Publications

Abstract

Background. Facial emotion recognition deficits are common after moderate-severe traumatic brain injury (TBI) and linked to poor social outcomes. We examine whether emotion recognition deficits extend to facial expressions depicted by emoji.
Methods. Fifty-one individuals with moderate-severe TBI (25 female) and fifty-one neurotypical peers (26 female) viewed photos of human faces and emoji. Participants selected the best-fitting label from a set of basic emotions (anger, disgust, fear, sadness, neutral, surprise, happy) or social emotions (embarrassed, remorseful, anxious, neutral, flirting, confident, proud).
Results. We analyzed the likelihood of correctly labeling an emotion by group (neurotypical, TBI), stimulus condition (basic faces, basic emoji, social emoji), sex (female, male), and their interactions. Participants with TBI did not significantly differ from neurotypical peers in overall emotion labeling accuracy. Both groups had poorer labeling accuracy for emoji compared to faces. Participants with TBI (but not neurotypical peers) had poorer accuracy for labeling social emotions depicted by emoji compared to basic emotions depicted by emoji. There were no effects of participant sex.
Discussion. Because emotion representation is more ambiguous in emoji than human faces, studying emoji use and perception in TBI is an important consideration for understanding functional communication and social participation after brain injury.

Abstract

Purpose

Real-world communication is situated in rich multimodal contexts, containing speech and gesture. Speakers often convey unique information in gesture that is not present in the speech signal (e.g., saying “He searched for a new recipe” while making a typing gesture). We examine the narrative retellings of participants with and without moderate-severe traumatic brain injury across three timepoints over two online Zoom sessions to investigate whether people with TBI can integrate information from co-occurring speech and gesture and if information from gesture persists across delays.

Methods

60 participants with TBI and 60 non-injured peers watched videos of a narrator telling four short stories. On key details, the narrator produced complementary gestures that conveyed unique information. Participants retold the stories at three timepoints: immediately after, 20-min later, and one-week later. We examined the words participants used when retelling these key details, coding them as a Speech Match (e.g., “He searched for a new recipe”), a Gesture Match (e.g., “He searched for a new recipe online), or Other (“He looked for a new recipe”). We also examined whether participants produced representative gestures themselves when retelling these details.

Results

Despite recalling fewer story details, participants with TBI were as likely as non-injured peers to report information from gesture in their narrative retellings. All participants were more likely to report information from gesture and produce representative gestures themselves one-week later compared to immediately after hearing the story.

Conclusion

We demonstrated that speech-gesture integration is intact after TBI in narrative retellings. This finding has exciting implications for the utility of gesture to support comprehension and memory after TBI and expands our understanding of naturalistic multimodal language processing in this population.

Abstract

Impaired facial affect recognition is common after traumatic brain injury (TBI) and linked to poor social outcomes. We explored whether perception of emotions depicted by emoji is also impaired after TBI. Fifty participants with TBI and 50 non-injured peers generated free-text labels to describe emotions depicted by emoji and rated their levels of valence and arousal on nine-point rating scales. We compared how the two groups’ valence and arousal ratings were clustered and examined agreement in the words participants used to describe emoji. Hierarchical clustering of affect ratings produced four emoji clusters in the non-injured group and three emoji clusters in the TBI group. Whereas the non-injured group had a strongly positive and a moderately positive cluster, the TBI group had a single positive valence cluster, undifferentiated by arousal. Despite differences in cluster numbers, hierarchical structures of the two groups’ emoji ratings were significantly correlated. Most emoji had high agreement in the words participants with and without TBI used to describe them. Participants with TBI perceived emoji similarly to non-injured peers, used similar words to describe emoji, and rated emoji similarly on the valence dimension. Individuals with TBI showed small differences in perceived arousal for a minority of emoji. Overall, results suggest that basic recognition processes do not explain challenges in computer-mediated communication reported by adults with TBI. Examining perception of emoji in context by people with TBI is an essential next step for advancing our understanding of functional communication in computer-mediated contexts after brain injury.

Abstract

Background: The concept of fluency is widely used to dichotomously classify aphasia syndromes in both research and clinical practice. Despite its ubiquity, reliability of fluency measurement is reduced due to its multi-dimensional nature and the variety of methods used to measure it.
Aims: The primary aim of the study was to determine what factors contribute to judgements of fluency in aphasia, identifying methodological and linguistic sources of disagreement.
Methods & Procedures: We compared fluency classifications generated according to fluency scores on the revised Western Aphasia Battery (WAB-R) to clinical impressions of fluency for 254 English-speaking people with aphasia (PwA) from the AphasiaBank database. To determine what contributed to fluency classifications, we examined syndrome diagnoses and measured the predictive strength of 18 spontaneous speech variables extracted from retellings of the Cinderella story. The variables were selected to represent three dimensions predicted to underlie fluency: grammatical competence, lexical retrieval, and the facility of speech production.
Outcomes & Results: WAB-R fluency classifications agreed with 83% of clinician classifications, although agreement was much greater for fluent than nonfluent classifications. The majority of mismatches were diagnosed with anomic or conduction aphasia by the WAB-R but Broca's aphasia by clinicians. Modifying the WAB-R scale improved the extent to which WAB-R fluency categories matched clinical impressions. Fluency classifications were predicted by a combination of variables, including aspects of grammaticality, lexical retrieval and speech production. However, fluency classification by WAB-R was largely predicted by severity, whereas the presence or absence of apraxia of speech was the largest predictor of fluency classifications by clinicians.
Conclusions: Fluency judgements according to WAB-R scoring and those according to clinical impression showed some common influences, but also some differences that contributed to mismatches in fluency categorization. We propose that, rather than using dichotomous fluency categories, which can mask sources of disagreement, fluency should be explicitly identified relative to the underlying deficits (word-finding, grammatical formulation, speech production, or a combination) contributing to each individual PwA's fluency profile. Identifying what contributes to fluency disruptions is likely to generate more reliable diagnoses and provide more concrete guidance regarding therapy, avenues we are pursuing in ongoing research.

