Previous research has demonstrated that individuals with Agenesis of the Corpus Callosum (AgCC), the congenital absence of all or part of the corpus callosum, exhibit a pattern of cognitive and psychosocial deficits, even with a FSIQ in the normal range (FSIQ > 80; Brown & Paul, 2019). This includes a core deficit in their complex reasoning and novel problem-solving (Brown & Paul, 2019), with secondary deficits in capacity to imagine complex emotional/cognitive consequences of potential actions involving others (Young et al, 2019), deficits in emotion

perception (Symington et at., 2010, Bridgman et al 2014), and difficulty with cognitively processing emotions within the context of social interactions (Anderson et al., 2017). This constellation of deficits is likely to also impact moral reasoning. While previous research has demonstrated differences in moral reasoning among other neuropsychological populations such as those with ventromedial prefrontal damage (Moretto et al., 2010) and frontotemporal dementia (Gleichgerrcht et al., 2011), there is no research reported regarding moral judgements in AgCC. This study employed the Moral Dilemmas Scale (Greene, 2001) to compare the moral judgements of persons with AgCC to neurotypical controls. It was predicted that individuals with AgCC would be less contextually nuanced than neurotypical controls in responding to moral dilemmas.

Results consist of data derived from 57 neurotypical control participants (ages 23 to 64 years) recruited from MTurk Cloud and 19 AgCC participants (ages 23 to 77 years) with normal-range FSIQ (>80) drawn from the individuals with AgCC involved with the Human Brain and Cognition Lab at the Travis Research Institute. All participants completed an online version of the Moral Dilemmas Scale (Greene, 2001). The scale consists of 25 dilemmas, of which 11 are considered high-conflict, 7 low-conflict and 7 impersonal. Participants were instructed to read each dilemma and rate whether they found the action to be “appropriate” or not. The high-conflict dilemmas share a similar structure in which responses reflect either a utilitarian or deontological judgement.

“Approve” responses to each of the 3 categories of dilemma were separately tallied for each individual and subjected to a 2group ANOVA. Results revealed the control group produced a significantly higher rate of “appropriate” responses to high-conflict dilemmas than did the individuals with AgCC (F=8.17, p = .006, n2 =.113). However, no significant differences were found among the two groups for results on low (n2 = .013) and impersonal (n2 = .003) dilemmas alone. Furthermore, a X2 analysis of responses to each high conflict dilemma revealed a significant difference in 5 out of the 11 such that more persons with AgCC gave a deontological judgement.

Results suggested that adults with AgCC respond similarly to neurotypical controls with respect to the low conflict or

impersonal dilemmas. However, with respect to high conflict dilemmas, compared to controls they tend to respond in a more deontological than utilitarian basis - that is, based on general principles without contextual nuance. These findings are consistent with the conclusion of Renteria-Vasquez et al. (2021) that persons with AgCC have difficulty imagining the wider implications of present information.

Digit Span has been a core Working Memory task, with extensive research conducted on the Forward and Backward components. The latest revision of the WAIS-IV introduced the Sequencing component, designed to increase the working memory and mental manipulation demands. However, relatively little research has been done to understand how Sequencing can be interpreted in clinical settings, as compared to Forward and Backward. The purpose of this study was to investigate how effectively individual components of the Digit Span task predict performance on four independent neuropsychological measures with high working memory demands.

Subjects included 148 adults (Age: M= 39.22, SD= 13.61; Handedness= 130 right, 10 left and 8 mixed; Males = 88) with refractory epilepsy. Two subjects had primary generalized seizures while 146 subjects had complex partial seizures (EEG Localization: 44 right temporal; 60 left temporal; 24 independent bitemporal; 1 left extratemporal; 17 indeterminant). Dependent variables included the 2.4 second ISI trial of the Paced Auditory Serial Addition Task (PASAT); the sum of correct responses on Trial 1 and List B of the California Verbal Learning Test (CVLT); the DKEFS Tower Test raw score; and completion time on Part B of the Trail Making Test. The independent variables included the individual raw scores for the Forward, Backward and Sequencing components of the WAIS-IV. Hierarchical linear regression was conducted to determine the variance accounted for by each component of the Digit Span and if that variance was redundant or unique. The four dependent variables were analyzed separately with Digits Forward, Backward and Sequencing entered in a single block.

