Minimum message length inference of secondary structure from protein coordinate data

Motivation: Secondary structure underpins the folding pattern and architecture of most proteins. Accurate assignment of the secondary structure elements is therefore an important problem. Although many approximate solutions of the secondary structure assignment problem exist, the statement of the problem has resisted a consistent and mathematically rigorous definition. A variety of comparative studies have highlighted major disagreements in the way the available methods define and assign secondary structure to coordinate data

STOP SHOUTING AT ME: The Influence of Case and Self-Referencing on Explicit and Implicit Memory

Evidence suggests that physical changes in word appearance, such as those written in all capital letters, and the use of effective encoding strategies, such as self-referential processing, improves memory. In this study we examined the extent both physical changes in word appearance (case) and encoding strategies engaged at study influence memory as measured by both explicit and implicit memory measures. Participants studied words written in upper and lower case under three encoding conditions (self-reference, semantic control, case judgment), which was followed by an implicit (word stem completion) and then an explicit (item and context) memory test. There were two primary results. First, analyses indicated a case enhancement effect for item memory where words written in upper case were better remembered than lower case, but only when participants were prompted to attend to the case of the word. Importantly, this case enhancement effect came at a cost to context memory for words written in upper case. Second, self-referencing increased explicit memory performance relative to control, but there was no effect on implicit memory. Overall, results suggest an item-context memory trade-off for words written in upper case, highlighting a potential downside to writing in all capital letters, and further, that both physical changes to the appearance of words and differing encoding strategies have a strong influence on explicit, but not implicit memory

The Effect of Emotional Faces on the Attentional Blink in Younger and Older Adults

The attentional blink occurs when detection of a second target (T2) is impaired when it occurs between 180 to 450 ms after the first target (T1) in a rapid serial visual presentation (RSVP). The attentional blink can be affected by relevant emotional stimuli, like emotional faces, such that an emotional T1 enhances the attentional blink, and an emotional T2 attenuates it. However, not all studies use the same type of face stimuli, and there is debate over whether schematic and photo-realistic faces are processed in the same way. Furthermore, the effect of emotion on the attentional blink should differ with age, given the tendency for younger adults to display a negativity bias and for older adults to display a positivity effect. Very little research has been conducted on the attentional blink with emotional stimuli in older adults. In fact, the effect of emotional faces, which are arguably more salient stimuli than other stimuli such as emotional words, on the attentional blink has not been investigated in older adults. Therefore, this study sought to examine the impact of emotional faces on the attentional blink in younger and older adults using photo-realistic faces with angry, happy, and neutral expressions as targets in a RSVP. Although older adults did perform worse overall, there were no age differences in the effect of emotion on the attentional blink. Angry faces, as well as happy faces to a limited extent, increased the attentional blink when they served as T1. Neither the angry or happy faces as T2 were able to attenuate the blink. Given that emotional faces affected the attentional blink at T1 but not at T2, it may be the case that the emotional expressions served to maintain attention, rather than to capture it. Future studies are necessary to test this idea, as well as to more directly test the differential effect of emotional photorealistic and schematic faces on the attentional blink

The Effect of Emotional Faces on the Attentional Blink in Younger and Older Adults

The attentional blink occurs when detection of a second target (T2) is impaired when it occurs between 180 to 450 ms after the first target (T1) in a rapid serial visual presentation (RSVP). The attentional blink can be affected by relevant emotional stimuli, like emotional faces, such that an emotional T1 enhances the attentional blink, and an emotional T2 attenuates it. However, not all studies use the same type of face stimuli, and there is debate over whether schematic and photo-realistic faces are processed in the same way. Furthermore, the effect of emotion on the attentional blink should differ with age, given the tendency for younger adults to display a negativity bias and for older adults to display a positivity effect. Very little research has been conducted on the attentional blink with emotional stimuli in older adults. In fact, the effect of emotional faces, which are arguably more salient stimuli than other stimuli such as emotional words, on the attentional blink has not been investigated in older adults. Therefore, this study sought to examine the impact of emotional faces on the attentional blink in younger and older adults using photo-realistic faces with angry, happy, and neutral expressions as targets in a RSVP. Although older adults did perform worse overall, there were no age differences in the effect of emotion on the attentional blink. Angry faces, as well as happy faces to a limited extent, increased the attentional blink when they served as T1. Neither the angry or happy faces as T2 were able to attenuate the blink. Given that emotional faces affected the attentional blink at T1 but not at T2, it may be the case that the emotional expressions served to maintain attention, rather than to capture it. Future studies are necessary to test this idea, as well as to more directly test the differential effect of emotional photorealistic and schematic faces on the attentional blink

Investigating the Impact of Explicit and Implicit Memory on Decisions to Approach or Avoid Social Targets

