Disambiguating ventral striatum fMRI-related bold signal during reward prediction in schizophrenia

Abstract

Reward detection, surprise detection and prediction-error signaling have all been proposed as roles for the ventral striatum (vStr). Previous neuroimaging studies of striatal function in schizophrenia have found attenuated neural responses to reward-related prediction errors; however, as prediction errors represent a discrepancy in mesolimbic neural activity between expected and actual events, it is critical to examine responses to both expected and unexpected rewards (URs) in conjunction with expected and UR omissions in order to clarify the nature of ventral striatal dysfunction in schizophrenia. In the present study, healthy adults and people with schizophrenia were tested with a reward-related prediction-error task during functional magnetic resonance imaging to determine whether schizophrenia is associated with altered neural responses in the vStr to rewards, surprise prediction errors or all three factors. In healthy adults, we found neural responses in the vStr were correlated more specifically with prediction errors than to surprising events or reward stimuli alone. People with schizophrenia did not display the normal differential activation between expected and URs, which was partially due to exaggerated ventral striatal responses to expected rewards (right vStr) but also included blunted responses to unexpected outcomes (left vStr). This finding shows that neural responses, which typically are elicited by surprise, can also occur to well-predicted events in schizophrenia and identifies aberrant activity in the vStr as a key node of dysfunction in the neural circuitry used to differentiate expected and unexpected feedback in schizophrenia.

Ventral Striatal Dysfunction and Symptom Expression in Individuals With Schizotypal Personality Traits and Early Psychosis

“…25,26 In contrast, the current study investigated a psychosis continuum from nonclinical participants to patients with early psychosis with a different psychopathological construct of apathy (partly secondary to positive and depressive symptoms). Furthermore, our results are consistent with findings of Morris and colleagues 53 who found the same relationship of exaggerated VS activity with negative symptoms and total symptom severity suggesting a more complex picture between aberrant ventral striatal activity and psychopathology.…”

Error Correction in Latent Inhibition and its Disruption by Opioid Receptor Blockade with Naloxone

“…However, it remains to be determined to what extent the decrement of these responses in latent inhibition or extinction similarly requires opioid activation. It is also worth noting that these results are consistent with the suggestion that the inability to ignore irrelevant stimuli, which characterizes positive symptoms in schizophrenia, may originate from dysfunctions in error-correction learning (eg, Corlett et al, 2007;Morris et al, 2012). The sensitivity of this learning to naloxone implicates endogenous opioids as a potential pharmacological target for the treatment of schizophrenia, and is consistent with post-mortem analysis showing alterations in cortical opioid receptors in the brains of schizophrenics (Volk et al, 2012).…”

Changes in White Matter Organization in Adolescent Offspring of Schizophrenia Patients

“…Moreover, these regions are key components of the reward network (McClure et al, 2004;Sesack and Grace, 2010). We and other have reported on changes in frontostriatal reward processing in schizophrenia patients (Morris et al, 2012;Nielsen et al, 2012), siblings (Grimm et al, 2014;de Leeuw et al, 2015b), and offspring (Vink et al, 2016b).…”

“…Indeed, neuroimaging studies have consistently shown frontostriatal impairments in schizophrenia patients. First, functional MRI studies have demonstrated reduced levels of frontostriatal activation in patients in the context of several cognitive tasks including working memory, reward processing, and inhibition (Morris et al, 2012;van Veelen et al, 2010van Veelen et al, , 2011Vink et al, 2006;Zandbelt et al, 2011). Second, patients show decreased frontal and striatal volumes (Emsley et al, 2015;Harms et al, 2010).…”