The role of semantic memory in the recognition of emotional valence conveyed by written words

The Importance of Being Familiar: The Role of Semantic Knowledge in the Activation of Emotions and Factual Knowledge from Music in the Semantic Variant of Primary Progressive Aphasia

BACKGROUND

The role of semantic knowledge in emotion recognition remains poorly understood. The semantic variant of primary progressive aphasia (svPPA) is a degenerative disorder characterized by progressive loss of semantic knowledge, while other cognitive abilities remain spared, at least in the early stages of the disease. The syndrome is therefore a reliable clinical model of semantic impairment allowing for testing the propositions made in theoretical models of emotion recognition.

OBJECTIVE

The main goal of this study was to investigate the role of semantic memory in the recognition of basic emotions conveyed by music in individuals with svPPA.

METHODS

The performance of 9 individuals with svPPA was compared to that of 32 control participants in tasks designed to investigate the ability: a) to differentiate between familiar and non-familiar musical excerpts, b) to associate semantic concepts to musical excerpts, and c) to recognize basic emotions conveyed by music.

RESULTS

Results revealed that individuals with svPPA showed preserved abilities to recognize familiar musical excerpts but impaired performance on the two other tasks. Moreover, recognition of basic emotions and association of musical excerpts with semantic concepts was significantly better for familiar than non-familiar musical excerpts in participants with svPPA.

CONCLUSION

Results of this study have important implications for theoretical models of emotion recognition and music processing. They suggest that impairment of semantic memory in svPPA affects both the activation of emotions and factual knowledge from music and that this impairment is modulated by familiarity with musical tunes.

Atrophy in Distinct Corticolimbic Networks Subserving Socioaffective Behavior in Semantic Variant Primary Progressive Aphasia

BACKGROUND

Although traditionally conceptualized as a language disorder, semantic variant primary progressive aphasia (svPPA) is often accompanied by significant behavioral and affective symptoms which considerably increase disease morbidity. Specifically, these neuropsychiatric symptoms are characterized by breaches in normative socioaffective function, for example, an inability to read social cues, excessive trusting of others, and decreased empathy. Our prior neuroimaging work identified 3 corticolimbic networks anchored in the amygdala, temporal pole, and frontoinsular cortex: an affiliation network, theorized to mediate social approach behavior; an aversion network, theorized to subserve the appraisal of social threat; and a perception network, theorized to mediate the detection of social cues. We hy-pothesized that degeneration of these networks could provide neuroanatomical substrates for socioaffective deficits in svPPA.

METHODS

We examined hypothesized relationships between subscores on the Social Impairment Rating Scale (SIRS) and atrophy in each of these 3 networks in a group of 16 svPPA patients (using matched cognitively normal controls as a reference).

RESULTS

Consistent with our predictions, the magnitude of atrophy in the affiliation network in svPPA patients correlated with the SIRS subscore of socioemotional detachment, while the magnitude of atrophy in the aversion network in svPPA patients correlated with the SIRS subscore of inappropriate trusting. We did not find the predicted association between perception network atrophy and the SIRS subscore of lack of attention to social cues.

CONCLUSION

These findings highlight specific socioaffective deficits in svPPA and provide a neuroanatomical basis for these impairments by linking them to networks commonly targeted in this disorder.