Role of the hippocampus and orbitofrontal cortex during the disambiguation of social cues in working memory

Human social interactions are complex behaviors requiring the concerted effort of multiple neural systems to track and monitor the individuals around us. Cognitively, adjusting our behavior on the basis of changing social cues such as facial expressions relies on working memory and the ability to disambiguate, or separate, the representations of overlapping stimuli resulting from viewing the same individual with different facial expressions. We conducted an fMRI experiment examining the brain regions contributing to the encoding, maintenance, and retrieval of overlapping identity information during working memory using a delayed match-to-sample task. In the overlapping condition, two faces from the same individual with different facial expressions were presented at sample. In the nonoverlapping condition, the two sample faces were from two different individuals with different expressions. fMRI activity was assessed by contrasting the overlapping and nonoverlapping conditions at sample, delay, and test. The lateral orbitofrontal cortex showed increased fMRI signal in the overlapping condition in all three phases of the delayed match-to-sample task and increased functional connectivity with the hippocampus when encoding overlapping stimuli. The hippocampus showed increased fMRI signal at test. These data suggest that lateral orbitofrontal cortex helps encode and maintain representations of overlapping stimuli in working memory, whereas the orbitofrontal cortex and hippocampus contribute to the successful retrieval of overlapping stimuli. We suggest that the lateral orbitofrontal cortex and hippocampus play a role in encoding, maintaining, and retrieving social cues, especially when multiple interactions with an individual need to be disambiguated in a rapidly changing social context in order to make appropriate social responses.     

Semantic diversity: A measure of semantic ambiguity based on variability in the contextual usage of words

Semantic ambiguity is typically measured by summing the number of senses or dictionary definitions that a word has. Such measures are somewhat subjective and may not adequately capture the full extent of variation in word meaning, particularly for polysemous words that can be used in many different ways, with subtle shifts in meaning. Here, we describe an alternative, computationally derived measure of ambiguity based on the proposal that the meanings of words vary continuously as a function of their contexts. On this view, words that appear in a wide range of contexts on diverse topics are more variable in meaning than those that appear in a restricted set of similar contexts. To quantify this variation, we performed latent semantic analysis on a large text corpus to estimate the semantic similarities of different linguistic contexts. From these estimates, we calculated the degree to which the different contexts associated with a given word vary in their meanings. We term this quantity a word’s semantic diversity (SemD). We suggest that this approach provides an objective way of quantifying the subtle, context-dependent variations in word meaning that are often present in language. We demonstrate that SemD is correlated with other measures of ambiguity and contextual variability, as well as with frequency and imageability. We also show that SemD is a strong predictor of performance in semantic judgments in healthy individuals and in patients with semantic deficits, accounting for unique variance beyond that of other predictors. SemD values for over 30,000 English words are provided as supplementary materials.     

Moral Clarity in Narratives Elicits Greater Cooperation than Moral Ambiguity

In disciplines such as moral psychology and media theory, investigations of moral clarity versus ambiguity in narratives are increasingly important. Untested mechanisms have been proposed for how moral clarity and ambiguity might affect audiences. Based on literature regarding joint action and coordinated experiences, we reason that morally clear narratives elicit coordinated responses across audience members, which should increase within-group cooperation. By contrast, we reason that morally ambiguous narratives elicit divergent, uncoordinated responses across audience members, and this experience decreases cooperation. We conducted three independent studies (one using short text narratives, one using feature-length films, and one using morally and emotionally neutral stimuli). Results indicate that moral clarity is indeed associated with subsequently higher levels of group cooperation than moral ambiguity, and the effect cannot be attributed to changes in affect or moral priming.     

Can Giving Clients a Choice in Food Selection Help to Meet Their Nutritional Needs?: Investigating a Novel Food Bank Approach for Asylum Seekers

The aim of this research was to investigate whether a foodbank working directly with people seeking asylum and incorporating client choice, located in Melbourne Australia, can meet the nutritional requirements of asylum seekers. A structured process of direct observation was used to document each item selected from the foodbank in a single basket. The food baskets of 116 asylum seekers, all over the age of 18, who were wholly reliant on the foodbank were analysed for nutritional content. Analysis revealed that an average basket was deficient in almost all micronutrients including vitamins A, C, D and E, folate, calcium and zinc. Baskets were found to have higher than recommended levels of sodium and fat. Despite the foodbank allowing clients to individually select the food they wish to consume, the food baskets remained nutritionally inadequate. This may be due the structure of the foodbank, the nature of relying on community donations of food and complexities surrounding healthy food choice among asylum seekers. Providing choice around food acquisition is one way to promote dignity in the refugee determination process; however, this may not be the best way to provide a nutritionally adequate diet. In addition to donor guidelines that highlight the need for nutritionally and culturally appropriate foods, further supplementary nutritional education may be required to encourage healthy food choices where they exist.     

Expanding the evidence: Developments and innovations in clinical practice,training and competency within voice and communication therapy for trans and gender diverse people

Background: Speech and language therapists (SLTs) deliver voice and communication therapy for trans and gender diverse people to facilitate authentic vocal and communicative expression. Davies, Papp, and Antoni (2015) have provided a comprehensive review of the literature, with recommendations for good clinical care. Several areas highlighted as gaps in the research were identified by the current authors as ones in which evidence is expanding.

Aims: To demonstrate 1) an expansion of the evidence base in particular innovations in voice group therapy for trans women and trans men; 2) the importance of delivering voice and communication therapy as part of a complete approach to trans and gender diverse health care; and (3) developments in training and competency in the UK.

Method: Data were drawn from three small-scale projects, two surveys, and one audit.