PASAT: The overall model was significant, R2= 0.36. When examining the individual components, Sequencing was the only significant predictor (ß = 0.422, p < 0.001). CVLT: The overall model was significant, R2 = 0.203. When examining the individual components, Sequencing was the only significant predictor (ß = 0.410, p < 0.001). Tower Test: The overall model was significant, R2 = 0.176. When examining the individual components, Sequencing was the only significant predictor (ß = 0.373, p = 0.004). Trail Making: The overall model was significant R2 = 0.315. When examining the individual components both Forward (ß = -0.287, p =0.005) and Sequencing (ß= -0.364, p < 0.001) accounted for a significant amount of the variance.

The combined model for Digit Span accounted for significant amounts of variance in performance on all dependent measures, ranging from 17.6% to 36%. Sequencing accounted for substantially more variance across all examined tasks. On the PASAT, CVLT and Tower Test, the variance accounted for by the components of Digit Span appears to be redundant. However, on Trail Making, both Forward and Sequencing accounted for significant amounts of variance that appear to be independent of one another. What specific task requirement(s) of the Trail Making Test versus the other measures analyzed are accounted for by Forward span is not clear. But this suggests that the individual components of the Digit Span test may measure different things across different tasks.

Determine associations between cognitive outcomes in remote TBI (i.e., at least 6 months post injury), a blood marker of neural degeneration (i.e., Tau), and diffusion kurtosis imaging (DKI) measures (e.g., mean or radial kurtosis). Because DKI imaging is sensitive to the environmental complexity of the imaged area, we sought to investigate regions known to be associated with the cognitive and emotional sequalae of TBI, such as the anterior thalamic radiations, uncinate fasciculus, and the corpus callosum.

41 individuals with mild-to-moderate TBI and a mean age(SD) of 36.1(10.4) years underwent DKI, a blood draw, and neuropsychological assessments. 23 healthy controls (HC) with a mean age(SD) of 35.2(15.2) years underwent the blood draw and assessments, but no imaging. Higher diffusion kurtosis indicates more restricted diffusion, possibly due to greater complexity within the imaged region. Thus, in the context of TBI, DKI can be used as a proxy measurement for biological processes that alter the complexity of imaged environments, such as reactive gliosis. Some people show cognitive deficits long after TBI and this could be associated with increased inflammation and membrane protein aggregates in damaged brain regions. We used bivariate correlations and general linear models to investigate the association of mean kurtosis (MK) in long white matter tracts and Tau (total or phosphorylated) to color-word Stroop scores; a measure of fronto-subcortical function.

In patients with TBI, MK was significantly associated with serum total Tau (TTau) in the right (r=-0.396) and left (r=-0.555) uncinate fasciculus (UF), right (r=-0.402) and left (r=-0.504) anterior thalamic radiations (ATR), and the genu (r=-0.526) and body (r=-0.404) of the corpus callosum (CC). TTau had a significant association with word Stroop scores, F(1,63)=-2.546, p=0.013. However, there was no significant effect of group (i.e., TBI or HC), F(2,63)=-0.426, p=0.672, on cognitive performance. When models were implemented that included both TTau and MK in either the UF or ATR as explanatory variables to predict word Stroop scores, TTau levels and MK in the right UF explained a significant amount of the variance in Stroop performance, F(1,29)=2.215, p=0.025. Further, there was also a significant association between radial kurtosis in the right UF and Stroop word scores (r= 0.366).

