Models to predict naturalness and image quality for images containing three memory colors: sky, grass, and skin

When evaluating the image quality, people mostly would like to concentrate on the color appearance of memory objects, representing the naturalness and reality of the image scene. Generally, an image with objects which have perfect memory colors reproduction will give natural and harmonious feelings. Many previous studies had proved the critical role of naturalness in image quality assessment, but it was still tough to scale the image naturalness precisely. In this study, natural images with blue sky, green grass, and skin colors were selected and partially rendered to develop the model of preference and naturalness of typical memory colors. A psychophysical experiment was conducted to collect the visual data of these images. Afterward, the psychophysical data were used to build the preference models and naturalness models, respectively. The models were then compared with previous studies. Results showed that the new models could accurately predict the preference and naturalness of target memory colors.

What do laboratory-forgetting paradigms tell us about use-inspired forgetting?

Directed forgetting is a laboratory task in which subjects are told to remember some information and forget other information. In directed forgetting tasks, participants are able to exert intentional control over which information they retain in memory and which information they forget. Forgetting in this task appears to be mediated by intentional control of memory states in which executive control mechanisms suppress unwanted information. Recognition-induced forgetting is another laboratory task in which subjects forget information. Recognizing a target memory induces the forgetting of related items stored in memory. Rather than occurring due to volitional control, recognition-induced forgetting is an incidental by-product of activating items in memory. Here we asked whether intentional directed forgetting or unintentional recognition-induced forgetting is a more robust forgetting effect. While there was a correlation between forgetting effects when the same subjects did both tasks, the magnitude of recognition-induced forgetting was larger than the magnitude of directed forgetting. These results point to practical differences in forgetting outcomes between two commonly used laboratory-forgetting paradigms.

EXPRESS: The Influence of Social Anxiety-Provoking Contexts on Context Reinstatement Effects

The context reinstatement (CR) effect is the finding that target stimuli are better remembered when presented in the same context as during initial encoding, compared to a different context. It remains unclear, however, whether emotional features of the context affect this memory benefit. In two experiments, we investigated whether the anxiety-provoking nature of a context scene might influence the CR benefit to memory. During encoding, participants viewed target faces paired with scenes validated as either highly anxiety-provoking or not, half of which contained other faces embedded within the scene. During retrieval, target faces were presented again with either the same or a new context scene. In Experiment 1, the expected CR benefit was observed when the contexts were low-anxiety scenes or high-anxiety scenes without embedded faces. In contrast, the CR benefit was absent when the contexts were high-anxiety scenes containing embedded faces. In Experiment 2, to determine whether the presence of embedded faces or anxiety level of scenes drove the reduced CR effect, we included an additional context type: low-anxiety scenes with embedded faces. Once again, the CR benefit was absent only when the context scene was highly anxiety-provoking with embedded faces: reinstating this context type failed to benefit memory for targets. Results suggest that the benefit to target memory via reinstating a context depends critically on emotional characteristics of the reinstated context.

Unravelling Quasi-Continuous 14C Profiles by Laser Ablation AMS

ABSTRACTLaser ablation (LA) accelerator mass spectrometry (AMS) is a novel method for rapid online radiocarbon (14C) analysis of carbonates. The quasi-continuous 14C profiles obtained with this technique demand a customized data evaluation protocol to relate the acquired 14C data to the analyzed sample. We take into account the mixing effects due to the minimal counting (integration) time of the AMS, the finite width of the laser beam and the gas washout of the ablation volume. Thereby we mathematically describe our LA setup with a system function that acts on the produced CO/CO2 (COX) from the sample resulting in a mixing of the 14C profiles obtained by AMS analysis. Furthermore, we analyze the long-term target memory effect in the gas ion source and establish a routine for correction. The correction routine is tested with a stalagmite comprising a growth stop that is analyzed at different scanning velocities indicating that only the slow scanning velocity can provide the necessary resolution to determine the width of the growth stop of 365 μm.

Cortical Mechanisms for Reaches Versus Saccades: Progression of Effector-Specificity Through Target Memory to Movement Planning and Execution

Effector-specific cortical mechanisms can be difficult to establish using fMRI, in part because low time resolution might temporally conflate different signals related to target representation, motor planning, and motor execution. Here, we used an event-related fMRI protocol and a cue-separation paradigm to temporally separate these three major sensorimotor stages for saccades vs. reaches. In each trial, subjects (N=12) 1) briefly viewed a target 4-7° left or right of midline fixation on a touchscreen, followed by an 8 second delay (effector-independent target memory phase), 2) were instructed by an auditory cue to perform a reach or a saccade, followed by a second delay of 8 seconds (effector-specific planning phase), and finally 3) were prompted to move by reaching-to-touch or performing a saccade towards the remembered target (effector-specific execution phase). Our analysis of saccade and reach activation (vs. a non-spatial control task) revealed modest effector-agnostic target memory activity (left AG, bilateral mIPS) followed by independent effector parietofrontal sites and time courses during the motor components of the task, specifically: more medial (pIPS, mIPS, M1, and PMd) activity during both reach planning and execution, and more lateral (mIPS, AG, and FEF) activity only during saccade execution. These motor activations were bilateral, with a left (contralateral) preference for reach. A conjunction analysis revealed that left mIPS and right AG, PCu, SPOC, FEF/PMv and LOTC showed activation for both saccades and reaches. Overall, effector-preference contrasts (reach vs. saccade) revealed significantly more parietofrontal activation for reaches than saccades during both planning and execution, with the exception of FEF. Cross-correlation of reach, saccade, and reach-saccade activation through time revealed correlated activation both within and across effectors in each hemisphere, but with a tendency toward higher correlations in the right hemisphere, especially between the eye and hand. These results demonstrate substantially independent but temporally correlated cortical networks for human eye, hand, and eye-hand control, that follow explicit spatiotemporal rules for effector-specific timing, medial-lateral distribution, and hemispheric lateralization.

Post-reactivation new learning impairs and updates human episodic memory through dissociable processes

Learning of competing information after reactivation has the potential to disrupt memory reconsolidation and thus impair a consolidated memory. Yet this effect has rarely been detected in episodic memory. By introducing an additional retrieving cue to the target memory, the current study detected significant impairment on the reactivated episodic memory, in addition to an integration of new information to the old memory. However, while the integration effect followed the time window of reconsolidation disruption, the impairment effect did not. MEG measurements further revealed alpha power change during reactivation and post-reactivation learning which showed different correlation patterns with the integration and impairment effects, confirming that the two effects relied on different processes. Therefore, post-reactivation new learning disrupts episodic memory but not through reconsolidation disruption. Further findings that the impairment effect was correlated with participants’ voluntary inhibition ability suggest an inhibition-based memory updating process underlying post-reactivation new learning.