Mélanie Brion

Beyond Cognition: Understanding Affective Impairments in Korsakoff Syndrome

As earlier research on Korsakoff syndrome (KS), a frequent neurological complication of alcohol-dependence (AD), mainly focused on cognition, affective impairments have been little investigated despite their crucial impact in AD. This article proposes new research avenues on this topic by combining two theoretical frameworks: (a) dual-process models, positing that addictions are due to an imbalance between underactivated reflective system and overactivated affective-automatic one; (b) continuity theory, postulating a gradual worsening of cognitive impairments from AD to KS. We suggest that this joint perspective may renew the current knowledge by clarifying the affective-automatic deficits in KS and their interactions with reflective impairments, but also by offering a direct exploration of the continuity between AD and KS regarding reflective and affective-automatic abilities.

Preserved crossmodal integration of emotional signals in binge drinking

Binge drinking is an alcohol consumption pattern with various psychological and cognitive consequences. As binge drinking showed qualitatively comparable cognitive impairments to those reported in alcohol-dependence, a continuum hypothesis suggests that this habit would be a first step toward alcohol-related disorders. Besides these cognitive impairments, alcohol-dependence is also characterized by large-scale deficits in emotional processing, particularly in crossmodal contexts, and these abilities have scarcely been explored in binge drinking. Emotional decoding, most often based on multiple modalities (e.g., facial expression, prosody or gesture), yet represents a crucial ability for efficient interpersonal communication and social integration. The present study is the first exploration of crossmodal emotional processing in binge drinking, in order to test whether binge drinkers already present the emotional impairments described among alcohol-dependent patients, in line with the continuum hypothesis. Twenty binge drinkers and 20 matched controls performed an experimental task requiring the identification of two emotions (happiness or anger) presented in two modalities (visual or auditory) within three conditions (unimodal, crossmodal congruent or crossmodal incongruent). In accordance with previous research in binge drinking and alcohol-dependence, this study was based on two main hypotheses. First, binge drinkers would present a reduced facilitation effect (i.e., classically indexed in healthy populations by faster reaction times when two congruent modalities are presented simultaneously). Second, binge drinkers would have higher difficulties to inhibit interference in incongruent modalities. Results showed no significant difference between groups in emotional decoding ability, whatever the modality or condition. Control participants, however, appeared slower than binge drinkers in recognizing facial expressions, also leading to a stronger facilitation effect when the two modalities were presented simultaneously. However, findings did not show a disrupted facilitation effect in binge drinkers, whom also presented preserved performance to inhibit incongruence during emotional decoding. The current results thus suggest that binge drinkers do not demonstrate a deficit for emotional processing, both in unimodal and crossmodal contexts. These results imply that binge drinking might not be characterized by impairments for the identification of primary emotions, which could also indicate that these emotional processing abilities are well-preserved at early stages of excessive alcohol consumption.

Crossmodal processing of emotions in alcohol-dependence and Korsakoff syndrome

ABSTRACT Introduction: Decoding emotional information from faces and voices is crucial for efficient interpersonal communication. Emotional decoding deficits have been found in alcohol-dependence (ALC), particularly in crossmodal situations (with simultaneous stimulations from different modalities), but are still underexplored in Korsakoff syndrome (KS). The aim of this study is to determine whether the continuity hypothesis, postulating a gradual worsening of cognitive and brain impairments from ALC to KS, is valid for emotional crossmodal processing. Methods: Sixteen KS, 17 ALC and 19 matched healthy controls (CP) had to detect the emotion (anger or happiness) displayed by auditory, visual or crossmodal auditory-visual stimuli. Crossmodal stimuli were either emotionally congruent (leading to a facilitation effect, i.e. enhanced performance for crossmodal condition compared to unimodal ones) or incongruent (leading to an interference effect, i.e. decreased performance for crossmodal condition due to discordant information across modalities). Reaction times and accuracy were recorded. Results: Crossmodal integration for congruent information was dampened only in ALC, while both ALC and KS demonstrated, compared to CP, decreased performance for decoding emotional facial expressions in the incongruent condition. Conclusions: The crossmodal integration appears impaired in ALC but preserved in KS. Both alcohol-related disorders present an increased interference effect. These results show the interest of more ecological designs, using crossmodal stimuli, to explore emotional decoding in alcohol-related disorders. They also suggest that the continuum hypothesis cannot be generalised to emotional decoding abilities.

New Perspectives in the Exploration of Korsakoff’s Syndrome: The Usefulness of Neurophysiological Markers

This perspective aims at underlining the usefulness of event-related potentials (ERP) to better understand the brain correlates of Korsakoff’s syndrome (KS), a neuropsychiatric disease characterized by severe memory impairment and most frequently resulting as a neurological complication of alcohol-dependence (AD). While ERP have been broadly used in AD, it has up to now been very little applied in KS or in the comparison of KS and AD. Within the framework of dual-process models, an influential theory postulating that addictive states result from an imbalance between under-activated reflective system and over-activated automatic-affective one, this paper proposes: (1) a brief synthesis of the main results of ERP studies in AD and KS, and (2) new research avenues using ERP to identify the electrophysiological correlates of cognitive and emotional dysfunction in KS. These experimental perspectives aim at exploring the continuity hypothesis, which postulates a gradient of impairments from AD to KS. We conclude on the possibility of developing neuropsychological strategies with electrophysiological follow-up to ensure KS diagnosis and test the efficacy of patient’s neurocognitive rehabilitation.

