Auditory emotion recognition (AER) is the process of extracting emotional content out of the acoustic features of speech, and is disrupted in many neuropsychiatric disorders including autism and schizophrenia. Both the encoding of this information in the auditory cortex as well as the knowledge of which brain areas participate in the circuit that underlies AER are not known. With a unique access to invasive intracranial neurophysiology in awake, behaving humans, we propose to study the neural basis of AER in patients undergoing invasive electrode monitoring as part of staged epilepsy surgery protocols. These subjects will perform an AER task while brain responses are recorded in an effort to decipher the neural processes that identify emotion and while specific areas of their brain are stimulated in order to causally link focal activation of AER circuit components to perception.
In Aim 1, we will identify the neuronal mechanisms underlying emotion recognition using a task that breaks down AER into three sequential steps: encoding, integration and judgment. First, we will identify the encoding of emotionally relevant acoustic cues by examining how sensory features such as pitch, intensity and modulation are encoded by neuronal responses in the auditory cortex and other brain areas involved in emotional processing such as the amygdala, insula and prefrontal cortex. Second, we will examine how these acoustic cues are integrated into an emergent emotional percept by measuring activity in putative areas as well as the interaction among these areas after relevant sensory input while subjects consider possible responses. Finally, we will examine the subjects? response to the AER task and correlate the judgment of emotion with the extent to which it can be predicted by neuronal activity in different brain regions of interest. While most analyses will focus on intraindividual data, differences in brain activity as it relates to AER will be compared in males versus females in order to examine biological differences in AER between sexes.
In aim 2, we will determine the effect of neural stimulation on AER. We will apply focal single pulse stimulation to brain areas at those critical time windows identified in aim 1 in order to bias emotional decisions. This type of stimulation results in very focal and temporally restricted disruption of function and can be used to determine a brain area?s causal role in perception. We seek to build a detailed neurobiological model of the AER. This would be a precursor to designing individualized therapeutic approaches to treat deficits in auditory emotional processing as well as identifying putative targets to treat affective disorders in general.
Identifying emotion in speech is a critical brain process required for social interaction and is impaired in many neuropsychiatric diseases. We will study how the brain codes the emotional content of speech and how stimulating specific brain areas can potentially improve this process. !
| Herrero, Jose L; Gieselmann, Marc A; Thiele, Alexander (2017) Muscarinic and Nicotinic Contribution to Contrast Sensitivity of Macaque Area V1 Neurons. Front Neural Circuits 11:106 |
