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Godfrey Pearlson

Publications and source records attributed to Godfrey Pearlson.

5 recordsLinked to original sources
PubMed2026

Evaluating psychosis-specific effects of trauma exposure in early-onset and adult-onset psychosis.

Trauma is a risk factor for early-onset (EOP) and adult-onset (AOP) psychosis and is also associated with other psychiatric diagnoses and poorer fputcomes in the general population. We examined (1) whether trauma effects are specific to psychosis and (2) whether these effects differ between EOP and AOP.Linear regression models evaluated trauma exposure in two samples (EOP: 647 cases, 694 controls; AOP: 162 cases, 230 controls) as a function of psychotic and nonpsychotic psychiatric diagnosis (NPD) status. Parallel models assessed associations between trauma and symptom severity, global functioning, and cognition. Relative to individuals without psychiatric disorders, participants with psychosis and comorbid NPDs reported the greatest trauma exposure (EOP: β = 0.95; AOP: β = 1.1), followed by those with psychosis only (EOP: β = 0.67; AOP: β = 0.41) and NPDs only (EOP: β = 0.47; AOP: β = 0.36). Greater numbers of NPDs were associated with higher trauma exposure regardless of psychosis status (EOP: β = 0.15; AOP: β = 0.24). Trauma was associated with greater symptom severity (EOP: β = 0.13; AOP: β = 0.14) and poorer global functioning (EOP: β = -0.21; AOP: β = -0.13), but not cognition. No psychosis-by-trauma interactions were observed.Psychosis-specific effects were limited to greater trauma exposure, while trauma-related impacts on outcomes were similar across diagnostic groups. Findings were consistent across EOP and AOP. Results highlight the need for trauma-informed care in psychiatry given broad effects that influence disease course and prognosis.

Humans↗
PubMed2007

Functional neural circuits for mental timekeeping.

Theories of mental timekeeping suggest frontostriatal networks may mediate performance of tasks requiring precise timing. We assessed whether frontostriatal networks are functionally integrated during the performance of timing tasks. Functional magnetic resonance imaging (fMRI) data from 31 healthy adults were collected during performance of several different types of discrete interval timing tasks. Independent component analysis (ICA) was used to examine functional connectivity within frontostriatal circuits. ICA identifies groups of spatially discrete brain regions sharing similar patterns of hemodynamic signal change over time. The results confirm the existence of a frontostriatal neural timing circuit that includes anterior cingulate gyrus, supplementary motor area, bilateral anterior insula, bilateral putamen/globus pallidus, bilateral thalamus, and right superior temporal gyrus and supramarginal gyrus. Several other distinct neural circuits were identified that may represent the neurobiological substrates of different information processing stages of mental timekeeping. Small areas of right cerebellum were engaged in several of these circuits, suggesting that cerebellar function may be important in, but not the primary substrate of, the mental timing tasks used in this experiment. These findings are discussed within the context of current biological and information processing models of neural timekeeping.

Acoustic Stimulation↗
PubMed2006

The vulnerability to alcohol and substance abuse in individuals diagnosed with schizophrenia.

Individuals with schizophrenia are at increased risk for developing substance abuse disorders. Here, we consider factors that might elevate their risk for substance abuse. The tendency among schizophrenic individuals to overvalue drug-like rewards and to devalue the potential negative consequences of substance abuse may be a contributing factor to their substance abuse risk. This bias, which may partly reflect the convergence of glutamatergic and dopaminergic input to the limbic striatum, also may contribute to disadvantageous decision-making and other impulsive behavior. This propensity to seek drug-like rewards is augmented by alterations in nicotinic cholinergic, GABAergic, glutamatergic, and cannabinnoid receptor function associated with schizophrenia that increase the abuse liability of low doses of nicotine, ethanol, and perhaps cannabis, and augment the dysphoric effects of higher doses of ethanol and cannabis. The distortions in reward processing and altered response to substances of abuse also increase the likelihood that individuals with schizophrenia will self-medicate their subjective distress with abused substances. The focus on distinctions between motivation and reward with respect to substance abuse risk by schizophrenic patients suggests a need for a reconsideration of the construct of "negative symptoms" for this dually-diagnosed patient group.

Alcoholism↗
PubMed2005

An adaptive reflexive processing model of neurocognitive function: supporting evidence from a large scale (n = 100) fMRI study of an auditory oddball task.

Recent hemodynamic imaging studies have shown that processing of low probability task-relevant target stimuli (i.e., oddballs) and low probability task-irrelevant novel stimuli elicit widespread activity in diverse, spatially distributed cortical and subcortical systems. The nature of this distributed response supports the model that processing of salient and novel stimuli engages many brain regions regardless of whether said regions were necessary for task performance. However, these latter neuroimaging studies largely employed small sample sizes and fixed-effect analyses, limiting the characterization and inference of the results. The present study addressed these issues by collecting a large sample size (n = 100) and employed random effects statistical models. Analyses were also conducted to determine the inter-subject reliability of the hemodynamic response and the effects of gender and age on target detection and novelty processing. Group data demonstrated highly significant activation in all 34 specified regions of interest for target detection and all 24 specified regions of interest for processing of novel stimuli. Neither age nor gender systematically influenced the results. These data are discussed within the context of a model that proposes that the mammalian brain has evolved to adopt a strategy of engaging distributed neuronal systems when processing salient stimuli despite the low probability that many of these brain regions are required for successful task performance. This process may be termed 'adaptive reflexive processing.' The implications of these results for interpreting functional MRI studies are discussed.

Adolescent↗