitment of additional neural resources are because of the subjective perception of the stimulus and thus cannot be driven by physical properties of the stimulus. Broadly, this suggests that the capacity for active storage in visual working memory is not fixed but that more meaningful stimuli recruit additional working memory resources, allowing them to be better remembered.

scholarly journals Revealing the neural networks that extract conceptual gestalts from continuously evolving or changing semantic contexts

2019 ◽  
Author(s):  
Francesca M. Branzi ◽  
Gina F. Humphreys ◽  
Paul Hoffman ◽  
Matthew A. Lambon Ralph
Keyword(s):  
Right Hemisphere ◽  
Internal Representation ◽  
Semantic Integration ◽  
Multivariate Techniques ◽  
List Type ◽  
Semantic Cognition ◽  
Narrative Processing ◽  
Time Space ◽  
Context Integration ◽  
Meaningful Stimuli

AbstractReading a book, understanding the news reports or any other behaviour involving the processing of meaningful stimuli requires the semantic system to have two main features: being active during an extended period of time and flexibly adapting the internal representation according to the changing environment. Despite being key features of many everyday tasks, formation and updating of the semantic “gestalt” are still poorly understood. In this fMRI study we used naturalistic stimuli and task manipulations to identify the neural network that forms and updates conceptual gestalts during time-extended integration of meaningful stimuli. Univariate and multivariate techniques allowed at drawing a distinction between networks that are crucial for the formation of a semantic gestalt (meaning integration) and those that instead are important for linking incoming cues about the current context (e.g., time, space cues) into a schema representation. Specifically, we revealed that time-extended formation of the conceptual gestalt was reflected in the neurocomputations of the anterior temporal lobe accompanied by multi-demand areas and hippocampus, with a key role of brain structures in the right hemisphere. This “semantic gestalt network” was strongly recruited when an update of the current semantic representation was required during narrative processing. A distinct fronto-parietal network, instead, was recruited for context integration, independently from the meaning associations between words (semantic coherence). Finally, in contrast with accounts positing that the default-mode-network (DMN) may have a crucial role in semantic cognition, our findings revealed that DMN activity was sensitive to task difficulty, but not to semantic integration. The implications of these findings for neurocognitive models of semantic cognition and the literature on narrative processing are discussed.HighlightsfMRI revealed areas and networks for semantic integration during narrative readingATL has a key role in the formation of the conceptual gestaltIFG, pMTG and dAG reflect the update of the conceptual gestaltLeft AG (Mid-PGp) has a key role in context integration

scholarly journals Associative learning rapidly establishes neuronal representations of upcoming behavioral choices in crows

2015 ◽  
Vol 112 (49) ◽  
pp. 15208-15213 ◽  
Author(s):  
Lena Veit ◽  
Galyna Pidpruzhnykova ◽  
Andreas Nieder
Keyword(s):  
Behavioral Flexibility ◽  
Single Session ◽  
Sensory Stimuli ◽  
Paired Associates ◽  
Sustained Activity ◽  
Behavioral Choices ◽  
Corvus Corone ◽  
Memory Representations ◽  
Meaningful Stimuli ◽  
Novel Associations

The ability to form associations between behaviorally relevant sensory stimuli is fundamental for goal-directed behaviors. We investigated neuronal activity in the telencephalic area nidopallium caudolaterale (NCL) while two crows (Corvus corone) performed a delayed association task. Whereas some paired associates were familiar to the crows, novel associations had to be learned and mapped to the same target stimuli within a single session. We found neurons that prospectively encoded the chosen test item during the delay for both familiar and newly learned associations. These neurons increased their selectivity during learning in parallel with the crows' increased behavioral performance. Thus, sustained activity in the NCL actively processes information for the upcoming behavioral choice. These data provide new insights into memory representations of behaviorally meaningful stimuli in birds, and how such representations are formed during learning. The findings suggest that the NCL plays a role in learning arbitrary associations, a cornerstone of corvids’ remarkable behavioral flexibility and adaptability.

Arousal threshold in the rat determined by “meaningful” stimuli

1972 ◽  
Vol 7 (2) ◽  
pp. 205-215 ◽  
Author(s):  
Henry Van Twyver ◽  
William Garrett
Keyword(s):  
Arousal Threshold ◽  
Meaningful Stimuli

Autokinesis for Meaningful Stimuli and the Effect of Set

1973 ◽  
Vol 36 (3) ◽  
pp. 979-986 ◽  
Author(s):  
Martin S. Lindauer ◽  
Lawrence O. Gostin
Keyword(s):  
Apparent Movement ◽  
Frame Of Reference ◽  
Slow Movement ◽  
Ambiguous Stimulus ◽  
Meaningful Stimuli

An autokinetic effect for 6 meaningful stimuli was measured in terms of speed, acceleration, and change in direction and as a function of stimulus labels suggesting sets for fast, neutral, or slow movement. Apparent movement was found for all stimuli on each of the three types of movement measures; the change-in-direction measure significantly differentiated the six stimuli; and the fast set of labels significantly influenced accelerations. A frame of reference conception of the perception of apparent movement, based on familiarity and expectation, which is likely to occur under ambiguous stimulus circumstances, was discussed.

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