Visual and Semantic Representations Predict Subsequent Memory in Perceptual and Conceptual Memory Tests

It is generally assumed that the encoding of a single event generates multiple memory representations, which contribute differently to subsequent episodic memory. We used functional magnetic resonance imaging (fMRI) and representational similarity analysis to examine how visual and semantic representations predicted subsequent memory for single item encoding (e.g., seeing an orange). Three levels of visual representations corresponding to early, middle, and late visual processing stages were based on a deep neural network. Three levels of semantic representations were based on normative observed (“is round”), taxonomic (“is a fruit”), and encyclopedic features (“is sweet”). We identified brain regions where each representation type predicted later perceptual memory, conceptual memory, or both (general memory). Participants encoded objects during fMRI, and then completed both a word-based conceptual and picture-based perceptual memory test. Visual representations predicted subsequent perceptual memory in visual cortices, but also facilitated conceptual and general memory in more anterior regions. Semantic representations, in turn, predicted perceptual memory in visual cortex, conceptual memory in the perirhinal and inferior prefrontal cortex, and general memory in the angular gyrus. These results suggest that the contribution of visual and semantic representations to subsequent memory effects depends on a complex interaction between representation, test type, and storage location.

Varieties of abstract concepts and their grounding in perception or action

For a very long time, theorizing in the cognitive sciences was dominated by the assumption that abstract concepts, which lack a perceivable referent, can only be handled by amodal or verbal linguistic representations. In the last years, however, refined grounded cognition theories emphasizing the importance of emotional and introspective information for abstract concepts, in addition to verbal associations and sensorimotor information, have received increasing support. Here, we review theoretical accounts of the structure and neural basis of conceptual memory and evaluate them in light of recent empirical evidence with regard to the processing of concrete and abstract concepts. Based on this literature review, we argue that abstract concepts should not be treated as a homogenous conceptual category, whose meaning is established by one single specific type of representation. Instead, depending on the feature composition, there are different subgroups of abstract concepts, including those with strong relations to vision or action, which are represented in the visual and motor brain systems similar to concrete concepts. The reviewed findings with regard to concrete and abstract concepts can be accommodated best by hybrid theories of conceptual representation assuming an interaction between modality-specific, multimodal and amodal hub areas.

Visual and semantic representations predict subsequent memory in perceptual and conceptual memory tests

It is generally assumed that the encoding of a single event generates multiple memory representations, which contribute differently to subsequent episodic memory. We used fMRI and representational similarity analysis (RSA) to examine how visual and semantic representations predicted subsequent memory for single item encoding (e.g., seeing an orange). Three levels of visual representations corresponding to early, middle, and late visual processing stages were based on a deep neural network. Three levels of semantic representations were based on normative Observed (“is round”), Taxonomic (“is a fruit”), and Encyclopedic features (“is sweet”). We identified brain regions where each representation type predicted later Perceptual Memory, Conceptual Memory, or both (General Memory). Participants encoded objects during fMRI, and then completed both a word-based conceptual and picture-based perceptual memory test. Visual representations predicted subsequent Perceptual Memory in visual cortices, but also facilitated Conceptual and General Memory in more anterior regions. Semantic representations, in turn, predicted Perceptual Memory in visual cortex, Conceptual Memory in the perirhinal and inferior prefrontal cortex, and General Memory in the angular gyrus. These results suggest that the contribution of visual and semantic representations to subsequent memory effects depends on a complex interaction between representation, test type, and storage location.

Structural Priming Is Supported By Different Components Of Non-Declarative Memory: Evidence From Priming Across The Lifespan

Structural priming is the tendency to repeat syntactic structure across sentences and can be divided into short-term (prime to immediately following target) and long-term (across an experimental session) components. This study investigates how non-declarative memory could support both the transient, short-term and the persistent, long-term structural priming effects commonly seen in the literature. We propose that these characteristics are supported by different subcomponents of non-declarative memory: Perceptual and conceptual non-declarative memory respectively. Previous studies have suggested that these subcomponents age differently, with only conceptual memory showing age-related decline. By investigating how different components of structural priming vary across the lifespan, we aim to elucidate how non-declarative memory supports two seemingly different components of structural priming. In 167 participants ranging between 20 and 85 years old, we find no change in short-term priming magnitude and performance on perceptual tasks, whereas both long-term priming and conceptual memory vary with age. We suggest therefore that the two seemingly different components of structural priming are supported by different components of non-declarative memory. These findings have important implications for theoretical accounts of structural priming.