Measurements: Data from survey and audits and pre- and post-group acoustic measures of and client self-perceptual measures, including the Transsexual Voice Questionnaire (TVQ^MtF); a client-generated set of questions for trans men; and the migration of vocal identity map, adapted from Narrative Therapy practices.

Results: Positive outcomes for both pitch measures and client perception were recorded. Audit and survey data provided evidence of developments in training and competency in the UK.

Conclusion: Evidence supports group therapy as a successful approach for trans individuals across a number of parameters of voice and self-perception. Voice group protocols for both trans men and trans women should take account of the social context within which to explore relational presence and authentic voice. SLTs within gender identity clinics provide voice and communication as part of a broader pathway of care, alongside sharing professional knowledge and skills. Current UK developments are documented as indicators of positive responses to the growth in the number of SLTs seeking to develop specialist skills within this field.     

3-minute smartphone-based and tablet-based psychomotor vigilance tests for the assessment of reduced alertness due to sleep deprivation

The psychomotor vigilance test (PVT) is widely used to measure reduced alertness due to sleep loss. Here, two newly developed, 3-min versions of the psychomotor vigilance test, one smartphone-based and the other tablet-based, were validated against a conventional 10-min laptop-based PVT. Sixteen healthy participants (ages 22–40; seven males, nine females) completed a laboratory study, which included a practice and a baseline day, a 38-h total sleep deprivation (TSD) period, and a recovery day, during which they performed the three different versions of the PVT every 3 h. For each version of the PVT, the number of lapses, mean response time (RT), and number of false starts showed statistically significant changes across the sleep deprivation and recovery days. The number of lapses on the laptop was significantly correlated with the numbers of lapses on the smartphone and tablet. The mean RTs were generally faster on the smartphone and tablet than on the laptop. All three versions of the PVT exhibited a time-on-task effect in RTs, modulated by time awake and time of day. False starts were relatively rare on all three PVTs. For the number of lapses, the effect sizes across 38 h of TSD were large for the laptop PVT and medium for the smartphone and tablet PVTs. These results indicate that the 3-min smartphone and tablet PVTs are valid instruments for measuring reduced alertness due to sleep deprivation and restored alertness following recovery sleep. The results also indicate that the loss of sensitivity on the 3-min PVTs may be mitigated by modifying the threshold defining lapses.     

The influence of action video game playing on eye movement behaviour during visual search in abstract,in-game and natural scenes

Action game playing has been associated with several improvements in visual attention tasks. However, it is not clear how such changes might influence the way we overtly select information from our visual world (i.e. eye movements). We examined whether action-video-game training changed eye movement behaviour in a series of visual search tasks including conjunctive search (relatively abstracted from natural behaviour), game-related search, and more naturalistic scene search. Forty nongamers were trained in either an action first-person shooter game or a card game (control) for 10 hours. As a further control, we recorded eye movements of 20 experienced action gamers on the same tasks. The results did not show any change in duration of fixations or saccade amplitude either from before to after the training or between all nongamers (pretraining) and experienced action gamers. However, we observed a change in search strategy, reflected by a reduction in the vertical distribution of fixations for the game-related search task in the action-game-trained group. This might suggest learning the likely distribution of targets. In other words, game training only skilled participants to search game images for targets important to the game, with no indication of transfer to the more natural scene search. Taken together, these results suggest no modification in overt allocation of attention. Either the skills that can be trained with action gaming are not powerful enough to influence information selection through eye movements, or action-game-learned skills are not used when deciding where to move the eyes.     

Intervening response events between identification targets do not always turn repetition benefits into repetition costs

When there is a relatively long interval between two successive stimuli that must be detected or localized, there are robust processing costs when the stimuli appear at the same location. However, when two successive visual stimuli that must be identified appear at the same location, there are robust same location costs only when the two stimuli differ in their responses; otherwise same location benefits are observed. Two separate frameworks that inhibited attentional orienting and episodic integration, respectively, have been proposed to account for these patterns. Recent findings hint at a possible reconciliation between these frameworks—requiring a response to an event in between two successive visual stimuli may unmask same stimulus and same location costs that are otherwise obscured by episodic integration benefits in identification tasks. We tested this hybrid account by integrating an intervening response event with an identification task that would otherwise generate the boundary between same location benefits and costs. Our results showed that the intervening event did not alter the boundary between location repetition benefits and costs nor did it reliably or unambiguously reverse the common stimulus-response repetition benefit. The findings delimit the usefulness of an intervening event for disrupting episodic integration, suggesting that effects from intervening response events are tenuous. The divide between attention and feature integration accounts is delineated in the context of methodological and empirical considerations.     

Failures of cognitive control or attention? The case of stop-signal deficits in schizophrenia

We used Bayesian cognitive modelling to identify the underlying causes of apparent inhibitory deficits in the stop-signal paradigm. The analysis was applied to stop-signal data reported by Badcock et al. (Psychological Medicine 32: 87-297, 2002) and Hughes et al. (Biological Psychology 89: 220-231, 2012), where schizophrenia patients and control participants made rapid choice responses, but on some trials were signalled to stop their ongoing response. Previous research has assumed an inhibitory deficit in schizophrenia, because estimates of the mean time taken to react to the stop signal are longer in patients than controls. We showed that these longer estimates are partly due to failing to react to the stop signal (“trigger failures”) and partly due to a slower initiation of inhibition, implicating a failure of attention rather than a deficit in the inhibitory process itself. Correlations between the probability of trigger failures and event-related potentials reported by Hughes et al. are interpreted as supporting the attentional account of inhibitory deficits. Our results, and those of Matzke et al. (2016), who report that controls also display a substantial although lower trigger-failure rate, indicate that attentional factors need to be taken into account when interpreting results from the stop-signal paradigm.