Self-Reported Home Program Adherence by People With Aphasia: Exploring Construct Validity.

PURPOSE: The study purpose was to compare the practice patterns captured by self-reported logbook data and those recorded by a computerized home program application. The current study is part of a larger single-case research design study aimed at investigating the effect of logbook use on home program adherence in people with aphasia poststroke. METHOD: Data from six adults with chronic aphasia with interest in improving their reading were used in this secondary analysis. Participants completed reading comprehension therapy tasks using a mobile application and tablet. The activities were self-directed and designed for people with aphasia to complete independently. We created an aphasia-friendly logbook based on best practices to allow participants to record their estimated total minutes practiced. Participants received instructions to practice the reading therapy application 80 min a day 7 days a week for the duration of the study. We calculated the difference in the total time per day recorded by each participant to the application data collected. RESULTS: All participants used the logbook to record their practice. There was a strong relationship between self-reported logbook practice and application-recorded practice for four of the six participants. Individual differences were noted and explored. CONCLUSION: These results suggest that some people with aphasia can use logbooks with aphasia-friendly modifications to accurately estimate the amount of practice completed outside of therapy sessions.

Online Aphasia Groups: Navigating Issues of Voice and Identity.

PURPOSE: Participation in aphasia groups is associated with increased communication, reduced feelings of social isolation, and increased quality of life. Despite the growing popularity of online aphasia groups, little is known about how to manage conversation in this format. We examined online aphasia book club sessions to examine how the facilitator supported group members' participation in conversation. METHOD: Interactional sociolinguistic discourse analysis was used to analyze the behaviors and actions of the facilitator and group members. Qualitative data for this study were drawn from four recorded online aphasia book club sessions held through a university's free aphasia clinic on the Zoom web-conferencing platform. RESULTS: Sociolinguistic discourse analysis revealed strategic facilitator behaviors that served to (a) give members with varying levels of verbal language abilities voice, (b) foreground or background aspects of voice, and (c) minimize her own voice to promote interactional symmetry between herself and group members. CONCLUSIONS: Identity formed the backdrop for facilitators' actions when leading online groups, guiding decisions about who got to talk, when, for how long, through what modality, and about what topics. A better understanding of the interactions that occur online, such as how to develop and protect the identities of group members, could equip facilitators with the tools necessary for facilitating positive, engaging aphasia therapy groups online.

Conversation Analysis of Texting Exchanges in Aphasia.

PURPOSE: Conversation analysis (CA) is an established method that has been used to understand how aphasia impacts the conversational success of individuals with aphasia (IWAs) and their conversation partners. This article demonstrates CA as a valuable analytic tool for studying text messaging in aphasia to better understand the specific co-constructed actions of IWAs and their partners as they engage in this communication modality. METHOD: CA was applied to transcribed text message data from eight IWAs. Conversational structures present in face-to-face interactions were identified, segmented, and explicated with a focus on how IWAs and their partners negotiate interaction in this medium. RESULTS: Three key elements of CA, namely, sequential organization, repair, and topic negotiation, were identified within the texting exchanges of participants and their texting partners and compared with existing CA studies on electronic messaging in adults without brain injury. CONCLUSIONS: Findings suggest a multitude of strategies that IWAs and their partners used to meet both transactional and interactional goals of communication. Understanding gained from applying CA to texting in aphasia can inform the development of interventions that improve access to digital communication for IWAs.

Transactional Success in the Texting of Individuals With Aphasia.

PURPOSE: Text messaging is a pervasive form of communication in today's digital society. Our prior research indicates that individuals with aphasia text, but they vary widely in how actively they engage in texting, the types of messages they send, and the number of contacts with whom they text. It is reported that people with aphasia experience difficulties with texting; however, the degree to which they are successful in conveying information via text message is unknown. This study describes the development of a rating scale that measures transactional success via texting and reports on the transactional success of a sample of 20 individuals with chronic aphasia. The relationships between texting transactional success and aphasia severity, texting confidence, and texting activity are explored. METHOD: Performance on a texting script was evaluated using a three-category rating in which turns elicited from participants with aphasia received a score of 0 (no transaction of message), 1 (partial transaction), or 2 (successful transaction). Internal consistency was assessed using Cronbach's alpha. Interrater reliability was determined using intraclass correlation coefficient and Krippendorff's alpha. RESULTS: Although preliminary, results suggest adequate internal consistency and strong interrater reliability. Texting transactional success on the script response items was significantly correlated with overall aphasia severity and severity of reading and writing deficits, but there was no relationship between transactional success and texting confidence or overall texting activity. CONCLUSIONS: This study describes initial efforts to develop a rating scale of texting transactional success and to evaluate the validity of scores derived from this measure. Information from a texting transactional success measure could inform treatment that aims to improve electronic messaging in people with aphasia.