Our results show that an indicator of biological complexity (DKI) in cognitively important brain regions is associated with cognitive performance and Tau in patients with remote mild-to-moderate TBI. The UF is a critical fronto-temporal/subcortical pathway that has previously been implicated in the manifestation of executive dysfunction and mood dysregulation in TBI. Tau is an important marker of neurodegeneration implicated in Alzheimer’s disease, Parkinson’s disease, and chronic traumatic encephalopathy (CTE), and DKI is potentially sensitive to markers of neurodegeneration. The association of Tau and DKI measures is novel and shows concordance between blood and brain imaging markers and cognitive performance in patients with mild to moderate TBI.

Accurate processing of facial displays of emotion is critical for effective communication. A robust literature has documented impairment in the ability to recognize facial affect in people with traumatic brain injury (TBI), but research is scarce about memory for facial affect. Disruptions in recognizing and remembering the emotions of others can undermine relationship quality and may result in psychosocial dysfunction. Importantly, the extant literature indicates that facial affect recognition dissociates from other cognitive abilities such that it is likely a distinct neuronal process. Thus, explicit measurement of affect recognition and memory for emotions may be critical for implementing and refining rehabilitation interventions. The present study examined the relationship between recognition and memory for emotions using a novel computerized task and explored its associations with other cognitive abilities.

Participants were adults who were neurologically healthy (n = 31) or had a history of moderate to severe TBI (n = 26). The battery included the novel Assessment of Facial Affect Recognition and Memory (AFARM), Cambridge Face Memory Test (face memory without emotion), Wechsler Test of Adult Reading, Rey Auditory Verbal Learning Test, Judgment of Line Orientation, Oral Symbol Digit Modalities, Digit Span, FAS, Animal Fluency, and the Affect Intensity Measure (experienced emotion). Spearman correlations examined the relationship of AFARM performance with the test battery. Logistic regression models examined whether immediate-delay (ID-EM) and long-delay face emotion-memory (LD-EM) accounted for unique variance in group membership beyond recognition accuracy of facial affect and memory for faces.

AFARM demonstrated relationships with neuropsychological and mood variables in the expected directions across and within groups, with the strongest associations observed for memory for verbal information (rs = .51 to .58) and processing speed (rs = .48 to .57). Consistent with traditional list-learning tests, ID- and LD-EM were highly correlated (r = .85). Experienced affect intensity was inversely associated with ID-EM (r = -.29) and LD-EM (r = -.38) but not with recognition accuracy (r = -.10). Logistic regression examining ID-EM was significant, χ2(3) = 26.05, p < .001, Nagelkerke R2 = .49. ID-EM accounted for unique variance in group status (p = .006; OR = 0.65) after accounting for recognition accuracy and face memory. Similarly, the model examining LD-EM was significant χ2(3) = 27.70, p < .001, Nagelkerke R2 = .43; LD-EM was significant after accounting for other variables (p = .017; OR = 0.69).

The findings are consistent with the hypothesis that memory for emotions represents a unique component of social cognition that is separate from recognition. Accuracy in identifying emotions, face recognition memory, and memory for emotions are strongly related but not wholly redundant processes. Consistent with prior literature, subjective experience of emotion had substantial effects on objective performance tasks, indicating that an individual's intense experience of their own emotions can disrupt sensitivity to the emotions of others. Future research should assess the extent to which memory for emotions relates to psychosocial outcomes such as the quality and quantity of interpersonal relationships.

The prism adaptation (PA) with rightward shifting lenses is a promising rehabilitation technique for left hemispatial neglect. The PA has also been applied in healthy individuals to investigate cognitive mechanism(s) underlining such adaptation. Importantly, studies have suggested that PA may primarily impact the functions of the dorsal or the ventral attentional stream, and we have previously reported that PA to the upward and downward shifting lenses leads to a significant aftereffect in vertical line bisection task. However, this post-adaptation effect, similarly to that seen in the horizontal plane, might have been modified by the presence of the vertical pseudoneglect healthy participants often experience prior to PA. Thus, the aim of this study was to test this hypothesis.