Research shows many social factors influence decisions to approach or avoid social targets, but less research has directly investigated the impact of cognitive factors like memory. The goal of the current study was to investigate how both explicit and implicit memory for initial impressions influence approach/avoidance decisions and to test whether mouse-tracking could be used to measure the impact of implicit memory. In addition, this study examined the extent memory strength influenced the impact of memory on approach/avoidance decisions. In this investigation, participants viewed social targets represented by a picture and a trait-implying behavior and formed positive or negative impressions of targets viewed once (single presentation) or twice (double presentation). Participants completed explicit memory measures followed by an approach/avoidance task using a computer mouse as the mouse trajectory was tracked as a possible indicator of implicit memory. Results provided continued support for the impact of explicit memory on approach/avoidance decisions, such that correctly remembering positive impressions led to approach decisions and correctly remembering negative impressions led to avoidance decisions. Additionally, results showed a stronger impact of explicit memory for double- than single-presentation targets, suggesting that stronger memories have a larger effect on approach/avoidance decisions. The results did not support the impact of implicit memory on approach/avoidance decisions nor use of mouse-tracking to measure the impact of implicit memory. These findings add to the limited research exploring the impact of memory on approach/avoidance decisions, but continued work is needed to better understand memory and its influence on social processes

The Impact of Emotional Faces on Younger and Older Adults’ Attentional Blink

The attentional blink (AB) is the impaired ability to detect a second target (T2) when it follows shortly after the first (T1) among distractors in a rapid serial visual presentation (RSVP). Given questions about the automaticity of age differences in emotion processing, the current study examined whether emotion cues differentially impact the AB elicited in older and younger adults. Twenty-two younger (18-22 years) and 22 older adult participants (62-78 years) reported on the emotional content of target face stimulus pairs embedded in a RSVP of scrambled-face distractor images. Target pairs included photo-realistic faces of angry, happy, and neutral expressions. The order of emotional and neutral stimuli as T1 or T2 and the degree of temporal separation within the RSVP systematically varied. Target detection accuracy was used to operationalize the AB. Although older adults displayed a larger AB than younger adults, no age differences emerged in the impact of emotion on the AB. Angry T1 faces increased the AB of both age groups. Neither emotional T2 attenuated the AB. Negative facial expressions held the attention of younger and older adults in a comparable manner, exacerbating the AB and supporting a negativity bias instead of a positivity effect in older adults

Examining the influence of brain stimulation to the medial prefrontal cortex on the self‐reference effect in memory

Abstract Past work shows that processing information in relation to the self improves memory which is known as the self‐reference effect in memory. Other work suggests that transcranial direct current stimulation (tDCS) can also improve memory. Given recent research on self‐reference context memory effects (improved memory for contextual episodic details associated with self‐referential processing), we were interested in examining the extent stimulation might increase the magnitude of the self‐reference context memory effect. In this investigation, participants studied objects superimposed on different background scenes in either a self‐reference or other‐reference condition while receiving either active or sham stimulation to the dorsal medial prefrontal cortex (dmPFC), a cortical region known to support self‐reference context memory effects. Participants then completed a memory test that assessed item memory (have you seen this object before?) and context memory (with which background scene was this object paired?). Results showed a self‐reference context memory effect driven by enhanced memory for stimuli processed in the self‐reference compared to the other‐reference condition across all participants (regardless of stimulation condition). tDCS, however, had no effect on memory. Specifically, stimulation did not increase the magnitude of the self‐reference context memory effect under active compared to sham stimulation. These results suggest that stimulation of the dmPFC at encoding may not add to the memory benefits induced by self‐referential processing suggesting a boundary condition to tDCS effects on memory

Lower constraint testing enhances the testing effect for some contextual details but not others

Abstract Introduction Retrieval practice has been shown to be an effective means of learning new information, a memory phenomenon known as the testing effect or the retrieval practice effect. Some work suggests that the magnitude of the testing effect can be enhanced when the test used for retrieval practice uses fewer cues to retrieve previously studied information. It is unclear, however, whether such testing benefits extend to peripheral contextual details associated with studied materials (e.g., location where stimuli appear, font color in which items are presented, etc.). In this experiment, we examine both item memory (i.e., memory for the studied items) and context memory under conditions where the intervening test offers fewer cues (i.e., lower constraint) compared to more cues (higher constraint) to better understand item and context memory testing effects. Methods Participants first studied word pairs presented in one of eight locations as well as in either red or green font color. Then, in the re‐exposure phase, participants processed materials in two types of intervening tests (lower constraint and a higher constraint test) as well as in a restudy condition, before a final memory test. Results For item memory, results showed that memory was better in the lower constraint testing condition compared to both the higher constraint testing condition as well as the restudy (control) condition. For context memory, results indicated improved memory for location context under lower constraint testing compared to both higher constraint testing and restudy conditions. There was no difference in memory, however, for color context across all conditions. Conclusion Overall, these findings suggest that providing fewer cues to aid retrieval in the intervening test can induce better memory for both items as well as some contextual details