Texting Behaviors of Individuals With Chronic Aphasia: A Descriptive Study.

PURPOSE: In today's digital world, text messaging is one of the most widely used ways that people stay connected. Although it is reported that people with aphasia experience difficulties with texting, little information is available about how they actually do text. This study reports texting behaviors, such as the number and type of messages sent and contacts individuals with aphasia have. The relationships between texting behaviors and aphasia severity, including writing impairments, and social connectedness are explored. METHOD: Twenty participants were sampled from an ongoing randomized clinical trial investigating an electronic writing treatment for aphasia (Clinical Trials Identifier: NCT03773419). Participants provided consent for researchers to view and analyze texts sent and received over a 7-day period immediately prior to the assessment. Participants' text messages were recorded, transcribed verbatim, and coded. RESULTS: Over the 7-day period, the number of contacts with whom participants texted ranged from one to 18. The mean number of text messages exchanged was 40.3 (SD = 48.24), with participants sending an average of 15.4 (SD = 23.45) texts and receiving an average of 24.9 (SD = 29.44) texts. Participants varied in the types of texts sent; some had a larger proportion of initiated texts, while others drafted more responses, either simple or elaborative in nature. There was no correlation between the total number of texting exchanges and the Western Aphasia Battery-Revised Aphasia Quotient (rs = .13, p = . 29) or the Western Aphasia Battery-Revised Writing subtest (rs = .05, p = .42). There was also no correlation between the total number of texting exchanges and scores on measures of social connectedness. CONCLUSIONS: Texting behaviors of individuals with aphasia are widely variable. Demographics, severity of aphasia and writing, and social connectedness may not predict texting behaviors. Therefore, it is clinically important to explore the unique texting abilities and preferences of each individual to meet their communication and social participation goals. Supplemental Material https://doi.org/10.23641/asha.14669664.

Web-based Oral Reading for Language in Aphasia (Web ORLA®): A pilot randomized control trial.

OBJECTIVE: To investigate an intensive asynchronous computer-based treatment delivered remotely with clinician oversight to people with aphasia. DESIGN: Single-blind, randomized placebo-controlled trial. SETTING: Free-standing urban rehabilitation hospital. PARTICIPANTS: Adults with aphasia (at least six months post-onset). INTERVENTIONS: Experimental treatment was Web ORLA® (Oral Reading for Language in Aphasia) which provides repeated choral and independent reading aloud of sentences with a virtual therapist. Placebo was a commercially available computer game. Participants were instructed to practice 90 minutes/day, six days/week for six weeks. MAIN MEASURES: Change in Language Quotient of the Western Aphasia Battery-Revised from pre-treatment to post-treatment and pre-treatment to six weeks following the end of treatment. RESULTS: 32 participants (19 Web ORLA®, 13 Control) completed the intervention and post-treatment assessment; 27 participants (16 Web ORLA®, 11 Control) completed the follow-up assessment six weeks after treatment had ended. Web ORLA® treatment resulted in significant improvements in language performance from pre-treatment to immediately post-treatment (X = 2.96; SD = 4.32; P < 0.01; ES = 0.68) and from pre-treatment to six weeks following the end of treatment (X = 4.53; SD = 3.16; P < 0.001; ES = 1.43). There was no significant difference in the gain from pre-treatment to post-treatment for the Web ORLA® versus Control groups. However, the Web ORLA® group showed significantly greater gains at the six-week follow-up than the control group (X = 2.70; SD = 1.01; P = 0.013; ES = 1.92). CONCLUSION: Results provide evidence for improved language outcomes following intensive, web-based delivery of ORLA® to individuals with chronic aphasia. Findings underscore the value of combining clinician oversight with the flexibility of asynchronous practice.

Acute NMDA receptor antagonism impairs working memory performance but not attention in rats-Implications for the NMDAr hypofunction theory of schizophrenia.