30 right-handed healthy adults (age M=22,4) performed a computerized line bisection (LB) in vertical and horizontal condition. The bisections were performed twice: before and after PA procedure. Participants took experimental procedure three times, each in at least 24 h of break, each time in one of three conditions of shifting lenses; down, up, control. Both LB tasks (vertical and horizontal) consisted of 24 lines, each centered on 23" touch screen. The participants were asked to find the middle of the line. Throughout the experiment, participants were comfortably seated with their head positioned on a chinrest. Participants were fitted with prismatic goggles that deviated their visual field by 10 degrees. For the adaptation we used the Peg-the-mole procedure consisting of 120 pointing movements.

To assess the effect of the vertical PA on landmark judgments we performed a repeated measures ANOVA with direction of PA (upward/downward), the condition of LB (vertical/ horizontal) and pre- vs post adaptation as a between-subjects factor. This analysis revealed a main effect of the direction of PA (p< 0.001) and a main effect of condition (p< 0.001). Overall, however, only adaptation in up-shifting lenses led to significant aftereffects (p<0.05). Further, when we excluded participants who did not exhibited horizontal pseudoneglect in preadaptation LB, the effect of PA in downshifting PA emerged in vertical LB (p<0.05). Further, this group also exhibited the aftereffect of PA in up-shifting lenses for the horizontal (p<0.01) and the vertical LB (p<0.05). Additionally, these participants exhibited a congruent tendency after upward and downward PA, and tended to allocate their attention more upward and rightward.

The results of this study confirm that the vertical PA evokes a visuo-spatial bias. Moreover, the PA aftereffect seems to be modified by the presence of the pre-adaptation pseudoneglect. Whereas the mechanism inducing this bias is not fully known, it might be explained in light of the interhemispheric activation-inhibition balance. Both the upward and downward PA may primarily lead to activation of the posterior regions of the right hemisphere, and this activation may result with the upward and rightward bias in the LB task. However, future research with neuroimaging techniques is needed to test this hypothesis.

The locus coeruleus (LC) plays a key role in cognitive processes such as attention, executive function, and memory. The LC has been identified as an early site of tau accumulation in Alzheimer’s disease (AD). LC neurons are thought to survive, albeit with limited functionality, until later stages of the disease, though how exactly this limited functionality impacts cognition through the course of AD is still poorly understood. We investigated the interactive effects of an imaging biomarker of the LC and AD-related cerebrospinal fluid (CSF) biomarkers on attention, executive function, and memory.

We recruited 67 older adults from the San Diego community (mean age=74.52 years; 38 cognitively normal, 23 with mild cognitive impairment, and 6 with probable AD). Participants had LC-sensitive magnetic resonance imaging (MRI) used to obtain a measure of LC signal relative to surrounding tissue, with lower LC signal possibly indicating limited functionality. Participants also underwent a lumbar puncture to obtain CSF measurements of amyloid-beta 42 (Ab42) and phosphorylated tau (p-tau). We calculated the p-tau/Ab42 ratio, which is positively correlated with AD progression. Finally, participants were administered a comprehensive neuropsychological battery, and cognitive composites were created for attention (Digit Symbol, Digit Span Forward, Trails A), executive function (Digit Span Backward, Trails B, Color-Word Inhibition Switching), and two measures of verbal memory [learning (CVLT List A 1-5, Logical Memory Immediate Recall) and delay (CVLT Long Free Recall, Logical Memory Delayed Recall)]. Four multiple linear regressions modeled the relationship between each composite with age, gender, education, p-tau/Ab42, average LC contrast, and interactions between average LC contrast and p-tau/Ab42. For models that were statistically significant, additional regressions were assessed to determine which segment of the LC (caudal, middle, rostral) contributed to the relationship.

