Biology subjects

Wittmann, M. K.

Publications and source records attributed to Wittmann, M. K..

5 recordsLinked to original sources

bioRxiv2026

A self without a "we": Individuals with Borderline personality disorder show signatures of disrupted social basis functions

A capacity to navigate social relationships is fundamental to human wellbeing. However, the cognitive mechanisms underlying social dysfunction in psychiatric conditions remain poorly understood. Using an abstract multi-person decision making task that isolates the relational structure of multi-person interactions, we compare non-clinical controls (NCC, n=51) and individuals with BPD symptoms (n=46), a condition characterized by disturbances in self-other boundaries and chronic feelings of loneliness. Generally, we found a pattern of less self-centered decision-making in BPD. More specifically, individuals with BPD showed signatures of perceiving opponents as a coherent group ("them"), but a markedly reduced tendency to represent themselves as part of their own team ("us"). This pattern of results points towards a disruption of a primary social basis function. Our laboratory findings extend to experienced loneliness in daily life as measured by ecological momentary assessments (EMA). Together, this suggests that BPD is characterized by an unbalanced representation of social structure, with an attenuated "we" alongside a heightened "they".

neuroscience↗

bioRxiv2026

Preserved self-other integration during social decision making among individuals with elevated autistic traits

Autistic people can find social interactions difficult to navigate, traditionally attributed to difficulties in taking others perspectives. However, we have a limited understanding of how autistic people integrate self and other information efficiently during social decision-making. We conducted four highly powered experiments (total N = 1,621) to determine whether autistic traits affect two aspects of self-other integration during social decision making: self-bias and social basis function use. Using Bayesian analyses, we found strong support for the absence of a relationship between autistic traits and either aspect of social decision making, even after controlling for potential confounds (BF01 = 32.13 for self-bias, BF01 = 7.04 for social basis function use). Our results indicate that variations along autistic traits do not impact how people prioritise self-relevant information (self-bias) or utilize compressed social patterns of interaction (social basis function use) to guide their decisions about oneself and other people. These findings nuance the conceptualisation of social-cognitive processes across autistic traits while highlighting the need for large samples to validate null effects.

neuroscience↗

bioRxiv2025

Low-intensity focused ultrasound to human amygdala reveals a causal role in ambiguous emotion processing and alters local and network-level activity

The amygdala is a core region changed in depression, a disorder characterized by compromised emotion, motivation and learning processes. However, lesion studies in humans examining amygdala function have largely focused on its role in processing fear. It currently remains unclear what causal role the human amygdala plays in more complex emotion, motivation and learning processes in daily life. This is because it has not been possible to reversibly modulate amygdala activity non-invasively in humans. Here, we used transcranial focused ultrasound stimulation (TUS) to bilaterally perturb neural activity in the basolateral amygdala (BLA). In separate sessions (n = 87), 29 healthy volunteers received offline-TUS to bilateral BLA, mid-insula or sham before playing a novel emotional learning task validated in an independent large cohort online (n = 210). 7T-resting-state and metabolite signals clearly demonstrated target engagement. BLA-TUS reduced the BLAs connectivity fingerprint and decreased its excitation/inhibition balance, suggesting an inhibitory effect of our TUS protocol on BLA activity. In behaviour, BLA-TUS caused a stimulation volume-dependent increase in the tendency to approach neutral, emotionally ambiguous faces, treating them more similarly to happy faces, and a slowing of reaction times for those two emotion categories. These effects were functionally and regionally specific and suggest a causal role for the amygdala in resolving emotional ambiguity. Our results provide important insights for future studies into mood disorders where ambiguous situations might be harder to resolve, which could contribute to existing emotional and learning biases.

neuroscience↗

bioRxiv2021

Neural activity tracking identity and confidence in social information

Humans learn about the environment either directly by interacting with it or indirectly by seeking information about it from social sources such as conspecifics. The degree of confidence in the information obtained through either route should determine the impact that it has on adapting and changing behaviour. We examined whether and how behavioural and neural computations differ during non-social learning as opposed to learning from social sources. Trial-wise confidence judgments about non-social and social information sources offered a window into this learning process. Despite matching exactly the statistical features of social and non-social conditions, confidence judgments were more accurate and less changeable when they were made about social as opposed to non-social information sources. In addition to subjective reports of confidence, differences were also apparent in the Bayesian estimates of participants subjective beliefs. Univariate activity in dorsomedial prefrontal cortex (dmPFC) and posterior temporo-parietal junction (pTPJ) more closely tracked confidence about social as opposed to non-social information sources. In addition, the multivariate patterns of activity in the same areas encoded identities of social information sources compared to non-social information sources.

neuroscience↗

bioRxiv2021

Dissociable mechanisms of reward learning co-mature during human adolescence as predicted by macaque lesion models

Reward-guided learning and decision-making is a fundamental adaptive ability and depends on a number of component processes. We investigate how such component processes mature during human adolescence. Our approach was guided by analyses of the effects of lateral orbitofrontal lesions in macaque monkeys, as this part of the brain shows clear developmental maturation in humans during adolescence. Using matched tasks and analyses in humans (n=388, 11-35yrs), we observe developmental changes in two key learning mechanisms as predicted from the monkey data. First, choice-reward credit assignment - the ability to link a specific outcome to a specific choice - is reduced in adolescents. Second, the effects of the global reward state - how good the environment is overall recently - exerts a distinctive pattern of influence on learning in humans compared to other primates and across adolescence this pattern becomes more pronounced. Both mechanisms were correlated across participants suggesting that associative learning of correct reward assignments and GRS based learning constitute two complementary mechanisms of reward-learning that co-mature during adolescence.

neuroscience↗