Cognitive deficits in schizophrenia, which include impairments in working memory and attention, represent some of the most disabling symptoms of this complex psychiatric condition, and lack effective treatments. NMDA receptor (NMDAr) hypofunction is a strong candidate mechanism underlying schizophrenia pathophysiology, and has been modeled preclinically using acute administration of NMDAr antagonists to rodents to investigate biological mechanisms underpinning cognitive dysfunction. However, whether and how NMDAr hypofunction specifically influences all affected cognitive domains is unclear. Here we studied the effects of the NMDAr antagonist MK-801 (dizocilpine) on tasks of attention and working memory in rats using automated touchscreen chambers. Adult male Wistar rats were trained to perform the trial-unique nonmatching to location (TUNL) task of spatial working memory, or the 5-choice serial reaction time task (5CSRTT) of attention. Once trained, rats received injection of vehicle (saline) or low-dose MK-801 (0.06 mg/kg sc) 10 min prior to commencing test sessions. MK-801 significantly impaired working memory, as evidenced by reduced performance accuracy on the TUNL task (p < .0001), compared with vehicle. However, we found no significant effects on attentional processing or perseveration on the 5CSRTT. Additional measures indicated that MK-801 impaired behavioral flexibility in the TUNL task, and decreased response inhibition in both tasks. Using the automated touchscreen system to measure different cognitive functions under the same testing environment, we demonstrate that spatial working memory, response inhibition, and behavioral flexibility are more vulnerable to NMDAr hypofunction than attentional processing. This may have implications for the NMDAr hypofunction hypothesis of schizophrenia. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

High flavivirus structural plasticity demonstrated by a non-spherical morphological variant.

Previous flavivirus (dengue and Zika viruses) studies showed largely spherical particles either with smooth or bumpy surfaces. Here, we demonstrate flavivirus particles have high structural plasticity by the induction of a non-spherical morphology at elevated temperatures: the club-shaped particle (clubSP), which contains a cylindrical tail and a disc-like head. Complex formation of DENV and ZIKV with Fab C10 stabilize the viruses allowing cryoEM structural determination to ~10 Å resolution. The caterpillar-shaped (catSP) Fab C10:ZIKV complex shows Fabs locking the E protein raft structure containing three E dimers. However, compared to the original spherical structure, the rafts have rotated relative to each other. The helical tail structure of Fab C10:DENV3 clubSP showed although the Fab locked an E protein dimer, the dimers have shifted laterally. Morphological diversity, including clubSP and the previously identified bumpy and smooth-surfaced spherical particles, may help flavivirus survival and immune evasion.

Pharmacological Mechanisms Involved in Sensory Gating Disruption Induced by (±)-3,4-Methylene- Dioxymethamphetamine (MDMA): Relevance to Schizophrenia.

Sensory gating deficits have been demonstrated in schizophrenia, but the mechanisms involved remain unclear. In the present study, we used disruption of paired-pulse gating of evoked potentials in rats by the administration of (±)-3,4-methylene-dioxymethamphetamine (MDMA) to study serotonergic and dopaminergic mechanisms involved in auditory sensory gating deficits. Male Sprague-Dawley rats were instrumented with cortical surface electrodes to record evoked potential changes in response to pairs of 85dB tones (S1 and S2), 500msec apart. Administration of MDMA eliminated the normal reduction in the amplitude of S2 compared to S1, representing disruption of auditory sensory gating. Pretreatment of the animals with the dopamine D1 receptor antagonist, SCH23390, the dopamine D2 receptor antagonist, haloperidol, the serotonin (5-HT)1A receptor antagonist, WAY100635, or the 5-HT2A receptor antagonist, ketanserin, all blocked the effect of MDMA, although the drugs differentially affected the individual S1 and S2 amplitudes. These data show involvement of both dopaminergic and serotonergic mechanisms in disruption of auditory sensory gating by MDMA. These and previous results suggest that MDMA targets serotonergic pathways, involving both 5-HT1A and 5-HT2A receptors, leading to dopaminergic activation, involving both D1 and D2 receptors, and ultimately sensory gating deficits. It is speculated that similar interactive mechanisms are affected in schizophrenia.

Facilitator Behaviors Leading to Engagement and Disengagement in Aphasia Conversation Groups.

