ABSTRACT
This paper describes the SocialVidStim-a database of video stimuli available to the scientific community depicting positive and negative social evaluative and neutral statements. The SocialVidStim comprises 53 diverse individuals reflecting the demographic makeup of the USA, ranging from 9 to 41 years old, saying 20-60 positive and 20-60 negative social evaluative statements (e.g. 'You are a very trustworthy/annoying person'), and 20-60 neutral statements (e.g. 'The sky is blue'), totaling 5793 videos post-production. The SocialVidStim are designed for use in behavioral and functional magetic resonance imaging paradigms, across developmental stages, in diverse populations. This study describes stimuli development and reports initial validity and reliability data on a subset videos (N = 1890) depicting individuals aged 18-41 years. Raters perceive videos as expected: positive videos elicit positively valenced ratings, negative videos elicit negatively valenced ratings and neutral videos are rated as neutral. Test-retest reliability data demonstrate intraclass correlations in the good-to-excellent range for negative and positive videos and the moderate range for neutral videos. We also report small effects on valence and arousal that should be considered during stimuli selection, including match between rater and actor sex and actor believability. The SocialVidStim is a resource for researchers and we offer suggestions for using the SocialVidStim in future research.
Subject(s)
Cognitive Neuroscience , Humans , Child , Adolescent , Young Adult , Adult , Reproducibility of Results , ArousalABSTRACT
The neuropeptide orexin/hypocretin is implicated in sleep and arousal, energy expenditure, reward, affective state and cognition. Our previous work using diurnal Nile grass rats (Arvicanthis niloticus) found that orexin mediates the effects of environmental light, particularly daytime light intensity, on affective and cognitive behaviours. The present study further investigated how daytime light intensity affects the central orexin system in male and female grass rats. Subjects were housed for 4 weeks in 12:12 hr dim light:dark (50 lux, dimLD) or in 12:12 hr bright light:dark cycle (1000 lux, brightLD). Day/night fluctuations in some orexin measures were also assessed. Despite similar hypothalamic prepro-orexin mRNA expression across all conditions, there were significantly more orexin-immunoreactive neurons, larger somata, greater optical density or higher orexin A content at night (ZT14) than during the day (ZT2), and/or in animals housed in brightLD compared to dimLD. Grass rats in brightLD also had higher cisternal CSF levels of orexin A. Furthermore, orexin receptor OX1R and OX2R proteins in the medial prefrontal cortex were higher in brightLD than dimLD males, but lower in brightLD than dimLD females. In the CA1 and dorsal raphe nucleus, females had higher OX1R than males without any significant effects of light condition, and OX2R levels were unaffected by sex or light. These results reveal that daytime light intensity alters the central orexin system of both male and female diurnal grass rats, sometimes sex-specifically, and provides insight into the mechanisms underlying how daytime light intensity impacts orexin-regulated functions.
ABSTRACT
Reasons for prospective remembering and forgetting after traumatic brain injury (TBI) were investigated using Ellis' (1996) five phases of prospective memory as a framework. Participants were 38 individuals with severe TBI and 34 controls. Participants self-rated their perceived reasons for prospective remembering and forgetting using section C of the Comprehensive Assessment of Prospective Memory (CAPM). Significant others also rated participants using the same scale. Analyses were conducted to examine the effect of group membership (TBI or control) on reported reasons for prospective remembering and forgetting. Findings highlighted the TBI group's difficulties with encoding, performance interval, and execution phases of prospective remembering.