Imbalance between cognitive systems in alcohol-dependence and Korsakoff syndrome: An exploration using the Alcohol Flanker Task

ABSTRACT Background: Alcohol-dependent individuals (ALC) simultaneously present decreased inhibitory control and increased attention towards alcohol-related cues. The dual-process models have proposed that these symptoms reflect an imbalance between prefrontal/reflective and limbic/automatic systems, respectively leading to cognitive dysfunctions in executive processes and to alcohol-related bias. However, most previous research has focused on a separate exploration of these systems among ALC, and the direct measure of their interactions remains to be conducted. Moreover, no study has explored the evolution of this imbalance across the successive stages of alcohol-related disorders, and particularly in Korsakoff syndrome (KS), the most frequent neurological complication of alcohol-dependence. Method: Ten KS, 14 ALC, and 14 matched control participants performed a modified Flanker task, the “Alcohol Flanker Task,” based on congruent, incongruent, and neutral conditions with alcohol-related stimuli. This task required inhibitory processing on alcohol-related stimuli and evaluated, through a behavioral approach, the interaction between reflective and automatic systems, as well as its evolution between ALC and KS. Results: ALC and KS both presented high reactivity towards alcohol-related stimuli, confirming the presence of alcohol-related bias. KS showed increased omission rates (related to distractor interference) while ALC showed higher false-alarm rates (related to prepotent response inhibition). These results suggest that different inhibitory subcomponents might be altered at the successive stages of the pathology, and experimentally confirms the crucial role of the interaction between reflective and automatic processes in alcohol-use disorders. Conclusion: The present results reinforce the proposal that alcohol-related cues significantly impact inhibitory control in alcohol-related disorders. However, ALC and KS present different patterns of deficits depending on task complexity (i.e., executive load), thus suggesting a dissociation in inhibitory functions when processing alcohol-related cues.

Affective impairments in binge drinking: Investigation through emotional facial expression decoding

OBJECTIVE Binge drinking, an excessive alcohol consumption pattern frequently observed in young people, is known to be associated with psychological and cerebral deficits. While cognitive dysfunctions have been widely investigated, emotional abilities have scarcely been explored. Such an exploration would however offer a more exhaustive understanding of the deficits associated with binge drinking, as well as of the possible transition towards alcohol-dependence. METHODS 46 young adults (23 binge drinkers, 12 women; 23 control participants, 12 women) were recruited among university students. They performed an emotional recognition task consisting of the visual decoding of six basic emotions (i.e. anger, contempt, disgust, fear, happiness, and sadness). Accuracy scores and detection thresholds were collected for each emotion. RESULTS Binge drinkers showed lower performance than control participants for the decoding of all emotions and increased detection threshold, this later reflecting less ability to capture an emotion. Binge drinking is thus associated with a need for higher emotional intensity to perform correct detection. Moreover, these emotional difficulties appear specifically related to alcohol consumption. CONCLUSION These findings reinforce previous experimental evidence of altered emotional processing among binge drinkers, and extend these results for various emotional contents. They support the hypothesis of a continuum between binge drinking and alcohol-dependence, in which massive emotional impairments have been documented. Indeed, these impairments could be involved in the onset and maintenance of excessive alcohol consumption, notably through the established relationship between emotional deficits and social distress.

Electrophysiological correlates of emotional crossmodal processing in binge drinking

Emotional crossmodal integration (i.e., multisensorial decoding of emotions) is a crucial process that ensures adaptive social behaviors and responses to the environment. Recent evidence suggests that in binge drinking—an excessive alcohol consumption pattern associated with psychological and cerebral deficits—crossmodal integration is preserved at the behavioral level. Although some studies have suggested brain modifications during affective processing in binge drinking, nothing is known about the cerebral correlates of crossmodal integration. In the current study, we asked 53 university students (17 binge drinkers, 17 moderate drinkers, 19 nondrinkers) to perform an emotional crossmodal task while their behavioral and neurophysiological responses were recorded. Participants had to identify happiness and anger in three conditions (unimodal, crossmodal congruent, crossmodal incongruent) and two modalities (face and/or voice). Binge drinkers did not significantly differ from moderate drinkers and nondrinkers at the behavioral level. However, widespread cerebral modifications were found at perceptual (N100) and mainly at decisional (P3b) stages in binge drinkers, indexed by slower brain processing and stronger activity. These cerebral modifications were mostly related to anger processing and crossmodal integration. This study highlights higher electrophysiological activity in the absence of behavioral deficits, which could index a potential compensation process in binge drinkers. In line with results found in severe alcohol-use disorders, these electrophysiological findings show modified anger processing, which might have a deleterious impact on social functioning. Moreover, this study suggests impaired crossmodal integration at early stages of alcohol-related disorders.