Purpose Researchers have identified features of successful aphasia conversation groups and clinician behaviors leading to engagement and group cohesion. There has been less focus in the literature on facilitator behaviors that hinder participation or result in disengagement. This study aims to explore the behaviors of graduate student facilitators that contribute to and detract from engagement in aphasia conversation groups. Method Data were drawn from 4 conversation group sessions from 2 different university settings. Groups included 1 graduate student facilitator and 3 or more persons with aphasia. Sociolinguistic discourse analysis was applied to transcripts of group sessions. Results Three broad patterns detailing facilitator behaviors were identified. Several facilitator actions contributing to engagement were noted, including strategic use of topic elicitors, multimodal communication supports, and techniques to avoid interactional asymmetry. Behaviors associated with participant disengagement were also noted across sessions, including restricted discourse behaviors and difficulty managing the competing needs of participants. Engagement and disengagement were the product of several coordinating actions of the facilitator and group members that together influenced participation in conversation. Conclusion Results suggest that novice facilitators exhibit behaviors that contribute to and detract from participant engagement in aphasia conversation groups. Findings, discussed within the context of the literature on well-managed groups, highlight the skill required in managing the needs of participants with aphasia and knowing how and when to employ clinician-led strategies.

Attention in individuals with aphasia: Performance on the Conners' Continuous Performance Test - 2nd edition.

Studies suggest that individuals with aphasia present with impairments in attention. However, most research has been conducted with small sample sizes using experimental protocols that lack established psychometric properties. We examined the attention performance of 114 individuals with chronic post-stroke aphasia using a standardised, norm-referenced assessment of attention, the Conners' Continuous Performance Test-II (CPT-II; Conners, C. K. (2000). Conners' Continuous Performance Test II. Toronto: Multi-Health Systems Inc). Participants completed the CPT-II and the Western Aphasia Battery-Revised (WAB-R; Kertesz, A. (2007). Western Aphasia Battery-Revised. San Antonio, TX: PsychCorp). As a group, variable performance on selected CPT-II measures was observed. Participants demonstrated impairments on omissions (48.2%) and hit reaction time (67.5%), with 11.4% demonstrating atypically slow performance and over half of the sample (56.1%) performing atypically fast. The Confidence Index, a summary score, was also within the impaired range for the majority of participants. However, there were also measures in which a greater percentage of participants demonstrated performance within normal limits. Using the WAB-R Aphasia Quotient (AQ) as a measure of severity, there was significantly worse performance in participants with more severe (AQ < 50) compared to less severe (AQ ≥ 50) aphasia. No significant differences in attention were identified between participants with fluent versus non-fluent aphasia. The CPT-II is a feasible measure for persons with aphasia, which may assist in identifying attention performance deficits that potentially affect language.

Attention Process Training-3 to improve reading comprehension in mild aphasia: A single-case experimental design study.

People with aphasia frequently present with nonlinguistic deficits, in addition to their compromised language abilities, which may contribute to their problems with reading comprehension. Treatment of attention, working memory and executive control may improve reading comprehension in individuals with aphasia, particularly those with mild reading problems. This single-case experimental design study evaluated the efficacy of Attention Process Training-3, an intervention combining direct attention training and metacognitive facilitation, for improving reading comprehension in individuals with mild aphasia. A multiple baseline design across six participants was used to evaluate treatment effects. The primary outcome measure was a maze reading task. Cognitive measures were administered pre- and post-treatment. Visual inspection of graphed maze reading performance data indicated a basic effect between APT-3 and improved maze reading for three of the six participants. Quantitative analyses, using Tau-U, corroborated findings identified through visual analysis. The overall effect size was significant (Tau = .48, p = .01). Results suggest that APT-3 has the potential to improve reading in individuals with aphasia, but that it may be more efficacious under certain conditions. Treatment and participant variables, including intensity of treatment and metacognitive strategy usage, are discussed as potential influences on participants' responsiveness to APT-3.

Optimising recovery in aphasia: Learning following exposure to a single dose of computer-based script training.