Abstract

When people talk, they gesture. Gesture is a fundamental component of language that contributes meaningful and unique information to a spoken message and reflects the speaker's underlying knowledge and experiences. Theoretical perspectives of speech and gesture propose that they share a common conceptual origin and have a tightly integrated relationship, overlapping in time, meaning, and function to enrich the communicative context. We review a robust literature from the field of psychology documenting the benefits of gesture for communication for both speakers and listeners, as well as its important cognitive functions for organizing spoken language, and facilitating problem-solving, learning, and memory. Despite this evidence, gesture has been relatively understudied in populations with neurogenic communication disorders. While few studies have examined the rehabilitative potential of gesture in these populations, others have ignored gesture entirely or even discouraged its use. We review the literature characterizing gesture production and its role in intervention for people with aphasia, as well as describe the much sparser literature on gesture in cognitive communication disorders including right hemisphere damage, traumatic brain injury, and Alzheimer's disease. The neuroanatomical and behavioral profiles of these patient populations provide a unique opportunity to test theories of the relationship of speech and gesture and advance our understanding of their neural correlates. This review highlights several gaps in the field of communication disorders which may serve as a bridge for applying the psychological literature of gesture to the study of language disorders. Such future work would benefit from considering theoretical perspectives of gesture and using more rigorous and quantitative empirical methods in its approaches. We discuss implications for leveraging gesture to explore its untapped potential in understanding and rehabilitating neurogenic communication disorders.

Abstract

Background: While persons with aphasia (PwA) are often dichotomised as fluent or nonfluent, agreement that fluency is not an all-or-nothing construct has led to the use of continuous variables as a way to quantify fluency, such as multi-dimensional rating scales, speech rate, and utterance length. Though these measures are often used in research, they provide little information about the underlying fluency deficit.
Aim: The aim of the study was to identify how well commonly used continuous measures of fluency capture variability in spontaneous speech variables at lexical, grammatical, and speech production levels. Methods & Procedures: Speech samples of 254 English-speaking PwA from the AphasiaBank database were analyzed to examine the distributions of four continuous measures of fluency: the WAB-R fluency scale, utterance length, retracing, and speech rate. Linear regression was used to identify spontaneous speech predictors contributing to each fluency outcome measure.
Outcomes & Results: All the outcome measures reflected the influence of multiple underlying dimensions, although the predictors varied. The WAB-R fluency scale, speech rate, and retracing were influenced by measures of grammatical competence, lexical retrieval, and speech production, whereas utterance length was influenced only by measures of grammatical competence and lexical retrieval. The strongest predictor of WAB-R fluency was aphasia severity, whereas the strongest predictor for all other fluency proxy measures was grammatical complexity.
Conclusions: Continuous measures allow a variety of ways to objectively quantify speech fluency; however, they reflect superficial manifestations of fluency that may be affected by multiple underlying deficits. Furthermore, the deficits underlying different measures vary, which may reduce the reliability of fluency diagnoses. Capturing these differences at the individual level is critical to accurate diagnosis and appropriately targeted therapy.

Abstract

When we talk, we often make hand movements called gestures at the same time. Although just about everyone gestures when they talk, we usually do not even notice the gestures. Our hand gestures play an important role in helping us learn and remember! When we see other people gesturing when they talk—or when we gesture when we talk ourselves—we are more likely to remember the information being talked about than if gestures were not involved. Our hand gestures can even indicate when we are ready to learn new things! In this article, we explain how gestures can help learning. To investigate this, we studied children learning a new mathematical concept called equivalence. We hope that this article will help you notice when you, your friends and family, and your teachers are gesturing, and that it will help you understand how those gestures can help people learn.

Abstract

During conversation, people integrate information from co-speech hand gestures with information in spoken language. For example, after hearing the sentence, "A piece of the log flew up and hit Carl in the face" while viewing a gesture directed at the nose, people tend to later report that the log hit Carl in the nose (information only in gesture) rather than in the face (information in speech). The cognitive and neural mechanisms that support the integration of gesture with speech are unclear. One possibility is that the hippocampus known for its role in relational memory and information integration is necessary for integrating gesture and speech. To test this possibility, we examined how patients with hippocampal amnesia and healthy and brain-damaged comparison participants express information from gesture in a narrative retelling task. Participants watched videos of an experimenter telling narratives that included hand gestures that contained supplementary information. Participants were asked to retell the narratives and their spoken retellings were assessed for the presence of information from gesture. For features that had been accompanied by supplementary gesture, patients with amnesia retold fewer of these features overall and fewer retellings that matched the speech from the narrative. Yet their retellings included features that contained information that had been present uniquely in. gesture in amounts that were not reliably different from comparison groups. Thus, a functioning hippocampus is not necessary for gesture-speech integration over short timescales. Providing unique information in gesture may enhance communication for individuals with declarative memory impairment, possibly via non-declarative memory mechanisms.