Our model predicted attention (p=.001, R2=.298) with main effects of average LC signal, p-tau/Ab42, and LC by p-tau/Ab42 interaction. Follow-up regressions revealed that each LC segment contributes to this relationship. Our model predicted executive function (p=.006, R2=.262) with a main effect of average LC signal and LC by p-tau/Ab42 interaction. Follow-up regressions revealed that this relationship was limited to the caudal and middle LC. Our models predicted both verbal learning (p<.001, R2=.512) and delayed memory (p<.001, R2=.364); both with main effects of gender and education. Follow-up regressions revealed that the rostral LC signal interacts with p-tau/Ab42 to predict both verbal learning and delayed memory. For all interactions, those with low p-tau/Ab42 exhibited a positive relationship between LC signal and cognition, whereas those with higher p-tau/Ab42 showed a negative relationship.

MR-assessed LC signal relates to attention, executive function, and verbal learning and memory in a manner that depends on CSF levels of p-tau and Ab42. The relationship between LC signal and cognition is positive at low levels and negative at higher levels of p-tau/Ab42. If lower LC signal indicates reduced integrity, these findings imply that MR-assessed LC signal may be a more meaningful marker of AD progression in earlier stages of the disease. Alternatively, this measure may capture a different underlying mechanism depending on tau and amyloid biomarker status.

There is a pressing need for sensitive, non-invasive indicators of cognitive impairment in those at risk for Alzheimer’s disease (AD). One group at an increased risk for AD is APOEε4 carriers. One study found that cognitively normal APOEε4 carriers are less likely to produce low frequency (i.e., less common) words on semantic fluency tasks relative to non-carriers, but this finding has not yet been replicated. This study aims to replicate these findings within the Wake Forest ADRC clinical core population, and examine whether these findings extend to additional semantic fluency tasks.

This sample includes 221 APOEε4 non-carriers (165 females, 56 males; 190 White, 28 Black/African American, 3 Asian; Mage = 69.55) and 79 APOEε4 carriers (59 females, 20 males; 58 White, 20 Black/African American, 1 Asian; Mage = 65.52) who had been adjudicated as cognitively normal at baseline. Semantic fluency data for both the animal task and vegetable task was scored for total number of items as well as mean lexical frequency (attained via the SUBTLEXus database). Demographic variables and additional cognitive variables (MMSE, MoCA, AMNART scores) were also included from the participants’ baseline visit.

APOEε4 carriers and non-carriers did not differ on years of education, AMNART scores, or gender (ps > 0.05). APOEε4 carriers were slightly younger and included more Black/African American participants (ps < 0.05). Stepwise linear regression was used to determine the variance in total fluency score and mean lexical frequency accounted for by APOEε4 status after including relevant demographic variables (age, sex, race, years of education, and AMNART score). As expected, demographic variables accounted for significant variance in total fluency score (p < 0.0001). Age accounted for significant variance in total fluency score for both the animal task (ß = -0.32, p <0.0001) and the vegetable task (ß = -0.29, p < 0.0001), but interestingly, not the lexical frequency of words produced. After accounting for demographic variables, APOEε4 status did not account for additional variance in lexical frequency for either fluency task (ps > 0.05). Interestingly, APOEε4 status was a significant predictor of total words for the vegetable semantic fluency task only (ß = 0.13, p = 0.01), resulting in a model that accounted for more variance (R2 = 0.25, F(6, 292) = 16.11, p < 0.0001) in total words than demographic variables alone (R2 = 0.23, F(5, 293) = 17.75, p < 0.0001).

Unsurprisingly, we found that age, AMNART, and education were significant predictors of total word fluency. One unexpected finding was that age did not predict the lexical frequency - that is - regardless of age, participants tended to retrieve words of the same lexical frequency, which stands in contrast to the notion that retrieval efficiency of infrequent words declines with age. With regard to APOEε4, we did not replicate existing work demonstrating differences in lexical frequency and semantic fluency tasks for ε4 carriers and non-carriers; possibly due to differences in the demographic characteristics of the sample.