Purpose: Intensity of therapy influences outcomes in aphasia treatment, but little is known about optimum dosage across treatment approaches. Improved understanding of the effects of dose could help facilitate clinical decisions that maximise patient outcomes. This study examines learning in individuals with aphasia following exposure to one 60-min dose of computer-delivered script training, with or without a rest break. Method: Twenty participants (6F, 14M; 17 nonfluent, 3 fluent) with chronic aphasia due to left-hemisphere stroke participated. Participants had a mean (SD) age of 56.9 (8.4) years, a mean time post onset of 55.1 (range: 6.4-396.4) months, and a mean (SD) Comprehensive Aphasia Test score of 47.8 (4.0). Participants were exposed to 60 min of training, with or without a rest break, of a three-turn conversational script about either weather or traffic. Treatment was delivered via computer using a virtual clinician that visually modelled speech and guided treatment, promoting treatment fidelity. Oral reading probes for script sentences were administered at baseline (3 times), mid-treatment, immediately post-treatment, and, at various times, up to 2 weeks post-treatment to track script acquisition and maintenance. The study also examined generalisation from a trained script to a conversation with a clinician via a generalisation probe at three time points: baseline, immediately post-treatment, and 2 weeks post-treatment. Result: Following exposure to one dose of script training, participants demonstrated statistically significant improvements in oral reading accuracy and rate of script production on trained probes from baseline to immediately post-treatment and 2 weeks post-treatment. Participants also demonstrated significant change from baseline in generalisation to a conversation with a clinician immediately post-treatment and at 2 weeks post-treatment. Conclusion: Exposure to a single dose of computer-delivered script training may facilitate learning. These results have implications for future research investigating optimal dosage and scheduling parameters.

Tau-U: A Quantitative Approach for Analysis of Single-Case Experimental Data in Aphasia.

Purpose: Tau-U is a quantitative approach for analyzing single-case experimental design (SCED) data. It combines nonoverlap between phases with intervention phase trend and can correct for a baseline trend (Parker, Vannest, & Davis, 2011). We demonstrate the utility of Tau-U by comparing it with the standardized mean difference approach (Busk & Serlin, 1992) that is widely reported within the aphasia SCED literature. Method: Repeated writing measures from 3 participants with chronic aphasia who received computer-based writing treatment are analyzed visually and quantitatively using both Tau-U and the standardized mean difference approach. Results: Visual analysis alone was insufficient for determining an effect between the intervention and writing improvement. The standardized mean difference yielded effect sizes ranging from 4.18 to 26.72 for trained items and 1.25 to 3.20 for untrained items. Tau-U yielded significant (p < .05) effect sizes for 2 of 3 participants for trained probes and 1 of 3 participants for untrained probes. A baseline trend correction was applied to data from 2 of 3 participants. Conclusions: Tau-U has the unique advantage of allowing for the correction of an undesirable baseline trend. Although further study is needed, Tau-U shows promise as a quantitative approach to augment visual analysis of SCED data in aphasia.

Validity, reliability and sensitivity of the NORLA-6: Naming and oral reading for language in aphasia 6-point scale.

PURPOSE: Evaluation of the Naming and Oral Reading for Language in Aphasia 6-point scale (NORLA-6), a scoring system of oral reading and naming performance in aphasia. METHOD: Data were drawn from 91 participants with non-fluent aphasia secondary to left-hemisphere stroke across four treatment studies. To assess validity, Spearman's correlations were calculated between the NORLA-6 and the Gray Oral Reading Test-Fourth Edition (GORT-4) Accuracy score, GORT-4 Rate score and the Boston Naming Test (BNT). Inter-rater and test-retest reliability were evaluated using correlations. Sensitivity to change following oral reading intervention was analysed using Wilcoxon Signed Rank tests between pre- and post-treatment NORLA-6 scores. RESULT: NORLA-6 performance was significantly correlated (p < 0.001) with all reference tests (GORT-4 Accuracy, rs=0.84; GORT-4 Rate, rs= 0.61; and BNT, rs= 0.92). Inter-rater (ICC ≥0.90) and test-retest (r > 0.92) reliability were both excellent. Sensitivity following oral reading intervention was demonstrated in both oral reading accuracy and rate (p < 0.004). CONCLUSION: The NORLA-6 is a valid and reliable measure of oral reading and naming performance. It also demonstrates sensitivity to change in treatment-targeted behaviours. Therefore, the NORLA-6 scale may enhance outcome measurement in both clinical practice and aphasia research.

Local NMDA receptor hypofunction evokes generalized effects on gamma and high-frequency oscillations and behavior.

The NMDA receptor (NMDAr) hypofunction theory of schizophrenia suggests that aberrant signaling through NMDAr underlies the pathophysiology of this disease. This is commonly modeled in rodents via treatment with NMDAr antagonists, which causes a range of behavioral effects that represent endophenotypes related to schizophrenia. These drugs also disrupt high-frequency neural oscillations within the brain, also potentially relevant to disease. We studied the effect of localized NMDAr hypofunction on the generation of neural oscillations occurring both locally and in distant brain regions, and on behaviors routinely used as endophenotypes to model psychosis in rodents. Wistar rats were implanted with local field potential recording electrodes in the prefrontal cortex, dorsal hippocampus and nucleus accumbens, as well as cannulae in these regions to facilitate drug infusion. Rats received bilateral infusions of MK801 (0, 5µg, 20µg, 50µg) into one of the three target regions and their behavior measured in an open field. We also assessed the effects of systemic MK801 injection (0.16mg/kg sc). Electrophysiological signals were recorded continuously, allowing assessment of gamma oscillations (30-80Hz) and high-frequency oscillations (HFO: 130-180Hz) occurring as a result of infusions. Regardless of MK801 infusion location, gamma oscillations and HFOs significantly and consistently increased in all three regions studied, similar to that observed following systemic injection. Locomotor activity, stereotypies and ataxia were also observed following infusion into all regions. We conclude that localized regions exhibiting NMDAr hypofunction are sufficient to disrupt local as well as diffuse neural circuits and global brain function, and concomitantly cause psychosis-related behavioral effects.

Impact of Personal Relevance on Acquisition and Generalization of Script Training for Aphasia: A Preliminary Analysis.

PURPOSE: The importance of personalization in script training in aphasia has been assumed but never tested. This study compared acquisition and generalization of personally relevant versus generic words or phrases appearing in the same scripts. METHOD: Eight individuals (6 men; 2 women) with chronic aphasia received 3 weeks of intensive computer-based script training. For each participant, 2 scripts, a trained and an untrained generalization script, were embedded with 4 personally relevant word choices and 2-4 generic items that were similar across participants. Scripts were probed for accuracy at baseline and posttreatment. Significance testing was conducted on baseline and posttreatment scores, and for gains in personally relevant versus generic items. Effect sizes were computed. RESULTS: Both personally relevant and generic items improved significantly on trained scripts. Improvements on untrained scripts were smaller, with only personally relevant items reaching significance. There was no significant difference on gains made on personalized versus generic items for trained scripts (p = .059), but the effect size was large (d = 0.90). For generalization scripts, this effect was small (d = 0.25) and nonsignificant. CONCLUSIONS: Personally relevant words and phrases were acquired, although not generalized, more successfully than generic words and phrases. Data supports the importance of personalization in script training, but the degree of that importance requires further investigation.

Switching to a 10-day Mediterranean-style diet improves mood and cardiovascular function in a controlled crossover study.

OBJECTIVES: Even short-term adherence to a Mediterranean-style diet may benefit aspects of psychological functioning. The aim of the present study was to assess the effects of switching to a 10-d Mediterranean-style diet on mood, cognition, and cardiovascular measures. METHODS: Using a crossover design, 24 women were randomly assigned to either the diet change (where they switched to a Mediterranean-style diet) or no diet change (normal diet) condition for 10 days before switching to the other condition for the same duration. Mood, cognition, and cardiovascular measures of blood pressure, blood flow velocity, and arterial stiffness were assessed at baseline and at the completion of the two diets (days 11 and 22). RESULTS: Independent of whether the Mediterranean-style diet was undertaken before or after the crossover, it was associated with significantly elevated contentment and alertness, and significantly reduced confusion. Additionally, aspects of cognition, such as memory recall, improved significantly as a result of switching to the Mediterranean-style diet. Regarding cardiovascular measures, there was a significant reduction in augmentation pressure associated with the Mediterranean-style diet intervention, but blood flow velocity through the common carotid artery did not change. CONCLUSIONS: This Mediterranean-style diet has the potential to enhance aspects of mood, cognition, and cardiovascular function in a young, healthy adult sample.

Structural changes in dengue virus when exposed to a temperature of 37°C.

Previous binding studies of antibodies that recognized a partially or fully hidden epitope suggest that insect cell-derived dengue virus undergoes structural changes at an elevated temperature. This was confirmed by our cryo-electron microscopy images of dengue virus incubated at 37°C, where viruses change their surface from smooth to rough. Here we present the cryo-electron microscopy structures of dengue virus at 37°C. Image analysis showed four classes of particles. The three-dimensional (3D) map of one of these classes, representing half of the imaged virus population, shows that the E protein shell has expanded and there is a hole at the 3-fold vertices. Fitting E protein structures into the map suggests that all of the interdimeric and some intradimeric E protein interactions are weakened. The accessibility of some previously found cryptic epitopes on this class of particles is discussed.